Showing papers in "Archives of Ophthalmology in 1992"
TL;DR: It is suggested that high levels of exposure to blue or visible light may cause ocular damage, especially later in life, and may be related to the development of age-related macular degeneration.
Abstract: • The relationship between exposure to sunlight and senile cataract, age-related macular degeneration, pterygium, and climatic droplet keratopathy was examined in 838 watermen who work on the Chesapeake Bay. The presence and severity of lenticular, corneal, and macular changes were assessed by either clinical examination or from stereo macular photographs. From detailed exposure histories, ocular exposure was estimated for three bands of visible radiation—violet (400 to 450 nm), blue (400 to 500 nm), or all visible (400 to 700 nm)—as well as for UV-A (320 to 340 nm) and UV-B (290 to 320 nm). The results with each band of visible radiation were similar. Neither cortical nor nuclear cataract was associated with ocular exposure to blue or all visible radiation, but pterygium and climatic droplet keratopathy were more common with higher exposures. Compared with age-matched controls, patients with advanced age-related macular degeneration (geographic atrophy or disciform scarring) had significantly higher exposure to blue or visible light over the preceding 20 years (odds ratio, 1.36 [1.00 to 1.85]) but were not different in respect to exposure to UV-A or UV-B. These data suggest that high levels of exposure to blue or visible light may cause ocular damage, especially later in life, and may be related to the development of age-related macular degeneration.
551 citations
TL;DR: Current experimental attempts to restore vision in diseased retinas by simulating or replacing photoreceptors are based on the premise that ganglion cells are retained after photoreceptor death, and the findings support this assumption.
Abstract: • There have been a number of histopathologic studies of retinas that were taken post mortem from patients with retinitis pigmentosa (RP), but few have addressed the question of transneuronal degeneration of ganglion cells secondary to photoreceptor death. We studied sectioned maculae that were obtained from 41 patients with different genetic forms of RP: autosomal dominant (n=11); X-linked (n=9); and simplex (n=21). We also studied sectioned maculae that were taken from 20 age-matched normal subjects. We counted cell bodies in the photoreceptor and ganglion cell layers at 100-μm (0.35°) intervals from the foveola to 1500-μm eccentricity and compared the mean cell counts among each group with RP. Each RP type had significantly fewer (P
469 citations
TL;DR: Findings provide evidence for the systemic nature of the pseudoexfoliation syndrome, which apparently involves an aberrant connective-tissue metabolism throughout the body.
Abstract: The pseudoexfoliation syndrome has recently been suggested to represent the local manifestation of a more widespread disorder. In this study, a case of classic bilateral pseudoexfoliation syndrome with systemic distribution of pseudoexfoliation material involving a variety of organ systems is described. Using transmission electron microscopy, typical pseudoexfoliation fibers were identified in autopsy tissue specimens of skin, heart, lungs, liver, kidney, and cerebral meninges in addition to the classic intraocular locations. The pseudoexfoliation material was mainly localized to connective-tissue portions or septa traversing the various organs. The pseudoexfoliation fibers were consistently associated with connective-tissue components, particularly fibroblasts and collagen and elastic fibers; myocardial tissue specimens; and heart-muscle cells. These findings provide evidence for the systemic nature of the pseudoexfoliation syndrome, which apparently involves an aberrant connective-tissue metabolism throughout the body.
400 citations
TL;DR: It is suggested that pseudoexfoliation is a systemic process involving abnormal matrix synthesis, particularly as related to elastic tissue components, in areas of skin and parabulbar tissues as well as intraocularly.
Abstract: • Evidence is increasing that pseudoexfoliative material develops in widespread areas of skin and parabulbar tissues as well as intraocularly. To determine whether this process is even more diffusely distributed, ultrastructural examination was performed on visceral and ocular tissues of a patient with longstanding glaucoma found to have bilateral ocular pseudoexfoliation at autopsy. Aggregates consistent with pseudoexfoliative material were present in the lung, heart, liver, and gallbladder, in addition to the classic intraocular sites. The aggregates were in the fibrovascular septa and stroma of these organs, most frequently adjacent to elastic and oxytalan fibers. They stained positively for elastin and human amyloid P protein, like the ocular sites, in preliminary immunologic testing. Rare atypical aggregates were seen in one of the four control patients. These findings suggest that pseudoexfoliation is a systemic process involving abnormal matrix synthesis, particularly as related to elastic tissue components.
355 citations
TL;DR: A pooled analysis (meta-analysis) of 5-year mortality rates among patients who had an eye enucleated for choroidal melanoma was performed to provide a more robust estimate of this rate than could be obtained from any single study.
Abstract: • With the use of data published during the period from 1966 through 1988, a pooled analysis (meta-analysis) of 5-year mortality rates among patients who had an eye enucleated for choroidal melanoma was performed to provide a more robust estimate of this rate than could be obtained from any single study. The literature concerning mortality following a diagnosis of choroidal melanoma has been reviewed systematically and described in a separate article. Of 76 reports published from 1966 through 1988, 29 were excluded from the meta-analysis because there were no cases treated by enucleation alone, mortality was not reported by time from enucleation, fewer than 10 cases were reported, or 5-year mortality rates were not reported or derivable from the data presented. Ten additional reports were excluded because they were based on data for the same set of patients as another article in the series. Of the remaining 37 reports, 29 contained data for patients with tumors of varying sizes that could not be separated into subgroups based on the size of the tumor at the time of treatment. The remaining eight articles reported 5-year mortality rates by tumor size, specifically for small, medium, or large tumors. The combined weighted estimates of 5-year mortality rates following enucleation were 16% for small tumors (95% confidence interval [CI]: [14%, 18%]), 32% for medium tumors (95% CI: [29%, 34%]), and 53% for large tumors (95% CI: [50%, 56%]). Different methods of pooling the data yielded consistent estimates for all three tumor size categories. These results supported the finding by other investigators that tumor size at time of enucleation is a major prognostic factor for patients who have choroidal melanoma.
343 citations
TL;DR: It is concluded that retinal photocoagulation in the rabbit eye produces blood-retinal barrier breakdown that is partially amenable to corticosteroid treatment.
Abstract: • The effect of corticosteroid treatment on blood-retinal barrier breakdown caused by argon-laser panretinal photocoagulation was evaluated in the rabbit eye. One day before photocoagulation, eyes were given either a sub-Tenon (20-mg) or intravitreal (2-mg) injection of triamcinolone acetonide. The severity of blood-retinal barrier breakdown was measured after photocoagulation using rapid sequential magnetic resonance imaging follow-ing intravenous administration of gadolinium diethylenetriaminepentaacetic acid. Leakage of gadolinium diethylenetriaminepentaacetic acid into the vitreous space was significantly lower in eyes that received intravitreal triamcinolone acetonide than in control eyes (P=.007); however, sub-Tenon triamcinolone acetonide produced no significant reduction in leak-age (P=.65) compared with controls. Fluorescein angiography supported the magnetic resonance imaging findings. We conclude that retinal photocoagulation in the rabbit eye produces blood-retinal barrier breakdown that is partially amenable to corticosteroid treatment.
302 citations
TL;DR: An algorithm for automated evaluation of single static threshold visual field test results in glaucoma, which uses empirically determined limits of normality for up-down differences in the Statpac probability maps of the Humphrey Field Analyzer to detect localized visual field loss.
Abstract: We have developed an algorithm, the Glaucoma Hemifield Test (GHT), for automated evaluation of single static threshold visual field test results in glaucoma. The GHT uses empirically determined limits of normality for up-down differences in the Statpac probability maps of the Humphrey Field Analyzer to detect localized visual field loss. It is also constructed to detect field loss that is symmetric around the horizontal meridian. Analysis is done in five corresponding pairs of sectors that are based on the normal anatomy of the retinal nerve fiber layer. Deviations from the age-corrected normal threshold in the most sensitive portions of the visual field are used to detect general reductions of sensitivity or abnormally high sensitivities. The GHT provides brief visual field evaluations printed on the field chart as plain text. The aim of this article is to describe the fundamentals of the analysis program and to provide clinical examples.
293 citations
TL;DR: It is demonstrated that 5-minute treatments with high concentrations of these drugs have prolonged effects on the proliferation of human Tenon's capsule fibroblasts in vitro, and single-dose regimens using high concentrationsof these drugs at the time of operation may achieve results similar to those of protocols that involve repeated applications.
