Influence of overhanging bleb on corneal higher‐order aberrations after trabeculectomy

Abstract

Recent advances in ocular aberrometry have revealed that ocular surgery increases ocular and corneal higher‐order aberrations. This retrospective single‐center study aimed to examine the effects of the overhanging bleb on corneal higher‐order aberrations using a wavefront analyzer. We included 61 eyes from 50 patients with overhanging bleb after trabeculectomy with a fornix‐based conjunctival flap using mitomycin C (overhanging bleb group) and 65 eyes from 54 glaucoma patients with no history of glaucoma surgery (control group). Corneal higher‐order aberrations (total higher‐order aberrations, coma aberrations, coma‐like aberrations, spherical aberrations, and spherical‐like aberrations) on a 4 mm pupil diameter were measured using the TOPCON KR‐1W wavefront analyzer. Corneal coma aberrations were higher in the overhanging bleb group than in the control group (0.16 ± 0.13 μm and 0.10 ± 0.05 μm, respectively; p = 0.042). Corneal coma‐like aberrations were also higher in the overhanging bleb group than in the control group (0.31 ± 0.32 μm and 0.16 ± 0.09 μm, respectively; p = 0.022). With an increasing ratio of cornea covered by the bleb to the entire cornea, all corneal higher‐order aberrations increased except for corneal coma‐like aberrations. Overhanging bleb after trabeculectomy with a fornix‐based conjunctival flap using mitomycin C and its size influenced corneal higher‐order aberrations.