Showing papers in "Acta Ophthalmologica Scandinavica in 2009"
TL;DR: New methods which take available knowledge of visual field physiology and pathophysiology into account are applied, and modern computer-intensive mathematical methods for real time estimates of threshold values and threshold error estimates are applied.
Abstract: PURPOSE: The purpose of this work was to develop a new family of test algorithms for computerized static threshold perimetry which significantly reduces test time without any reduction of data quality.METHODS: A comprehensive visual field model constructed from available knowledge of normal and glaucomatous visual fields is continuously updated during testing. The model produces threshold estimates and also estimates of the certainty to which the threshold is known at each point. Testing is interrupted at each test location at predetermined levels of threshold certainty. New time-saving methods are employed for estimation of false answers, and test pacing is optimized. After completion of the test, all threshold estimates are re-computed, taking into account the complete body of patient responses. Computer simulations were used to optimize the different parameters of the new algorithms, to evaluate the relative importance of those parameters, and to evaluate the performance of the algorithm as a whole in comparison with a standard algorithm.RESULTS: Simulated test results obtained with this algorithm were slightly more accurate than those of the Humphrey Full Threshold test algorithm. The number of simulated stimuli presented was reduced by an average of 29% in normal fields and 26% in glaucomatous fields. Actual clinical test time should be further reduced, since the influence of the improved timing algorithm was not included in the simulations.CONCLUSIONS: We applied new methods which take available knowledge of visual field physiology and pathophysiology into account, and employ modern computer-intensive mathematical methods for real time estimates of threshold values and threshold error estimates. In this way it was possible to design a family of testing algorithms which significantly reduced perimetric test time without any loss of quality in results. (Less)
403 citations
TL;DR: Great inter-and intrafamiliar variation in visual acuity and visual decline is found in patients from three large Danish families with autosomal dominant optic atrophy, making DOA the most common hereditary optic atropy.
Abstract: Sixty-two patients from three large Danish families with autosomal dominant optic atrophy were clinically examined, and retrospective follow-up was made on 30 patients. We found great inter-and intrafamiliar variation in visual acuity and visual decline. One hundred and seventy-five chromosomal markers were analyzed in 118 family members. Linkage was demonstrated between the disease gene (OPA1) and the microsatellite markers D3S1314, D3S1262, D3S1265 and D3S1601, with the highest Lod score to D3S1601 Z=11.75. All markers are located on chromosome 3q in the telomeric area, the most probable location for the OPA1 gene being D3S1601-OPA1-D3S1265. Using data from the Danish Family Register of Hereditary Eye Diseases, the minimum prevalence rate was estimated to 1:12.301, making DOA the most common hereditary optic atrophy.
167 citations
TL;DR: Examining the sensitivity and specificity of oblique flashlight, peripheral slit beam and ultrasonographic evaluation of the anterior chamber depth to gonioscopy in detecting cases of PACG found that home visits indicated that respondents for screening were similar to the population as a whole.
Abstract: 562 residents of Jin Shan aged 40 years and above underwent examinations to compare the sensitivity and specificity of oblique flashlight, peripheral slit beam and ultrasonographic evaluation of the anterior chamber depth to gonioscopy in detecting cases of PACG. Among 5441 eligible individuals aged 40 and above, 562 (10.3%) underwent screening for PACG, of whom 17 (3.02%) were defined as cases, and 10 (1.78%) as suspects. Home visits indicated that respondents for screening were similar to the population as a whole. Only 35% of PACG cases reported symptoms consistent with acute angle closure, and only 18% were previously diagnosed. When compared to gonioscopy, only ultrasonographic measurement of AC depth provided an adequate mix of sensitivity and specificity. Ultrasonography in combination with tonometry provided a sensitivity of 88% with a specificity of 92%. Sensitivity and specificity for ultrasonography in combination with refractive status were 84% and 83% respectively. Shallower AC depth (p = 0.0001), shorter axial globe length (p = 0.001), greater than 2D of hyperopia (p < 0.001), high grades of nuclear sclerotic cataract (p < 0.0001) and an increased cup-to-disc ratio (p = 0.002) were significantly correlated with a diagnosis of PACG.
160 citations
TL;DR: Keratoconjunctivitis sicca was most frequent in persons aged 50-59 years and was equally common in men and women and primary Sjögren's syndrome could only be diagnosed in one person according to the Copenhagen criteria (cut-off the Schirmer-1 test < or = 5 mm/5 min), and in three persons according toThe preliminary European criteria.
Abstract: Purpose: To investigate the presence of keratoconjunctivitis sicca and primary Sjogren's syndrome a sample of 504 persons aged 30–60 years from Copenhagen was studied.
