Showing papers in "Archives of Ophthalmology in 1995"

Optical Coherence Tomography of the Human Retina

Abstract: Objective: To demonstrate optical coherence tomography for high-resolution, noninvasive imaging of the human retina. Optical coherence tomography is a new imaging technique analogous to ultrasound B scan that can provide cross-sectional images of the retina with micrometer-scale resolution. Design: Survey optical coherence tomographic examination of the retina, including the macula and optic nerve head in normal human subjects. Setting: Research laboratory. Participants: Convenience sample of normal human subjects. Main Outcome Measures: Correlation of optical coherence retinal tomographs with known normal retinal anatomy. Results: Optical coherence tomographs can discriminate the cross-sectional morphologic features of the fovea and optic disc, the layered structure of the retina, and normal anatomic variations in retinal and retinal nerve fiber layer thicknesses with 10-??m depth resolution. Conclusion: Optical coherence tomography is a potentially useful technique for high depth resolution, cross-sectional examination of the fundus.

Quantification of Nerve Fiber Layer Thickness in Normal and Glaucomatous Eyes Using Optical Coherence Tomography: A Pilot Study

Abstract: Purpose: Quantitative assessment of nerve fiber layer (NFL) thickness in normal and glaucomatous eyes, and correlation with conventional measurements of the optic nerve structure and function. Methods: We studied 59 eyes of 33 subjects by conventional ophthalmologic physical examination, Humphrey 24-2 visual fields, stereoscopic optic nerve head photography, and optical coherence tomography. Results: Nerve fiber layer thickness as measured by optical coherence tomography demonstrated a high degree of correlation with functional status of the optic nerve, as measured by visual field examination ( P =.0001). Neither cupping of the optic nerve nor neuroretinal rim area were as strongly associated with visual field loss as was NFL thickness ( P =.17 and P =.21,respectively). Cupping correlated with NFL thickness only when the cup was small (cup-to-diameter ratio, 0.1 to 0.3) or large (cup-to-diameter ratio, 0.8 to 1.0) ( P =.006); there was no correlation between cupping and NFL thickness otherwise. Nerve fiber layer, especially in the inferior quadrant, was significantly thinner in glaucomatous eyes than in normal eyes ( P =.04). Finally, we found a decrease in NFL thickness with aging, even when controlling for factors associated with the diagnosis of glaucoma ( P =.03). Conclusions: Nerve fiber layer thickness can be measured using optical coherence tomography. These measurements provide good structural and functional correlation with known parameters.

Quantitative Assessment of Macular Edema With Optical Coherence Tomography

Abstract: Objective: To evaluate optical coherence tomography, a new technique for high-resolution cross-sectional imaging of the retina, for quantitative assessment of retinal thickness in patients with macular edema. Design: Survey examination with optical coherence tomography of patients with macular edema. Setting: Referral eye center. Patients: Forty-nine patients with the clinical diagnosis of diabetes or diabetic retinopathy and 25 patients with macular edema secondary to retinal vein occlusion, uveitis, epiretinal membrane formation, or cataract extraction. Main Outcome Measures: Correlation of optical coherence tomograms with slit-lamp biomicroscopy, fluorescein angiography, and visual acuity. Results: Optical coherence tomograms of cystoid macular edema closely corresponded to known histopathologic characteristics. Quantitative measurement of retinal thickness is possible because of the well-defined boundaries in optical reflectivity at the inner and outer margins of the neurosensory retina. Serial optical coherence tomographic examinations allowed tracking of both the longitudinal progression of macular thickening and the resolution of macular edema after laser photocoagulation. In patients with diabetic retinopathy, measurements of central macular thickness with optical coherence tomography correlated with visual acuity, and optical coherence tomography was more sensitive than slit-lamp biomicroscopy to small changes in retinal thickness. Conclusions: Optical coherence tomography appears useful for objectively monitoring retinal thickness with high resolution in patients with macular edema. It may eventually prove to be a sensitive diagnostic test for the early detection of macular thickening in patients with diabetic retinopathy.

Risk factors for open-angle glaucoma. The Barbados Eye Study.

Abstract: Objective: To evaluate risk factors for open-angle glaucoma among black participants in the Barbados Eye Study. Design: Population-based study of demographic, medical, ocular, familial, and other factors possibly related to open-angle glaucoma. Setting and Participants: The Barbados Eye Study included 4709 Barbados residents identified by a simple random sample of Barbadian-born citizens, 40 to 84 years of age; participation was 84%. This report is based on the 4314 black participants examined at the study site; 302 (7%) met the Barbados Eye Study criteria for open-angle glaucoma. Data Collection: A standardized protocol included applanation tonometry, Humphrey perimetry, fundus photography, blood pressure, anthropometry, and an interview. An ophthalmologic examination was performed for participants who met specific criteria. Main Outcome Measures: Open-angle glaucoma was defined by the presence of both characteristic visual field defects and optic disc damage. Association of open-angle glaucoma with specific factors was evaluated in logistic regression analyses. Results: Age, male gender, high intraocular pressure, and family history of open-angle glaucoma were major risk factors; the latter association was stronger in men than women. Lean body mass and cataract history were the only other factors related to open-angle glaucoma. Although hypertension and diabetes were common in Barbados Eye Study participants, they were unrelated to the prevalence of open-angle glaucoma. However, associations were found with low diastolic blood pressure-intraocular pressure differences and low systolic and diastolic blood pressure/intraocular pressure ratios. Conclusions: In the Barbados Eye Study black population, persons most likely to have open-angle glaucoma were older men and had a family history of open-angle glaucoma, high intraocular pressure, lean body mass, and cataract history. These results suggest the importance of possible genetic or familial factors in open-angle glaucoma. The role of vascular risk factors is consistent with our finding of low blood pressure to intraocular pressure relationships, but the results could be explained by the high intraocular pressure in open-angle glaucoma.