Abstract: • Proliferating human Tenon's capsule fibroblasts were exposed for 5 minutes to a wide range of concentrations of fluorouracil, floxuridine, and mitomycin. High concentrations of all three agents had prolonged effects on cell proliferation and morphologic characteristics compared with untreated control cells up to 36 days. The highest concentrations of both floxuridine (15000 μg/mL) and mitomycin (1000 μ g mL) had an apparent cidal effect, reducing cell numbers below initial cell density. In contrast, although the highest concentration of fluorouracil (25000 μg/mL) inhibited cell proliferation by more than 50% relative to the untreated control cells at 36 days, the cell numbers still increased fourfold compared with the initial cell density. These results demonstrate that 5-minute treatments with high concentrations of these drugs have prolonged effects on the proliferation of human Tenon's capsule fibroblasts in vitro. Single-dose regimens using high concentrations of these drugs at the time of operation may achieve results similar to those of protocols that involve repeated applications.
275 citations
TL;DR: This new intraocular drug delivery system offers many advantages compared with intravenous therapy or repeated intravitreal ganciclovir injections for the management of CMV retinitis in patients with AIDS.
Abstract: • A surgically implantable device for sustained intravitreal release of ganciclovir has been developed. The device delivers ganciclovir intraocularly over approximately 4 to 5 months. Eight patients with acquired immunodeficiency syndrome (AIDS) and associated cytomegalovirus (CMV) retinitis were recruited as part of a phase 1 study. Thirteen eyes with active CMV retinitis underwent surgical implantation of the ganciclovir device. All eyes showed resolution of the CMV retinitis; none showed progression. Visual acuity remained unchanged in three eyes, improved in six eyes, and decreased in four eyes. Surgical complications included mild vitreous hemorrhage, astigmatism, and suprachoroidal placement of the device. Retinal detachment occurred in three eyes as the retinitis resolved. This new intraocular drug delivery system offers many advantages compared with intravenous therapy or repeated intravitreal ganciclovir injections for the management of CMV retinitis in patients with AIDS.
266 citations
TL;DR: A significant decline in the log maximum asymptotic amplitude with age accounted for most of the amplitude decline inThe standard protocol rod response, consistent with previous studies showing little decrease in photopigment optical density with age.
Abstract: • Full-field electroretinograms were obtained in 269 normal subjects with the International Standardization Protocol endorsed by the International Society for Clinical Electrophysiology of Vision and the National Retinitis Pigmentosa Foundation Inc. Log rod and cone amplitudes decreased exponentially with age in adults; amplitudes declined to one half those in the young adult level (ages 15 to 24 years) by ages 69 and 70 years for rod and cone responses, respectively. B-wave implicit times increased with age for all responses. Lower limits of normal peak-to-peak amplitude and upper limits of normal b-wave implicit time (P
265 citations
TL;DR: Findings suggest a primary interference in Müller cell function, possibly through dexamethasone-induced alterations in retinal glutamate or glucose metabolism, and suggest the intravitreal injection of steroids may be potentially useful in the treatment of endophthalmitis and other ocular inflammatory diseases.
Abstract: • The intravitreal injection of steroids may be potentially useful in the treatment of endophthalmitis and other ocular inflammatory diseases. The retinal toxicity and intraocular turnover of aqueous solutions of dexamethasone sodium phosphate in doses ranging from 440 to 4000 μg were evaluated in the rabbit; evaluation was also performed for a 0.1-mL injection of a commercially available preparation (dexamethasone phosphate [Decadron] injection, 4 mg/mL). After the 440-μg dose, a transient increase in staining of the Muller cells was observed, which normalized after 2 days. Progressively higher doses resulted in an increasing spectrum of disorganization in Muller and other retinal cells. The half-life of the intravitreally injected drug was 3.48 hours. These findings suggest a primary interference in Muller cell function, possibly through dexamethasoneinduced alterations in retinal glutamate or glucose metabolism.
TL;DR: The patients with the 3460 mutation had a higher incidence of visual recovery, a higher percentage of pedigrees with more than one affected family member, and a greater frequency of tobacco and alcohol abuse.
Abstract: • Objective. —To define the clinical features of Leber's hereditary optic neuropathy associated with the 14484 mitochondrial DNA mutation and to compare these features with those associated with three other pathogenetic mutations. Design and Patients. —Clinical and historical data were collected from 19 visually symptomatic patients from 17 independent pedigrees with the molecularly confirmed 14484 mutation. Main Outcome Measures. —Demographic features, age of onset of visual loss, nadir of visual acuity, occurrence and timing of visual recovery, family history of visual loss, and associated medical and environmental conditions. Results. —Clinical characteristics associated with the 14484 mutation are similar overall to those of the three other primary mutations. One notable distinguishing feature is the higher incidence of visual recovery among patients with the 14484 mutation. Thirty-seven percent of our patients experienced visual recovery compared with 5% with the 11778 mutation ( P Conclusions. —Leber's hereditary optic neuropathy associated with the 14484 mitochondrial DNA mutation may have a better prognosis for visual recovery. The phenotypic expression of the 14484 mutation may be influenced by concurrent medical and environmental factors. Molecular genetic testing in suspected Leber's hereditary optic neuropathy is useful to confirm the diagnosis and to assess visual prognosis.
