Showing papers in "British Journal of Ophthalmology in 2003"

Bacterial keratitis: predisposing factors, clinical and microbiological review of 300 cases

Abstract: Aim: To identify predisposing factors and to define clinical and microbiological characteristics of bacterial keratitis in current practice. Methods: A retrospective analysis of the hospital records of patients presenting with bacterial keratitis and treated at the Quinze-Vingts National Center of Ophthalmology, Paris, France, was performed during a 20 month period. A bacterial keratitis was defined as a suppurative corneal infiltrate and overlying epithelial defect associated with presence of bacteria on corneal scraping and/or that was cured with antibiotic therapy. Risk factors, clinical and microbiological data were collected. Results: 300 cases (291 patients) of presumed bacterial keratitis were included. Potential predisposing factors, usually multiple, were identified in 90.6% of cases. Contact lens wear was the main risk factor (50.3%). Trauma or a history of keratopathy was found in 15% and 21% of cases, respectively. An organism was identified in 201 eyes (68%). 83% of the infections involved Gram positive bacteria, 17% involved Gram negative bacteria, and 2% were polymicrobial. Gram negative bacteria were associated with severe anterior chamber inflammation (p=0.004), as well as greater surface of infiltrates (p=0.01). 99% of ulcers resolved with treatment, but only 60% of patients had visual acuity better than the level at admission, and 5% had very poor visual outcome. Conclusions: Contact lens wear is the most important risk factor. Most community acquired bacterial ulcers resolve with appropriate treatment.

Intraocular pressure after intravitreal injection of triamcinolone acetonide

Abstract: Aim: To investigate the intraocular pressure (IOP) response after intravitreal injections of triamcinolone acetonide as treatment of intraocular neovascular or oedematous diseases. Methods: The prospective consecutive non-comparative interventional case series study included 71 patients (75 eyes) with progressive exudative age related macular degeneration (n = 64 eyes) or diffuse diabetic macular oedema (n = 11 eyes), who received an intravitreal injection of 25 mg triamcinolone acetonide. Mean follow up time was 6.86 (SD 2.52) months (range 3.1–14.47 months). Results: IOP increased significantly (p<0.001) from 15.43 (3.26) mm Hg preoperatively to a mean maximum of 23.38 (8.37) mm Hg (range 13–64 mm Hg) postoperatively. An IOP rise to values higher than 21 mm Hg was observed in 39 (52%) eyes. Elevation of IOP occurred about 2 months after the injection. Preoperative predictive factor for the rise in IOP was younger age (p=0.013). It was statistically independent of refractive error, presence of diabetes mellitus, and indication for the injection. In all but one eye, IOP could be lowered to the normal range with topical medication, without development of glaucomatous optic nerve head changes. In the eyes with an elevation of IOP, IOP normalised about 6 months after the injection, without further medication. Eyes undergoing repeatedly intravitreal injections of triamcinolone acetonide showed only an elevation of IOP, if after the first injection a rise of IOP had occurred. Conclusions: After intravitreal injections of 25 mg of triamcinolone acetonide, an IOP elevation can develop in about 50% of eyes, starting about 1–2 months after the injection. In the vast majority, IOP can be normalised by topical medication, and returns to normal values without further medication about 6 months after the injection.

Choroidal vascular remodelling in central serous chorioretinopathy after indocyanine green guided photodynamic therapy with verteporfin: a novel treatment at the primary disease level.

Abstract: Aims: To evaluate the changes in the choroidal vasculature in central serous chorioretinopathy (CSC) after photodynamic therapy (PDT) with verteporfin and to assess its potential role as a treatment option. Methods: A prospective, non-comparative, interventional study was performed in eyes with persistent CSC or chronic CSC that had fluorescein leakage at the fovea. All eyes received one single session of PDT with verteporfin (6 mg/m 2 body surface area) followed by application of 50 J/cm 2 laser at 689 nm. The laser spot size was guided by findings in ICG-A. Results: Six eyes from six patients with a mean follow up of 12.7 months were analysed. Narrowing of the original dilated choroidal vessels and decrease in extravascular leakage could be demonstrated in all (100%) PDT treated eyes. 3 months after PDT, the mean diameter of the dilated choroidal vessel reduced from 546 μm to 371 μm (p = 0.028). Five (83%) patients had improvement in visual symptoms and best corrected visual acuity. Fluorescence leakage stopped at the 1 month follow up in five eyes (83%) and at 3 months in all six eyes (100%). One eye developed choroidal neovascularisation at 3 month follow up. There was no other serious ocular or systemic complication. Conclusions: PDT is successful in stopping the fluorescein leakage in all six patients without recurrence of CSC. The ICG-A findings of choroidal vascular remodelling and decreased choroidal permeability after PDT are encouraging. As the sample size is small and the mean follow up period is short, further trials of PDT with verteporfin for CSC are required to address the optimal parameters in ensuring longer term safety and efficacy outcome.

Retinal thickness decreases with age: an OCT study.