Hypertension, Perfusion Pressure, and Primary Open-angle Glaucoma: A Population-Based Assessment

Abstract: Objective: To evaluate the association of vascular factors with primary open-angle glaucoma (POAG). Design: A population-based prevalence survey of ocular disease among black and white residents. Setting: Communities of east Baltimore, Md. Participants: A stratified cluster sample of 5308 residents 40 years of age or older. Main Outcome Measures: Primary open-angle glaucoma as defined by demonstrable glaucomatous optic nerve damage based on visual fields and/or optic disc findings. Intraocular pressure level was not a criterion for diagnosis. Results: Systolic and diastolic blood pressure showed modest, positive association with POAG. The effect of blood pressure on POAG was modified by age, with a stronger association among older subjects. Lower perfusion pressure (blood pressure-intraocular pressure) was strongly associated with an increased prevalence of POAG, with a sixfold excess for those in the lowest category of perfusion pressure. Conclusion: These results suggest that POAG is associated with an alteration in factors related to ocular blood flow and a breakdown of autoregulation.

Hypoxic Regulation of Vascular Endothelial Growth Factor in Retinal Cells

Abstract: Background: Vascular endothelial growth factor (VEGF) is an angiogenic protein and vasopermeability factor whose intraocular concentrations are closely correlated with active neovascularization in patients with diabetes mellitus, central retinal vein occlusion, retinopathy of prematurity, and rubeosis iridis. Objective: To determine whether hypoxia could induce expression of VEGF in retinal cells, which then promotes retinal endothelial cell proliferation. Methods: Retinal pigment epithelial cells, pericytes, and microvascular endothelial cells were exposed to hypoxic conditions in vitro, and RNA expression of VEGF was evaluated by Northern blot analysis. The VEGF-specific proliferative potential of the medium was measured by means of retinal endothelial cell growth assays and VEGF-neutralizing VEGF receptor IgG chimeric protein. Results: The VEGF RNA levels increased within 4 hours and reached elevations of threefold to 30-fold after 18 hours of hypoxia (0% to 5% oxygen, 5% carbon dioxide, 90% to 95% nitrogen) in all cell types (.01 Conclusion: Hypoxia increases VEGF expression in retinal cells, which promotes retinal endothelial cell proliferation, suggesting that VEGF plays a major role in mediating intraocular neovascularization resulting from ischemic retinal diseases.

The Wisconsin Epidemiologic Study of Diabetic Retinopathy

Abstract: In the September 1994 issue of theArchives, Klein et al1conclude that their study confirms current guidelines for ophthalmologic care of patients with diabetes. After a thorough review of their data, we think that their results contradict the guideline that all people with diabetes need annual screening examinations. The annual examination standard does not reflect the findings of Klein et al1-4that the risk of treatable retinopathy depends on the status of the retina at a baseline examination. We conclude that the data of Klein et al1support a screening interval of 2 years or more, depending on the sensitivity of the method, for patients with retinopathy levels 21 or less at their last examination. Tables 7 and 8 in the article by Klein et al1show that among 708 patients with no retinopathy at baseline, in only 1.2% to 2.5% did proliferative diabetic retinopathy

Ocular Surface Changes and Discomfort in Patients With Meibomian Gland Dysfunction

Abstract: Objective: To determine the importance of meibomian gland dysfunction (MGD) on the ocular surface. Design: Prospective study. Setting: A university-based referral practice. Patients: Patients with ocular discomfort (147 eyes) and without ocular discomfort (54 eyes) were examined. In the total 201 eyes, MGD was defined as the presence of an obstruction of the meibomian orifices (obstruction group [n=54]) or the absence of a gland structure (gland dropout group [n=36], or both of these findings (combined group [n=38]). There were not any findings of MGD in 73 eyes (non-MGD group). Main Outcome Measures: Scores that were obtained from fluorescein and rose bengal staining, the breakup time of the tear film, the rates of tear evaporation and tear production, and meibography. Results: Of the 147 eyes with ocular discomfort, 95 (64.6%) had either an obstruction of an orifice or gland dropout, or both. The combined group had higher scores for staining with fluorescein ( P =.002) and rose bengal ( P =.021) compared with that in the non-MGD group. The rate of tear production was increased more in the gland dropout group than in the non-MGD group ( P =.002). The rate of tear evaporation was significantly increased in the gland dropout group ( P =.017). Conclusion: Meibomian gland dysfunction is a major cause of ocular surface abnormalities and ocular discomfort.

