Abstract
Abstract: :
Purpose:To present results of a community-based glaucoma screening using the FDT, IOP and undilated direct ophthalmoscopy. Methods:226 African Americans were screened. Mean age 43.27 years (range 6-83), 111 (49.1%) women. Screening included FDT perimetry, Goldmann tonometry and direct ophthalmoscopy. Overall pass/fail criteria was based on failing any of three portions: IOP greater than 21 mm Hg; signs of glaucomatous optic nerve damage (focal rim loss, cupping equal to or greater than 0.6, flame hemorrhage); two points flagged at any probability level on FDT C 20-1 screening test for two repeat tests with one repeatable point. All subjects who failed initial screening were offered an immediate reexamination which consisted of IOP, dilated stereoscopic optic nerve evaluation and Humphrey 24-2 SITA STD perimetry. Failure criteria for reexamination were visual field defect defined as 3 points flagged in cluster in one hemifield with at least 1 point at the 0.5% level or signs of optic nerve damage. Results::63 (27.8%) individuals failed general screening, 5 (2.1%) were unable to complete screening, and 8 (3.5%) had a diagnosis of glaucoma before screening began. Of the 63 individuals (118 eyes) failing the screening, 53 of 118 (44.9%) eyes failed FDT, 69 of the 118 (58.5%) failed ophthalmoscopy, and 32 of the 118 (27.1%) failed tonometry. 22 (41 eyes) subjects took part in the re-examination. Of these, 16 eyes originally failed FDT and 14 of the 16 gave abnormal visual fields. 31 eyes failed ophthalmoscopy of which 28 also failed a dilated repeat examination. 10 of the 10 eyes that failed tonometry were found to have raised IOP on re-examination. 13 of 41 reexamined eyes (31.2%) were found to have glaucoma, 5/41 (12.2%) to have ocular hypertension and 16/41 (39%) with suspicious optic nerves. In total, 34 of 41 eyes (82.9%) were found to either have or be at risk for glaucoma. Conclusion: Approximately 28% of individuals failed this glaucoma screening. Nearly half that failed were identified by a screening FDT and more than half by direct ophthalmscopy. The accuracy of the positive screening results were very high as judged by the rate of positive reexamination results. The estimated total number of eyes with glaucoma, extrapolated from the positive reexamination results was 38 of 118 screening failures, giving an estimated prevalence of 7.96%.
Keywords: 624 visual fields • 498 optic disc • 357 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials