Visual conditions affecting eye growth alter diurnal levels of vitreous DOPAC

In chicks, the diurnal patterns of retinal dopamine synthesis and release are associated with refractive development. To assess the within-day patterns of dopamine release, we assayed vitreal levels of DOPAC (3,4-dihydroxyphenylacetic acid) using high performance liquid chromatography with electrochemical detection, at 4-h intervals over 24 h in eyes with experimental manipulations that change ocular growth rates. Chicks were reared under a 12 h light/12 h dark cycle; experiments began at 12 days of age. Output was assessed by modelling using the robust variance structure of Generalized Estimating Equations. Continuous spectacle lensdefocus or form deprivation: One group experienced non-restricted visual input to both eyes and served as untreated "normal" controls. Three experimental cohorts underwent monocular visual alterations known to alter eye growth and refraction: wearing a diffuser, a negative lens or a positive lens. After one full day of device-wear, chicks were euthanized at 4-h intervals over 24 h (8 birds per time/condition). Brief hyperopic defocus: Chicks wore negative lenses for only 2 daily hours either in the morning (starting at ZT 0; n = 16) or mid-day (starting at ZT 4; n = 8) for 3 days. Vitreal DOPAC was assayed. In chicks with bilateral non-restricted vision, or with continuous defocus or form-deprivation, there was a diurnal variation in vitreal DOPAC levels for all eyes (p < 0.001 for each). In normal controls, DOPAC was highest during the daytime, lowest at night, and equivalent for both eyes. In experimental groups, regardless of whether experiencing a growth stimulatory input (diffuser; negative lens) or growth inhibitory input (positive lens), DOPAC levels were reduced compared both to fellow eyes and to those of normal controls (p < 0.001 for each). These diurnal variations in vitreous DOPAC levels under different visual conditions indicate a complexity for dopaminergic mechanisms in refractive development that requires further study.

The King-Devick test as a determinant of head trauma and concussion in boxers and MMA fighters

OBJECTIVE

Sports-related concussion has received increasing attention as a cause of short- and long-term neurologic symptoms among athletes. The King-Devick (K-D) test is based on measurement of the speed of rapid number naming (reading aloud single-digit numbers from 3 test cards), and captures impairment of eye movements, attention, language, and other correlates of suboptimal brain function. We investigated the K-D test as a potential rapid sideline screening for concussion in a cohort of boxers and mixed martial arts fighters.

METHODS

The K-D test was administered prefight and postfight. The Military Acute Concussion Evaluation (MACE) was administered as a more comprehensive but longer test for concussion. Differences in postfight K-D scores and changes in scores from prefight to postfight were compared for athletes with head trauma during the fight vs those without.

RESULTS

Postfight K-D scores (n = 39 participants) were significantly higher (worse) for those with head trauma during the match (59.1 ± 7.4 vs 41.0 ± 6.7 seconds, p < 0.0001, Wilcoxon rank sum test). Those with loss of consciousness showed the greatest worsening from prefight to postfight. Worse postfight K-D scores (r(s) = -0.79, p = 0.0001) and greater worsening of scores (r(s) = 0.90, p < 0.0001) correlated well with postfight MACE scores. Worsening of K-D scores by ≥5 seconds was a distinguishing characteristic noted only among participants with head trauma. High levels of test-retest reliability were observed (intraclass correlation coefficient 0.97 [95% confidence interval 0.90-1.0]).

CONCLUSIONS

The K-D test is an accurate and reliable method for identifying athletes with head trauma, and is a strong candidate rapid sideline screening test for concussion.

Meta-regression with partial information on summary trial or patient characteristics

We present a model for meta-regression in the presence of missing information on some of the study level covariates, obtaining inferences using Bayesian methods. In practice, when confronted with missing covariate data in a meta-regression, it is common to carry out a complete case or available case analysis. We propose to use the full observed data, modelling the joint density as a factorization of a meta-regression model and a conditional factorization of the density for the covariates. With the inclusion of several covariates, inter-relations between these covariates are modelled. Under this joint likelihood-based approach, it is shown that the lesser assumption of the covariates being Missing At Random is imposed, instead of the more usual Missing Completely At Random (MCAR) assumption. The model is easily programmable in WinBUGS, and we examine, through the analysis of two real data sets, sensitivity and robustness of results to the MCAR assumption.

Vision related quality of life in multiple sclerosis: correlation with new measures of low and high contrast letter acuity

OBJECTIVE

To examine the relation between low contrast letter acuity, a new visual function test for multiple sclerosis (MS) trials, and vision targeted health related quality of life (HRQOL).

METHODS

Patients in this cross sectional study were part of an ongoing investigation of visual function in MS. Patients were tested binocularly using low contrast letter acuity and Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity (VA) charts. The 25 Item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25), 10 Item Neuro-Ophthalmic Supplement to the NEI-VFQ-25, Impact of Visual Impairment Scale and Short Form 36 Health Survey (SF-36) were administered.

RESULTS

Among 167 patients, mean age was 48 (10) years, with median Expanded Disability Status Scale (EDSS) 2.0 (range 1.0-7.5), and median binocular Snellen acuity equivalent (ETDRS charts) 20/16 (range 20/12.5 to 20/100). Reductions in vision specific HRQOL were associated with lower (worse) scores for low contrast letter acuity and VA (p<0.001, linear regression, accounting for age). Two line differences in visual function were associated, on average, with >4 point (6.7-10.9 point) worsening in the NEI-VFQ-25 composite score, reductions that are considered clinically meaningful. Scores for the 10 Item Neuro-Ophthalmic Supplement to the NEI-VFQ-25 also correlated well with visual function. Associations between reduced low contrast acuity and worse vision targeted HRQOL remained significant in models accounting for high contrast VA, EDSS and history of acute optic neuritis.

CONCLUSIONS

Low contrast letter acuity scores correlate well with HRQOL in MS. Two line differences in scores for low contrast acuity and VA reflect clinically meaningful differences in vision targeted HRQOL. Low contrast acuity testing provides information on patient reported aspects of vision, supporting use of these measures in MS clinical trials.

Contrast letter acuity as a visual component for the Multiple Sclerosis Functional Composite

BACKGROUND

Visual dysfunction is one of the most common causes of disability in multiple sclerosis (MS). The Multiple Sclerosis Functional Composite (MSFC), a new clinical trial outcome measure, does not currently include a test of visual function.

OBJECTIVE

To examine contrast letter acuity as a candidate visual function test for the MSFC.

METHODS

Binocular contrast letter acuity testing (Sloan charts) was performed in a subgroup of participants from the International Multiple Sclerosis Secondary Progressive Avonex Controlled Trial (IMPACT Substudy) and in MS patients and disease-free control subjects from a cross-sectional study of visual outcome measures (Multiple Sclerosis Vision Prospective cohort [MVP cohort]). High-contrast visual acuity was measured in both studies; MVP cohort participants underwent additional binocular testing for contrast sensitivity (Pelli-Robson chart), color vision (D-15 desaturated test), and visual field (Esterman test, Humphrey Field Analyzer II).

RESULTS

Contrast letter acuity (Sloan charts, p < 0.0001, receiver operating characteristic curve analysis) and contrast sensitivity (Pelli-Robson chart, p = 0.003) best distinguished MS patients from disease-free control subjects in the MVP cohort. Correlations of Sloan chart scores with MSFC and Expanded Disability Statue Scale (EDSS) scores in both studies were significant and moderate in magnitude, demonstrating that Sloan chart scores reflect visual and neurologic dysfunction not entirely captured by the EDSS or MSFC.

CONCLUSIONS

Among clinical measures, contrast letter acuity (Sloan charts) and contrast sensitivity (Pelli-Robson chart) demonstrate the greatest capacity to identify binocular visual dysfunction in MS. Sloan chart testing also captures unique aspects of neurologic dysfunction not captured by current EDSS or MSFC components, making it a strong candidate visual function test for the MSFC.

Macular pigment and lutein supplementation in retinitis pigmentosa and Usher syndrome

PURPOSE

To determine macular pigment (MP) in patients with inherited retinal degeneration and the response of MP and vision to supplementation of lutein.

METHODS

Patients with retinitis pigmentosa (RP) or Usher syndrome and normal subjects had MP optical density profiles measured with heterochromatic flicker photometry. Serum carotenoids, visual acuity, foveal sensitivity, and retinal thickness (by optical coherence tomography [OCT]) were quantified. The effects on MP and central vision of 6 months of lutein supplementation at 20 mg/d were determined.

RESULTS

MP density in the patients as a group did not differ from normal. Among patients with lower MP, there was a higher percentage of females, smokers, and light-colored irides. Disease expression tended to be more severe in patients with lower MP. Inner retinal thickness by OCT correlated positively with MP density in the patients. After supplementation, all participants showed an increase in serum lutein. Only approximately half the patients showed a statistically significant increase in MP. Retinal nonresponders had slightly greater disease severity but were otherwise not distinguishable from responders. Central vision was unchanged after supplementation.

CONCLUSIONS

Factors previously associated with lower or higher MP density in normal subjects showed similar associations in RP and Usher syndrome. In addition, MP in patients may be affected by stage of retinal disease, especially that leading to abnormal foveal architecture. MP could be augmented by supplemental lutein in many but not all patients. There was no change in central vision after 6 months of lutein supplementation, but long-term influences on the natural history of these retinal degenerations require further study.

Corneal surface area: an index of anterior segment growth

Corneal surface area and perimeter were assessed as novel indices to monitor anterior segment growth, using chicks reared under different photoperiods. We obtained central and mid-peripheral corneal curvatures using photokeratometry. Anatomical tracings of the anterior corneal surface also were made from freeze-dried non-fixed preparations of the anterior segments of the same eyes. Using either photokeratometry or anatomical data, the profile of the anterior corneal surface was fit to a general equation for conical sections; corneal surface area was estimated from surfaces of revolution. Optical techniques modeled the chick cornea as a circle or as an ellipse closely resembling a circle. The anatomical technique, in contrast, modeled the chick corneal profile as a hyperbola. Potential explanations of this discrepancy are discussed. Regardless of which model is evaluated, the corneal surface area and perimeter of two-week-old chicks are affected by the photoperiod of rearing. Corneal surface area in particular proved more sensitive than conventional measurements in identifying anterior segment effects of rearing under different photoperiods. Analysis of corneal area may prove useful in evaluating the mechanisms governing anterior segment growth.

Laser burn intensity and the risk for choroidal neovascularization in the CNVPT Fellow Eye Study

OBJECTIVE

To explore the relationship between laser burn intensity and the subsequent risk for development of choroidal neovascularization (CNV) in eyes assigned to the treatment group of the Fellow Eye Study (FES) of the Choroidal Neovascularization Prevention Trial (CNVPT), using computerized methods for laser burn quantitation, and to examine the association between laser burn intensity and (1) drusen reduction and (2) visual acuity.

METHODS

Color fundus images before and immediately after laser treatment in the CNVPT FES were available for 53 of 59 eyes. Prelaser and postlaser treatment images were analyzed using custom-developed computer software, allowing for laser burn identification and quantitation. As measures of laser burn intensity, we derived integrated burn rating (IBR) (the integral of the normalized intensity difference divided by the burn pixels), and the maximum burn intensity (MAX). We identified CNV using fluorescein angiography. A Cox proportional hazards model was fit to the time to development of CNV. Baseline and 6-month color photographs were used to determine reduction in drusen. Visual acuity was measured using a standardized protocol.

RESULTS

The IBR and MAX spanned 4.5 logarithm units. After adjusting for smoking history and predominant drusen size, the risk ratio for CNV per logarithm unit of increasing laser burn intensity for each measure was 2.0 (P =.05) for MAX and 1.7 (P =.07) for IBR. When patients were divided into high- and low-intensity treatment groups of equal size, the high-intensity group had more drusen reduction (57% vs 32%; P =.14). There was no effect of laser intensity on change in visual acuity at 6 months.

CONCLUSION

Higher-intensity prophylactic laser applications appear to be associated with a greater risk for development of CNV and with more extensive drusen reduction.

Visual loss in children with neurofibromatosis type 1 and optic pathway gliomas: relation to tumor location by magnetic resonance imaging

PURPOSE

To examine the potential for visual acuity loss, and its relation to extent and location of optic pathway gliomas in a cohort of children with neurofibromatosis type 1 studied with magnetic resonance imaging.

METHODS

We reviewed the neuro-ophthalmologic records and brain/orbital magnetic resonance imaging scans for 43 consecutive pediatric patients with neurofibromatosis type 1 and optic pathway gliomas who were followed at the Children's Hospital of Philadelphia. The presence of visual loss, defined as abnormal visual acuity for age in one or both eyes, was determined. Optic pathway gliomas were classified by tumor extent and location according to involvement of the optic nerves, chiasm, and postchiasmal structures by magnetic resonance imaging.

RESULTS

Involvement of the optic tracts and other postchiasmal structures at tumor diagnosis was associated with a significantly higher probability of visual acuity loss (P =.048, chi-square test). Visual loss was noted in 20 of 43 patients (47%) at a median age of 4 years; however, three patients developed visual acuity loss for the first time during adolescence.

CONCLUSIONS

In pediatric patients with neurofibromatosis type 1 and optic pathway gliomas, the likelihood of visual loss is dependent on the extent and location of the tumor by magnetic resonance imaging and is particularly associated with involvement of postchiasmal structures. Furthermore, older age during childhood (adolescence) does not preclude the occurrence of visual loss. Close follow-up beyond the early childhood years, particularly for those with postchiasmal tumor, is recommended.

Self-reported visual dysfunction in multiple sclerosis: results from the 25-Item National Eye Institute Visual Function Questionnaire (VFQ-25)

Visual impairment is one of the most common clinical manifestations of Multiple Sclerosis (MS), and is strongly related to overall health-related quality of life (HRQOL) in MS and other disorders. However, the assessment of vision-specific HRQOL in patients with MS has been limited. The purpose of this study was to examine self-reported visual dysfunction in a clinically heterogeneous MS cohort using the 25-Item National Eye Institute Visual Function Questionnaire (VFQ-25). The VFQ-25 was administered by telephone interview to a subset of participants in a follow-up study to a phase III trial of interferon beta-1a for relapsing-remitting MS. Mean VFQ-25 composite scores and selected sub-scale scores were significantly lower (worse) among patients in our MS cohort (n=35) compared with a published reference group of patients with no history of chronic eye disease (n= 118). These differences were observed despite a relatively younger age and tighter distribution of binocular visual acuities in the MS cohort Patients with MS in this study thus demonstrated a greater degree of self-reported visual dysfunction, as measured by the VFQ-25, compared with an eye disease-free reference group. The VFQ-25 is a potentially useful measure of vision-specific HRQOL in patients with MS.