Effects of Brimonidine on Aqueous Humor Dynamics in Human Eyes

Abstract: Objective: To evaluate the mechanism by which brimonidine, a selective α 2 -adrenergic agonist, lowers intraocular pressure (IOP) in humans. Subjects: Twenty-one volunteers with ocular hypertension. Methods: Brimonidine tartrate (0.2%) was given topically twice daily for 1 week to one eye in a randomized, double-masked study. The fellow eye was similarly treated with brimonidine vehicle. Before (baseline) and after 1 week (day 8) of dosing, IOP, aqueous flow, episcleral venous pressure, and tonographic outflow facility were directly measured. Fluorophotometric outflow facility and uveoscleral outflow were calculated. Brimonidinetreated eyes were compared with vehicle-treated contralateral control eyes and with baseline measurements after 1 week of dosing. Results: Brimonidine significantly ( P t test) reduced IOP mean±SE of 4.7±0.7 and 4.2±0.4 mm Hg compared with the baseline day and with the vehicle-treated contralateral control eyes, respectively. Compared with the baseline day, aqueous flow was reduced by 20% ( P =.002) and uveoscleral outflow was increased ( P =.04). A slight contralateral decrease in IOP of 1.2±0.6 mm Hg ( P =.05) and in aqueous flow of 12% ( P =.05) was noted. No significant difference was seen in the outflow facility values or episcleral venous pressure compared with the baseline day or with the contralateral control eye. Conclusions: The brimonidine-induced reduction in IOP in humans is associated with a decrease in aqueous flow and an increase in uveoscleral outflow. The decrease in IOP and aqueous flow in the contralateral control eye on day 8 compared with the baseline day suggests a mild contralateral effect.

Serum antioxidants and age-related macular degeneration in a population-based case-control study

Abstract: Objective: To investigate relationships between levels of tocopherols and carotenoids in the serum and age-related macular degeneration (ARMD). Design: A nested case-control study within a population-based cohort. Participants: Cases included a sample of subjects with retinal pigment abnormalities with the presence of soft drusen (n=127) or with late ARMD (geographic atrophy [n=9]) or neovascular and exudative macular degeneration (n=31). An equal number of controls (167 pairs) were selected from among participants in the Beaver Dam Eye Study. The controls had no photographic evidence of soft drusen, retinal pigment abnormalities, or late ARMD and were matched with cases for age, sex, and current smoking status. Data Collection: Presence and severity of ARMD were determined from masked grading of fundus photographs obtained from 1988 to 1990. Levels of individual carotenoids and tocopherols were determined in serum collected at the same time. Results: Average levels of individual carotenoids were similar in cases and controls. Average levels of vitamin E (α-tocopherol) were lower in people with exudative macular degeneration (P=.03). However, the difference was no longer statistically significant after controlling for levels of cholesterol in the serum. Persons with levels of lycopene, the most abundant carotenoid in the serum, in the lowest quintile were twice as likely to have ARMD. Levels of the carotenoids that compose macular pigment (lutein with zeaxanthin) in the serum were unrelated to ARMD. Conclusions: Very low levels of one (lycopene) but not other dietary carotenoids or tocopherols were related to ARMD. Lower levels of vitamin E in subjects with exudative macular degeneration compared with controls may be explained by lower levels of serum lipids.

Dietary fat and age-related maculopathy

Abstract: Objective: To describe the relationship between type and level of fat in the diet and the prevalence of age-related maculopathy. Design: Retrospective population-based study. Setting and Participants: Residents of Beaver Dam, Wis, between the ages of 45 and 84 years, participating in the Beaver Dam Eye Study and Nutritional Factors in Eye Disease Study. Data Collection: Presence and severity of age-related maculopathy were determined from masked grading of fundus photographs taken from 1988 through 1990. Diets in the past (1978 through 1980) were assessed retrospectively using a food frequency questionnaire during in-person home interviews. Results: Persons with intake of saturated fat and cholesterol in the highest compared with the lowest quintile had 80% and 60% increased odds for early age-related maculopathy, respectively, after adjusting for age and intake of beer. These relationships were not influenced by adjusting for several other potential confounding variables (carotenoid intake, intake of vitamins C or E in supplements, smoking, body mass index, time spent outdoors in the summer, gender, and history of diabetes, hypertension, or cardiovascular disease). Odds ratios for late age-related maculopathy were in similar directions but were not statistically significant. Conclusions: High intake of saturated fat and cholesterol is associated with increased risk for early age-related maculopathy in the Beaver Dam population. This supports the hypothesis that atherosclerosis or its risk factors are related to age-related maculopathy. Confirmation of this finding in other populations and in prospective studies is needed.