Methods: The presence of keratoconjunctivitis sicca and primary Sjogren's syndrome was estimated according to both the Copenhagen set of criteria and the preliminary European criteria.
Results: Symptoms of dry eye and oral dryness were very common and with no significant correlation to age or sex. Keratoconjuncitivis sicca was most frequent in persons aged 50–59 years and was equally common in men and women. Primary Sjogren's syndrome could only be diagnosed in one person according to the Copenhagen criteria (cut-off the Schirmer-1 test ≤ 5 mm/5 min), and in three persons according to the preliminary European criteria.
Conclusion: The frequency of keratoconjunctivitis sicca in persons aged 30–60 years in Copenhagen may be estimated to be 11% according to the Copenhagen criteria and 8% according to the preliminary European criteria. The frequency of primary Sjogren's syndrome in persons aged 30–60 years in Copenhagen may be estimated to be between 0.2% and 0.8% according to the Copenhagen criteria and between 0.6% and 2.1% according to the preliminary European criteria.
152 citations
TL;DR: A video camera, a microscope, and a PC-based digital image processing board were assembled for in vitro studies of corneal biomechanics as discussed by the authors, where the authors found that the elastic and visco-elastic behaviour of the human cornea was closely related to changes in cornea hydration.
Abstract: A video camera, a microscope, and a PC-based digital image processing board were assembled for in vitro studies of corneal biomechanics Central tangential corneal strain was determined by placing pairs of tiny mercury droplets on the epithelial surface and on the endothelial surface of the cornea A distance of 32 mm could be determined with a standard deviation of 12 micron Central corneal radius of curvature was measured from digital traces of the corneal surface contour The standard deviation on estimating the radius of an 8 mm steel sphere was 15 microns Corneal thickness was measured by digital optical pachometry The standard deviation on measuring a thickness of 1 mm was 46 microns The corneal extensibility was investigated in a total of 10 enucleated human eyes with increased corneal hydration Tension was applied by varying the intraocular pressure from 2 to 100 mmHg with a column of isotonic saline The epithelial side corneal strain and the increase in corneal curvature were approximately 1% for a change in intraocular pressure from 2 to 100 mmHg When a high intraocular pressure was kept constant for 2 h the corneal thickness, radius of curvature, and the epithelial side strain gradually decreased, whereas the endothelial side strain increased The elastic and visco-elastic behaviour of the human cornea was found to be closely related to changes in corneal hydration We found digital image processing useful for in vitro biomechanical studies of the cornea
140 citations
TL;DR: The most important predisposing factors for an early large with the-rule-astigmatism or rapid changes in the postoperative astigmatism were large preoperative with-the-ruleAstigmatism, young age, low preoperative intraocular pressure, if an ECCE were chosen as the extraction type, anterior (corneal) location of the incision at surgery, and, finally, the surgeon.
Abstract: There has been a striking increase in the number of cataract operations in the referral region of the Lund Health Care District during 1986 through 1990, in 1990 reaching 3.6 per 1000 inhabitants. Different preoperative, intraoperative and postoperative variables and observations were registered and analysed for 5878 consecutive cataract cases operated in the period studied. Women predominate in the material and despite the increased number of operations during the period studied there was no drop in patient age. Young patients and diabetic patients show an increased standardised mortality ratio (SMR) compared to the normal population. Of the population, 78% had a preoperative astigmatism of <1.5 diopters. The amount of astigmatism was found to deviate more from the normal both in large and in small eyes. A second degree polynomial model was found to give the best description of the relation between axial length and keratometric powers. A cataract patient with glaucoma and operated on by an inexperienced surgeon runs a significantly increased risk for complications at surgery, as indicated by capsule or zonule rupture. At two years after cataract surgery we found the risk for retinal detachment to be 0.18%. The relative risk for detachment was found to be 4.9 after a YAG-laser capsulotomy. It changed by a factor of 1.3 with an increase in the axial length by one unit (=1 mm) and with 0.94 for each added patient age year. Besides age, five variables significantly influenced the risk of having postoperative YAG laser treatment. They were gender, iris sphincterotomy, operation date and the community from which the patient came from. After about four to five years, the percentage of patients not having had a YAG laser capsulotomy was reduced to around 50% for women and 60% for men. The most important predisposing factors for an early large with the-rule-astigmatism or rapid changes in the postoperative astigmatism were large preoperative with-the-rule astigmatism (polar value), young age, low preoperative intraocular pressure, if an ECCE were chosen as the extraction type, anterior (corneal) location of the incision at surgery, and, finally, the surgeon.
138 citations
TL;DR: PEX prevalence was higher in men than in women and increases with age, as does bilaterality, and a correlation between increased PEX prevalence and high altitude may exist.
Abstract: .
