Permanent ocular remodeling in the setting of chronic hypotony after trabeculectomy: A case report

Abstract

Purpose: Trabeculectomy surgery is a commonly performed procedure for treatment of glaucoma. While the goal is to lower intraocular pressure, over-filtration may cause hypotony with ocular structural changes and vision loss.

Observations: A 53-year-old woman with primary open-angle glaucoma was referred to our service for further evaluation. The patient previously underwent trabeculectomy 9 years prior and was found to have a cataract and hypotony maculopathy in the right eye. Treatment options included cataract surgery alone, bleb revision alone, or combined cataract extraction and bleb revision. Biometry revealed corneal astigmatism in the right eye, and significant disparity in axial length between the two eyes. Since the axial length and corneal astigmatic changes were presumed to be at least partially reversible, measurements from the non-operative left eye influenced the lens selection for the hypotonous right eye. The patient underwent combined phacoemulsification and bleb revision. While IOP increased and hypotony was partly reversed, there was hyperopic and astigmatic refractive surprise after surgery.The patient subsequently underwent intraocular lens exchange using biometric values of the previously hypotonous eye and met the target post-operative refractive goal.

Conclusions and importance: This case demonstrates changes to the axial length and ocular structure following longstanding hypotony maculopathy may be permanent, even after restoration of normotensive intraocular pressure.

Keywords: Glaucoma; Hypotony; Intra-ocular lens; Trabeculectomy.

Fig. 1

Pre-bleb revision and cataract extraction. Baseline testing prior to cataract extraction and trabeculectomy revision. A) Photograph taken at the start of surgery for bleb revision and cataract extraction showing avascular bleb. Corneal light shield in place B) Optical coherence tomography of the macula showed choroidal folds. C) Ocular biometry showed significant differences in axial length and corneal astigmatism between fellow eyes (right eye had chronic hypotony).

Fig. 2

Post-bleb revision and cataract extraction. A) After revision, the bleb was low, diffuse, and without ischemia. B) Optical coherence tomography of the macula showed an incomplete improvement in choroidal folds. C) Ocular biometry measurements showed a slight increase in axial length and reduction in corneal astigmatism in the right eye.