Prevalence of diabetes mellitus and diabetic retinopathy in Filipino vs Caucasian Americans: a retrospective cross-sectional epidemiologic study of two convenience samples.

OBJECTIVES: To compare the prevalence of diabetic retinopathy in Filipino and Caucasian Americans in two clinic populations. DESIGN: Retrospective cross-sectional epidemiologic study of two convenience samples. PARTICIPANTS AND SETTING: Five hundred twelve Filipino and 600 Caucasian patients aged 40 years or older examined by two community-based comprehensive ophthalmology clinics during a one-year period. RESULTS: The prevalence of self-reported type 2 diabetes mellitus among Filipino (F) and Caucasian Americans (C) was 40.6% and 24.8%, respectively (P<.001). In the subpopulation with type 2 diabetes mellitus (n=375: 208 Filipino; 149 Caucasian), there was a statistically insignificant higher prevalence of diabetic retinopathy among Filipino diabetics compared to Caucasians (F vs C: all forms of diabetic retinopathy, 24.5% vs 16.8%, P=.08; non-proliferative retinopathy, 17.3% vs 12.8%, P=.24; proliferative retinopathy, 7.2% vs. 4.0%, P=.21). In multivariate analyses of the diabetic subpopulation, Filipino ethnicity was not a significant predictor of diabetic retinopathy. CONCLUSIONS: Filipino Americans may have a higher prevalence of type 2 diabetes mellitus and diabetic retinopathy than Caucasian Americans. Among those with type 2 diabetes, however, Filipino Americans were not found to be more likely to show manifestations of diabetic retinopathy than Caucasian Americans.

Anterior Segment Parameters of Filipino-Americans Compared to Chinese-Americans and Caucasian Americans Using Anterior Segment Optical Coherence Tomography.

PURPOSE: We compare anterior segment characteristics of Filipino- versus Chinese- and Caucasian-Americans to describe the differences in risk factors among each ethnic group. METHODS: A cross-sectional study was conducted among Filipino, Chinese, and Caucasian subjects without glaucoma who underwent a standardized set of ocular examinations and anterior segment optical coherence tomography (Visante ASOCT) imaging. Zhongshan Angle Assessment Program (ZAAP) 4 was used for ASOCT image analysis. The following quantitative parameters wereobtained from ZAAP: (1) angle opening distance (AOD500, AOD750), angle recess area at 750 µm (ARA), and trabecular-iris space area at 500 and 750 µm (TISA500, TISA750); (2) iris parameters, including iris thickness at 750 µm from the scleral spur (IT750), iris area (IArea), iris curvature or convexity (ICurv), and pupil diameter; 3) anterior chamber parameters; and (4) lens vault. RESULTS: The Filipino (122 eyes), Chinese (121 eyes), and Caucasian (111 eyes) subject groups were similar in terms of demographic and clinical characteristics. We reported pairwise comparisons of Filipino parameter values to Chinese or Caucasian values, represented as B-coefficients and P values. In multivariate analysis, Filipinos had narrower angles than Caucasians (AOD750, TISA 500, TISA 750, ARA, P < 0.001). Filipinos had thicker and more convex irises than Caucasians (IT750, IT 2000, ICurv P < 0.003). Angle and iris parameters were similar overall for Filipino and Chinese. CONCLUSIONS: Filipinos appear to have more convex and thicker irises, smaller lens vault and narrower angles compared to Caucasians. Filipino eyes closely resembled Chinese eyes with similar iris and angle parameters. TRANSLATIONAL RELEVANCE: The anatomic angle parameters of Filipinos may contribute to angle closure risk among this population, thus ASOCT and thorough angle analysis is recommended in this population.

Optical coherence tomography and histologic measurements of nerve fiber layer thickness in normal and glaucomatous monkey eyes.

PURPOSE: To investigate optical coherence tomography (OCT) measurements of retinal nerve fiber layer (RNFL) thickness change associated with elevated intraocular pressure (IOP) over a period of time, and to compare in vivo OCT RNFL thickness measurements with morphologic measurements of the same tissues. METHODS: One eye of each of 12 cynomolgus monkeys was treated with argon laser to the anterior chamber angle to induce elevated IOP. OCT measurements were made weekly in the treated and the contralateral eyes of each monkey for 14 weeks after the laser insult. The monkeys were killed at the conclusion of the experiment, and comparisons were made between the terminal OCT RNFL measurements and quantitative histomorphometric assessments in the same eyes. Effects of exposure to elevated IOP on RNFL were characterized by a mixed-effects model. Linear mixed-effects models provided unbiased analysis of balanced and unbalanced repeated-measures data, detection of group effects (fixed effects), and individual subject effects (random effects), thereby making the best use of all available data. RESULTS: Increased IOP was achieved in 10 eyes. Exposure to high IOP was associated with the loss of mean RNFL thickness at a median rate of 3.77 +/- 0.08 microm/wk. On average, OCT RNFL thickness measurements were higher than histomorphologic measurements by 5.7 microm (95% confidence interval, 3.6-7.8; P = 0.003). CONCLUSIONS: Thinning of the RNFL associated with elevated IOP was demonstrated with OCT in a group of experimentally glaucomatous monkey eyes over a period. OCT measurements corresponded with histomorphometric measurements of the same tissues.

Open-angle glaucoma in Filipino and white Americans: a comparative study.

BACKGROUND: To compare the frequency of open-angle glaucoma (OAG) subtypes between Filipino and white Americans in a general ophthalmology clinic population. PATIENTS AND METHODS: In this retrospective cross-sectional epidemiologic study with prospective sampling, medical charts of 1113 patients aged 40 years or older (513 Filipinos, 600 whites) seen in 2008 were randomly sampled from 2 private comprehensive ophthalmology clinics. Glaucoma was diagnosed based on optic nerve appearance, visual field defects, and other ocular findings using the International Society of Geographical and Epidemiological Ophthalmology (ISGEO) scheme. The normal-tension subtype of OAG [normal-tension glaucoma (NTG)] was defined by intraocular pressure ≤21 mm Hg as determined by review of medical records. RESULTS: NTG comprised a greater proportion of all glaucomatous disease in Filipino subjects [Filipino (F) vs. white (W): 46.7% vs. 26.8%; P=0.02]. Filipinos were more commonly diagnosed with OAG and NTG than whites (F vs. W: OAG, 11.9% vs. 8.2%; NTG, 6.8% vs. 2.5%; P=0.04, 0.001, respectively). There was no significant difference in central corneal thickness between Filipino and white subjects with NTG (P=0.66). CONCLUSIONS: Both OAG and NTG may be more common in Filipino Americans than in white Americans with the propensity for NTG being particularly high in the former relative to the latter group.