Transpupillary Thermotherapy in Choroidal Melanomas

Abstract: Objective: To determine safety and efficacy of transpupillary thermotherapy (TTT) as a new treatment for choroidal melanoma. Methods and Patients: To perform TTT, diode laser energy at 810 nm was used with a beam diameter of 1.5 to 4.5 mm for a 1-minute exposure. All 12 patients had choroidal melanoma. Six had had insufficient response to ruthenium 106 (106Ru) brachytherapy. Three patients with tumors more than 5 mm in height were treated simultaneously with106Ru and TTT. Three patients with juxtapapillary or macular tumors were treated by TTT only. Results: All but one tumor exhibited a reduction of tumor height in a follow-up period of 3 to 14 months. Side effects were minimal. Severe visual loss occurred in two patients due to radiation retinopathy, in two patients whose foveas were included in the TTT area, and in one patient resulting from a serous retinal detachment that extended over the posterior pole. Conclusions: Treatment with TTT may be useful as a complementary modality to brachytherapy. A longer follow-up period is required for final evaluation.

A Double-Masked, Randomized 1-Year Study Comparing Dorzolamide (Trusopt), Timolol, and Betaxolol

Abstract: Objective: To investigate the safety profile and efficacy of 2.0% dorzolamide hydrochloride, when administered three times daily for up to 1 year, compared with that of 0.5% timolol maleate and 0.5% betaxolol hydrochloride, each administered twice daily. In addition, the effect of adding dorzolamide to the regimen of patients with inadequate ocular hypotensive efficacy while they were receiving one of the two β-adrenoceptor antagonists and the effect of adding timolol to the regimen of patients receiving dorzolamide were also evaluated. Design: A double-masked, randomized, parallel comparison. Setting: Multinational study at 34 international sites. Patients: Five hundred twenty-three patients with open-angle glaucoma or ocular hypertension, 17 to 85 years of age. Patients currently using ocular hypotensive medications were required to undergo a washout. Intervention: Two percent dorzolamide three times a day, 0.5% timolol (Timoptic, Merck, Whitehouse Station, NJ) twice daily, and 0.5% betaxolol solution (Betoptic, Alcon, Fort Worth, Tex) twice daily. Results: At 1 year, the mean percent reduction in intraocular pressure at peak of 2% dorzolamide, 0.5% timolol, and 0.5% betaxolol was approximately 23%, 25%, and 21%, respectively. At afternoon trough, the mean percent reduction in intraocular pressure was 17%, 20%, and 15% for dorzolamide, timolol, and betaxolol, respectively. Conclusions: The ocular hypotensive efficacy of 2.0% dorzolamide, given three times a day, is comparable with that of 0.5% betaxolol, given twice daily, for up to 1 year. In addition, long-term use of dorzolamide was not associated with clinically meaningful electrolyte disturbances or systemic side effects commonly observed with the use of oral carbonic anhydrase inhibitors.

Photodynamic Therapy of Experimental Choroidal Neovascularization Using Lipoprotein-Delivered Benzoporphyrin

Abstract: Objective: To investigate photodynamic therapy of experimental choroidal neovascularization using benzoporphyrin derivative monoacid (Verteporfin). Methods: Photodynamic therapy using benzoporphyrin derivative monoacid was investigated in cynomolgus monkeys. Following intravenous injection of benzoporphyrin derivative monoacid (1 to 2 mg/kg) complexed with low-density lipoprotein, the eyes were irradiated with 692-nm light at a fluence of 50 to 150 J/cm 2 and irradiance of 150 to 600 mW/cm 2 . Choroidal neovascularization was documented before photodynamic therapy and closure was demonstrated by fundus photography, fluorescein angiography, and light and electron microscopic examination. Results: Following photodynamic therapy, vessels within choroidal neovascularization were occluded, and there was damage to the choroidal neovascularization endothelium and the subjacent choriocapillaris. Damage to the retinal pigment epithelium and photoreceptors was also observed. Conclusion: Photodynamic therapy with lipoprotein-delivered benzoporphyrin derivative monoacid was effective in this animal model of choroidal neovascularization and may be a promising, potentially selective, therapy for choroidal neovascularization.

Effects of Ocular Surface Area and Blink Rate on Tear Dynamics

Abstract: Objective: To study the effects of exposed ocular surface area and blink rate on tear dynamics by the measurement of tear evaporation under a range of conditions. Methods: Tear evaporation was measured in three gaze positions in 15 normal volunteers, and the ocular surface area was determined as a function of the width of the palpebral fissure. In 17 normal volunteers, the effect of blink rate on tear evaporation was assessed. Results: The ocular surface area was 1.2±0.27,2.2±0.39, and 3.0±0.33 cm 2 with patients looking down, ahead, and up, respectively. The corresponding tear evaporation rates per eye were 7.0±3.5, 17.6±6.6, and 23.7±6.3×10 -7 g/s, respectively. The tear evaporation per square meter also increased proportionally with the ocular surface area. When the blink rate was changed from 10 to 60 per minute, the tear evaporation did not change in those individuals with evaporation rates more than 7.8×10 -7 g/s per square centimeter, whereas it did increase with the blink rate in those whose evaporation rates were lower. Conclusions: Ocular surface area and blink rate affect tear dynamics. Moderate palpebral fissure width and blink rate are necessary for the prevention of desiccation of the ocular surface.