TL;DR: Parapapillary chorioretinal atrophy was associated with shallow glaucomatous cupping, diffuse nerve fiber loss, a marked tessellated fundus, and only moderately elevated intraocular pressure and showed a spatial correlation to neuroretinal rim loss inside the optic disc.
Abstract: Glaucomatous optic nerve damage is typically associated with intrapapillary changes, such as neuroretinal rim loss. In this study, parapapillary chorioretinal atrophy was evaluated in 691 normal eyes, 1081 glaucomatous eyes, and 31 eyes with ocular hypertension. It was significantly larger and occurred more often in the glaucomatous eyes (parapapillary atrophy area, 1.07 +/- 0.83 mm2) (mean +/- SD) than in the normal eyes (0.55 +/- 0.64 mm2) or in the eyes with ocular hypertension (0.55 +/- 0.37 mm2). These differences were significant also for eyes with moderate glaucomatous damage (0.86 +/- 0.62 mm2). Parapapillary chorioretinal atrophy was associated with shallow glaucomatous cupping, diffuse nerve fiber loss, a marked tessellated fundus, and only moderately elevated intraocular pressure. It increased with a decreasing neuroretinal rim area. It showed a spatial correlation to neuroretinal rim loss inside the optic disc. In unilateral glaucoma, it was larger in the affected eye than in the unaffected eye. Parapapillary chorioretinal atrophy is associated with glaucoma.
TL;DR: It is surprising to discover that rose bengal is not a vital dye; after staining, cells actually lost vitality, as evidenced by instant morphologic changes, subsequent loss of cellular motility, cell detachment, and cell death.
Abstract: • It has been believed that 1% rose bengal does not stain normal, healthy cells but rather stains degenerated or dead cells and mucous strands. In contrast to this conventional knowledge, we discovered that both commercial additive-containing and additive-free rose bengal solutions stained four different types of healthy cultured cells, including rabbit corneal epithelial cells. Rose bengal staining was rapid, dose dependent, predominantly nuclear, and detectable with the naked eye at concentrations as low as 0.05% and 0.025% for the commercial additive-containing or additive-free solutions, respectively, and with the fluorescence microscope at a concentration of 0.001%. It is surprising to discover that rose bengal is not a vital dye; after staining, cells actually lost vitality, as evidenced by instant morphologic changes, subsequent loss of cellular motility, cell detachment, and cell death. Such an intrinsic toxic effect was augmented by light exposure. The rose bengal staining of live as well as detergent-treated (Triton X-100) cells could be blocked by such tear components as mucin and albumin, suggesting that normally negative rose bengal staining is due to the protective function of the preocular tear film, ie, staining is not dictated by lack of cell vitality. These data indicate that rose bengal staining ensues whenever there is poor protection of surface epithelium by the preocular tear film; this represents a new interpretation for rose bengal stains seen in various ocular surface disorders.
TL;DR: Age-specific rates for principal and secondary diagnoses of ocular trauma were distributed bimodally, with the highest peak in adolescents and young adults, and another peak among those 75 years or older.
Abstract: • The discharge rate for ocular trauma resulting in hospitalization and variations in rates between US census subdivisions were examined by using hospital discharge abstracts from the 1984 through 1987 National Hospital Discharge Surveys. The average annual rate of hospitalization with a principal diagnosis of ocular trauma was 13.2 per 100000. The rate for any ocular trauma (principal or secondary diagnosis) was 29.1 per 100000. Males were three times more likely to be hospitalized for a principal diagnosis of ocular trauma than females. Age-specific rates for principal and secondary diagnoses of ocular trauma were distributed bimodally, with the highest peak in adolescents and young adults, and another peak among those 75 years or older. This study has begun the first step in profiling ocular trauma resulting in hospitalization in the United States.