Abstract: Background/aim: In three dimensional optic disc tomography a reference plane is required to calculate optic disc rim or cup values. The position of the reference plane often depends on the retinal thickness at the temporal disc margin. Originally it was assumed that the retinal thickness at the temporal disc margin is independent of age. The aim of the study was to check this hypothesis using optical coherence tomography, and additionally to determine the reproducibility of OCT measurements in this area. Methods: 100 eyes of 100 healthy volunteers were included in this study. Three OCT scans were performed on each eye. The scans were aligned vertically and placed at the temporal edge of the optic disc. For each eye, the thickness of the whole retina as well as the thickness of the retinal nerve fibre layer were calculated together with their coefficients of variation. Thereafter retinal thickness and nerve fibre layer thickness were correlated with age. Results: The mean retinal thickness was 249 (SD 22) μm. The mean nerve fibre layer thickness was 109 (22) μm. The mean coefficients of variation were 3.5% (total retinal thickness) and 8.0% (nerve fibre layer thickness). Both the total retinal thickness and the nerve fibre layer thickness were significantly correlated with age (total retina: y = 269.5 − 0.53 × x; R2 = 0.133; p = 0.0002, nerve fibre layer: y = 126.8 − 0.44 × x; R2 = 0.094; p<0.0019. Conclusions: Using OCT scans the total retinal thickness can be calculated with high reproducibility (coefficient of variation = 3.5%). The reproducibility of nerve fibre layer thickness measurements is clearly lower (coefficient of variation = 8.0%). Both the total retinal thickness and the nerve fibre layer thickness significantly decrease with age. This influence of the age related decrease in RNFL/retinal thickness on the reference plane, however, is negligible.

In vivo confocal microscopy of the human cornea.

Abstract: Aims: To describe the optics of in vivo confocal microscopy, its advantages over previous methods, and to summarise the literature that arose from its use for the observation of the human cornea. A critical review of the clinical usefulness of this new technology for the corneal examination is undertaken. Methods: Confocal microscopes obtain increased resolution by limiting the illumination and observation systems to a single point. Rapid scanning is used to reconstruct a full field of view and allows for “real time” viewing. Results: Coronal sections of the in situ epithelium, Bowman’s membrane, stroma, and endothelium can be visualised at a resolution of 1–2 μm. A backscattered light intensity curve allows objective measurements of sublayer thickness and corneal haze to be taken. In vivo confocal microscopy is therefore particularly useful in the areas of infective keratitis, corneal dystrophies, refractive surgery, and contact lens wear, where it aids in differential diagnosis and detection of subtle short and long term changes. Real time endothelial cell assessment can also be performed. Conclusion: Because of their ability to visualise living tissue at cellular levels, confocal microscopes have proved useful additions to the current clinical tools.

Architecture of arachnoid trabeculae, pillars, and septa in the subarachnoid space of the human optic nerve: anatomy and clinical considerations

Abstract: Aims: To describe the anatomy and the arrangement of the arachnoid trabeculae, pillars, and septa in the subarachnoid space of the human optic nerve and to consider their possible clinical relevance for cerebrospinal fluid dynamics and fluid pressure in the subarachnoid space of the human optic nerve. Methods: Postmortem study with a total of 12 optic nerves harvested from nine subjects without ocular disease. All optic nerves used in this study were obtained no later than 7 hours after death, following qualified consent for necropsy. The study was performed with transmission (TEM) and scanning electron microscopy (SEM). Results: The subarachnoid space of the human optic nerve contains a variety of trabeculae, septa, and stout pillars that are arranged between the arachnoid and the pia layers of the meninges of the nerve. They display a considerable numeric and structural variability depending on their location within the different portions of the optic nerve. In the bulbar segment (ampulla), adjacent to the globe, a dense and highly ramified meshwork of delicate trabeculae is arranged in a reticular fashion. Between the arachnoid trabeculae, interconnecting velum-like processes are observed. In the mid-orbital segment of the orbital portion, the subarachnoid space is subdivided, and can appear even loosely chambered by broad trabeculae and velum-like septa at some locations. In the intracanalicular segment additionally, few stout pillars and single round trabeculae are observed. Conclusion: The subarachnoid space of the human optic nerve is not a homogeneous and anatomically empty chamber filled with cerebrospinal fluid, but it contains a complex system of arachnoid trabeculae and septa that divide the subarachnoid space. The trabeculae, septa, and pillars, as well as their arrangement described in this study, may have a role in the cerebrospinal fluid dynamics between the subarachnoid space of the optic nerve and the chiasmal cistern and may contribute to the understanding of the pathophysiology of asymmetric and unilateral papilloedema. All the structures described are of such delicate character that they can not even be visualised with high resolution magnetic resonance imaging (MRI).

Automated identification of diabetic retinal exudates in digital colour images.

Abstract: Aim: To identify retinal exudates automatically from colour retinal images. Methods: The colour retinal images were segmented using fuzzy C-means clustering following some key preprocessing steps. To classify the segmented regions into exudates and non-exudates, an artificial neural network classifier was investigated. Results: The proposed system can achieve a diagnostic accuracy with 95.0% sensitivity and 88.9% specificity for the identification of images containing any evidence of retinopathy, where the trade off between sensitivity and specificity was appropriately balanced for this particular problem. Furthermore, it demonstrates 93.0% sensitivity and 94.1% specificity in terms of exudate based classification. Conclusions: This study indicates that automated evaluation of digital retinal images could be used to screen for exudative diabetic retinopathy.

Patchy atrophy and lacquer cracks predispose to the development of choroidal neovascularisation in pathological myopia

Abstract: Aims: To determine the incidence and predisposing findings for choroidal neovascularisation (CNV) in a large series of highly myopic patients. Methods: The medical records of 218 consecutive patients (325 eyes) with myopic fundus changes in the macula were reviewed. The incidence of CNV during a follow up of at least 3 years of highly myopic patients and identification of predisposing findings for the development of myopic CNV were examined. Results: Among 325 highly myopic eyes examined, 33 eyes (10.2%) developed myopic CNV. The incidence was higher (34.8%) among the fellow eyes of patients with pre-existing CNV than among eyes of patients without pre-existing CNV (6.1%). CNV developed in 3.7% with diffuse chorioretinal atrophy, in 20.0% with patchy atrophy, and in 29.4% with lacquer cracks. Conclusion: Approximately one in 10 highly myopic eyes developed myopic CNV in average 130.2 months. Patchy atrophy and lacquer cracks were shown to be important predisposing findings for CNV development.