Impact of pill organizers and blister packs on adherence to pill taking in two vitamin supplementation trials

The impact of pill organizers on pill taking was determined in the Trial of Antioxidant Vitamins C and E (TRACE) Study, a factorial trial of vitamin C and vitamin E supplementation in 184 individuals. Participants were recruited in 1996-1997 and randomized to one of two groups (pill organizer or no organizer) and to one of four supplement groups for 2 months. The pill count (observed/expected X 100%) distribution was similar in the organizer and no organizer group for both vitamins. Mean differences in changes in serum vitamin levels between active and placebo groups did not differ by pill organizer use. The impact of pill organizers and blister packs was compared in another trial, the Vitamins, Teachers, and Longevity (VITAL) Study, in 297 individuals randomized in 1993-1994 to receive study pills either in blister packs or in pill organizers and to take one of two supplements. Among those with lower adherence, the pill count distribution in the blister-pack group exceeded that in the organizer group. Mean differences in serum vitamin E levels between active and placebo groups did not differ by types of pill packaging. In summary, use of blister packs, but not pill organizers, improved adherence as measured by pill counts among those with lower adherence. Neither pill delivery system improved adherence as measured by serum vitamin levels.

Portable pupillography of the swinging flashlight test to detect afferent pupillary defects

OBJECTIVE

To investigate the ability of a portable, personal computer-driven, pupillometer to record the pupillary response curve during the swinging flashlight test. Also, to determine whether these response curves can be used to identify and quantify relative asymmetry in the pupillary light reflex between eyes in healthy volunteers with simulated afferent pupil defects (APDs) and patients with optic neuropathies.

DESIGN

Comparative, observational case series and instrument validation.

PARTICIPANTS

Healthy volunteers with no known ocular disease and patients (n = 20) with various optic neuropathies noted to have relative APDs on examination.

METHODS

Pupillary response curves of the right eye were recorded with a portable, electronic, infrared pupillometer from healthy volunteers (with and without simulated APDs) and patients with APDs while the light stimulus alternated between eyes, simulating the swinging flashlight test. Simulated APDs in healthy volunteers were created with increasingly dense neutral density filters in front of the left eye.

MAIN OUTCOME MEASURES

Differences in constriction amplitude, latency, and constriction velocity of the pupillary response with right eye stimulation versus left eye stimulation in both groups of subjects.

RESULTS

A significant correlation between neutral density filter strength and intereye differences was seen for all measurement parameters in volunteers with simulated APDs. Depending on the measurement parameter and stimulus intensity, simulated APDs of 0.6 log units or more could be distinguished from normal responses. Clinically graded true APDs had intereye differences similar to simulated APDs of the same density. Those with real and simulated APDs of 0.9 log units or more could be distinguished from healthy volunteers with 80% sensitivity and 92% specificity. Responses from those with real and simulated small APDs of 0.3 to 0.6 log units could not be distinguished reliably.

CONCLUSIONS

Portable, personal-computer driven, electronic, infrared pupillography can record the swinging flashlight test accurately and identify large afferent pupillary defects. An affordable, portable, reliable device for identifying relative APDs would be useful in the identification and follow-up of patients with neurogenic vision loss.

New low-contrast vision charts: reliability and test characteristics in patients with multiple sclerosis

The quantitative assessment of visual function in multiple sclerosis (MS) clinical trials has been limited to Snellen visual acuity. The purpose of this study was to examine the inter-rater reliability and test characteristics of a new visual outcome measure, the Low-Contrast Sloan Letter Charts, in patients with MS and visually-asymptomatic volunteers. Contrast letter acuity scores (letter scores) were measured at each of four contrast levels (100, 5, 1.25 and 0.6%) by two independent raters. Inter-rater agreement was described with the intraclass correlation coefficient (ICC) and comparison of mean scores. Excellent inter-rater agreement (ICC=0.86 - 0.95) was demonstrated at each contrast level among MS patients (n=100) and visually-asymptomatic volunteers (n=33). Average letter scores at the lowest contrast level (0.6%) were highly variable in the MS group, even among patients with visual acuities of 20/20 or better, and among those who required no assistance for ambulation. Low-Contrast Sloan Letter Chart testing is a highly reliable method of visual assessment, and provides information on an aspect of neurologic impairment in MS which is not captured by Snellen visual acuity or ambulation status. This new method demonstrates excellent potential as a visual function outcome measure for future MS clinical trials.

Correlation of postoperative extraocular muscle suture adjustment with its immediate effect on the strabismic deviation

PURPOSE

To determine if any relationship exists between the amount of adjustment using this surgical technique and resulting changes in the strabismic deviation.

METHODS

A prospective database obtained between the years 1991 and 1996 was used to obtain retrospective clinical information and data for this study. We found in the database 172 postoperatively adjusted muscles in 159 patients who could be included in this study. All patients had their muscles adjusted postoperatively within the first 24 hours after surgery. Information retrieved specific to this study included the post-surgical, pre-adjustment strabismic deviation, the amount and direction of the adjustment and the resulting deviation immediately after this postoperative adjustment. Statistical analysis was performed on the total and individual muscles, as well as the direction of adjustment, comparing pre- to post-adjustment binocular deviations.

RESULTS

There was a significant overall relationship between the millimeters of postoperative adjustment and the amount of change in the binocular deviation (p<.0001). This relationship was more linear under 3.0 mm of postoperative adjustment. The effect of the amount of postop' adjustment when advancing the muscle was significantly greater than when recessing the muscle (p<.0001). There was more effect per mm of postop' adjustment of horizontal muscles than vertical muscles (p=.004).

CONCLUSIONS

There is a linear correlation of postoperative extraocular muscle adjustment when advancing an adjustable muscle but this correlation is more variable for adjustments over 3.0 mm. The effect of adjustment per mm is greater when adjusting horizontal than vertical muscles. There is a poor correlation for further recession. Prediction Equations are provided to enhance clinical results of this technique.

One-year outcomes of panretinal photocoagulation in proliferative diabetic retinopathy

PURPOSE

To describe the clinical features and complications of diabetic retinopathy, visual acuity, and number of repeat treatments after panretinal photocoagulation for proliferative diabetic retinopathy in a tertiary care center.

METHODS

A cohort study was conducted with data collection from medical records of patients undergoing panretinal photocoagulation between 1985 and 1995 at the Scheie Eye Institute; 297 eyes of 186 patients were eligible for study.

