Evaluation of retinal nerve fiber layer thickness in eyes with hypertensive uveitis.

Abstract

Uveitic glaucoma is among the most common causes of irreversible visual loss in uveitis. However, glaucoma detection can be obscured by inflammatory changes. To determine whether retinal nerve fiber layer (RNFL) measurement can be used to detect glaucoma in uveitic eyes with elevated intraocular pressure (IOP). Comparative case series of RNFL measurement using optical coherence tomography performed from May 1, 2010, through October 31, 2012, at a tertiary referral center. We assigned 536 eyes with uveitis (309 patients) in the following groups: normal contralateral eyes with unilateral uveitis (n = 72), normotensive uveitis (Uv-N) (n = 143), raised IOP and normal optic disc and/or visual field (Uv-H) (n = 233), and raised IOP and glaucomatous disc and/or visual field (Uv-G) (n = 88). Eyes with uveitis and elevated IOP (>21 mm Hg) on at least 2 occasions. Comparison of RNFL values between groups of eyes and correlation with clinical data; risk factors for raised IOP, glaucoma, and RNFL thinning. Mean (SD) global RNFL was thicker in Uv-N (106.4 [21.4] µm) compared with control (96.0 [9.0] µm; P < .001) eyes and was thicker in Uv-N eyes with active (119.6 [23.2] µm) compared with quiescent (102.3 [20.8] µm; P = .001) uveitis, which in turn was not significantly different from control eyes (P = .07). Compared with Uv-N eyes, significant RNFL thinning was seen in all quadrants except the temporal in Uv-G eyes and significant thinning in the inferior quadrant of Uv-H eyes with no evidence of disc or visual field changes (P = .03). Risk factors for elevated IOP were male sex and anterior uveitis. Age, higher peak IOP, longer duration of follow-up, and uveitis-induced elevation of IOP were risk factors for glaucoma and RNFL defect. Screening for glaucomatous RNFL changes in uveitis must be performed during quiescent periods. Thinning of the inferior quadrant suggests that glaucomatous damage, more than uveitic ocular hypertension, is in fact occurring. Measurement of RNFL may detect signs of damage before disc or visual field changes and therefore identifies a subgroup that should receive more aggressive treatment.