Visual loss in uveitis of childhood

Abstract: Aims: To investigate the manifestations and severity of uveitis in children and to identify the risk and specific causes of blindness in this population. Methods: Retrospective study of data of 123 consecutive patients examined with active uveitis and the onset of ocular disease before the age of 16 years. Numerous variables were assessed including age and sex distribution, laboratory data, the presence of systemic diseases, onset and course of ocular inflammation, clinical features and complications, therapeutic strategies and their outcomes, final visual acuity, and characteristics associated with poor visual outcome. Results: Systemic disease was observed in 36/123 patients (29%), with juvenile idiopathic arthritis being the most frequent (25/123, 20%). Toxoplasma retinochoroiditis was diagnosed in 12/23 patients with posterior uveitis (52%; 10% of all with uveitis). Severe intraocular inflammation required systemic drugs in 57 (46%) patients. Ocular complications were observed in 93 patients (76%), of which the most common was cataract (43/123, 35%). Intraocular surgery was required in 35 patients (28%; in total 75 procedures). Three patients (2%) became legally blind and an additional 20/121 (17%) had one legally blind eye caused by uveitis. The most frequent causes of blindness were chorioretinal scars in the macular area and glaucoma in contrast with cystoid macular oedema (CMO) in adults. Conclusions: Uveitis in childhood is a potentially blinding disease, in the majority of patients characterised by a chronic course and a high complication rate.

Types of macular hole closure and their clinical implications.

Abstract: Aims: To evaluate the clinical significance of macular hole closure types assessed by optical coherence tomography (OCT). Methods: This study involved 34 eyes of 32 patients who had undergone anatomically successful idiopathic macular hole surgery. The closed macular holes were categorised into two patterns based on OCT; type 1 closure (closed without foveal neurosensory retinal defect) and type 2 closure (closed with foveal neurosensory retinal defect). Association between visual prognosis, type of hole closure, and possible prognostic factors were analysed. Results: 19 eyes (61.3%) were classified into the type 1 closure and 12 eyes (38.7%) into the type 2 closure. The extent of postoperative visual improvement of type 1 closure group was larger than that of type 2 closure group (p=0.002). The preoperative macular hole size of type 2 closure group was significantly larger than that of type 1 closure group (p=0.006). The duration of symptoms was positively correlated with the preoperative macular hole size (p=0.01). Recurrence of macular hole occurred only in the type 2 closure group. Conclusion: The type of macular hole closure, which was influenced by the preoperative hole diameter, was associated with postoperative visual prognosis. Early detection and intervention in macular hole should be emphasised.

Human recombinant interferon alfa-2a for the treatment of Behçet's disease with sight threatening posterior or panuveitis

Abstract: Background: Behcet's disease is a multisystem vasculitis of unknown origin. Standard treatment mainly comprises systemic immunosuppressive agents. Ocular involvement, mostly posterior uveitis with retinal vasculitis, leads to blindness in 20–50% of the involved eyes within 5 years. The efficacy of interferon alfa-2a was studied in patients with sight threatening posterior uveitis or retinal vasculitis. Methods: 50 patients were included in this open, non-randomised, uncontrolled prospective study. Recombinant human interferon alfa-2a (rhIFNα-2a) was applied at a dose of 6 million units subcutaneously daily. Dose reduction was performed according to a decision tree until discontinuation. Disease activity was evaluated every 2 weeks by the Behcet's disease activity scoring system and the uveitis scoring system. Results: Response rate of the ocular manifestations was 92% (three non-responder, one incomplete response). Mean visual acuity rose significantly from 0.56 to 0.84 at week 24 (p<0.0001). Posterior uveitis score of the affected eyes fell by 46% every week (p<0.001). Remission of retinal inflammation was achieved by week 24. Mean Behcet's disease activity score fell from 5.8 to 3.3 at week 24 and further to 2.8 at week 52. After a mean observation period of 36.4 months (range 12–72), 20 patients (40%) are off treatment and disease free for 7–58 months (mean 29.5). In the other patients maintenance IFN dosage is three million units three times weekly. Conclusions: rhIFNα-2a is effective in ocular Behcet's disease, leading to significant improvement of vision and complete remission of ocular vasculitis in the majority of the patients.

Five year risk of progression of primary angle closure suspects to primary angle closure: a population based study

Abstract: Aim: To report progression of primary angle closure suspects (PACS) to primary angle closure (PAC) at the 5 year follow up of a population based sample. Methods: 82 of 118 PACS who could be contacted and 110 randomly selected normals from a population based survey in 1995 were invited for a follow up examination in 2000. Progression to PAC was based on the development of raised IOP or synechiae in a PACS. Results: 50 of the 82 PACS contacted were examined. 11 (22%; 95% CI 9.8 to 34.2) developed PAC (seven synechial and four appositional); all were bilateral PACS. Two of 50 people previously diagnosed as PACS were reclassified as normal. One person among the 110 normals progressed to PAC. The relative risk of progression among PACS was 24 (95% CI 3.2 to 182.4). There was no significant difference in axial length, anterior chamber depth, or lens thickness between those who progressed and those who did not. None of the patients developed optic disc or field damage attributable to angle closure. One angle closure suspect was diagnosed to have normotensive glaucoma. Conclusion: In this population based study of PACS the 5 year incidence of PAC was 22%; none developed functional damage. Bilateral PACS was a clinical risk factor for progression.