Efficacy of Ofloxacin vs Cefazolin and Tobramycin in the Therapy for Bacterial Keratitis: Report From the Bacterial Keratitis Study Research Group

Abstract: Purpose: To compare ofloxacin solution with a combination of fortified antibiotic cefazolin sodium and tobramycin sulfate solutions in the treatment of bacterial keratitis. Methods: Patients under care at any one of 28 participating clinical centers who had an eye with suspected bacterial keratitis were randomly allocated in a double-masked manner to treatment with 0.3% ofloxacin solution or a combination of the fortified antibiotics (1.5% tobramycin and 10.0% cefazolin solutions). Main Outcome Measures: Time to healing defined as complete re-epithelization, accompanied by a nonprogressive stromal infiltrate for two consecutive visits. Secondary outcome measures included patient symptoms and signs of infection and adverse reactions to study medications. Only patients with a positive bacterial corneal culture were included in most analyses. Results: A positive bacterial corneal culture was obtained in 140 (56%) of the 248 enrolled patients. The time to healing was similar among the 73 patients receiving ofloxacin and the 67 patients receiving fortified antibiotics (P=.70). By 7 days after study entry, the keratitis in 37% of the ofloxacin group and 38% of the fortified antibiotics group had healed. By 28 days, keratitis in 89% of the ofloxacin group and 86% of the fortified antibiotics group had healed. Two patients receiving ofloxacin and one receiving fortified antibiotics discontinued study medication because of lack of efficacy. Patients receiving ofloxacin reported substantially less burning and stinging on instillation than the patients receiving fortified antibiotics (P Conclusions: The efficacy of ofloxacin solution in treating bacterial keratitis is equivalent to that of the fortified cefazolin and tobramycin solutions. The reduced frequency of ocular toxic effects and the relative ease of preparation of ofloxacin are additional considerations.

Five-year incidence and disappearance of drusen and retinal pigment epithelial abnormalities. Waterman study

Abstract: Purpose: To obtain 5-year longitudinal data on age-related macular degeneration (AMD) that might be useful for disease prognosis, public health planning, and clinical trial development. Patients and Methods: Baseline (1985) and 5-year follow-up (1990) fundus photographs of 483 watermen over 30 years of age who participated in a cohort study conducted on the eastern shore of Maryland were graded independently in a reliable, standardized fashion. Eyes in which AMD appeared or disappeared also were graded in a side-by-side fashion. Results: Development of definite choroidal neovascularization and/or disciform scarring occurred in one of 50 participants over 70 years of age, specifically one of 15 participants over 70 years of age with AMD-3 (defined as large or confluent drusen, focal hyperpigmentation of the retinal pigment epithelium [RPE], and/or nongeographic atrophy of the RPE). Appearance of large drusen, focal hyperpigmentation, or AMD-3 was age related, occurring in 5%, 1%, and 7%, respectively, of participants aged 50 to 59 years; 17%, 3%, and 14%, respectively, of participants aged 60 to 69 years; and 17%, 9%, and 26%, respectively, of participants aged 70 years or more. Disappearance of large drusen, hyperpigmentation, or AMD-3 occurred in 16 (34%) of 47 participants, 11 (58%) of 19 participants, and 17 (28%) of 61 participants, respectively, who had each feature photographically present in 1985. Among the 47 eyes identified in which AMD-3 developed by independent gradings, 38 cases of AMD-3 (81%) were confirmed on side-by-side grading. Among the 16 eyes identified as having AMD-3 that disappeared, nine disappearances (56%) were confirmed. Borderline differences in appearance of pigment, drusen size, drusen location, or photographic quality may have accounted for disappearance in seven cases (44%). Conclusions: Prospective studies on the nonneovascular features of AMD (including large drusen and abnormalities of the RPE) must account for the appearance and disappearance of these features and support the idea that side-by-side gradings can complement independent gradings identifying appearance or disappearance of features of AMD.

Vasoproliferative tumors of the ocular fundus. Classification and clinical manifestations in 103 patients

Abstract: Objective: To describe the clinical features of vasoproliferative tumors of the ocular fundus and to propose a comprehensive classification of these tumors. Methods: A retrospective review of all cases that were diagnosed as acquired retinal hemangioma or vasoproliferative retinal tumor was conducted on the Ocular Oncology Service at Wills Eye Hospital, Philadelphia, Pa. Results: There were 129 vasoproliferative tumors in 113 eyes of 103 patients. The tumors were classified as idiopathic in 84 eyes (74%) and secondary to preexisting ocular disease in 29 (26%). Subclassification into solitary (88 eyes), multiple (17 eyes), and diffuse (eight eyes) involvement was made. Of the 84 eyes with idiopathic tumors, 73 (87%) had solitary tumors, five (6%) had multiple tumors, and six (7%) had diffuse tumors. The lesion was located in the inferior, inferotemporal, or temporal region of the fundus in 78% and developed within 6 mm of the ora serrata retinae in 88%. Associated vitreoretinal findings included intraretinal exudation (82%), secondary exudative retinal detachment (48%), vitreous cells (46%), vitreous hemorrhage (21%), preretinal macular fibrosis (31%), and macular edema (18%). Of the 29 eyes with secondary tumors, the tumor was solitary in 15 (52%), multiple in 12 (41%), and diffuse in two (7%). The most common preexisting ocular disease included intermediate uveitis (pars planitis) in eight eyes (28%), retinitis pigmentosa in six (21%), toxoplasmic retinitis in two (7%), toxocariasis in two (7%), retinochoroidal coloboma in two (7%), and traumatic chorioretinopathy in two (7%). Retinal pigment epithelial hyperplasia was a prominent feature that was adjacent to 58% of the secondary tumors. Overall, management of the 129 tumors consisted of observation in 63 (49%), cryotherapy in 54 (42%), laser photocoagulation in seven (5%), plaque radiotherapy in three (2%), and other modes of treatment in two (2%). Conclusions: Vasoproliferative retinal tumors can be idiopathic, or they can develop secondary to congenital, inflammatory, vascular, traumatic, dystrophic, and degenerative ocular diseases. They can produce a variety of complications. Awareness and recognition of these tumors and differentiation from other retinal vascular tumors are important.

