Frequency of hypotonic maculopathy observed by spectral domain optical coherence tomography in post glaucoma filtration surgery eyes

Abstract

PurposeTo report the frequency of post glaucoma filtration surgery hypotonic maculopathy determined by spectral domain optical coherence tomography (SD-OCT). MethodsA cross-sectional retrospective observational study. Post glaucoma filtration surgery patients whose intraocular pressures (IOP) achieved 30% reduction from baseline or was controlled to IOP <14 mm Hg and had SD-OCT images and fundus photographs were enrolled. Hypotonic maculopathy was diagnosed independently on SD-OCT images and on fundus photographs. Results112 eyes of 88 patients were included in this study. 17 eyes of 14 patients were diagnosed with hypotonic maculopathy on SD-OCT images (17/112, 15.2%). Among these eyes, only 3 eyes were also diagnosed with hypotony maculopathy on fundus photography. Hypotonic maculopathy on SD-OCT was found only in eyes with IOP ≤10 mm Hg. (17.4% in eyes with IOPs between 7 and 10 mm Hg, and 22.7% in eyes with IOP ≤ 6 mm Hg). Associations with age, sex, central corneal thickness, refractive error, IOP reduction rate and interval between surgery and OCT acquisition were not significant (P > 0.05). ConclusionIn most cases, hypotonic maculopathy detected by SD-OCT were not recognizable on fundus photographs. Hypotonic maculopathy was detected not only in eyes with conventional ocular hypotony (IOP < 6 mm Hg) but also in eyes with IOP between 7 and 10 mm Hg.