RESULTS

The presence of neovascularization of the disk at baseline, an earlier onset of diabetes, and a shorter duration of disease before panretinal photocoagulation were the strongest risk factors for needing an additional panretinal photocoagulation treatment. Sixty-two percent of eyes with poor visual acuity (< or =20/200) at baseline still had poor visual acuity at 1 year, and 76% with good visual acuity (> or =20/40) at baseline maintained good visual acuity at 1 year. Poor vision at baseline was the only risk factor for having poor vision at 1 year. Vitreous hemorrhage was present in 44% of eyes at baseline. New vitreous hemorrhage developed in 37% of eyes during the first year after panretinal photocoagulation. A traction retinal detachment was present in 4% of eyes at baseline and newly developed in 6% of eyes during follow-up. A repeat panretinal photocoagulation treatment was performed in 39% of eyes after initial treatment. A vitrectomy was performed in 10% of eyes from baseline through the 1-year follow-up visit.

CONCLUSIONS

The data from this study are useful for counseling patients with respect to likely visual outcome, possibility of major complications from proliferative diabetic retinopathy, and the chance of undergoing additional laser treatment after panretinal photocoagulation.

Psychophysical evidence for rod vulnerability in age-related macular degeneration

PURPOSE

To determine whether there is rod system dysfunction in the central retina of patients with age-related macular degeneration (AMD).

METHODS

Dark-adapted sensitivity (500-nm stimulus) and light-adapted sensitivity (600 nm) were measured psychophysically at 52 loci in the central 38 degrees (diameter) of retina in 80 patients with AMD, and results were compared with those from older adult normal controls. All dark-adapted data were corrected for preretinal absorption.

RESULTS

Mean field dark-adapted sensitivity was significantly lower in AMD patients as a group than in normal subjects. Within the AMD group were subsets of patients with normal mean dark- and light-adapted sensitivities; reduced dark-adapted sensitivities without detectable light-adapted losses; both types of losses; and, least commonly, only light-adapted losses. Regional retinal analyses of the dark-adapted deficit indicated the greatest severity was 2 degrees to 4 degrees or approximately 1 mm from the fovea, and the deficit decreased with increasing eccentricity.

CONCLUSIONS

These psychophysical results are consistent with histopathologic findings of a selective vulnerability for parafoveal rod photoreceptors in AMD. The different patterns of rod and cone system losses among patients at similar clinical stages reinforces the notion that AMD is a group of disorders with underlying heterogeneity of mechanism of visual loss. Dark-adapted macula-wide testing may be a useful complement to the more traditional outcome measures of fundus pathology and foveal cone-based psychophysics in future AMD trials.

Laser-induced drusen reduction improves visual function at 1 year. Choroidal Neovascularization Prevention Trial Research Group

OBJECTIVE

To describe the relationship of laser-induced drusen reduction to change in visual function at 1 year among patients enrolled in the Choroidal Neovascularization Prevention Trial (CNVPT).

DESIGN

Comparison of groups with and without drusen reduction; follow-up of a randomized controlled trial.

PARTICIPANTS

Evaluations of drusen and visual acuity at baseline and at 1 year were performed for 351 eyes of the 432 eyes enrolled in the CNVPT Bilateral Drusen Study and Fellow Eye Study (81%). One hundred eighty-four eyes were assigned to observation, and 167 eyes were assigned to laser treatment. Eyes with conditions that precluded an analysis of drusen reduction, such as those that developed choroidal neovascularization (CNV) within the first year, are excluded from this analysis.

METHODS

Change in macular drusen between initial visit and after 1 year was assessed by side-by-side grading by evaluators masked to information on visual function. Visual acuity, contrast threshold, and critical print size were measured by certified visual function examiners.

MAIN OUTCOME MEASURES

Change in visual acuity is the primary outcome. Change in contrast threshold and change in critical print size are secondary outcome measures.

RESULTS

Laser-treated eyes with 50% or more drusen reduction at 1 year had more 1- and 2-line increases in visual acuity and less losses in visual acuity compared with laser-treated eyes with less drusen reduction or with observed eyes (P = 0.001). Similar improvements were noted for contrast threshold but not critical print size at 1 year.

CONCLUSIONS

Laser-induced drusen reduction is associated with improved visual acuity and contrast sensitivity in eyes at 1 year. Longer term effects of laser-induced drusen reduction on visual function require additional observation. The overall potential value of laser treatment in eyes with high-risk drusen requires consideration of not only short-term effects on vision but also the effects of CNV and atrophy on vision.

Optic nerve blood flow in glaucoma: effect of systemic hypertension

PURPOSE

To investigate optic nerve head blood flow in patients with glaucoma and to assess the effect of systemic hypertension.

METHODS

This study included 24 eyes of 24 patients with primary open-angle glaucoma. Eleven of these patients had a history of systemic hypertension. Results in patients with glaucoma were compared with those of 13 eyes of 13 age-matched normal controls. Determinations of relative optic nerve head blood velocity, volume, and flow were obtained with laser Doppler flowmetry in the superotemporal and inferotemporal neuroretinal rim and also in the cup. Means of the velocity, volume, and flow of these three measurement sites were calculated for each subject.

RESULTS

Mean overall optic nerve head blood flow was 29% lower in glaucoma patients than in normal controls (t test, P < .001). This decrease in flow was mainly caused by a decrease of 23% in mean blood velocity (P < .001). Mean flow in glaucoma patients without systemic hypertension was 26% lower than that of glaucoma patients with hypertension (Tukey honest significant difference test, P = .05). A significant direct correlation was observed between mean flow and mean blood pressure (R = 0.51, P < .02).

CONCLUSIONS

Optic nerve blood flow is reduced in glaucoma patients. Glaucoma patients without systemic hypertension have lower optic nerve blood flow than those with hypertension. Our results raise concerns that treatment of systemic hypertension may further decrease optic nerve blood flow in glaucoma patients.

Idiopathic intracranial hypertension: relation of age and obesity in children

The relation between obesity and age in children with idiopathic intracranial hypertension (pseudotumor cerebri) has remained uncertain. The authors reviewed the records of 45 consecutive children with newly diagnosed idiopathic intracranial hypertension seen at two medical centers. Forty-three percent of patients aged 3 to 11 years were obese, whereas 81% of those in the 12- to 14-year age group and 91% of those in the 15- to 17-year age group met criteria for obesity (p = 0.01). Younger children with idiopathic intracranial hypertension are less likely to be obese than are older children or adults.

Association of dietary protein intake and coffee consumption with serum homocysteine concentrations in an older population

BACKGROUND

Elevated blood concentrations of total homocysteine (tHcy) have been implicated in the pathogenesis of atherosclerotic cardiovascular disease. Previous studies identified suboptimal nutritional status and dietary intake of folate, vitamin B-6, and vitamin B-12 as determinants of elevated tHcy.

OBJECTIVE

We identified other nutritional factors associated with tHcy in 260 retired schoolteachers in the Baltimore metropolitan area.

DESIGN

We performed observational analyses of baseline and 2-4-mo follow-up data collected in a study designed to test the feasibility of conducting a large-scale clinical trial of vitamin supplements by mail. The study population consisted of 151 women and 109 men with a median age of 64 y. At baseline, each participant completed a food-frequency questionnaire. At follow-up, fasting serum tHcy was measured.