TL;DR: It is concluded that long-term use of corticosteroids to maintain the initial beneficial effect on refraction would be unacceptable, and these agents should not be used after photorefractive keratectomy.
Abstract: In this study, we report the results of a prospective, double-blind trial to determine whether high-dose topical corticosteroids have an effect on refractive outcome or anterior stromal haze after photorefractive keratectomy. A total of 113 patients were allocated randomly to either placebo- or steroid-treated groups (0.1% dexamethasone metasulphobenzoate for 3 months) and underwent either -3.00-diopter (D) or -6.00-D procedures. At 6 weeks, the mean change in refraction was significantly greater in the steroid-treated group than in the placebo-treated group (-3.00-D group, P = .0015; -6.00-D group, P = .0011). However, when corticosteroids were discontinued at 3 months, this difference became statistically insignificant. There was no statistically significant effect on anterior stromal haze at any stage. Since long-term use of corticosteroids to maintain the initial beneficial effect on refraction would be unacceptable, we conclude that these agents should not be used after photorefractive keratectomy.
TL;DR: A 29-year-old white man with myopia and a history of bilateral penetrating keratoplasties 10 years previously for congenital hereditary endothelial dystrophy was referred with elevated in traocular pressure despite receiving maximum tolerated medical therapy.
Abstract: Although hypotony occurs frequently after glaucoma filtration surgery, decreased visual acuity due to macular changes is rare. We report a case of hypotony maculopathy with marked decrease in visual acuity following an otherwise uncomplicated trabeculectomy using intraoperative mitomycin C. Report of a Case. —A 29-year-old white man with myopia and a history of bilateral penetrating keratoplasties 10 years previously for congenital hereditary endothelial dystrophy was referred with elevated in traocular pressure despite receiving maximum tolerated medical therapy. Best corrected visual acuity was 20/300 OD with a -11.00+2.00×130 and 20/60 OS with a -14.00+4.75×161. Intraocular pressure ranged from 32 to 44 mm Hg OU. Slit-lamp examination revealed clear corneal grafts in both eyes, deep anterior chambers in botheyes, normal irides, and clear crystalline lenses. The angles were wide open and without peripheral anterior synechiae. Funduscopic examination disclosed a tilted disc with an inferior notch in the right eye and a tilted
TL;DR: Surgery for major trichiasis produced a significant improvement in visual acuity in operated vs nonoperated fellow eyes in a regression model incorporating the between-eyes correlation of visual Acuity.
Abstract: • The effectiveness of commonly used procedures to correct trachomatous trichiasis of the upper lid was examined in a clinical trial in Oman. Lids were graded as having minor trichiasis (five or fewer lashes), major trichiasis (more than five lashes), and defective lid closure. Randomly allocated surgery specific for lid grade was completed in 384 lids, of which 369 (96%) were followed up once or twice approximately 9 and 21 months after surgery. The definition of operative success included no evidence of trichiasis and complete lid closure. Tarsal rotation was the most effective operation and was successful in 80% of cases of minor trichiasis, compared with success rates of 29% for electrolysis and 18% for cryoablation. Tarsal rotation was successful in 77% of cases of major trichiasis, compared with a 41% success rate for tarsal advance and rotation. Surgery for major trichiasis produced a significant improvement in visual acuity in operated vs nonoperated fellow eyes in a regression model incorporating the between-eyes correlation of visual acuity.
TL;DR: The medical records of 52 patients with culture-proven gram-negative endophthalmitis between January 1982 and December 1990 were reviewed and their sensitivities to ceftazidime, ciprofloxacin, and imipenem were obtained.
Abstract: • The medical records of 52 patients (53 eyes) with culture-proven gram-negative endophthalmitis between January 1982 and December 1990 were reviewed.Pseudomonas aeruginosa(23% [12/53]) andHaemophilus influenzae(19% [10/53]) were the most frequent isolates in this series. Overall, 26 (49%) of 53 treated patients achieved 20/400 or better visual acuity. Fifty-two (98%) of the original 53 gram-negative isolates were sensitive to the aminoglycoside antibiotics. To determine their sensitivity to recently developed antibiotics, 35 of the isolates were again grown on culture media and their sensitivities to ceftazidime, ciprofloxacin, and imipenem were obtained. Only ceftazidime demonstrated in vitro efficacy for all the organisms tested.
TL;DR: All but two patients had a return of their best corrected preoperative visual acuity to within one Snellen line at 6 months, and this preliminary study shows excimer photorefractive keratectomy to be a promising surgical treatment for patients with higher myopia.