Purpose: To evaluate the pseudoexfoliation (PEX) prevalence in the island of Crete (Greece).
Method: Organized visits to various villages, to examine a predetermined number of people born and living in these villages, in collaboration with the local birth register offices.
Results: PEX prevalence in Crete, in people aged 40 years and more, was found to be 16.1% (men: 21.3%, women: 12.6% - Prefecture of: Heraklion 11.5%, Chania 13.4%, Lasithi 16.9%, Rethymnon 27%). 28.8% of PEX-patients presented IOP >21 mmHg. In unilateral PEX-patients, mean IOP of PEX-eyes was found to be 17.82 mmHg versus 15.6 mmHg in fellow eyes.
Conclusion: PEX prevalence was higher in men than in women and increases with age, as does bilaterality. A correlation between increased PEX prevalence and high altitude may exist. PEX is a risk factor for the development of IOP disturbances which seem to appear earlier in women.
118 citations
TL;DR: On the basis of the experience, it is thought that GON and the visual field damage found in LTG can be attributed to an alteration in the endothelial self-regulating sections and consequent vascular insufficiency, particularly pronounced in the posterior ciliary arteries which, since it is these that provide the blood supply to the optic nerve head, leads to irreversible functional damage.
Abstract: Endothelin-1 (ET-1) is a potent vasoconstrictor peptide produced by vascular endothelin cells There are reports in the literature that ET-1 plasma levels are raised in low tension glaucoma (LTG). ET-1 plasma concentration and Color Doppler Imaging (CDI) evaluation in ophthalmic and posterior ciliary arteries were measured in 15 LTG patients and in 15 healthy subjects. The blood flow index recorded for the ophthalmic artery in normal subjects was a PSV of 36.646 +/- 6.611 cm/sec with RI of 0.717 +/- 0.019 while in the LTG patients it was 32.961 +/- 3.045 cm/sec (p < 0.003) with RI of 0.789 +/- 0.018 (p < 0.001). For the posterior ciliary arteries in the same two groups, we obtained a PSV of 13.878 +/- 4.149 cm/sec vs 8.720 +/- 1.645 cm/sec (p < 0.001) and an RI of 0.679 +/- 0.039 vs 0.722 +/- 0.024 (p < 0.001). The plasma ET-1 level in normal subjects was 1.720 +/- 0.174 pg while in LTG patients it was 2.947 +/- 0.217 pg (p < 0.001). On the basis of our experience, we think that GON and the visual field damage found in LTG can be attributed to an alteration in the endothelial self-regulating sections and consequent vascular insufficiency, particularly pronounced in the posterior ciliary arteries which, since it is these that provide the blood supply to the optic nerve head, leads to irreversible functional damage.
113 citations
TL;DR: The incidence and prevalence rates of acute anterior uveitis associated with ankylosing spondylitis were 2.0 and 10.3 per 100,000 population, respectively, and this disease association occurred more often in men than in women (p < 0.001).
Abstract: . We studied the case records of 1122 patients with endogenous uveitis including 418 new cases treated at the University Eye Clinic in Turku during the years 1980–1982 and 1988. The mean annual incidence and prevalence rates (per 100 000 population) of idiopathic acute anterior uveitis were 17.1 and 48.5, respectively, sarcoid anterior uveitis 0.5 and 1.5, Posner-Schlossman syndrome 0.4 and 1.9, herpes zoster uveitis 0.4 and 0.7, idiopathic chronic anterior uveitis 0.3 and 7.3, herpes simplex keratouveitis 0.3 and 0.5, juvenile rheumatoid arthritis 0.2 and 2.4, Fuchs' heterochromic iridocyclitis 0.2 and 0.5, intermediate uveitis 0.3 and 1.4, and of toxoplasmic retinochoroiditis 0.3 and 2.4. The incidence and prevalence rates of acute anterior uveitis associated with ankylosing spondylitis were 2.0 and 10.3 per 100 000 population, respectively, and this disease association occurred more often in men than in women (p < 0.001). The mean annual incidence of idiopathic acute anterior uveitis was significantly lower in the age group 0–19 years than in the other age groups (p < 0.001).
108 citations
TL;DR: The potential for developing full vision appears influenced and reduced and this applies to the total group of ex-prematures, but in particular it is valid for myopia of prematurity.