Reproducibility and Responsiveness of the VF-14: An Index of Functional Impairment in Patients With Cataracts

Abstract: Objective: To assess the test-retest reliability and responsiveness of the VF-14, which is an index of functional impairment in patient with cataracts. Design: Observational longitudinal study. Patients were enrolled prior to undergoing their first cataract surgery between July 15 and December 15, 1991, and they were followed up for 1 year after surgery. Setting: Patients were recruited from 72 ophthalmologists' practices in three US cities. Patients: Five hundred fifty-two patients who had undergone a surgical procedure in only one eye by the 4-month postoperative follow-up (responsiveness analyses) and a subset of these (n=426) who had not subsequently undergone surgery for the second eye by the 12-month postoperative follow-up (reproducibility analyses). Main Outcome Measures: Two health status measures (the VF-14 and the Sickness Impact Profile, two global measures of a patient's trouble and satisfaction with his or her vision, and best corrected visual acuity in each eye. Results: The VF-14 is highly reproducible, with an intraclass correlation coefficient of.79 when patientrated criteria are used to define stable patients. The intraclass correlation coefficient was lower (.57 to.71) when various measures of visual acuity were used to define stable patients. The VF-14 is also about three times more responsive to a change in vision than the Sickness Impact Profile, which is a generic health status measure (effect size of approximately 1.00 vs 0.30). Estimates of the responsiveness of the VF-14 and the Sickness Impact Profile were not associated with preoperative visual acuity in the operated on or better eye. Responsiveness of the VF-14, however, was higher in patients with greater self-rated trouble with vision preoperatively. Conclusions: The VF-14 was reproducible in stable patients during an 8-month period, and it was more responsive to clinically significant changes in vision than was a generic health status measure (ie, the Sickness Impact Profile).

Age-Related Eye Disease and Survival: The Beaver Dam Eye Study

Abstract: Objective: To investigate the relationship of cataract, age-related maculopathy, glaucoma, and visual impairment to survival in the population-based Beaver Dam Eye Study. Design: In this population-based study, visual acuity was measured with use of standardized protocols. At baseline, stereoscopic color fundus photographs and color slit-lamp and retroillumination photographs were graded in a masked fashion to determine the presence of age-related maculopathy and cataract, respectively. Deaths were ascertained by contacting family members, daily review of obituaries, and use of vital status records. Participants: Subjects aged 43 through 84 years who lived in Beaver Dam, Wis, were identified and examined between 1988 and 1990. Results: From the time of the baseline examination until a median of 4 years later, 9.5% (467/4926) of the population had died. After correcting for age and sex, poorer survival was associated with more severe nuclear sclerosis (5-year survival of 88.9% for the most severe compared with 94.1% for the least severe stage) and visual impairment (5-year survival of 87.5% for impaired compared with 91.8% for unimpaired vision). However, after controlling for systemic factors, only more severe nuclear sclerosis in people without diabetes was significantly associated with poorer survival (hazard ratio per level of severity, 1.19; 95% confidence interval, 1.00 to 1.40). Conclusions: These data suggest that after controlling for age and sex, nuclear sclerotic cataract severity, cataract surgery, and visual impairment are risk indicators for poorer survival. Cortical cataract, posterior subcapsular cataract, glaucoma, and age-related maculopathy were unrelated to poorer survival.

Features of Age-Related Macular Degeneration in a Black Population

Abstract: Objective: To report on the frequency of features of agerelated macular degeneration in a black population based on fundus photograph gradings. Design: Population-based study. Setting: Barbados, West Indies. Study Population: Residents of Barbados, selected by a random sample of Barbados-born citizens, aged 40 to 84 years. Main Outcome Measure: Gradings from 30° stereoscopic macular photographs. Results: Black participants (n=3444) completed examinations at the study site and had gradable macular photographs in both eyes. Drusen larger than 63 μm occurred with comparable frequency in men and women. The frequency of small drusen decreased with age, while medium and large drusen were more common in older participants. Frequencies of all age-related macular degeneration-related characteristics were similar for men and women except for small drusen, which occurred more commonly in women. Confluent drusen and pigment atrophy also increased significantly with age. Exudative features occurred in 0.5% of the participants. Conclusions: This study provides population-based data on the frequency of features of age-related macular degeneration based on photographic gradings of a black population. Features of early age-related macular degeneration were common, but appeared at a lower frequency than has been reported for white populations. Exudative disease was infrequent, occurring in about one of 200 participants.