Intravitreal triamcinolone acetonide for exudative age related macular degeneration

Abstract: Aim: To evaluate the effect of intravitreal triamcinolone acetonide on the visual acuity of patients with exudative age related macular degeneration, to assess the duration of a possible effect, and to evaluate clinical side effects of the treatment. Methods: The study included 67 patients (71 eyes) who presented with exudative age related macular degeneration of predominantly or total occult type (n = 68) or classic type (n = 3), and who received once, or repeatedly, an intravitreal injection of 25 mg of crystalline triamcinolone acetonide. Mean follow up time was 7.46 (SD 3.54) months (range 3.1–19.57 months). Results: Visual acuity increased significantly (p <0.001) from 0.16 (0.11) to a mean maximum of 0.23 (0.17). Postoperative visual acuity was highest 1–3 months after the injection. 47 (66.2%) eyes gained in maximal visual acuity and 11 (15.5%) eyes lost in visual acuity. Intraocular pressure increased significantly (p <0.001) from 15.1 (3.1) mm Hg at baseline to a maximal value of 23.0 (8.25) mm Hg. At the end of follow up, intraocular pressure again decreased significantly (p<0.001) to 16.8 (4.9) mm Hg. No cases of postoperative infectious endophthalmitis, rhegmatogenous retinal detachment, or proliferative vitreoretinopathy occurred. Owing to a decrease in visual acuity after an initial increase, six patients received a second intravitreal triamcinolone acetonide injection after which visual acuity increased again in three eyes. Conclusions: Intravitreal injection of 25 mg of crystalline triamcinolone acetonide merits further study for the treatment of exudative age related macular degeneration.

How big is the burden of visual loss caused by age related macular degeneration in the United Kingdom

Abstract: Aims: To predict the burden of blindness, partial sight, and visual impairment (binocular visual acuity 6/18 or less) due to late stage age related macular degeneration (AMD) in the ageing population of the United Kingdom. Methods: A systematic review, followed by a request for data, was used to establish a pooled prevalence of AMD and corresponding visual loss. Prevalence figures were applied to the UK population. Using UK population trends, the future burden of AMD over the coming decade was established. Results: Pooled data from six studies showed that the prevalence of visual loss caused by AMD increased exponentially from the age of 70–85 years of age, with 3.5% (95% CI 3.0 to 4.1) having visual impairment beyond the age of 75 years. The authors estimate that there are currently 214 000 (95% CI 151 000 to 310 000) with visual impairment caused by AMD (suitable for registration). This number is expected to increase to 239 000 (95% CI 168 000 to 346 000) by the year 2011. Currently there are 172 000 (95% CI 106 000 to 279 000) and 245 000 (95% CI 163 000 to 364 000) with geographical and neovascular AMD, respectively. Conclusions: Estimates of visual impairment agree with official statistics for the number registered partially sighted or blind, caused by AMD, and are well below other figures often cited. Although these estimates are associated with wide confidence intervals (CI) and a number of caveats, they represent the best available data, which can be used to guide health and social care provision for older people in the UK setting. Implications for low vision services are outlined.

Ocular biometry in occludable angles and angle closure glaucoma: a population based survey

Abstract: Aim: To compare ocular biometric values in a population based sample of eyes with occludable angles, angle closure glaucoma, and normal subjects. Method: 2850 subjects from a population based glaucoma prevalence study underwent complete ocular examination including indentation gonioscopy. Ocular biometry was performed in all subjects classified to have occludable angles (n = 143); angle closure glaucoma (n = 22), and a random subgroup of 419 normal subjects. Ocular biometry readings between the groups were compared and statistically analysed using “t,” “z,” and Mann-Whitney U tests. Results: The mean age among subjects with occludable angles (54.43 (SD 9.53) years) and angle closure glaucoma (57.45 (8.5) years) was significantly higher (p<0.001) than normal subjects (49.95 (9.95) years). Axial length was shorter (p<0.001) in the occludable angle group (22.07 (0.69) mm) compared to the normal group (22.76 (0.78) mm). Anterior chamber depth (ACD) was shallower (p<0.001) among subjects with occludable angles (2.53 (0.26) mm) than normal subjects (3.00 (0.30) mm). Lens thickness (LT) was greater (p<0.001) in people with occludable angles (4.40 (0.53) mm) compared to normal subjects (4.31 (0.31) mm). No significant difference was noted in axial length, ACD (p = 0.451), and LT (p = 0.302) between angle closure glaucoma and occludable eyes. Conclusion: South Indian eyes with angle closure glaucoma and occludable angles seem to have significantly shorter axial lengths, shallower anterior chambers and greater lens thickness compared to the normal group.

Behçet’s disease: from Hippocrates to the third millennium

Abstract: Behcet’s disease (BD) is characterised by recurrent episodes of orogenital aphthae, systemic vasculitis, and systemic and retinal venous thrombosis. An association between HLA-B51 and BD was first identified over 20 years ago, but recently identified gene associations implicate regions both within and without the MHC in the immunological events underlying the lesions in BD. These include allelic variants within the tumour necrosis factor gene region and within the MHC class I chain related gene region, the factor V Leiden mutation, which is associated with retinal vascular occlusion, and alleles of the intercellular adhesion molecule gene. No single causative gene for BD has emerged; the evidence indicates that the underlying immune events in BD are triggered by a microbial antigen and subsequently driven by genetic influences which control leucocyte behaviour and the coagulation pathways. Knowledge of these risk factors may permit a more accurate prognosis for a given patient, and identify new pathways for more targeted intervention than is currently available.

Features of abnormal choroidal circulation in central serous chorioretinopathy

Abstract: Aims: To evaluate abnormalities in the choroidal circulation in cases of central serous chorioretinopathy (CSC). Methods: A complete clinical ophthalmological examination was performed using simultaneous fluorescein and indocyanine green (ICG) angiography with a confocal scanning laser ophthalmoscopy and the digital images analysed in 36 consecutive patients with acute CSC. To quantify the choroidal circulation, the foveal choroidal blood flow was measured in 11 patients using laser Doppler flowmetry. Results: Fluorescein angiography showed focal leakage from the retinal pigment epithelium in all patients. ICG angiography revealed delays in arterial filling in 27 eyes (75%), and fluorescein angiography showed small hypofluorescent points around the leakage in 27 eyes (75%). Abnormal choroidal hyperfluorescence was observed in 30 eyes (83%). The choroidal blood flow in eyes with CSC was 45% lower than in fellow eyes (p<0.01). Conclusion: Decreased choroidal blood flow in CSC was demonstrated for the first time. The decreased choroidal blood flow might be correlated with the small, localised hypofluorescent areas, which may indicate non-perfused areas of the choriocapillaris that are frequently seen during ICG angiography.