RESULTS

In multivariable linear regression and generalized linear models, there was an independent, inverse dose-response relation between dietary protein and In tHcy (P = 0.002) and a positive, significant dose-response relation between coffee consumption and In tHcy (P for trend = 0.01). Other significant predictors of In tHcy were creatinine (positive; P = 0.0001) and prestudy use of supplemental B vitamins (inverse; P = 0.03). In stratified analyses restricted to persons receiving standard multivitamin therapy, the association of 1n tHcy with dietary protein and coffee persisted.

CONCLUSIONS

These results support the hypothesis that increased protein intake and decreased coffee consumption may reduce tHcy and potentially prevent atherosclerotic cardiovascular disease and other disease outcomes.

Variability in visual cortex activation during prolonged functional magnetic resonance imaging

This study was conducted to test whether cortical activation varies across successive epoques during functional magnetic resonance imaging (fMRI) studies. Ten normal adult volunteers were studied with a 1.5-T MR scanner. Pseudocoronal study planes were chosen perpendicular to the tentorium cerebelli, at two thirds the distance from the posterior edge of the splenium of the corpus callosum to the transverse sinuses. Functional images were acquired with a T2*-weighted spoiled gradient echo sequence. The visual cortex was stimulated by goggles flashing at 8 Hz. Each study consisted of 82 sequential scans, lasting 15 seconds each for a total of 20.5 minutes. Two scans without stimulation were alternated with two scans of visual stimulation. Scans 3 through 83 were divided into five sequences of 16 scans. For each sequence, the number of pixels within a predefined rectangular region of interest that showed increased activity during stimulation were counted. Least squares regression models of straight lines were fit to the data. The initial level of visual cortex activation in the region of interest, as measured by the y-intercept, varied substantially from subject to subject (range: 4-68, p < 0.001). There was sufficient evidence of systematic change with time to reject the hypothesis of constant activation with the same stimulus over time (p=0.02). The observed visual cortex activation with single-plane fMRI varied both with time over successive epoques and among subjects. Possible factors responsible for the variation may include head movement, eyelid position, attention, and physiologic fatigue. These factors must be accounted for in experimental design and in data analysis and interpretation.

A model of the incidence and consequences of choroidal neovascularization secondary to age-related macular degeneration. Comparative effects of current treatment and potential prophylaxis on visual outcomes in high-risk patients

OBJECTIVE

To describe the comparative impact of current and preventive treatments on incidence of choroidal neovascularization (CNV) and severe vision loss in patients with bilateral soft drusen (BSD).

DESIGN

Stochastic model.

SETTING

US population.

PATIENTS

Prevalence cohort of white patients 43 years or older with BSD.

INTERVENTIONS

Application of prophylaxis of 10% to 50% efficacy to 1 or both eyes of patients with BSD, application of laser photocoagulation to eligible CNV lesions, or both.

MAIN OUTCOME MEASURES

Proportion of patients with BSD after 10 years with unilateral and bilateral CNV and resultant unilateral and bilateral vision loss to visual acuity of 20/200 or worse.

RESULTS

The natural history of patients with BSD generated by the model shows that 12.40% of these patients develop either unilateral or bilateral CNV within 10 years of their entry into the BSD prevalence cohort. Bilateral disease occurs in 3.86% of patients with BSD within 10 years. The proportion of patients with BSD becoming legally blind from CNV within 10 years is 2.54% if no treatment is performed. Current laser treatment for CNV decreases the proportion with legal blindness within 10 years to 2.24%. The addition of a preventive treatment of 10% efficacy applied bilaterally to the current laser treatment regimen decreases the proportion with legal blindness to 1.86%; a 25% effective preventive treatment decreases it to 1.34%. Comparatively, preventive treatment of 10% and 25% efficacy given to the fellow eye only after the first eye has developed CNV decreases the proportion of legally blind patients at 10 years only to 2.06% and 1.77%, respectively. All outcomes vary with sex and age at entry into the BSD cohort.

CONCLUSIONS

Patients with BSD face a 12.40% risk of developing CNV within 10 years. The addition of even a modest (10% effective) bilateral preventive treatment to the current regimen for CNV would more than double the prevention of legal blindness in the BSD population relative to current laser treatment; a preventive treatment of 33% efficacy more than halves the rate of legal blindness caused by CNV. Preventive treatment given to the fellow eye only after the first develops CNV has substantially less impact.

Foveolar choroidal blood flow in age-related macular degeneration

PURPOSE

To compare measurements of the foveolar choroidal blood circulation in subjects with nonexudative, age-related macular degeneration (AMD) with those of control subjects.

METHODS

Laser Doppler flowmetry was used to assess relative choroidal blood velocity (ChBVel), volume (ChBVol), and flow (ChBFlow) in the center of the fovea. Measurements were obtained in 20 eyes of 20 subjects with 10 or more large drusen, visual acuity of 20/32 or better, and no evidence of choroidal neovascularization. Findings obtained in these subjects were compared with those of 10 eyes of 10 age- and blood pressure-matched control subjects with no large drusen. Foveolar choroidal blood flow measurements were obtained by asking the study participants to fixate on a probing laser beam.

RESULTS

No significant differences in average age, blood pressure, or intraocular pressure were observed between subjects with AMD and control subjects. In subjects with AMD, average ChBVol was 0.24 +/- 0.08 (+/- 1 SD) arbitrary units (AU); this value was 33% lower than that of control subjects (0.36 +/- 0.11 AU; two-tailed, independent Student's t-test, P = 0.005). Average ChBVel, conversely, was not significantly different from normal (0.44 +/- 0.07 AU) in subjects with AMD (0.44 +/- 0.10 AU). Average ChBFlow in subjects with AMD (8.7 +/- 3.1 AU) was 37% lower than that of control subjects (13.7 +/- 3.5 AU) (P = 0.0005). Average blood flow pulsatility was 6% higher in subjects with AMD (0.71 +/- 0.15) than in control subjects (0.66 +/- 0.14), but this difference was not statistically significant (P = 0.42).

CONCLUSIONS

Average ChBFlow in the nonexudative stages of AMD is lower than that of age-matched controls, and the effect is caused mainly by a decrease in ChBVol. Further studies are needed to elucidate whether decreased ChBFlow plays a role in the development of choroidal neovascularization, and whether ChBFlow measurements may help identify subjects with AMD at risk for developing choroidal neovascularization.

Occult choroidal neovascularization in age-related macular degeneration. A natural history study

OBJECTIVE

To explore morphological and vision changes in untreated eyes with subfoveal choroidal neovascularization (CNV) that have poorly demarcated boundaries.

DESIGN

Analysis of photographs of untreated patients with poorly demarcated occult CNV participating in a prospective clinical trial evaluating laser treatment compared with observation.

SETTING

Two tertiary retinal referral centers.

PATIENTS

Symptomatic individuals with poorly demarcated subfoveal occult CNV associated with age-related macular degeneration.

MAIN OUTCOME MEASURES

Change in size of lesion, development of classic CNV, change in vision, and development of subretinal fibrosis.

RESULTS

During follow-up (9-12 months), 32% of the occult choroidal neovascular lesions more than doubled their original size. Classic CNV developed in 52% of eyes that started without it. The median loss in visual acuity was 2.5 lines. Eyes with classic CNV or subretinal blood or both at baseline developed subretinal fibrosis more frequently and lost more visual acuity, but not to a statistically significant degree.

