Abstract
PURPOSE: To characterize patients with suspected glaucoma who were referred to the clinic for suspected glaucoma in a tertiary public hospital in southern Brazil and to evaluate differences in functional and structural damages between patients diagnosed with different types of glaucoma, those with normal eye examination results, and those who remained as glaucoma suspects. METHODS: This is a cohort study of patients referred by general ophthalmologists to the clinic for suspected glaucoma at Hospital Nossa Senhora da Conceição, Porto Alegre, Brazil, between March 2016 and December 2018. The patients were followed up until they had undergone reliable examinations (eye examination, visual field screening, and optic coherence tomography for classification as normal and having a suspected glaucoma, glaucoma with an elevated intraocular pressure, normotensive glaucoma, or ocular hypertension. RESULTS: A total of 135 patients were included in this study. Of the patients, 117 subjects completed all examinations and met the inclusion criteria. Most patients were normal (36.8%), followed by those with suspected glaucoma (25.64%), normal tension glaucoma (18.8%), glaucoma with elevated intraocular pressure (12%), and ocular hypertensive (6%). The main reason for referral was increased optic nerve head cupping. The patients with normal tension glaucoma were older than the other subjects on average (p=0.03). In addition, the normal tension glaucoma group had a significantly worse baseline visual field index and mean deviation of the visual field than the normal, glaucoma suspect, and ocular hypertensive groups. The circumpapillary retinal nerve fiber layer on OCT was thinner on average in the normal tension glaucoma group than in the normal and glaucoma suspect groups (p<0.002) but did not significantly differ between the glaucoma group with elevated intraocular pressure and the other groups. CONCLUSIONS: Patients with normal tension glaucoma tend to be diagnosed later because of their normal intraocular pressures; thus, the optic nerve cupping must be greater to raise the suspicion of glaucoma. In this study, we found that the patients with normal tension glaucoma had worse disease at the time of diagnosis.