Trypan blue staining of internal limiting membrane and epiretinal membrane during vitrectomy: visual results and histopathological findings.

Abstract: Aims: To report on the use of trypan blue (TB) 0.06% for staining the internal limiting membrane (ILM) and epiretinal membrane (ERM) during vitrectomy and report on their histology. Method: 14 consecutive patients with idiopathic macular hole or macular pucker (seven patients each) were prospectively recruited for ILM or ERM peel respectively. After pars plana vitrectomy and induction of posterior vitreous detachment, 0.5 ml TB 0.06% in phosphate buffered saline (VisonBlue) was injected over the posterior pole in an air filled eye and left for 2 minutes. The stained tissue was peeled with intraocular forceps. Specimens were evaluated using histochemical and immunohistochemical methods. Results: The average follow up was 4.4 months. Internal limiting membranes and epiretinal membranes were stained satisfactorily in all cases and removed successfully. Eight patients (57%) had improvement of 2 or more Snellen lines. All seven macular holes closed. In the ERM cases, no residual membranes were observed clinically, at the latest follow up. No complications relating to the use of the dye were encountered intraoperatively or postoperatively. Of the 14 procedures, nine (four macular hole and five macular pucker) yielded sufficient tissue for histopathological evaluation. Histological and immunohistological assessment revealed that the morphology of these specimens was similar to that observed in macular hole ILM and macular pucker ERM removed without the aid of dye. Conclusion: TB staining facilitated the identification and delineation of ILM and ERM removal during the surgical management of macular holes and macular pucker. The visual outcome of this series and the specimens removed suggest they are no different from those without TB staining. Its use in posterior segment appears to be safe but further studies are required to investigate its long term safety.

Prevalence of glaucoma in Thailand: a population based survey in Rom Klao District, Bangkok

Abstract: Aim: To determine prevalence, demography, mechanism, and visual morbidity of glaucoma in urban Thai people. Methods: 790 subjects aged 50 years or older from Rom Klao district, Bangkok, Thailand, were enumerated in a population based cross sectional study. Each subject underwent the following investigations: visual acuity, visual field testing, slit lamp examination, applanation tonometry, gonioscopy, and an optic disc examination after mydriasis. Main outcome measures included visual acuity (logMAR), visual fields, intraocular pressure (IOP), gonioscopic characteristics, vertical cup/disc ratio (VCDR), prevalence of types of glaucoma. Glaucoma was diagnosed on the basis of optic disc appearance and visual field defects. In eyes in which the optic disc could not be examined, glaucoma was diagnosed when visual acuity was 99.5th percentile or there was evidence of previous glaucoma surgery. Results: 701 subjects were examined (response rate 88.7%). In eyes with “normal” suprathreshold visual fields, the mean IOP was 13.3 mm Hg (97.5th percentile = 20 mm Hg). The 97.5th and 99.5th percentiles of VCDR were 0.72 and 0.86 respectively. Of the 701 subjects examined in the clinic, 27 had glaucoma (3.8%, 95% CI: 2.5 to 5.6), 16 had primary open angle glaucoma (POAG, prevalence 2.3%, 95% CI: 1.3 to 3.7), six were primary angle closure glaucoma (PACG, prevalence 0.9%, 95% CI: 0.3 to 1.9), and five were secondary glaucoma (SecG, prevalence 0.7%, 95% CI: 0.2 to 1.7). Among the 43 unilaterally blind subjects, glaucoma was the cause in five subjects (12%). One subject was bilaterally blind due to glaucoma (prevalence 11%, 95% CI: 0.3 to 61.9). 28 people (4%) were glaucoma suspects on the basis of optic disc appearance and six on the basis of visual fields only. 98 subjects (14%) had “occludable angles” in either eye, 22 of whom had primary angle closure (PAC, prevalence 3.1%, 95% CI: 1.9 to 4.7); 14 had peripheral anterior synechiae in either eye and eight had ocular hypertension (OHT). Conclusions: POAG accounted for 67% of all glaucoma, PACG 21%, and secondary glaucomas 12%. Glaucoma was the second most common cause of severe unilateral visual loss.

IOLMaster biometry: refractive results of 100 consecutive cases

Abstract: Aims: To study the refractive outcome of cataract surgery employing IOLMaster biometry data and to compare it with that of applanation ultrasonography in a prospective study of 100 eyes that underwent phacoemulsification with intraocular lens implantation. Methods: The Holladay formula using IOLMaster data was employed for the prediction of implanted intraocular lenses (IOLs). One month after cataract surgery the refractive outcome was determined. Preoperative applanation ultrasonography data were used retrospectively to calculate the IOL prediction error. The two different biometry methods are compared. Results: 100 patients, 75.42 (SD 7.58) years of age, underwent phacoemulsification with IOL implantation. The optical axial length obtained by the IOLMaster was significantly longer (p<0.001, Student’s t test) than the axial length by applanation ultrasound, 23.36 (SD 0.85) mm v 22.89 (0.83) mm. The mean postoperative spherical equivalent was 0.00 (0.40) D and the mean prediction error −0.15 (0.38) D. The mean absolute prediction error was 0.29 (0.27) D. 96% of the eyes were within 1 D from the intended refraction and 93% achieved unaided visual acuity of 6/9 or better. The Holladay formula performed better than the SRK/T, SRK II, and Hoffer Q formulas. Applanation ultrasonography after optimisation of the surgeon factor yielded a greater absolute prediction error than the optimised IOLMaster biometry, 0.41 (0.38) D v 0.25 (0.27) D, with 93% of the eyes within 1 D from the predicted refraction. Conclusion: IOLMaster optical biometry improves the refractive results of selected cataract surgery patients and is more accurate than applanation ultrasound biometry.