CONCLUSIONS

The morphological changes of eyes with subfoveal occult CNV in which the boundaries are poorly demarcated in variable; the presence of subretinal blood or a component of classic CNV may influence the prognosis for further loss of vision.

Interval between onset of mild nonproliferative and proliferative retinopathy in type I diabetes

OBJECTIVE

To describe the interval between first appearance of mild nonproliferative diabetic retinopathy (NPDR) and first appearance of neovascularization (NV) in type I diabetes.

SETTING

A longitudinal study of 269 patients followed up annually.

PARTICIPANTS

Participants had insulin-dependent diabetes and were free of proliferative diabetic retinopathy in both eyes at the baseline visit.

MAIN OUTCOME MEASURE

Stereoscopic color fundus photographs of each eye at each study visit, graded for features of retinopathy.

RESULTS

Among the 305 eyes for which the duration of diabetes at the first appearance of mild NPDR could be determined, NV developed in 28 by the end of the study. Survival analysis showed that the later the onset of mild NPDR was, the shorter the time from onset of mild NPDR to onset of NV (relative hazard for each additional year to onset of mild NPDR, 1.22; 95% confidence interval, 1.10-1.35). Adjustment for systolic and diastolic blood pressure, proteinuria, and glycosylated hemoglobin (Hgb A10) levels did not change the relative hazard estimate for onset of mild NPDR. Higher levels of Hgb A10 were associated with a shorter time from onset of mild NPDR to onset of NV (relative hazard, 1.26; 95% confidence interval, 1.05-1.51 [after adjusting for time at onset of mild NPDR]), as were higher levels of diastolic blood pressure, although not significantly (relative hazard for 10-mm Hg increase in diastolic blood pressure, 1.52; 95% confidence interval, 0.82-2.83 [adjusting for onset of mild NPDR, Hgb A10 level, systolic blood pressure, and proteinuria]). Neither proteinuria nor systolic blood pressure had an effect on time from onset of mild NPDR to onset of NV, after adjustment for time at onset of mild NPDR, Hgb A10 level, and diastolic blood pressure.

CONCLUSION

Later onset of mild NPDR is not necessarily associated with delayed development of NV in patients with type I diabetes. Caution must therefore be used in assessing the value of interventions that delay the onset of mild NPDR without evidence of delayed onset of NV.

Macular scatter ('grid') laser treatment of poorly demarcated subfoveal choroidal neovascularization in age-related macular degeneration. Results of a randomized pilot trial

OBJECTIVES

To determine the effects of macular scatter ("grid") laser photocoagulation compared with observation on the visual function of eyes with subfoveal choroidal neovascularization (CNV) that has poorly demarcated boundaries and to provide preliminary data for the evaluation of the feasibility and design of a larger, definitive trial.

DESIGN

Randomized pilot clinical trial.

SETTING

Two tertiary care retinal referral practices.

PATIENTS

Symptomatic individuals with subfoveal CNV secondary to age-related macular degeneration in whom fluorescein angiography showed occult CNV with poorly demarcated boundaries; classic CNV was allowed but did not need to be present for entry into the study.

MAIN OUTCOME MEASURE

Change in visual acuity from baseline to specified time periods.

RESULTS

Fifty-two eyes were assigned to observation. Fifty-one eyes were assigned randomly to treatment consisting of macular scatter ("grid") laser photocoagulation to the area of CNV. The treatment protocol for 8 of these eyes also included confluent laser photocoagulation to areas of classic CNV. The average visual acuity decrease from baseline was greater in the treated than in the observed group. The difference between these groups was greatest within the first year after study enrollment. At 24 months, slightly more than 40% of the eyes in each group had lost 6 or more lines of visual acuity. Similar results were noted for the subgroup of eyes initially with angiographic features of occult CNV but no classic CNV.

CONCLUSIONS

These short-term study results suggest that macular scatter ("grid") laser treatment is not beneficial and is possibly harmful compared with observation for symptomatic subfoveal CNV with poorly demarcated boundaries in age-related macular degeneration. With or without treatment, a significant proportion of these patients are at risk of severe visual loss within 2 years of seeking treatment, even when the eye initially has occult CNV and no classic CNV.

Efficacy of ofloxacin vs cefazolin and tobramycin in the therapy for bacterial keratitis. Report from the Bacterial Keratitis Study Research Group

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 < .001). Five of six patients among the 140 with positive bacterial cultures who had study medications discontinued because of ocular side effects were in the fortified antibiotics group; an additional three patients, all in the fortified antibiotics group, among the remaining 108 receiving study medications had ocular side effects.

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.

Clinically significant macular edema in type I diabetes. Incidence and risk factors

PURPOSE

To examine incidence of and risk factors for clinically significant macular edema in persons with type I diabetes.

METHODS

A group of 189 persons with type I diabetes, recruited from a summer camp for children with diabetes and from practices of local physicians, were participants in a longitudinal study with annual follow-up visits which included physical and ophthalmologic examinations and color stereo fundus photographs of each eye, centered on the disc and macula. Subjects were free of proliferative retinopathy at study baseline. Ages ranged from 3 to 40 years, duration of diabetes ranged from 0 to 12 years, mean glycosylated hemoglobin (Hgb A1c) was 12.2% (range, 6.4%-21.5%), and average follow-up was 6.1 years. Presence of clinically significant macular edema was defined as in the Early Treatment Diabetic Retinopathy Study.

RESULTS

In a total of 41 persons (62 eyes), clinically significant macular edema developed during study follow-up. Cumulative risk of clinically significant macular edema was 0 until 7 years' duration of diabetes. The cumulative risk of clinically significant macular edema increased linearly for each year of duration between 10 and 20 years, with an average annual increase of approximately 6.7%. Significant risk factors for clinically significant macular edema were older age at diagnosis, male sex, and higher Hgb A1c level. Systolic and diastolic blood pressure, proteinuria, body mass index, race, initial presence of retinopathy, and use of antihypertensives did not significantly affect the risk of clinically significant macular edema.

CONCLUSION

Older age at diagnosis of diabetes, male sex, and higher Hgb A1c levels (poorer control of blood glycemic levels) significantly increase the risk of clinically significant macular edema in persons with type I diabetes. These data extend the evidence implicating worse glycemic control as a cause of clinically significant macular edema, even within a population with relatively loose control.

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

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.

Scanning laser ophthalmoscopic analysis of the pattern of visual loss in age-related geographic atrophy of the macula

PURPOSE

We explored the clinical impression that geographic atrophy of the retinal pigment epithelium, a form of advanced age-related macular degeneration, is perceived by the patient as progressing gradually, even when fixation switches from foveal to extrafoveal.

METHODS

We analyzed the responses of 60 patients with geographic atrophy to a questionnaire administered as part of a five-year study of the natural course of geographic atrophy, funded by the National Eye Institute. We performed scanning laser opthalmoscope perimetry on all patients. We examined two additional patients with geographic atrophy who reported abrupt visual loss.

