The prevalence of diabetic retinopathy in Trang province determined by retinal photography and comprehensive eye examination.

OBJECTIVE: To determine the prevalence of diabetic retinopathy (DR) in Trang province using retinal photography and comprehensive eye examination. METHOD: Seven hundred fourteen patients with diabetes (7% of the total number of diabetes in the province) were examined by single-field digital retinal photography interpreted by a retinal specialist and a stereoscopic method using indirect ophthalmolscopy and slit lamp biomicroscopy with wide field contact lens. The latter method was performed by an experienced ophthalmologist assisted by the same retinal specialist. RESULTS: There was 19.2% nonproliferative diabetic retinopathy (NPDR), and 1.1% proliferative diabetic retinopathy (PDR), identified by the comprehensive examination for the right eyes. This modality also identified 18.5% NPDR, and 1.3% PDR, for the left eyes. There was 23.8% nonproliferative diabetic retinopathy (NPDR), and 1.4% proliferative diabetic retinopathy (PDR) identified by retinal photography for the right eyes. This modality also identified 22.6% NPDR, and 1.3% PDR for the left eyes. The sight-threatening cases were identified by both modalities with approximately 3% for both eyes. The photography had moderate agreement (K = 0.5, both eyes) with the comprehensive examination for the identification of diabetic macular edema with 78.6% and 68.8% sensitivity for the right and left eyes. For the identification of moderate NPDR, severe NPDR, and PDR, the photography had substantial agreement (K = 0.7, both eyes) with 88.2% and 83.3 sensitivity for the right and left eyes. CONCLUSIONS: Trang province may have approximately 300 sight-threatening DR patients. This may project to 180,000 patients nationwide. Retinal photography may determine more cases than clinical examination. Combination of both modalities for DR identification may yield a closer estimate to the real prevalence.

The high-dose, alternate-week intravitreal ganciclovir injections for cytomegalovirus retinitis in acquired immune deficiency syndrome patients on highly active antiretroviral therapy.

OBJECTIVES: To evaluate the efficacy, and complications of the high-dose, alternate-week, intravitreal ganciclovir injection for cytomegaloviral retinitis (CMVR) in acquired immune deficiency syndrome (AIDS) patients on highly active antiretroviral therapy (HAART). DESIGN: Retrospective case series. PARTICIPANTS: AIDS patients with CMVR and on HAART MATERIAL AND METHOD: The high-dose, 4 mg/0.1 ml, ganciclovir was injected intravitreally to the enrolled patients on an alternate-week basis. The patients were monitored clinically until the retinitis was inactive, then the injections were withdrawn. The injections were re-initiated if relapse occurred. MAIN OUTCOME MEASURES: The number of eyes achieved inactive retinitis and corresponded to the number of injections, number of relapses and corresponded duration, visual acuity during the injection, and complications of the injection. RESULTS: Inactive lesions were found in 42/51 eyes (82.40%), the corresponding mean number of injections was 5.4 (1-18) per eye. There was no relapse and the corresponded duration of follow-up was 5.1 months (1-16). The final visual outcomes were improved or stable in 26 eyes (50.9%). These visual outcomes were statistically related to initial visual acuity (p = 0.022) but not statistically related to the number of injections (p = 0.929). Complications were found in 7/51 eyes (13.7%). They were vitreous haze, immune recovery uveitis, rhegmatogenous retinal detachment, and infectious endophthalmitis. CONCLUSION: The high-dose, alternate-week, intravitreal injection of ganciclovir may be an alternative for the treatment of CMVR in AIDS patients who are on HAART However, the induction course is longer than the weekly regimen and close monitoring of patients is essential.

The fundoscopic features for differentiation between polypoidal choroidal vasculopathy and choroidal neovascularization from age-related macular degeneration.