Imaging of chorioretinal anastomoses in vascularized retinal pigment epithelium detachments.

Abstract: Objective: To identify specific features of pigment epithelium detachments with limited hyperfluorescent lesions (hot spots). Design: One hundred eighty-two consecutive patients (186 eyes) who had vascularized pigment epithelium detachments and recent onset of symptoms were examined with indocyanine green and fluorescein videoangiography using the scanning laser ophthalmoscope. The choroidal neovascularization complex and macular retinal vessels were studied. The natural history and the effect of laser treatment were evaluated. Results: Fifty-four eyes had hot spots on indocyanine green angiography. In 50 of these 54 eyes, the video analysis showed an anastomosis of one or more retinal vessels, with the choroidal neovascularization within the hot spot. One or two retinal veins or arteries or both filled with both dyes and were seen to enter into the hot spot. Results of indocyanine green-guided photocoagulation of the hot spot in 28 eyes were disappointing. Conclusion: Continuous recording of the early phases of fluorescein and indocyanine green angiography allowed identification of chorioretinal anastomoses in vascularized pigment epithelium detachments with hot spots at an early exudative stage of age-related macular degeneration in 50 (26.8%) of 186 eyes. The poor outcome of laser photocoagulation for choroidal neovascularization in this setting could be related not only to the development of an overlying pigment epithelium detachment, but also to the retinal and choroidal vascularization of the lesion.

The Wisconsin Epidemiologic Study of Diabetic Retinopathy-Reply

Abstract: In reply Drs Batchelder and Barricks suggest that our data on the long-term incidence and progression of retinopathy contradict rather than support the guidelines 1 of yearly dilated retinal examinations 5 years after diagnosis of insulindependent diabetes mellitus (IDDM) in people younger than 30 years of age and 1 year after diagnosis of non—insulindependent diabetes mellitus (NIDDM) in people 30 years of age or older. 2 They suggest that the guidelines do not take into account the epidemiologic observations that people with any type of diabetes and no retinopathy or minimal retinopathy consisting of only microaneurysms are unlikely to progress to vision-threatening retinopathy over a 4-year period. 3-5 They suggest that the "screening interval should be tailored to a patient's risk" and that our "data do not suggest any difference in effectiveness for screening intervals of 1, 2, or even 4 years for this group of lowrisk patients." In 1991,

Magnetic Resonance Imaging in Patients With Low-Tension Glaucoma

Abstract: Objective: To study diagnoses and anatomic findings found on magnetic resonance imaging in patients with low-tension glaucoma. Patients: We included in this study magnetic resonance images of 20 consecutive patients with low-tension glaucoma. We individually matched each patient with low-tension glaucoma to a control with normal ocular findings who had magnetic resonance imaging for reasons unrelated to the visual pathway. Design: We studied axial and coronal images of the orbit and optic nerve with digitizing software (Image-Pro Plus, Media Cybernetics, Silver Spring, Md). Statistical evaluation was with a Wilcoxon Signed Rank Test for anatomic findings and a McNemar Test for diagnosis. Results: We found no difference between groups in the optic nerve diameter or length, the carotid artery area, or the distance from the optic nerve to the carotid artery ( P >.05). Left optic nerve area was greater in the control patients than patients with low-tension glaucoma ( P =.026). The prevalence of intracranial abnormalities, including meningioma, aneurysm, and arteriovenous abnormality, was similar between groups ( P >.05). However, diffuse cerebral small-vessel ischemic changes were found more in patients with low-tension glaucoma (n=8) than control patients (n=1) ( P =.0196). Conclusions: This study proposes a hypothesis that cerebral small-vessel ischemia is more common in patients with low-tension glaucoma and potentially reflects indirectly a vascular cause of the optic nerve head damage at least in a subgroup of patients. Importantly, further research still is required to provide direct evidence for a vascular cause involved in low-tension glaucoma.

360° Trabeculotomy for Primary Congenital Glaucoma

Abstract: We have refined a technique for performing 360 degrees trabeculotomy in a single procedure using a 6-0 polypropylene (Prolene) suture fragment and have used it in 15 patients (26 eyes) with primary congenital glaucoma. The refined technique can be performed via a single nasal surgical site. This procedure avoids many of the difficulties encountered with metal trabeculotomes and preserves conjunctiva should further glaucoma surgery be necessary.

Adverse Effects of Topical Antiglaucoma Medication

Abstract: In their excellent article, Broadway and colleagues 1 follow an established convention in defining surgical success in trabeculectomy as an intraocular pressure (IOP) of 21 mm Hg or less without medication. The aim of glaucoma surgery is to reduce IOP to a level where there is nonprogression of visual field loss. The IOP likely to achieve that aim is unknown, but a value of less than 15 mm Hg has been suggested by Hitchings. 2 Field stability is found when the IOP is below 17 mm Hg, 3 with 58% of fields stable in eyes with pressures below 15 mm Hg compared with only 15% of eyes with pressures above 15 mm Hg. 4 However, the matter may not be quite this clear-cut, as a 20-year follow-up of trabeculectomy in a stable, white population in England was unable to demonstrate field stability "... whatever cut off point is used for IOP."