Pseudo-endophthalmitis after intravitreal injection of triamcinolone.

Abstract: Aims: To describe an unusual endophthalmitis-like reaction after an intravitreal injection of triamcinolone acetonide in four patients. Methods: Retrospective case series. Results: Four patients are reported with an endophthalmitis-like reaction following an intravitreal injection of triamcinolone acetonide. There was a dense vitreous haze with severe reduction of fundus view in all cases. One case was treated as an infectious endophthalmitis but the vitreous tap showed no evidence of an endophthalmitis and no bacterial or fungal growth in culture. In all four cases, the vitreous haze cleared without specific treatment. The anterior chamber remained quiet in all cases but one, which was examined 30 minutes after the injection, and there was no periorbital inflammation or pain. Conclusion: Pseudo-endophthalmitis after an intravitreal injection of triamcinolone acetonide seems to be a distinct clinical entity that may resolve without specific treatment.

Severe infective keratitis leading to hospital admission in New Zealand

Abstract: Aim: To identify key risk factors and the management and outcome of severe infective keratitis leading to public hospital admission in New Zealand. Methods: Over a 2 year period, all admissions of presumed infective keratitis to Auckland Hospital were identified. The clinical records of all 103 cases were retrospectively reviewed with respect to clinical features, risk factors, management, and outcomes. Results: The mean time from first symptoms or signs and presentation to hospital was 8.9 (SD 15.5) days. The majority of subjects, 88%, had at least one of the risk factors commonly associated with infective keratitis including previous ocular surgery (30%), contact lens wear (26%), topical corticosteroid use (25%), and ocular trauma (24%). Corneal scraping was performed in 92% and of a total of 105 scrapes, 71% were positive. Bacteria were isolated in all these cases, the majority being Gram positive organisms (72%). The most common isolates identified were coagulase negative Staphylococcus (16%), Propionibacterium acnes (14%), Staphylococcus epidermidis (11%), and Streptococcus pneumoniae (9%). In addition, yeasts were isolated in 5%, fungi in 4%, virus in 2%, and chlamydia in 1%. Importantly, polymicrobial infection accounted for 33% of culture positive cases. Antimicrobial treatment was changed on the basis of culture results in 17 cases (16.5%). Median initial visual and final best corrected visual acuity was 6/36–6/48 (logMAR 0.86) (IQR 0.39–2.00) and 6/12–6/15 (logMAR 0.360) (IQR 0.15–1.70), respectively. Previous ocular surgery and topical corticosteroid use were significantly associated with poorer visual acuity. The mean hospital stay was 5.8 days and the median 4.0 (IQR 2.0–8.0) days. Longer duration of stay was associated with the presence of hypopyon, larger ulcers, previous ocular surgery, and poor visual acuity. Conclusions: Infectious keratitis is an important cause of ocular morbidity. A significant proportion of cases have potentially modifiable risk factors. Previous ocular surgery and topical corticosteroid use, in particular, were associated with poorer visual outcomes. Many cases of severe keratitis might be avoided, or their severity reduced, by appropriate education of patients and ophthalmologists.

Risk factors for nuclear, cortical and posterior subcapsular cataracts in the Chinese population of Singapore: the Tanjong Pagar Survey

Abstract: Aim: To describe risk factors for nuclear, cortical, and posterior subcapsular (PSC) cataracts in Chinese Singaporeans. Methods: A population based cross sectional study was carried out on ethnic Chinese men and women aged 40–81 years. A stratified, clustered, disproportionate (more weights to older people), random sampling procedure was used to initially select 2000 Chinese names of those aged 40–79 years from the 1996 electoral register in the Tanjong Pagar district in Singapore. Eligible subjects (n = 1717) were invited for a standardised ocular examination and interview at a centralised clinic, following which an abbreviated examination was conducted for non-respondents in their homes. Cataract was graded clinically using to the Lens Opacity Classification System (LOCS) III system. The main outcome measures were adjusted odds ratio for risk factors for specific cataract types (nuclear, cortical and PSC), any cataract and cataract surgery, examined in multiple logistic regression models. Results: Out of the 1232 (71.8%) examined, 1206 (70.2%) provided lens data for this analysis. Increasing age was associated with all cataract types, any cataract, and cataract surgery. There was no significant sex difference in presence of any cataract, specific cataract types or cataract surgery. After controlling for age, sex, and other factors, diabetes was associated with cortical cataract (3.1; 95% CI: 1.6 to 6.1), PSC cataract (2.2; 95% CI 1.2 to 4.1), any cataract (2.0; 95% CI: 0.9 to 4.5), and cataract surgery (2.3; 95% CI: 1.3 to 4.1). Lower body mass index was associated with cortical cataract (1.8; 95% CI: 1.1 to 2.9; lowest versus highest quintile) and any cataract (2.3; 95% CI: 1.3 to 4.0). Current cigarette smoking was associated with nuclear cataract (1.7, 95% CI: 1.0 to 2.9; more than 10 cigarettes per day versus none). A non-professional occupation was associated with nuclear cataract (2.9; 95% CI: 1.5 to 5.8; for production or machine operators and 2.6; 95% CI: 1.2 to 5.5; for labourers or agricultural workers, both versus professionals). Lower education was associated with nuclear cataract (2.3; 95% CI: 1.0 to 5.2, none versus tertiary), while lower household income was associated with PSC cataract (4.7, 95% CI: 1.1 to 20.0; income S$4000). Conclusions: Age related cataracts are associated with a variety of risk factors among Chinese people in Singapore, similar to those reported in European, Indian, and African derived populations. These data support common aetiological mechanisms for age related cataracts, irrespective of ethnic origin.

Impact of an interdisciplinary low vision service on the quality of life of low vision patients

Abstract: Aim: To investigate the impact of an interdisciplinary low vision service on the vision related quality of life of service users. Methods: 71 patients were interviewed 2 weeks before their appointment with the service and again 6 months later to assess any changes in their vision related quality of life. The majority of these patients had age related macular degeneration. Results: After contact with the service the majority of patients indicated a reduction in concern about most quality of life issues. They were significantly less anxious about deterioration of their vision, safety within the home, and coping with everyday life. Conclusion: Improvements in many areas of their vision related quality of life indicate that this interdisciplinary low vision service has a positive impact on the lives of service users. However many patients were still unable to carry out their preferred everyday activities, and feelings of loneliness and isolation were unchanged. The identification of issues unrelieved by input from the service will be important in planning future service delivery.

Polymerase chain reaction analysis of aqueous humour samples in necrotising retinitis

Abstract: Aim: To evaluate the diagnostic value of polymerase chain reaction (PCR) performed on aqueous humour for the detection of viral DNA in patients with necrotising herpetic retinitis. Methods: The clinical features and laboratory results of 22 patients (29 eyes) presenting with necrotising herpetic retinitis between March 1999 and June 2001 were reviewed retrospectively. Aqueous humour was obtained after anterior chamber paracentesis and PCR was performed in all cases. Results: Viral DNA was detected in the aqueous humour of 19 patients (86.4%). Epstein-Barr virus (EBV) seroconversion was evidenced in one additional patient. In the acute retinal necrosis (ARN) group (n = 19), varicella zoster virus (VZV) DNA was identified in six patients, herpes simplex virus 1 (HSV-1) DNA in two patients, herpes simplex virus 2 (HSV-2) DNA in four patients, and cytomegalovirus (CMV) genome in four patients. In the progressive outer retinal necrosis (PORN) group (n = 3), VZV DNA was detected in all patients. No sample was positive for more than one virus. Conclusions: PCR analysis of aqueous humour in patients with clinical features of necrotising viral retinitis can provide specific aetiological orientation and the method appears to be safe and highly sensitive.

Impact of smoking on the response to treatment of thyroid associated ophthalmopathy

Abstract: Background: In patients with Graves’ disease, smoking considerably increases the incidence and severity of thyroid associated ophthalmopathy (TAO). The authors sought to determine if smoking also influences the course of TAO during treatment, and the efficacy of therapy. Methods: 41 smokers and 19 non-smokers with moderate untreated TAO were included in this prospective study. All patients were treated with steroids and, 6 weeks after the beginning of drug therapy, with orbital irradiation. Follow up was performed 1.5, 4.5, 7.5, and 12 months after the beginning of the study. Proptosis, clinical activity score (CAS), and motility were evaluated. The extent of smoking was derived from the concentration of the haemoglobin adduct N-2-hydroxyethylvaline (HEV), a parameter of long term smoking. Results: There was no difference in the clinical manifestations of TAO between smokers and non-smokers at the beginning of treatment. However, CAS decreased (p<0.05) and motility improved (p<0.02) significantly faster and to a greater extent in non-smokers than smokers. Inverse correlations between the CAS decrease and the HEV levels observed 4.5 and 7.5 months after the beginning of treatment and between the improvement of motility and the HEV levels after 1.5, 4.5, and 7.5 months indicated a dose dependence. Mean HEV levels did not vary much during the follow up period and were significantly different in smokers (mean 5.4 (SD 2.7) μg/l) and non-smokers (mean 1.8 (1.3) μg/l; p<0.01). Conclusion: Smoking influences the course of TAO during treatment in a dose dependent manner. The response to treatment is delayed and considerably poorer in smokers.

Prevalence and causes of blindness and visual impairment in Bangladeshi adults: results of the National Blindness and Low Vision Survey of Bangladesh.

Abstract: Aim: To determine the age, sex, and cause specific prevalences of blindness and visual impairment in adults 30 years of age and older in Bangladesh. Methods: A nationally representative sample of 12 782 adults 30 years of age and older was selected based on multistage, cluster random sampling with probability proportional to size procedures. The breakdown of the cluster sites was proportional to the rural/urban distribution of the national population. The examination protocol consisted of an interview, visual acuity (VA) testing, autorefraction, and optic disc examination on all subjects. Corrected VA retesting, cataract grading, and a dilated fundal examination were performed on all visually impaired subjects. The definitions of blindness (<3/60) and low vision (<6/12 to ≥3/60) were based on the presenting visual acuity in the better eye. The World Health Organization/Prevention of Blindness proforma and its classification system for identifying the main cause of low vision and blindness for each examined subject was used. Results: In total, 11 624 eligible subjects were examined (90.9% response rate) across the 154 cluster sites. A total of 162 people were bilaterally blind (1.53% age standardised prevalence) while a further 1608 subjects (13.8%) had low vision ( 6/12 in the “better eye” in the remaining 9854 subjects (84.8%); however, 748 of these people had low vision in the fellow eye. The main causes of low vision were cataract (74.2%), refractive error (18.7%), and macular degeneration (1.9%). Cataract was the predominant cause (79.6%) of bilateral blindness followed by uncorrected aphakia (6.2%) and macular degeneration (3.1%). Conclusions: There are an estimated 650 000 blind adults (95% CI 552 175 to 740 736) aged 30 and over in Bangladesh, the large majority of whom are suffering from operable cataract. This survey indicates the need for the development and implementation of a national plan for the delivery of effective eye care services, aimed principally at resolving the large cataract backlog and the inordinate burden of refractive error.