OBJECTIVES: To evaluate the fundus features that can differentiate polypoidal choroidal vasculopathy (PCV) from choroidal neovascularization (CNV) due to age-related macular degeneration (AMD). DESIGN: Retrospective, case-control study. MATERIAL AND METHOD: The fundoscopic features of AMD-related CNV and PCV were compared for evaluation of relative risks for PCV. The odds ratio, sensitivity and specificity of each feature were also calculated. RESULTS: A total of 30 patients, 15 PCV and 15 age-matched non-PCV cases, approved by indocyanine green angiography (ICG), were enrolled. The odds ratio is highest for subretinal polyp-like structure and lowest in scar formation (28 and 0, respectively) and these ratios are statistically significant differences (p = 0.001 and 0.032 respectively). The ratio for either circinate exudates, or larger than 4-disc area of subretinal fluid, or retinal pigment epithelial detachment is 1.75. The ratio for peripapillary location is 1.63. Subretinal membrane has a ratio of 1 while subretinal hemorrhage and subretinal fibrin have less than 1; they are 0.31 and 0.23 respectively. All these ratios are not statistically significant differences (p > 0.05). CONCLUSION: The orange polyp-like structures beneath retina are hallmarks for diagnosis of PCV. The "serosanguineous retinopathy", described as serous retinal deatchment or retinal pigment epithelial detachment with circinate exudates with or without subretinal hemorrhage at the posterior pole or peripapillary region, may also suggest the condition.

Screening for diabetic retinopathy in rural area using single-field, digital fundus images.

OBJECTIVE: To evaluate the practicability of using single-field, 2.3 million-pixel, digital fundus images for screening of diabetic retinopathy in rural areas. MATERIAL AND METHOD: All diabetic patients who regularly attended the diabetic clinic at Kabcheang Community Hospital, located at 15 kilometers from the Thailand-Cambodia border, were appointed to the hospital for a 3-day diabetic retinopathy screening programme. The fundi of all patients were captured in single-field, 45 degrees, 2.3 million-pixel images using nonmydriatic digital fundus camera and then sent to a reading center in Bangkok. The fundi were also examined through dilated pupils by a retinal specialist at this hospital. The grading of diabetic retinopathy from two methods was compared for an exact agreement. RESULTS: The average duration of single digital fundus image capture was 2 minutes. The average file size of each image was 750 kilobytes. The average duration of single image transmission to a reading center in Bangkok via satellite was 3 minutes; via a conventional telephone line was 8 minutes. Of all 150 patients, 130 were assessed for an agreement between dilated fundus examination and digital fundus images in diagnosis of diabetic retinopathy. The exact agreement was 0.87, the weighted kappa statistics was 0.74. The sensitivity of digital fundus images in detecting diabetic retinopathy was 80%, the specificity was 96%. For diabetic macular edema the exact agreement was 0.97, the weighted kappa was 0.43, the sensitivity was 43%, and the specificity was 100%. CONCLUSION: The image capture of the nonmydriatic digital fundus camera is suitable for screening of diabetic retinopathy and single-field digital fundus images are potentially acceptable tools for the screening. The real-time image transmission via telephone lines to remote reading center, however, may not be practical for routine diabetic retinopathy screening in rural areas.

The Thai logarithmic visual acuity chart.

OBJECTIVE: To evaluate visual acuity scores from the Thai and the standard logarithmic visual acuity chart. DESIGN: Comparative non-randomized clinical study. PARTICIPANTS AND METHOD: 153 subjects, calculated from sample size estimation, without any ocular disease and aged between 18 and 80 years old who could read English and at least 3 out of 5 letters of the largest line of both charts were enrolled to use only their right eyes to read the Thai and the standard logarithmic visual acuity chart without any refractive correction. 27 subjects came back for second measurements of visual acuity in the same manner as the first a week later. MAIN OUTCOME MEASUREMENT: The visual acuity scores were divided into the Snellen or the whole line score and the ETDRS or the letter-by-letter score. The former was compared by weighted Kappa and the latter was compared by the paired t-test. RESULTS: There was high agreement in weighted Kappa between the Snellen scores from the Thai and standard chart (k = 0.7375). There was also high agreement in weighted Kappa between the Snellen scores from the first and second reading of the Thai chart (k = 0.7304) and the standard chart (k = 0.7282). A high correlation was observed between the ETDRS scores from the Thai and standard charts (r = 0.947). Also there was a high correlation between the ETDRS scores of the first and second reading of both the Thai chart (r = 0.962) and the standard chart (r = 0.952). There was a significant difference between the ETDRS scores from the Thai and standard chart (p<0.0001). There was no significant difference between the ETDRS scores from the first and second reading of either the Thai chart (p = 0.794) or the standard chart (p = 0.62). CONCLUSION: The Snellen visual acuity score from the Thai chart is comparable to the standard chart. Although the ETDRS score from the Thai chart is different statistically from the standard chart, its test-retest variability tends to be low. This suggests the possibility of using the Thai chart for monitoring of the ETDRS score in research studies.