RESULTS

No eye with geographic atrophy was reported by any patient to have had sudden visual loss. Although most patients with geographic atrophy show foveal fixation until the fovea is atrophic and then show extrafoveal fixation, scanning laser ophthalmoscope perimetry in three patients with geographic atrophy showed alternation between a foveal and an extrafoveal retinal locus for fixation. Two patients with geographic atrophy who complained of abrupt visual loss were found to have occult choroidal neovascularization, which evolved in one patient to classic choroidal neovascularization. The neovascularization was difficult to detect because of the presence of geographic atrophy and its associated ophthalmoscopic and fluorescein angiographic features.

CONCLUSIONS

Visual loss in geographic atrophy is nearly always perceived by the patient as being gradual, even when considerable decreases in visual acuity occur and when foveal vision and fixation are lost. A possible explanation for this perception is that there is a transitional period during which a patient uses both a foveal and extrafoveal site for fixation. The complaint of abrupt visual loss in a patient with geographic atrophy should raise the suspicion of choroidal neovascularization, which may be occult and difficult to detect.

Patient-reported symptoms associated with graft reactions in high-risk patients in the collaborative corneal transplantation studies. Collaborative Corneal Transplantation Studies Research Group

The Collaborative Corneal Transplantation Studies (CCTS) were designed to evaluate the effect of donor-recipient histocompatibility matching and cross-matching on the survival of corneal transplants in high-risk patients. We now report on the role of symptoms in the detection of corneal allograft reactions in the CCTS and on the relationship between symptom reporting and graft survival. The 456 patients transplanted in the CCTS were followed for a minimum of 2 years or until graft failure. The follow-up protocol included 11 scheduled examinations in the first year, four examinations during the second year, and examinations every 6 months thereafter. Interim examinations were performed in response to patient-reported symptoms. At every examination, patients were asked specifically if they had redness, sensitivity to light, loss of vision, or pain (RSVP). Of the 456 patients transplanted, 62% had at least one graft reaction. Patients diagnosed with reactions at scheduled visits in the first postoperative year were 2.5 times more likely to report symptoms than those without reactions. Reports of red eye and vision loss were strongly associated with allograft reaction. However, these symptoms were neither highly sensitive nor specific for reaction (sensitivity = 46%, specificity = 70% at 6 months). The severity of reaction influenced the reporting of symptoms: 69% of patients with severe reactions reported symptoms versus 48% of patients with mild reactions (p < 0.001). The only patient characteristic associated with reliable symptom reporting was age, with younger patients with reactions being more likely to report symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Detecting recurrent choroidal neovascularization. Comparison of clinical examination with and without fluorescein angiography

OBJECTIVE/DESIGN

To evaluate prospectively the ability of three retina specialists to detect recurrent choroidal neovascularization (CNV) after clinical examination alone and then with fluorescein angiography at 3 and 6 weeks and at 3, 6, 9, and 12 months after laser photocoagulation.

SETTING

Single tertiary retinal referral center.

PATIENTS

All patients who had laser treatment for CNV within 14 months of their study visit. One hundred thirty-seven eyes of 134 patients were evaluated during 401 visits.

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive predictive value, and negative predictive value of clinical examination with biomicroscopy to detect recurrent CNV when defined as leakage on the periphery of the laser-treated area on the fluorescein angiogram.

RESULTS

Ninety-seven definite or probable recurrences in 56 eyes were identified on the fluorescein angiogram. Clinical examination had a sensitivity of 59%, specificity of 94%, positive predictive value of 76%, and negative predictive value of 88%. These figures varied somewhat by underlying cause, age, time since treatment, and lesion location. Using either a reported or measured loss of vision with the results of biomicroscopy as an indication of recurrence increased the sensitivity to 77% but reduced the specificity to 81%.

CONCLUSIONS

Clinical examination probably cannot replace fluorescein angiography in detecting all recurrent CNV after laser treatment. However, for follow-up visits in which recurrent CNV was not suspected on biomicroscopy, definite or questionable recurrent CNV was identified on the fluorescein angiogram only 12% of the time, while the absence of recurrent CNV using this method was confirmed 88% of the time.

Risk factors for corneal graft failure and rejection in the collaborative corneal transplantation studies. Collaborative Corneal Transplantation Studies Research Group

PURPOSE

To evaluate comprehensively the magnitude of suspected risk factors for corneal graft failure from any cause, failure from rejection, and immunologic reaction in patients at high risk for graft failure after corneal transplantation.

METHODS

The records of the 457 participants in the Collaborative Corneal Transplantation Studies were reviewed. All participants had at least two quadrants of stromal vascularization and/or a history or previous graft rejection. Patients were followed for 2 to 5 years. Characteristics of the patient, study eye, donor, donor-recipient histocompatibility, and surgical procedure were examined for their association with the graft outcomes of failure from any cause, rejection failure, and immunologic reaction. Multivariate survival analysis techniques were used to estimate rates of graft outcome events and to estimate the magnitude of risk factors.

RESULTS

Many apparent risk factors did not maintain their association with graft outcomes after adjustment for other risk factors. Young recipient age, the number of previous grafts, history of previous anterior segment surgery, preoperative glaucoma, quadrants of anterior synechiae, quadrants of stromal vessels, a primary diagnosis of chemical burn, and blood group ABO incompatibility were among the strongest risk factors identified for graft failure. Donor and corneal preservation characteristics had little influence on graft outcome.

CONCLUSIONS

Risk of graft failure varies substantially, even within a high-risk population. The number of risk factors present should be considered by the patient and surgeon when contemplating transplantation and planning follow-up.

Effectiveness of histocompatibility matching in high-risk corneal transplantation: a summary of results from the Collaborative Corneal Transplantation Studies

The Collaborative Corneal Transplantation Studies (CCTS) were designed to evaluate the effect of donor-recipient histocompatibility matching and crossmatching on the survival of corneal transplants in high-risk patients. Corneas were allocated to the 419 patients in the double-masked Antigen Matching Study on the basis of HLA-A,-B and HLA-DR antigen match. ABO blood group compatibility was determined but not used for recipient selection. The 37 patients in the Crossmatch Study were randomly assigned to receive a cornea from either a positively or negatively crossmatched donor. All patients received topical steroid therapy according to a standard protocol. Matching for HLA-A,-B and HLA-DR antigens had no effect on overall graft survival, the incidence of irreversible rejection, or the incidence of rejection episodes. The positive group in the Crossmatch Study had fewer graft failures, rejection failures, and rejection episodes than the negative group; however, these differences were not statistically significant. The estimated proportion of eyes with failure from rejection by 3 years was 30% for the ABO-incompatible group and 16% for the ABO-compatible group (relative risk, 1.98; 95% confidence interval, 1.15 to 3.13). These studies demonstrate that, for high-risk patients who are immunosuppressed by topical steroid therapy: 1) neither HLA-A.-B nor HLA-DR antigen matching substantially reduced the likelihood of corneal graft failure; 2) a positive donor-recipient crossmatch did not increase the risk of corneal graft failure; and 3) ABO blood group matching may be effective in reducing the risk of graft failure from rejection.