Abstract: Refractive findings are reported in a follow-up study comprising 88 children aged 7-10 years, who were submitted to regular control for retinopathy of prematurity (ROP) in the first months after their pre-term delivery 1982-84 (mean birthweight 1467 g, mean gestational age 31 weeks). The refractive range was -13 to +6.75 D. In four subjects with fully-blown ROP both eyes were left blind and dysmorphic. Twenty-four had had ROP with regression; myopia of prematurity (MOP) appeared in six (25%). At follow-up the myopia frequency in the remaining 60 without ROP was 5%. Out of the 9 subjects with uni- or bilateral myopia of prematurity three had no evidence of early ROP. With a median corrected acuity of 0.5 only, the eyes with MOP had a lower corrected visual score than in the rest of the material (median monocular acuity 0.9). The latter value is even a little lower than what was previously reported in full-terms of a similar age (median acuity above 1.0). Obviously, as a sequel to the pre-term delivery we are dealing not only with early myopia in some subjects; further, the potential for developing full vision appears influenced and reduced. This applies to the total group of ex-prematures, but in particular it is valid for myopia of prematurity.
106 citations
TL;DR: The long-term survival and tumour-related mortality were studied in 340 patients and pair-wise comparisons of the parameters indicated that large tumours were more common in the anterior choroid or ciliary body than in the posterior choroids, and large tumors were more often necrotic, composed of epitheloid cells, or featured extrascleral extension.
Abstract: Most previous reports on survival following enucleation for uveal malignant melanoma do not contain cumulative survival rates, do not use a multivariate approach and are liable to a considerable loss to follow-up. In this study, the long-term survival and tumour-related mortality were studied in 340 patients. Archival specimens containing posterior uveal melanomas were initially examined and sectioned by one pathologist. There was no loss to follow-up 6 to 22 years after enucleation. At the end of study, 233 (68.5%) individuals were dead; 137 (40.3%) of melanoma-related causes and 96 (28.2%) of other causes. Melanoma-related deaths appeared from 24 to 6848 days (18 years 8 months) after enucleation. The cumulative 5-year survival proportion based on melanoma-related deaths was 70% and the corresponding 10-year proportion was 56%. Multivariate Cox regression indicated that the largest tumour dimension, cell type, and tumour location all had independent prognostic value, the associated hazard ratios ranged from 1.2 to 1.4, suggesting a moderate increase of the relative risk. Pair-wise comparisons of the parameters indicated that large tumours were more common in the anterior choroid or ciliary body than in the posterior choroid. Similarly, large tumours were more often necrotic, composed of epitheloid cells, or featured extrascleral extension. Tumours with significant scleral invasion or extrascleral extension were more common in elderly patients.
TL;DR: Dorzolamide is an effective ocular hypotensive agent that accelerates blood velocity in the retinal and superficial optic nerve head without an apparent effect upon retrobulbar hemodynamics.
Abstract: .
Purpose: Topical carbonic anhydrase inhibitors such as dorzolamide have been developed as ocular hypotensive agents devoid of the side effects plaguing their systemic predecessors. We evaluated the influence of dorzolamide on retinal and retrobulbar blood flow markers to determine if the drug has orbital vascular as well as ocular hypotensive effects.
Methods: Eleven persons with healthy eyes received either placebo or two drops 2% dorzolamide, 2 h prior to studies conducted in double-masked, counterbalanced fashion. Four retrobulbar vessels (nasal and temporal posterior ciliary, central retinal, and ophthalmic arteries) were analyzed by color Doppler imaging; scanning laser ophthalmoscopy was used to examine retinal and superficial optic nerve head blood linear velocity.
Results: Dorzolamide lowered IOP from 15.7 ± 0.7 to 13.7 ± 0.7 mmHg (p < 0.05). The drug also hastened retinal arteriovenous passage of fluorescein dye, and accelerated capillary dye transit in the macula and optic nerve head. The drug, however, left unaltered blood velocity or resistance index in any retrobulbar vessel.
Conclusions: Dorzolamide is an effective ocular hypotensive agent that accelerates blood velocity in the retinal and superficial optic nerve head without an apparent effect upon retrobulbar hemodynamics.
TL;DR: New pattern deviation change probability maps were developed from a prospectively collected glaucoma material and designed to be sensitive to changes in localized field loss, but to be unaffected by media-induced perimetric change.
Abstract: We describe a new method for analysis of change in glaucomatous visual fields with the object to differentiate between changes caused by glaucoma from those caused by cataract. New pattern deviation change probability maps were developed from a prospectively collected glaucoma material and designed to be sensitive to changes in localized field loss, but to be unaffected by media-induced perimetric change. We compared the new change probability maps with the commercially available total deviation change probability maps in series of Humphrey perimetric tests in a glaucoma material of 43 eyes of 35 patients, who had undergone cataract surgery. When using the total deviation maps, considerable differences were seen between fields obtained before and after cataract surgery. Much smaller differences were seen when using the new change probability maps, that almost eliminated the common and disturbing effect of increasing cataract. This new tool could be of considerable help in differentiation between progressive glaucomatous visual field loss and deterioration caused by increasing media opacities.
