Association between central corneal thickness, intro ocular pressure and visual field changes in primary open angle glaucoma

Abstract

Background and Aim: Primary open angle glaucoma (POAG) suspects are individuals with at least one of the following features in one or both eyes like suspicious cupping of optic disc/ visual field defect suspicious for glaucomatous damage/elevated intraocular pressure in the presence of normal optic disc, visual fields. Our objective is to correlate Central corneal thickness, intraocular pressure & Visual field changes in patients diagnosed as the POAG suspects. In order to accurately identify patients at risk of developing glaucoma so that treatment of high-risk individuals can be considered to prevent/delay the development of POAG. Material and Methods: It was a prospective comparative study conducted at tertiary care institute of Gujarat after taking ethical approval of the institutional ethical committee. The study included 300 eyes of 150 patients who attended the outpatient department over a period of 1 year. Slit lamp bio microscopy, ultrasound pachymetry was done to measure CCT and IOP was measured with Goldman applanation tonometer the visual field assessment was done with the octopus field analyzer. Results: The mean CCT was 521.12± 23.10 µm, 524.67±22.42 µm among females, males respectively. The mean uncorrected IOP (GAT) was 19.34 mm Hg and 20.01 mmHg on right, left sides respectively statistically significant (P≤0.05). Highest percentage of abnormal visual field changes was seen in eyes with low CCT (<510µm) (P≤0.05). Mean corrected IOP reading was 21.78 mmHg for the 23 patients with abnormal visual fields on right side and this was statistically significant at P≤0.05. Conclusion: Thinner corneal readings in population especially when presenting at younger age should alarm the ophthalmologist to evaluate the patient thoroughly for glaucoma and should be followed up for the progression of glaucoma. CCT is one factor that is necessary to adjust IOP to achieve a more accurate IOP and it allows monitoring for the risk of progression to be more precise.