Capsule staining as an adjunct to cataract surgery: a report from the American Academy of Ophthalmology.

OBJECTIVE: This document evaluates currently available data in the published literature to answer the question of whether the use of dye such as indocyanine green or trypan blue to stain the lens capsule to improve visualization is safe and effective as an adjunct to cataract surgery. METHODS: Literature searches conducted in March 2003 and May 2004 retrieved 139 citations. The panel members reviewed the abstracts and selected 47 of possible clinical relevance for review. An additional 14 articles were identified for evaluation. Of the 61 articles reviewed, the panel members selected 36 for the panel methodologist to review and rate according to the strength of the evidence. A level I rating was assigned to properly conducted, well-designed, randomized clinical trials; a level II rating was assigned to well-designed cohort and case-control studies; and a level III rating was assigned to case series and case reports. RESULTS: There is level III evidence that indocyanine green, trypan blue, and fluorescein are each effective in staining the lens capsule and that indocyanine green and trypan blue provide better ease of use and visualization of the capsule than fluoroscein. There is level II evidence that staining the capsule is helpful in completing capsulorrhexis and that it is helpful for pediatric patients under age 5 years and in cases of white cataract. The overall surgical advantage of a completed continuous curvilinear capsulorrhexis using dye has not been demonstrated, but this may be related to the outcome measures chosen rather than a failure to confer advantage. There are substantial data indicating that trypan blue 0.1% is not toxic to the cornea. There are limited data suggesting that indocyanine green 0.125% to 0.5% is not toxic to anterior segment structures. CONCLUSIONS: There are data confirming that dye is safe and effective as an adjunct for capsule visualization in cataract surgery. It is reasonable to use dye when inadequate capsule visualization may compromise the outcome in cataract surgery. More studies are needed to confirm a lack of toxicity of indocyanine green and trypan blue, particularly in the event of posterior segment or longer duration exposure.

Racial differences in central corneal thickness and refraction among refractive surgery candidates.

PURPOSE: To examine the preoperative central corneal thickness and refractive status of Caucasians, Hispanics, Asians, and African Americans in a refractive surgery patient population. METHODS: In a retrospective case series, a total of 803 consecutive eyes, which had no history of anterior segment surgery, underwent central corneal thickness and refraction measurement as part of a preoperative evaluation for refractive surgery from December 1999 to October 2002. Preoperative central corneal thickness was measured by a DGH-550 ultrasonic pachymeter, and spherical equivalence was determined by manifest refraction. RESULTS: This study included Caucasian (34.4%), Hispanic (34.5%), Asian (20.7%), African American (8.9%), and other (1.5%) patients. A one-way analysis of variance (ANOVA) revealed no significant differences in the central corneal thickness measurements among Asians, Hispanics, and Caucasians. However, mean central corneal thickness was 14 microm thinner in African Americans compared to Caucasians, and was significantly different at the 95% confidence interval. A one-way ANOVA revealed a significant difference in the preoperative spherical equivalence among the four groups (F=4.91; df=3; P<.05) but no significant differences were noted in the preoperative astigmatism among any of the four groups (F=1.08; df=3; P>.05). A significant difference was noted in age in the four preoperative groups. CONCLUSIONS: Among the refractive population, African Americans were found to have thinner central corneal thickness than Caucasians. Asians were significantly (P<.05) more myopic compared to Caucasians, Hispanics, and African Americans. No difference was noted in the preoperative astigmatism among any of the four groups. Asians sought refractive surgery at a younger age whereas Caucasians sought it at an older age.

Pax-6 expression in posthatch chick retina during and recovery from form-deprivation myopia.

The expression of Pax-6 in fully-differentiated chick retina remains largely confined to the amacrine and ganglion cell layers. In the developing posthatch chick retina, Pax-6 expression shows a biphasic pattern; a decrease by posthatch day 17 followed by a steady increase in the adult eye. Interestingly, we find that this biphasic expression of Pax-6 is reflected in the biphasic growth pattern of the posthatch chick eye, which is disrupted by form-deprivation myopia (FDM). We have now examined the pattern of Pax-6 accumulation in 3-day-old chick eyes subjected to 2 weeks of FDM followed by 2 weeks of recovery from FDM. Quantitative RT-PCR (with a homologous internal control) revealed that after 2 weeks of occlusion the contralateral non occluded eyes, the occluded eyes and the normal nonexperimental chick eyes did not show any drastic changes in the number of Pax-6 transcripts. The data obtained suggests that the contralateral eye does not represent a 'normal' control eye; similar but nonidentical changes are seen, at the molecular level, in both the contralateral and the occluded eyes. Comparisons with the control nonexperimental animals, however, are meaningful. Even after 2 weeks of recovery under normal light conditions, the occluded eyes do not seem to reach the same level of Pax-6 expression (number of molecules per mg tissue) as seen in normal control eyes, suggesting that exposure of the posthatch chick eye to FDM impedes developmental progression that normally culminates in emmetropia.

Vision loss among diabetics in a group model Health Maintenance Organization (HMO).

PURPOSE: To report the management of diabetic retinopathy in one group model health maintenance organization and assess the quality of care. METHODS: Cross-sectional study. A chart review of 1200 randomly identified patients with diabetes mellitus, continuously enrolled for 3 years in Kaiser Permanente (KP) Southern California, the largest provider of managed care in Southern California, was performed. A total of 1047 patients were included in the analyses. Patient characteristics as well as information from the last eye examination were abstracted. Charts from patients with visual acuity less than 20/200 in their better eye (legal blindness) were selected for extensive chart review to determine the cause of visual loss and the antecedent process of care. T tests or the Wilcoxon rank sum test was used to compare continuous variables. The chi(2) test or the Fisher exact test was used to compare categorical variables. All analyses were performed on the Statistical Analyses System (SAS Institute, North Carolina). RESULTS: Our study population of 1047 diabetic patients was 51.7% male, had a mean age of 60.4 years, a mean duration of diabetes of 9.6 years, and a mean hemoglobin A1c of 8.3%. During the study period, 77.5% of patients received a screening eye examination with examination by an ophthalmologist, an optometrist, or review of a retinal photograph. Of those with a visual acuity assessment (n = 687, 65.6% of 1047), 1.5% had visual acuity of 20/200 or worse (legally blind) in the better eye, while 8.2% had this level of visual acuity in the worse eye. Of eyes with new onset clinically significant macular edema and visual acuity < 20/40, 40% had documentation of focal laser performed within 1 month of diagnosis. Of eyes with vitreous hemorrhage and visual acuity < 20/40, 50% had documentation of vitrectomy. Among eyes that had vitrectomy, over 80% had this procedure within 1 year of diagnosis of vitreous hemorrhage. CONCLUSIONS: The current report is the largest study of diabetic retinopathy outcomes among patients enrolled in a prepaid health plan. Further research is necessary to investigate the impact of managed care on health outcomes.