TL;DR: Examination for keratoconjunctivitis sicca should be repeated in test negative cases where symptoms indicate 1 degree SS, andCornea sensitivity was not found to be an appropriate test at all.
Abstract: Results of dry eye tests and ocular symptoms were compared and correlated in patients with primary Sjogren's syndrome (1 degree SS), in patients with connective tissue disease differing from 1 degree SS, and in normal controls. Patients with 1 degree SS had many and pronounced ocular complaints, however, non-diagnostic for the disease. Break-up time and Schirmer-1 test results below 10 mm/5 min both had high sensitivity but low specificity, whereas the reverse was true for Rose-Bengal score and Schirmer-1 test below 5 mm/5 min. Presence of snake-like chromatin in conjunctival imprints and the lactotest on tear fluid did not qualify as alternative tests since they had very low specificity and were less sensitive than the Schirmer-1 test and break-up time. Cornea sensitivity was not found to be an appropriate test at all. In 21% of eyes the presence of keratoconjunctivitis sicca changed from one consultation to the next in patients with 1 degree SS. Examination for keratoconjunctivitis sicca should therefore be repeated in test negative cases where symptoms indicate 1 degree SS.
TL;DR: It is suggested that long-term applications of topical anti glaucoma medications damage the ocular surface.
Abstract: Topical medications have a very important role in chronic glaucoma treatment. Long-term use of these medications can cause significant changes on ocular surfaces. In this study, the ocular surfaces of 20 control subjects (group I), 20 primary open-angle glaucoma patients (group II) treated (mean 21.20 ± 1.32 months) with 0.50% timolol maleate, and 20 primary open-angle glaucoma patients (group III) treated (mean 21.70 ± 1.34 months) with 0.50% timolol maleate +1% dipivefrin hydrochloride were evaluated. Studied parameters included Schirmer's test, tear break-up time, conjunctiva impression cytology and goblet cell density. These results suggest that long-term applications of topical anti glaucoma medications damage the ocular surface.
TL;DR: No release may mediate much of the vasodilating effect of flicker in cats, and play a role in maintaining normal vascular tone in the optic nerve head.
Abstract: Purpose: To elucidate the role of nitric oxide (NO) in the eye and the flicker-induced vascular response
Methods: The blood flow in the retina and different parts of the optic nerve was compared in cats treated with the NO-synthase blocker, NG-nitro-L-arginine methyl ester and in control animals In both groups, one of the eyes was dark-adapted, the other was subjected to 8 Hz flickering light The regional blood flow was measured with the microsphere method
Results: In control animals, flickering light increased blood flow in the retina and optic nerve head by 39% and 256%, respectively Pretreatment with NG-nitro-L-arginine methyl ester prevented this increase in retinal blood flow and markedly reduced the blood flow in the optic nerve heads
Conclusion: NO release may mediate much of the vasodilating effect of flicker in cats, and play a role in maintaining normal vascular tone in the optic nerve head
TL;DR: Sociologically was found statistically significant lower frequency of living with a partner, while educational level was significantly higher and rate of employment did not differ regarding the persons without further impairments, diagnosed as visually impaired in their youth, compared to an age-specific control group of 3150.
Abstract: Knowledge of the epidemiology of visual impairment in children forms one of the cornerstones in paediatric ophthalmology. To gain an overview of the situation in Sweden an epidemiological study was performed. Totally 2373 visually impaired children were found, giving an age-specific prevalence of 10,9/10 000. Childhood blindness (i.e. vision <0,05) was seen in 25%. Male/female ratio was 1,20. Additional impairments were present in 60%. Aetiologies were prenatal in 64%, peri-/neonatal in 20%, infantile/juvenile in 7% and unknown in 9%. The most frequent disorders were cerebral visual impairment, non-hereditary optic atrophy, retinal dystrophy (as a general entity), congenital hypoplasia of the optic nerve and congenital cataract.
To produce a pilot-study regarding visual and social outcome, a study from 1980 was revisited. The same inclusion-criteria as in the nation-wide study were used, which reduced the material from initially 219 to 128 individuals. A comparison to the current findings in the larger study showed only minor differences, with the exception of peri-/neonatal aetiologies, which had increased.
At follow-up 59% were still visually impaired, 23% had improved their vision to 0,3 or above, 13% were deceased. All deceased had additional impairments. The best prognosis was found in albinism and congenital nystagmus. Sociologically was found statistically significant lower frequency of living with a partner, while educational level was significantly higher and rate of employment did not differ regarding the persons without further impairments, diagnosed as visually impaired in their youth, compared to an age-specific control group of 3150.
TL;DR: Although these findings add to the clinical and histopathological evidence that ganglion cell degeneration occurs in Alzheimer's disease, the difficulty in obtaining and evaluating retinal nerve fiber layer photographs, especially in advanced cases, may limit the clinical usefulness of retinal nerves fiber layer analysis in such patients.