Retinal Microaneurysm Counts and 10-Year Progression of Diabetic Retinopathy

Abstract: Objective: To determine the relationship of change in the number of retinal microaneurysms to the 10-year progression to significant retinopathy, proliferative retinopathy, and clinically significant macular edema. Design: Population-based study of persons with youngerand older-onset diabetes with 10 years of follow-up. Setting and Patients: Eleven-county area in southern Wisconsin, where 189 patients with diabetes who had only retinal microaneurysms in photographs at baseline participated in 4- and 10-year follow-up examinations. Outcome Measures: Ten-year incidence of moderate nonproliferative diabetic retinopathy or worse, proliferative retinopathy, or clinically significant macular edema as determined by masked grading of stereoscopic color fundus photographs of seven standard fields. Results: The increase in the number of retinal microaneurysms and the ratio of the number of retinal microaneurysms at the 4-year follow-up to the number at baseline were positively associated with incidence of proliferative retinopathy or clinically significant macular edema at the 10-year follow-up. Proliferative retinopathy was approximately 4.6 times and clinically significant macular edema was approximately 9.1 times more likely to develop at 10-year follow-up in eyes in which the number of microaneurysms increased by 16 or more from baseline to the 4-year follow-up than in eyes with no increase. Proliferative retinopathy was 3.4 times and clinically significant macular edema was 6.7 times more likely to develop at 10-year follow-up in eyes that had ratios of 3 or greater of the number of retinal microaneurysms at the 4-year follow-up to the number at baseline than in eyes in which the ratios were smaller. These relationships remained after controlling for the level of glycosylated hemoglobin and type of diabetes. Conclusions: Microaneurysm counts using stereoscopic color fundus photographs are an early important measure of progression of retinopathy and may serve as a surrogate end point for severe change in some clinical trials.

Laser-induced chorioretinal venous anastomosis for treatment of nonischemic central retinal vein occlusion.

Abstract: Objectives: To determine whether a chorioretinal venous anastomosis could be created in humans and to evaluate the influence this has on patients with non-ischemic central retinal vein occlusions in whom progressive visual loss developed. Design: Retrospective study. Patients: A total of 24 patients with nonischemic central retinal vein occlusions and progressive visual loss. Intervention: An attempt was made to create a chorioretinal venous anastomosis using laser photocoagulation to enable obstructed venous blood to enter the choroid, thus bypassing the site of occlusion. Main Outcome Measures: Visual acuity, fundoscopic appearance, and rapid sequence fluorescein angiograms. Results: A successful chorioretinal venous anastomosis was created in eight cases (33%), with improvement in visual acuity and resolution of the funduscopic appearance of venous occlusion in all eight cases. Of the 16 patients (67%) in whom an anastomosis was not successfully created, the ischemic form of central retinal vein occlusion developed in five (31%), and eight (50%) were left with various degrees of macular damage and reduced visual acuity. Conclusions: Peripheral chorioretinal venous anastomoses can be created in a nonischemic central retinal vein occlusion and appear to be well tolerated. This technique may have some value in the treatment of patients with this condition; however, to address this fully, a properly constructed randomized prospective clinical trial will need to be performed.

Tear Function Index: A New Measure of Dry Eye

Abstract: Objective: To develop an efficient way to evaluate tear dynamics clinically. Participants: Three hundred fifty-two patients with dry eye, 64 of whom had Sjogren syndrome, and 55 normal subjects. Design: Because various forces that affect tear drainage are reflected in the values of the Schirmer test with anesthesia and the tear clearance rate, we introduced a new measure of tear dynamics, the tear function index, which is the value obtained from dividing the value of the Schirmer test with anesthesia by the tear clearance rate. Results: The tear function index was more specific (91.8%) and sensitive (78.9%) in diagnosing dry eye associated with Sjogren syndrome than was the Schirmer or tear clearance rate test alone. Tear function indexes below 96 were consistent with dry eye and those below 34 were seen primarily in patients with Sjogren syndrome. Conclusions: The tear function index offers a new method to evaluate tear production with the Schirmer test, introduces an extended way to measure tear flow combining with tear drainage, and gives a practical measure to diagnose dry eye.

The Effects of Ablation Diameter on the Outcome of Excimer Laser Photorefractive Keratectomy: A Prospective, Randomized, Double-Blind Study

Abstract: Objective: To determine the effects of the ablation diameter on the outcome of excimer laser photorefractive keratectomy. Design: Eighty patients were randomized to either a 5.00-mm or a 6.00-mm treatment group and within these groups underwent either a −3.00-diopter (D) ora −6.00-D correction based on their preoperative refraction. A Summit Omnimed excimer laser was used throughout the study. Results: In eyes treated with a 6.00-mm-diameter ablation, the initial hyperopic shift was reduced, with significant differences at 1 week with −3.00-D corrections and at 1 and 4 weeks with −6.00-D corrections (P Conclusions: Treatment with 6.00-mm ablation diameters precipitated less initial overcorrection, greatly improved the predictability of photorefractive keratectomy, and was associated with a reduction in complications impairing postoperative visual performance.