Abstract: • Excimer photorefractive keratectomy was performed at three centers on 16 highly myopic eyes (8 diopters [D] or more) and followed up for 6 months. Ablation depths ranged from 137 to 230 μm. The preoperative spherical equivalent of myopia ranged from −8.62 D to −14.50 D (mean±SD, −11.57±1.62 D). Six months after surgery, the mean refraction (spherical equivalent) was −0.90±2.1 D. Eleven of 16 eyes achieved refractions within 2 D of that attempted. All eight patients at one site were treated with a maximum-beam diameter of 6.0 mm and were corrected to within 2 D of that attempted, and all were 20/40 or better uncorrected. Three of eight eyes at the other two sites were treated with a 5.5- or 5.6-mm maximum-beam diameter, which achieved corrections within 2 D of that attempted. The epithelium healed within 3 to 4 days, and there were no erosions. Mild subepithelial reticular haze, similar to that seen with excimer photorefractive keratectomy for lower myopia, was seen in all patients, with two patients experiencing more significant corneal haze. This peaked at 3 to 6 weeks and then gradually diminished. All but two patients had a return of their best corrected preoperative visual acuity to within one Snellen line at 6 months. This preliminary study shows excimer photorefractive keratectomy to be a promising surgical treatment for patients with higher myopia.
TL;DR: Investigation indicates that these devices can maintain therapeutic levels of drug for extended periods and are well tolerated in the rabbit eye, and may prove useful in the clinical management of cytomegalovirus retinitis in patients with acquired immunodeficiency syndrome.
Abstract: • Current treatment of cytomegalovirus retinitis in patients with acquired immunodeficiency syndrome involves frequent intravenous administration of sodium ganciclovir that often results in unacceptable side effects. We have developed devices that release ganciclovir at rates of 2 μg/h and 5 μg/h in vitro. When implanted into the vitreous of rabbit eyes, mean intravitreal ganciclovir levels of 9 mg/L and 16 mg/L were maintained for more than 80 and 42 days, respectively. Devices were well tolerated, with no toxic effects attributable to the polymers used in the devices. This investigation indicates that these devices can maintain therapeutic levels of drug for extended periods and are well tolerated in the rabbit eye. They may prove useful in the clinical management of cytomegalovirus retinitis in patients with acquired immunodeficiency syndrome.
TL;DR: Eyes with macular edema caused by retinal branch vein occlusion underwent masked evaluation of fluorescein angiography to determine complete macular perfusion vs incomplete macular performance (capillary dropout, ischemia), which showed a greater frequency of improvement in visual acuity.
Abstract: Eyes with macular edema caused by retinal branch vein occlusion underwent masked evaluation of fluorescein angiography to determine complete macular perfusion vs incomplete macular perfusion (capillary dropout, ischemia) Cases evaluated as incomplete macular perfusion showed a greater frequency of improvement (91%) in visual acuity than did perfused cases (29%) (P = 003) after a mean follow-up of 39 months Ischemic edema is often transient, and is associated with a good outcome in visual acuity (median final visual acuity was 20/30) Perfused macular edema has a poorer prognosis for visual acuity (median final visual acuity was 20/80) Macular ischemia is usually associated with a broken foveal capillary ring Previous animal research on ischemic brain edema has shown that following brain ischemia, an intracellular and an extracellular hypertonic environment lead to intracellular and extracellular edema (cytotoxic edema), which is often followed by vascular protein leakage (vasogenic edema) A similar occurrence in ischemic retina could explain the transient edema reported herein, with good outcome in visual acuity following the spontaneous resolution of edema
TL;DR: The healing response to selective photocoagulation of the retinal pigment epithelium was studied in rabbits during a period of 4 weeks, and only minimal inflammatory response was found.
Abstract: • Multiple short argon laser pulses can coagulate the retinal pigment epithelium selectively, while sparing the adjacent neural retina and choroid; in contrast, continuous-wave laser irradiation typically damages the neural retina and choroid. The healing response to selective photocoagulation of the retinal pigment epithelium was studied in rabbits during a period of 4 weeks. The lesions were never visible ophthalmoscopically. During the healing period, the epithelium was reformed by a single sheet of hypertrophic retinal pigment epithelial cells. In contrast to continuous-wave photocoagulation, only minimal inflammatory response was found. Retinal pigment epithelial cells showed clear signs of viability, eg, phagocytized outer segments. The local edema in the photoreceptor layer and subretinal space found in the early stage disappeared when the blood-retinal barrier was reestablished. The choriocapillaris remained unaffected. No subsequent damage to the photoreceptors was found. This type of photocoagulation may be useful for retinal pigment epithelium—related diseases, eg, diffuse diabetic macular edema.