Abstract: Retinal nerve fiber layer (RNFL) photographs from 26 patients with Alzheimer's disease and 23 normal, age-matched, control subjects were reviewed for quality and abnormalities by two observers. A higher proportion of Alzheimer's patients showed RNFL abnormalities when compared to control subjects. There was some disagreement between the two observers regarding quality and frequency of abnormalities, reflecting suboptimal quality of the photographs obtained in patients with advanced Alzheimer's disease. Although these findings add to the clinical and histopathological evidence that ganglion cell degeneration occurs in Alzheimer's disease, the difficulty in obtaining and evaluating retinal nerve fiber layer photographs, especially in advanced cases, may limit the clinical usefulness of retinal nerve fiber layer analysis in such patients.
TL;DR: Ophthalmologists should be aware of the diagnosis of AZOOR and should consider an ERG in the evaluation of any patient with unexplained visual field loss even in the presence of normal visual acuity, color vision, fluorescein angiography, or retinal examination.
Abstract: Retinal photoreceptor dysfunction is an uncommon and often unrecognized cause of acute visual loss. Acute zonal occult outer retinopathy (AZOOR) has been reported to cause cone and rod dysfunction. Patients with AZOOR may present with normal visual acuity, normal fluorescein angiography, and a normal fundus examination despite severe loss of visual field. A healthy young white female presented with acute, unilateral loss of visual field and an afferent pupillary defect, but normal visual acuity, color vision, fundus examination, and fluorescein angiogram. A pattern visual evoked potential was normal, but an electroretinogram showed a unilateral peripheral photoreceptor dysfunction consistent with the diagnosis of AZOOR. Ophthalmologists should be aware of the diagnosis of AZOOR and should consider an ERG in the evaluation of any patient with unexplained visual field loss even in the presence of normal visual acuity, color vision, fluorescein angiography, or retinal examination.
TL;DR: Binocularity patterns in subsamples were not significantly influenced by regressed ROP, and the subgroup with severe CNS damage appeared more deviant, confirming the established association between brain damage and strabismus.
Abstract: Refractive findings are reported in a follow-up study comprising 88 children aged 7–10 years, who were submitted to regular control for retinopathy of prematurity (ROP) in the first months after their pre-term delivery 1982-84 (mean birthweight 1467 g, mean gestational age 31 weeks). The refractive range was -13 to +6.75 D. In four subjects with fully-blown ROP both eyes were left blind and dysmorphic. Twenty-four had had ROP with regression; myopia of prematurity (MOP) appeared in six (25%). At follow-up the myopia frequency in the remaining 60 without ROP was 5%. Out of the 9 subjects with uni- or bilateral myopia of prematurity three had no evidence of early ROP. With a median corrected acuity of 0.5 only, the eyes with MOP had a lower corrected visual score than in the rest of the material (median monocular acuity 0.9). The latter value is even a little lower than what was previously reported in full-terms of a similar age (median acuity above 1.0). Obviously, as a sequel to the pre-term delivery we are dealing not only with early myopia in some subjects; further, the potential for developing full vision appears influenced and reduced. This applies to the total group of ex-prematures, but in particular it is valid for myopia of prematurity.
TL;DR: An epidemiological study of all known visually impaired children in Sweden found a large proportion of the children, especially in the groups with neuro-ophthalmological disorders and malformations of the posterior segment had additional impairments, emphasizing the importance of a multi-disciplinary approach when assessing multi-handicapped children.
Abstract: PURPOSE To gain an overview of the spectrum of diagnoses among Swedish visually impaired children. METHODS An epidemiological study of all known visually impaired children was made by review of medical records. RESULTS AND CONCLUSION In all we found 2373 children, 0-19 years of age, with an age-specific prevalence of 10.9/10,000. The two largest diagnostic groups included neuro-ophthalmological and retinal diseases. The most frequent disorders were cerebral visual impairment, non-hereditary optic atrophy, retinal dystrophy (when regarded as a general entity), congenital hypoplasia of the optic nerve and congenital cataract. Nystagmus secondary to brain disorder, albinism, congenital nystagmus, retinopathy of prematurity and high myopia were also found in a considerable number of patients. The leading diagnoses in children with WHO-defined childhood blindness were non-hereditary optic atrophy, cerebral visual impairment and retinopathy of prematurity. A large proportion of the children, especially in the groups with neuro-ophthalmological disorders and malformations of the posterior segment had additional impairments, emphasizing the importance of a multi-disciplinary approach when assessing multi-handicapped children.
TL;DR: The extensibility of 10 human corneas was evaluated in vitro by measuring central epithelial side and endothelial side tangential strain induced by intraocular pressure loads ranging from 2 to 100 mmHg.