Comparison of two reference standards in validating two field mydriatic digital photography as a method of screening for diabetic retinopathy

Abstract: Aim: To compare two reference standards when evaluating a method of screening for referable diabetic retinopathy. Method: Clinics at Oxford and Norwich Hospitals were used in a two centre prospective study of 239 people with diabetes receiving an ophthalmologist’s examination using slit lamp biomicroscopy, seven field 35 mm stereophotography and two field mydriatic digital photography. Patients were selected from those attending clinics when the ophthalmologist and ophthalmic photographer were able to attend. The main outcome measures were the detection of referable diabetic retinopathy as defined by the Gloucestershire adaptation of the European Working Party guidelines. Results: In comparison with seven field stereophotography, the ophthalmologist’s examination gave a sensitivity of 87.4% (confidence interval 83.5 to 91.5), a specificity of 94.9% (91.5 to 98.3), and a kappa statistic of 0.80. Two field mydriatic digital photography gave a sensitivity of 80.2% (75.2 to 85.2), specificity of 96.2% (93.2 to 99.2), and a kappa statistic of 0.73. In comparison with the ophthalmologist’s examination, two field mydriatic digital photography gave a sensitivity of 82.8% (78.0 to 87.6), specificity of 92.9% (89.6 to 96.2), and a kappa statistic of 0.76. Seven field stereo gave a sensitivity of 96.4% (94.0 to 98.8), a specificity of 82.9% (77.4 to 88.4), and a kappa statistic of 0.80. 15.3% of seven field sets, 1.5% of the two field digital photographs, and none of the ophthalmologist’s examinations were ungradeable. Conclusion: An ophthalmologist’s examination compares favourably with seven field stereophotography, and two field digital photography performs well against both reference standards.

Quality of life with macular degeneration: perceptions of patients, clinicians, and community members

Abstract: Background/aims: Age related macular degeneration (ARMD) is a common ophthalmological disorder that can significantly impair a patient’s ability to function independently and potentially have a dramatic impact on health related quality of life. The aim of this study is to evaluate the quality of life of patients with ARMD, through the use of utility evaluation, and assess whether clinicians and healthy volunteers appreciate the impact of ARMD on health related quality of life. Methods: A standardised questionnaire using the time-tradeoff method of utility analysis was created to assess health related quality of life. This questionnaire was distributed to 115 patients with ARMD. A similar questionnaire was distributed to 142 healthy volunteers and 62 clinicians who were asked to assume that they had ARMD. Comparisons were made among the responses from the members of the three groups. Results: There was a significant difference in the utility scores among respondents with mild, moderate, and severe ARMD when compared to members of the general public and clinicians who were asked to assume they had each severity of ARMD. For mild ARMD the mean utility scores were 0.932, 0.960, and 0.832, for the general public, clinicians, and patients respectively (F = 21.7; p <0.001). No significant difference was found between the community members and clinicians (p <0.166); however, the patient group differed significantly from the general public (p<0.001) and clinician (p <0.001) groups. The utility scores for moderate ARMD for the general public, clinicians, and patients were 0.918, 0.877, and 0.732, respectively. (F = 34.6, p <0.001). There was no significant difference between the general public and clinicians (p <0.143); however, the patient group differed significantly compared with the general public (p <0.001) and clinician (p <0.001) groups. The utility scores for people with severe ARMD in the general public, clinician, and patient groups were 0.857, 0.821, and 0.566, respectively (F = 45.5; p <0.001). No significant difference was shown between the community members and clinicians (p <0.386); however, a significant difference was seen when comparing the patient group with the community member and clinician (p<0.001) groups. Conclusion: Clinicians and community members may greatly underestimate the impact of mild, moderate, and severe ARMD on health related quality of life.

Mechanical endonasal dacryocystorhinostomy with mucosal flaps.

Abstract: Aims: To describe and assess the efficacy of mechanical endonasal dacryocystorhinostomy (MENDCR). This is a new technique that involves creation of a large rhinostomy and mucosal flaps. The study involved a prospective non-randomised interventional case series with short perioperative follow up. Method: A prospective series of 104 consecutive endonasal DCRs performed from January 1999 to December 2001 were entered into the study. Patients included in the study had nasolacrimal duct obstruction and had not had previous lacrimal surgery. The technique involved anastomosis of nasal mucosal and lacrimal sac flaps and a large bony ostium. Surgery was performed by two surgeons (AT/PJW). Follow up assessment included nasoendoscopy as well as symptom evaluation. Success was defined as anatomical patency with fluorescein flow on nasoendoscopy and patency to lacrimal syringing. The average follow up time was 9.7 months (range 2–28, SD 6.7 months). Results: There were 104 DCRs performed on 86 patients (30 male, 56 female). The average age of the patients was 59 years (range 3–89, SD 24.1 years). Common presentations were epiphora (77%) and/or mucocele (19%). Septoplasty (SMR) was required in 48 DCRs (46%) and 13 DCRs (12.5%) needed other endoscopic surgery in conjunction with the lacrimal surgery. The surgery was successful in 93 cases (89%). Of the 11 cases that were classified as a failure six patients was anatomically patent but still symptomatic and another two had preoperative canalicular problems. The anatomical patency with this new technique was thus 95% (99 of 104 DCRs). Conclusion: MENDCR involves creation of a large ostium and mucosal preservation for the construction of flaps. The anatomical success is 95% and is similar to external DCR and better then other endonasal approaches. The authors suggest that creation of a large ostium as well as mucosal flaps improves the efficacy of this endonasal technique.