Reproducibility of HLA-A, B, and DR typing using peripheral blood samples: results of retyping in the collaborative corneal transplantation studies. Collaborative Corneal Transplantation Studies Group (corrected)

Recipients enrolled in the Collaborative Corneal Transplantation Studies were retyped as part of a quality assurance program. Because the observed percentage of HLA-DR homozygosity on original typing was more than twice as high as expected from CCTS allele frequencies, the sample selected for retyping was heavily weighted with patients whose original typing identified fewer than two DR antigens. Retyping was performed in a different laboratory from the laboratory performing the original typing. For the 129 patients who were retyped, agreement between the original and retyping laboratories was 88% for HLA-A, 79% for HLA-B, and 55% for HLA-DR. When criteria was relaxed to consider only discrepancies involving readily identifiable antigens, the agreement improved to 95% for HLA-A, 91% for HLA-B, and 59% for HLA-DR. Identification of a second HLA-DR antigen on retyping when only one DR antigen had been identified on original typing was by far the most common form of disagreement. There were no significant differences in the amount of disagreement among the laboratories. Of special interest is that 50% of the discrepancies involved DR3, DR5, and/or DR6, which have structural similarities. Based on the results of the project, we recommend: (1) replicate testing for all DR typing; and (2) retyping using a second source of antiserum for all subjects having DR blanks.

Frequency of adverse systemic reactions after fluorescein angiography. Results of a prospective study

Intravenous fluorescein angiography is a commonly performed and extraordinarily valuable diagnostic procedure. The frequency of adverse reactions after angiography has varied considerably in previous reports. In a prospective study of 2789 angiographic procedures in 2025 patients, the authors found that the percentage of adverse reactions depended strongly on the patient's angiographic history. Overall, adverse reactions followed 4.8% of the angiographic procedures. These reactions included nausea (2.9%), vomiting (1.2%), flushing/itching/hives (0.5%), and other reactions (dyspnea, syncope, excessive sneezing) (0.2%). No cases of anaphylaxis, myocardial infarction, pulmonary edema, or seizures occurred. The percentage of reactions was 1.8% for patients who had had previous angiography without ever having had an adverse reaction. In contrast, the percentage of reactions was 48.6% for patients who had had an adverse reaction to angiography previously.

Visual results after laser treatment for peripapillary choroidal neovascular membranes

To investigate the potentially harmful effects of laser photocoagulation in the papillomacular bundle (PMB), the records of patients treated for idiopathic neovascular membranes or membranes secondary to histoplasmosis extending into the PMB were reviewed. Twenty-eight eyes of 27 patients were identified. Most eyes (75%) were treated with the krypton red laser, while the remainder (25%) were treated with either argon green (18%) or a combination of the two (7%). After treatment 21 eyes (75%) had stable or improved visual acuity and three eyes (11%) lost more than three lines. Four eyes (14%) had changes in the optic disc and one eye developed a permanent arcuate scotoma. These data suggest that severe visual loss and extensive visual field defects occur rarely after photocoagulation of peripapillary choroidal neovascular membranes.

Relationship of drusen and abnormalities of the retinal pigment epithelium to the prognosis of neovascular macular degeneration. The Macular Photocoagulation Study Group

We graded macular features of 127 fellow eyes of participants in the Macular Photocoagulation Study who had an extrafoveal choroidal neovascular membrane secondary to age-related macular degeneration in the first eye and no initial evidence of the neovascular form of age-related macular degeneration in the fellow eye. Our aims were to determine the relationship of drusen characteristics and retinal pigment epithelial abnormalities to the risk of subsequent development of neovascularization in the fellow eye and the risk of subsequent development of recurrent neovascular membranes after photocoagulation in the first eye. Regression analysis demonstrated that the presence of large drusen and focal hyperpigmentation of the retinal pigment epithelium were independent risk factors for the subsequent development of neovascularization in the fellow eye (relative risk, 2.4 and 2.5, respectively). Only 10% of eyes with no large drusen or any retinal pigment epithelial hyperpigmentation compared with 58% of eyes with both large drusen and retinal pigment epithelial hyperpigmentation developed neovascularization in the fellow eye within 5 years. Using multivariate Cox regression analysis, we noted that the risk of developing recurrent neovascular membranes in the first eye was significantly increased when large drusen (relative risk, 2.8) were noted in the fellow eye at the time of laser treatment in the first eye. Fundus features in the fellow eye appear to help identify patients at high risk of developing visual loss from recurrent neovascular membranes following laser treatment in the first eye and from development of a neovascular membrane in the fellow eye.

The use of fundus photographs and fluorescein angiograms in the identification and treatment of choroidal neovascularization in the Macular Photocoagulation Study. The Macular Photocoagulation Study Group

The Macular Photocoagulation Study (MPS) Fundus Photograph Reading Center has developed a standard set of methods for assessing color photographs and fluorescein angiograms on study patients. For pretreatment angiograms, these methods are used to determine the location and extent of the choroidal neovascularization. For posttreatment color fundus photographs, these methods are used to assess the extent and intensity of treatment. Although these methods were developed to judge eligibility and treatment of patients enrolled in the MPS, they provide an excellent way for all treating ophthalmologists to evaluate their patients' angiograms and to assess immediately the intensity and extent of laser photocoagulation. The technique requires a microfilm reader or slide projection device to determine the completeness of treatment. The authors superimpose independent drawings made from pre- and posttreatment photographs. The techniques described can be applied readily in clinical practice. Since persistent neovascularization is highly correlated with incomplete and/or inadequate photocoagulation treatment, clinicians may adopt these Reading Center techniques to minimize the frequency of persistent neovascularization and, possibly, to reduce the frequency of visual loss in treated eyes.

Pathological stage is higher in older men with clinical stage B1 adenocarcinoma of the prostate

We examined the relationship between age and pathological stage in 444 consecutive patients who underwent pelvic lymphadenectomy and radical retropubic prostatectomy for clinically localized adenocarcinoma of the prostate. Pathological stage of cancer was determined postoperatively as organ-confined, capsular penetration (cancer through prostatic capsule), seminal vesicle involvement or lymph node metastases. Patient age ranged from 34 to 75 years. The majority of the patients had clinical stage B1 disease with induration confined to less than 1 lobe of the gland. In this group a statistically significant (p equals 0.001, chi-square test for trend) correlation between increased age and higher pathological stage was found. We also found that older men with clinical stage B1 disease had a statistically significant trend toward higher Gleason grade. An explanation for our findings might be the masking of prostatic induration by benign prostatic hypertrophy, clearly a disease of aging men. We suggest that increased age is a relative risk factor for advanced pathological findings in men with clinical stage B1 prostatic cancer.

Assessment of visual function in patients with age-related macular degeneration and low visual acuity

The visual function of 100 eyes with low visual acuity of 100 patients with age-related macular degeneration was examined using measurements of visual acuity, peak contrast sensitivity, and the ability to read, to tell time, and to distinguish colors, products, and facial expressions. Visual acuity and peak contrast sensitivity were correlated (r = .62); however, a range of peak contrast sensitivities was observed at each level of acuity. When considered individually, visual acuity and peak contrast sensitivity were related to the ability to perform each of the tasks. When multivariate methods were applied, both visual acuity and peak contrast sensitivity contributed independently to the ability to read and tell time. Among patients with the same contrast sensitivity, visual acuity had little or no relationship to the ability to identify colors, products, and faces.