TL;DR: The hydroxyapatite orbital implant appears to be well tolerated and provides prosthesis motility with few problems and was most impressive in adults who had the peg in place and in children.
Abstract: • The hydroxyapatite orbital implant is designed to provide the enucleated patient with improved motility of the prosthesis. We report the results of our first 100 consecutive cases of hydroxyapatite implantation in eyes enucleated primarily for intraocular neoplasms. During a median of 11 months' follow-up, there have been no cases of orbital infection, implant extrusion, or implant migration. Minor postoperative problems have included transient orbital pain in six patients, Tenon's fascia edema and buried peg from tissue overgrowth in two patients each, wound erosion and peg extrusion in one patient each, and audible click of the peg in three patients. Movement of the socket and fornices was excellent in 99% of patients. Motility was cosmetically satisfactory with 10° to 15° rapid darting prosthesis movement present in 96% of patients regardless of whether the peg had been placed. Large-degree prosthesis motility (>15°) was present in 24% of all patients and was most impressive in those adults who had the peg in place and in children. The hydroxyapatite implant appears to be well tolerated and provides prosthesis motility with few problems.
TL;DR: Human vitreous samples from patients with proliferative diabetic retinopathy and without diabetes were analyzed for collagen crosslinks, as well as for the early glycation products, gluc itolyllysine and glucitolylhydroxylysine, and advanced glycation end products.
Abstract: • Vitreous changes in diabetes can exacerbate proliferative diabetic retinopathy. These changes may be due to the effects of diabetes on vitreous collagen. Vitreous samples from 19 patients with proliferative diabetic retinopathy and 23 patients without diabetes were analyzed for collagen crosslinks, as well as for the early glycation products, glucitolyllysine and glucitolylhydroxylysine. Fluorometry was performed to measure advanced glycation end products. Vitreous collagen derived from diabetic patients was found to have significantly higher levels of the crosslink dihydroxylysinonorleucine (3.15 vs 1.24 mol/mol collagen,P
TL;DR: National Eye Trauma System Registry data are useful to identify strategies to prevent occupational eye injuries such as wider use of safety glasses and improvement in engineering controls.
Abstract: • Occupational eye injuries are common and preventable. Between 1985 and 1991, there were 635 work-related penetrating eye injuries among the 2939 cases (22%) reported to the National Eye Trauma System Registry by 48 collaborating centers in 28 states and Washington, DC. The median age of the injured workers was 30 years; 75% were younger than 40 years; and 97% were male. The commonest causes of injuries were projectiles (457 cases), sharp objects (166 cases), blunt objects (60 cases), and blasts (22 cases); these terms are not mutually exclusive. Specific objects causing injuries included nails, wire, screwdrivers, and other hand tools. There was evidence of alcohol use by at least 2% of the injured workers. When they were injured, 6% of the workers were wearing safety glasses; 3% were wearing nonsafety eyewear. Posterior segment trauma, which occurred in 63% of the cases, included vitreous hemorrhage (42%), intraocular foreign bodies (35%), and retinal detachment (10%). Hyphema occurred in 35% and traumatic cataract in 32% of the cases. Initial visual acuity after injury was hand motion or worse in 43% of the cases. National Eye Trauma System Registry data are useful to identify strategies to prevent occupational eye injuries such as wider use of safety glasses and improvement in engineerina controls.
TL;DR: The general linear model and polychotomous logistic regression approaches of Rosner and the estimating equation approach of Liang and Zeger are considered and it is concluded that these models should be used more frequently in ophthalmologic research.