Abstract: The extensibility of 10 human corneas was evaluated in vitro by measuring central epithelial side and endothelial side tangential strain induced by intraocular pressure loads ranging from 2 to 100 mmHg. Corneal normo-hydration was attempted by immersing and perfusing the eyes with 8% Dextran 500 in isotonic saline. The relationship between corneal strain and intraocular pressure was found to be non-linear, showing a typical stress-stiffening behaviour. Strain changes were approximately 10% higher on the endothelial side compared with the epithelial side. This difference could be fully explained by pressure induced changes in corneal volume. Compared to previous experiments performed on swollen corneas, the stiffness of the normo-hydrated human cornea was found to be higher. Young's modulus of elasticity for the corneal stroma was estimated to 3, 9, and 20 MPa for intraocular pressure intervals of 2-10, 10-25, and 25-100 mmHg, respectively.
TL;DR: A population-based survey of 760 people 65-74 years of age was conducted in the municipality of Tierp, central Sweden, and capsular glaucoma accounted for 60%, whereas 84% of cases detected during the survey were chronic simpleglaucomas, which was significantly more prevalent in males than in females.
Abstract: A population-based survey of 760 people 65-74 years of age was conducted in the municipality of Tierp, central Sweden. The methods used to identify glaucoma suspects were applanation tonometry, automatic perimetry (Competer 350), and binocular assessment of the optic disc. For a diagnosis of definite open-angle glaucoma, a visual field defect was required. Open-angle glaucoma was found at a prevalence of 5.70% (95% confidence interval: 4.12-7.27), which is higher than those figures reported for comparable surveys carried out on white populations. The occurrence of capsular glaucoma may in part explain this finding. Twenty of the 45 open-angle glaucomas were diagnosed before the survey. In this category, capsular glaucoma accounted for 60%, whereas 84% of cases detected during the survey were chronic simple glaucomas. Eight cases (18%) were classified as normal tension glaucoma, all of whom were diagnosed during the survey. Chronic simple glaucoma was significantly more prevalent in males than in females.
TL;DR: Levels of glycated hemoglobin and duration of diabetes were associated with retinopathy in the group with younger onset, but hyperglycemia less so in the older-onset group.
Abstract: To study the frequency of diabetic retinopathy in relation to age at diagnosis, treatment, duration of diabetes and glycemic control as measured by means of HbA1c levels, we performed a cross-sectional, registered-based study in the Helsingborg area of southern Sweden, comprising 2232 diabetic patients. Of the known diabetic population or = 30 years the prevalence of retinopathy was 57% in insulin-treated, and 26% in non-insulin treated patients. Levels of glycated hemoglobin and duration of diabetes were associated with retinopathy in the group with younger onset. In the older-onset group, there was a relationship between retinopathy and duration of diabetes and insulin treatment; glycated hemoglobin had a relationship which was of borderline significance with any retinopathy, but clearly significant with the pooled group: severe non-proliferative, proliferative retinopathy and/or macular edema. Hyperglycemia and duration of diabetes were thus associated with retinopathy in both younger- and older-onset diabetes, but hyperglycemia less so in the older-onset group.
TL;DR: An improved method for estimation of false positive answers by using information already available in current ordinary computerized visual field testing, without increasing test time is developed and evaluation shows that the new method reduces measurement errors considerably and significantly as compared with the traditional catch trials method.
Abstract: Reliability of patient performance in static computerized perimetry is important for evaluation of results. False positive answers tend to falsely increase measured threshold sensitivity. The frequency of false positive responses is traditionally measured by adding extra questions, catch trials, to the test. Catch trials are few and limited because of time constraints, leading to inexact estimates. We developed an improved method for estimation of false positive answers by using information already available in current ordinary computerized visual field testing, without increasing test time. We here describe the method and evaluate it in a prospectively collected material of 49 glaucoma eyes of 49 patients. The results show that the new method reduces measurement errors considerably and significantly as compared with the traditional catch trials method. Test-retest change was only half with the new method as compared to the traditional method of catch trials. Furthermore, it can reduce test time by eliminating the need to use catch trials to estimate the frequency of false positive responses.
TL;DR: Although there is considerable clinical heterogeneity in ADC, the phenotype is usually consistent within families, and specific cataract phenotypes appear to be associated with mutations at more than one chromosome locus.
Abstract: As part of a linkage study we have reviewed over 150 patients with autosomal dominant cataract and suggest a clinical classification of the different phenotypes consisting of anterior and posterior polar, nuclear, cortical, blue-dot, lamellar, coralliform and pulverulent cataracts.
TL;DR: The frequency of ROP in this study is compared to that of other population-based studies in the Nordic countries, and incidence differences are discussed.
