Changes in Corneal Thickness in Patients With Treated and Untreated Ocular Hypertension :

To estimate age- and gender-specific prevalences of ocular hypertension and open-angle glaucoma (OAG) in adult Latinos. Population-based, cross-sectional study. Six thousand three hundred fifty-seven Latinos 40 years and older from 6 census tracts in Los Angeles, California. The study cohort consisted of all self-identified Latinos of primarily Mexican ancestry 40 years and older residing in 6 census tracts in La Puente, California. All participants underwent a complete ophthalmologic examination, including measurement of intraocular pressure (IOP), visual field (VF) testing using an automated field analyzer, and simultaneous stereoscopic fundus photography of the optic disc. Ocular hypertension was defined as IOP of >21 mmHg and the absence of optic disc damage or abnormal VF test results. Open-angle glaucoma was defined as the presence of an open angle and various criteria that included a glaucomatous VF abnormality and/or evidence of glaucomatous optic disc damage in at least one eye. Prevalence of open-angle glaucoma and ocular hypertension. For the 6142 participants who underwent a complete ophthalmologic examination at the clinical center, the prevalence of OAG was 4.74% (95% confidence interval [CI], 4.22%-5.30%). The prevalence of ocular hypertension was 3.56% (95% CI, 3.12%-4.06%). The prevalences of OAG and ocular hypertension were higher in older Latinos than in younger Latinos (P<0.0001). No gender-related differences in prevalences of OAG and ocular hypertension were present. The mean IOP, mean deviation, and mean vertical cup-disc ratio in persons with OAG were 17 mmHg, -9.6 decibels, and 0.6, respectively. Seventy-five percent of Latinos with OAG and 75% of Latinos with ocular hypertension were previously undiagnosed. Further, 17% of Latinos with OAG and 23% of Latinos with ocular hypertension had received treatment for "glaucoma." Our data suggest that the prevalence of OAG is high among Latinos of Mexican ancestry. The higher prevalence of OAG in older Latinos emphasizes the public health importance of providing eye care services for the early diagnosis and management of this condition in Latinos.

To perform a cross-sectional study on the distribution of central corneal thickness and its association with intraocular pressure in an elderly population. We measured central corneal thickness and intraocular pressure in 395 subjects (352 control subjects, 13 patients with ocular hypertension, and 30 patients with primary open-angle glaucoma) aged 55 years or more. Mean central corneal thickness in the 352 control subjects was 537.4 microm (95% confidence interval [CI], 533.8 to 540.9 microm; range, 427 to 620 microm), with a maximal difference between eyes of 42 microm. There were no differences between sexes and no significant association with age. Linear regression analysis showed an increase of 0.19 mm Hg in intraocular pressure with each 10-microm increase in central corneal thickness (95% CI, 0.09 to 0.28 mm Hg). This association was similar in both eyes and in both sexes. The 13 patients with ocular hypertension had corneas a mean of 16.0 microm thicker (95% CI, -2.6 to +34.6 microm) compared with control subjects (P = .093); the 30 patients with primary open-angle glaucoma had corneas a mean of 21.5 microm thinner (95% CI, 8.8 to 34.1 microm) compared with control subjects (P = .001). Mean central corneal thickness was similar to that found in clinical studies, was slightly higher in patients with ocular hypertension, and was significantly lower in patients with primary open-angle glaucoma. Intraocular pressure was positively related with central corneal thickness. Central corneal thickness may influence the division between normal and increased intraocular pressure at a simple cutoff point of 21 mm Hg.

To determine the relationship between central corneal thickness (CCT) and applanation intraocular pressure (IOP) in normal, glaucomatous, and ocular hypertensive eyes. One hundred nine subjects (184 eyes) were studied. Forty-eight patients (74 eyes) had glaucoma, 28 patients (51 eyes) had ocular hypertension, and 33 patients (59 eyes) were normal. Intraocular pressure as measured by applanation tonometry, refractive status, CCT, and axial length were measured for all subjects. The CCT (mean +/- SD) of eyes with ocular hypertension was significantly greater (0.606 +/- 0.041 mm) than that of glaucomatous eyes (0.554 +/- 0.022 mm) (P < .001) or of normal controls (0.561 +/- 0.026 mm) (P < .001). There was no significant difference in CCT between normal and glaucomatous eyes (P = .40). The axial length (mean +/- SD) of eyes with ocular hypertension (23.54 +/- 1.34 mm) was not different compared with glaucomatous eyes (23.93 +/- 0.96 mm) (P = .13) or normal eyes (23.62 +/- 1.21 mm) (P = .83). There was no significant difference between the axial length for glaucomatous eyes compared with normal eyes (P = .18). Those eyes with glaucoma being treated with topical dorzolamide hydrochloride had a significantly increased CCT (0.560 +/- 0.025 mm) compared with those eyes with glaucoma not being treated with dorzolamide (0.551 +/- 0.20 mm) (P = .02). The mean CCT is increased in eyes with ocular hypertension when compared with normal or glaucomatous eyes, which confirms the findings of other investigators. Increased CCT may give an artificially high IOP measurement by applanation tonometry. The CCT must be considered when developing a treatment approach for patients with ocular hypertension.