Marilyn D. Farber

Risk factors for hemiretinal vein occlusion : Comparison with risk factors for central and branch retinal vein occlusion the eye disease case-control study

OBJECTIVE Possible risk factors for hemiretinal vein occlusion were identified and compared with risk factor profiles for central and branch retinal vein occlusion. DESIGN The design was a multicenter case-control study. METHODS The authors identified 79 patients with hemiretinal vein occlusion (HRVO), 258 patients with central retinal vein occlusion (CRVO), 270 patients with branch retinal vein occlusion (BRVO), and 1142 control subjects at 5 clinical centers. Risk factor data were obtained through interviews, clinical examinations, and laboratory analyses of blood specimens. RESULTS Systemic hypertension and history of diabetes mellitus were associated with increased risk of HRVO. Risk of CRVO increased with history of diabetes, systemic hypertension, and higher erythrocyte sedimentation rate (females only); risk of CRVO decreased with increasing amounts of physical activity and increasing amounts of alcohol consumption. Systemic hypertension, higher body mass index, and higher alpha2-globulin levels were associated with increased risk of BRVO, whereas higher high-density lipoprotein levels and increasing levels of alcohol consumption were associated with decreased risk of BRVO. Glaucoma history was associated with all three types of retinal vein occlusion. CONCLUSION Patients presenting with retinal vein occlusion should be evaluated for cardiovascular disease, diabetes, and glaucoma.

Arteriovenous Crossing Patterns in Branch Retinal Vein Occlusion

PURPOSE The study was designed to evaluate the relative anatomic position of the crossing vessels at the site of occlusion in eyes with branch retinal vein occlusion (BRVO). METHODS Fundus photographs of 106 eyes (104 patients) with recent BRVO from the Eye Disease Case-Control Study were used to examine the relative position of artery and vein at occluded crossings. Three separate comparison groups were formed by identifying corresponding arteriovenous crossings for each occluded crossing in: (1) the ipsilateral but opposite vessel arcade within eyes affected by BRVO; (2) the same quadrant in unaffected eyes of BRVO patients; and (3) the same quadrant in eyes of patients without BRVO, matched by age, sex, and race with the BRVO patients. RESULTS The site of obstruction of the branch vein was an arteriovenous crossing in all affected eyes. In 99% of eyes with BRVO, the artery was located anterior to the vein at the obstructed site. In the three comparison groups, the artery was anterior to the vein in 62%, 61%, and 54% of the crossings, respectively, yielding statistically significant differences for each group of control crossings compared with BRVO crossings (P < 0.001). CONCLUSION Finding the vein to be consistently between the more rigid artery and the retina at almost all arteriovenous crossings affected by BRVO suggests a possible role for mechanical obstruction in the pathogenesis of BRVO.

Cooperative Study of Sickle Cell Disease: Demographic and socioeconomic characteristics of patients and families with sickle cell disease.

Socioeconomic data on 3538 black patients enrolled in the Cooperative Study of Sickle Cell Disease (CSSCD) from 1979 to 1981 are summarized and compared with the U.S. black population (USBP) where appropriate. The following contrasts between the patients and families with Sickle Cell Disease (SCD) and the USBP were found: family structure differed, with fewer two-parent families (40 vs 54%) and more single female heads-of-household (53 vs 42%) within the SCD population; of those employed, twice as many of the SCD patients of both sexes worked in white collar positions; a higher percentage of patients were unemployed and disabled; and male SCD patients had a lower median personal income than USBP males. Several similarities were also noted: the percentage of high school graduates was 71% for SCD patients and 75% for the USBP; female heads-of-household employed full time earned approximately the same salary as USBP females. These data will help health professionals who counsel SCD patients and their families.

Retinal arterial macroaneurysms:risk factors and natural history

A case control study was conducted to identify the systemic and ocular risk factors for retinal arterial macroaneurysms. Forty-three patients with 52 photographically confirmed macroaneurysms were located. Forty-three age-matched, race-matched concurrent control patients were also identified. The patients with macroaneurysms had decreased visual acuity (p less than 0.0001) and a higher prevalence of hypertension (p = 0.037), female sex (p = 0.099), and retinal vein occlusions (p = 0.055) than controls. In patients with both a macroaneurysm and venous occlusion there was a 12.0 times higher prevalence of macroaneurysms in the area of retina drained by the occluded vein (p less than 0.05). Common findings associated with macroaneurysms included retinal haemorrhage (81% of patients), retinal exudate (70%), vitreous haemorrhage (30%), macular involvement (30%), and distal arteriolar narrowing (26%). Arteriolar occlusion occurred spontaneously (8%) or after laser photocoagulation (16%).

Effects of Topical Glaucoma Drugs on Fistuliezed Rabbit Conjunctiva

Conjunctival fibroblastic proliferation with contracting scar formation has been implicated as a possible cause of glaucoma filtering surgery failure. The effects of glaucoma medications on bulbar conjunctiva were evaluated in both eyes of 20 pigmented rabbits, with 5 rabbits per group each receiving singular topically applied daily doses of either 0.5% timolol, 1% epinephrine, 4% pilocarpine, or artificial tears in a masked fashion for 4 months. Posterior lip sclerectomies were performed in 16 rabbits--4 from each treatment group. The remaining four rabbits served as nonsurgical controls. Four additional rabbits, which had not received eye drops, were included as a nonmedicated control group, with one rabbit serving as a nonsurgical control. Immunostaining was performed to identify the presence of myofibroblasts in fistulized conjunctiva. Treated surgical eyes, regardless of medication, had higher myofibroblastic cell proliferation than treated nonsurgical eyes. Among fistulized eyes, all medications increased cell proliferation, with pilocarpine eliciting the most dramatic increase compared with all other groups.

Recruitment in the Cooperative Study of Sickle Cell Disease (CSSCD).

The Cooperative Study of Sickle Cell Disease (CSSCD) is a multiinstitutional investigation of the natural history of clinical course of sickle cell disease from birth through adulthood. The study is not a trial; rather, it involves data collection at 23 institutions in a uniform, standardized fashion on 3800 patients. Recruitment aspects that were addressed include issues related to recruitment of different age groups, ranging from newborns to pregnant women to patients over 50 years of age; the need to include mildly affected patients to ensure that the study would not reflect only a severe hospital-based population; recruitment from rural populations; and the need to screen and enter a newborn population at birth. The recruitment goal of entering 3200 patients, including 2100 patients with SS hemoglobinopathy, over a 24-month period was accomplished after 27 months.

Branch Retinal Vein Occlusion and Quadratic Variation in Arteriovenous Crossings

To explore further the origin and clinically observed regional variation of branch retinal vein occlusion, we studied fluorescein angiograms of 42 patients (42 eyes) with branch retinal vein occlusion and a control population of 126 consecutive patients. In a statistically significant percentage of crossings, the artery was anterior to the vein in those areas of the retina clinically predisposed to branch retinal vein occlusion. Thirty-nine of the 42 patients with branch retinal vein occlusion sites had artery-anterior-to-vein crossings (P = .002), whereas 183 of all 266 arteriovenous crossings in these same eyes were similarly positioned. The artery lay anterior to the vein in significantly more temporal retinal crossings (337 of 457) than nasal retinal crossings (89 of 149; P = .002). Similarly, significantly more superotemporal quadrant crossings (164 of 209) than inferotemporal quadrant crossings (173 of 248) had the artery anterior to the vein (P = .0045). These results suggested that variation in the pattern of arteriovenous crossings may have a role in the clinical distribution of branch retinal vein occlusion.

Intraocular Lens implantation versus No Intraocular Lens Implantation in Patients with Chronic Iridocyclitis and Pars Planitis: A Randomized Prospective Study

PURPOSE The authors studied the safety of intraocular lens (IOL) implantation in patients with uveitis. METHODS The authors prospectively randomized 26 patients with chronic iridocyclitis (22 patients) or pars planitis (4 patients) to undergo IOL implantation or no IOL implantation at the time of cataract surgery. RESULTS There was no statistical difference in visual acuity results at 1 year between the two groups. There was a trend toward better visual acuity in patients with chronic iridocyclitis without IOLs. Cocoon-like dense fibrous membranes enveloped the IOL in two patients. CONCLUSION The authors conclude that IOLs are relatively safe in patients with chronic iridocyclitis but that only a much larger study could determine if the trend toward better visual acuity without an IOL was real.

Aminocaproic Acid versus Prednisone for the Treatment of Traumatic Hyphema: A Randomized Clinical Trial

One hundred twelve patients who sustained hyphema after blunt trauma were enrolled in a double-blind randomized clinical trial to determine the relative efficacies of aminocaproic acid (Amicar) and systemic prednisone for reducing the rate of secondary hemorrhage. Fifty-six patients received an oral dosage of 50 mg/kg of aminocaproic acid every 4 hours for 5 days, up to a maximum of 30 g daily, and 56 patients received an oral dosage of 40 mg of prednisone daily (adjusted for weight) in two divided doses. Placebo pills and liquids were given to each patient to mask the treatment schedules. There were no statistically significant differences between the patient populations for any demographic or clinical characteristic (e.g., visual acuity, intraocular pressure [IOP], initial hyphema size) measured in the study. Blacks comprised 53% of the study population, and the mean age of the patients was 23.5 years. Four patients in each of the treatment groups experienced a secondary hemorrhage; the rebleed rate was 7.1% in each group.

A Randomized Clinical Trial of Feeder Vessel Photocoagulation of Proliferative Sickle Cell Retinonathy: II. Update and Analysis of Risk Factors

Abstract Follow-up of patients enrolled in a randomized prospective trial of feeder vessel photocoagulation for proliferative sickle cell retinopathy has shown that photocoagulation is effective in preventing vitreous hemorrhage and visual loss from vitreous hemorrhage. In addition, a reduction of visual loss from all causes in photocoagulated eyes approaches statistical significance. Analysis of control eyes shows that there are three independent risk factors for the occurrence of vitreous hemorrhage: (1) the presence of the SC genotype, (2) the presence of vitreous blood at the initial evaluation and, (3) the presence of greater than 60° of perfused neovascularization.