Abstract: We have investigated the incidence of retinopathy of prematurity (ROP) among premature infants with birth weight less than 1500 g in two Norwegian counties during the years 1989-1993. Two hundred and seven out of 244 such infants (84.8%) were examined at the neonatal intensive care unit; 66 of those examined (31.9%) had a birth weight below 1000 g. ROP was found in 21 patients (10.1%), and stage 3 disease was present in 7 (3.4%). No patient had more advanced ROP than stage 3. Assuming that no cases of stage 3 ROP were missed among the total of 244 children, the incidence of stage 3 disease was 2.9%. The frequency of ROP in this study is compared to that of other population-based studies in the Nordic countries, and incidence differences are discussed.
TL;DR: A systematic analysis of the screening programs for detection of visual dysfunction in children in Sweden and Canada and recommendations are made on programs for vision screening in children that could be applied more widely.
Abstract: According to the general principles of screening, detection of visual impairment in children is worthwhile, since the condition is a serious health problem, reliable diagnostic tests are available and effective treatment is possible in most instances of ocular and visual dysfunction. However, an evaluation of the screening procedures has not been properly done and the cost-benefit of screening has not been studied. The aim of the present study is to perform a systematic analysis of the screening programs for detection of visual dysfunction. In the screening two parts can be separated, one that concerns the more serious ocular and visual conditions which have to be discovered by general survey methods very early in life, and one that involves detection of less serious conditions, mainly amblyopia, which can be diagnosed by testing for monocular reduction of visual acuity at about 3-4 years of age. The performance characteristics of the screening programs used in Sweden and Canada were evaluated and found to be very favourable. Based on the analysis and the evaluation, recommendations are made on programs for vision screening in children that could be applied more widely. The program could involve all or parts of the following: 1) A careful inspection of the eyes in the neonatal period and preferably also examination of the red reflex with the ophthalmoscope. 2) Children at high risk for ocular and visual disorder, i.e. those born prematurely before 32 weeks of age, or with genetic disease, hearing deficit and/or neurological and mental disorder, should be examined at the proper age by an ophthalmologist. 3) All staff at pediatric departments and child health care centers should be familiar with the visual development of the normal baby and should be alerted to the various symptoms and signs which first warn parents that there may be a visual defect. An inspection of the eyes to detect squint should be part of all pediatric examinations. 4) A screening test of monocular visual acuity in 4 year-old children can be reliably performed by non-ophthalmic personnel after proper training. The screening test should be repeated by school nurses during the first grade of school, and at regular intervals during the school years. 5) The children that screen positively should be seen by ophthalmologists, and in some cases by orthoptists, without undue delay for diagnosis and treatment.
TL;DR: The survey shows that mean IOP of the Mediterranean population studied is similar to the IOP found in other epidemiologic investigations; the prevalence of glaucoma, however, seems to be rather high.
Abstract: IOP was measured in 1062 middle-aged and elderly subjects of a small Sicilian town, enrolled in a population based survey. The mean IOP was 15.1 +/- 3.7 mmHg without interocular or sex differences. A small but significant age-dependent increase of IOP was found. Circadian and seasonal influences were recorded: IOP was higher in the morning and in winter. The prevalence of chronic open-angle glaucoma was 1.2%, but it grew to 3.6 if only subjects aged 70 years or more were considered. IOP of 24 mmHg or more was found in 2.7%, while 4.3% of subjects showed IOP of 21 mmHg or more. This survey shows that mean IOP of the Mediterranean population studied is similar to the IOP found in other epidemiologic investigations; the prevalence of glaucoma, however, seems to be rather high.
TL;DR: Postinjury endophthalmitis is the eye infection with the worst prognosis, and was more common in patients with posterior pole involvement than in purely corneal trauma, with its relation to the type of wound and the presence of intraocular foreign bodies.
Abstract: Postinjury endophthalmitis is the eye infection with the worst prognosis. A retrospective 9-year study was made of penetrating eye injuries, with an analysis of the incidence of infection and its relation to the type of wound and the presence of intraocular foreign bodies. There were 403 cases of penetrating eye injury; of these, 233 affected the cornea and 170 involved the posterior pole. Intraocular foreign bodies were present in 40 cases. Endophthalmitis developed in 4.2% of cases (17/403), and was more common in patients with posterior pole involvement (7%) than in purely corneal trauma (2.1%) (p = 0.03, Chi-square). Infection was in turn more frequent in the presence of intraocular foreign bodies (15%) (p = 0.17, Chi-square). Staphylococcus epidermidis was the most common cause (23.4%), while in three cases (17.6%) mixed infection was detected. The visual results were evisceration or non-perception of light in 82.3% of cases.