Abstract: • Regression techniques that appropriately use all available eyes have infrequently been applied in the ophthalmologic literature, despite advances both in the development of statistical models and in the availability of computer software to fit these models. We considered the general linear model and polychotomous logistic regression approaches of Rosner and the estimating equation approach of Liang and Zeger, applied to both linear and logistic regression. Methods were illustrated with the use of two real data sets: (1) impairment of visual acuity in patients with retinitis pigmentosa and (2) overall visual field impairment in elderly patients evaluated for glaucoma. We discuss the interpretation of coefficients from these models and the advantages of these approaches compared with alternative approaches, such as treating individuals rather than eyes as the unit of analysis, separate regression analyses of right and left eyes, or utilization of ordinary regression techniques without accounting for the correlation between fellow eyes. Specific advantages include enhanced statistical power, more interpretable regression coefficients, greater precision of estimation, and less sensitivity to missing data for some eyes. We concluded that these models should be used more frequently in ophthalmologic research, and we provide guidelines for choosing between alternative models.
TL;DR: Early repeated excimer laser ablation of the monkey cornea apparently induces vigorous stromal wound healing and use of shallower ablations, corticosteroids, or a longer delay between ablations may be necessary for repeated laser surgery to be practical clinically.
Abstract: • Five rhesus monkey eyes underwent repeated argon fluoride (193 nm) excimer laser myopic photorefractive keratectomy 3 months following an initial ablation that had produced mild subepithelial haze. At 3 months all eyes had development of a dense subepithelial opacity and a thickened epithelium (12 cells, 80 μm) with vacuolization of basal cells, fragmented basement membrane, and a layer of subepithelial fibrosis containing activated fibroblasts. By 6 months the opacity was clearing; epithelium was thinner (50 μm); subepithelial fibrosis was more lamellar. By 15 months only mild haze persisted clinically; epithelium was 30 μm thick, with persistent basal vacuolization and focal basement membrane disruption; subepithelial fibrous tissue was more organized. Early repeated excimer laser ablation of the monkey cornea apparently induces vigorous stromal wound healing. Use of shallower ablations, corticosteroids, or a longer delay between ablations may be necessary for repeated laser surgery to be practical clinically.
TL;DR: Dorzolamide appears to have substantial potential in the treatment of glaucoma and ocular hypertension.
Abstract: • The multiple-dose, dose-response relationship and duration of action of the novel topical carbonic anhydrase inhibitor dorzolamide (previously known as MK-507) were investigated in a doublemasked, randomized, placebo-controlled, parallel study in 73 patients with bilateral primary open angle glaucoma or ocular hypertension. Dorzolamide (0.7%, 1.4%, or 2%) or placebo was administered every 12 hours for 5 days and then every 8 hours for 7 days. Intraocular pressure was investigated with multiple 12-hour diurnal curves. All concentrations of dorzolamide demonstrated substantial lowering of intraocular pressure throughout the day when given twice daily (9% to 21%) or three times daily (14% to 24%). Although a dose-dependent response was observed immediately following the first dose, there were no significant differences between concentrations or dose response at either the twice or three times daily dosing regimen. Three times daily administration of 2% dorzolamide demonstrated a mean percent decrease in intraocular pressure of 18% to 22% throughout the day (mean decrease, 4.5 to 6.1 mm Hg). Dorzolamide appears to have substantial potential in the treatment of glaucoma and ocular hypertension.
TL;DR: The cul- de-sacs provide a major portion of the normal outflow resistance, the cul-de-sac area is markedly reduced in pigmentary glaucoma and primary open angle glaucolysis, and macrophages are the major cell type responsible for trabecular meshwork clearance of pigment and debris.
Abstract: To localize the site of outflow obstruction in glaucoma, we evaluated the trabecular meshwork tissues by morphometric methods. Thirty-three specimens from 27 patients with primary open angle glaucoma (n = 13), pigmentary glaucoma (n = 4), and pigment dispersion syndrome (n = 2), and from nonglaucomatous normal subjects (n = 8) were compared. In these specimens, the extent of aqueous channels and the area occupied by these channels where they terminate in cul-de-sacs were measured. In 32 nonglaucomatous normal specimens (six of the eight mentioned plus an additional 26), we discovered that 94% of the surface area of the cul-de-sacs is lined by trabecular cells. These measurements were used to calculate the resistance to aqueous outflow offered by cul-de-sacs. Three new concepts are advanced in this report: (1) the cul-de-sacs provide a major portion of the normal outflow resistance, (2) the cul-de-sac area is markedly reduced in pigmentary glaucoma and primary open angle glaucoma, accounting for a major portion of the increase in resistance in these conditions, and (3) macrophages are the major cell type responsible for trabecular meshwork clearance of pigment and debris. A common pathophysiologic sequence of events is proposed for the development of glaucoma in pigmentary glaucoma and primary open angle glaucoma.