In the present study, a case of diffuse lamellar keratitis after trabeculectomy in a patient who had received laser in situ keratomileusis many years prior is reported.

A 54-year-old male diagnosed with binocular primary open-angle glaucoma underwent trabeculectomy in the left eye because of poor intraocular pressure control and visual field defect progression even with maximal medical treatments. Faint, non-progressing subepithelial opacities pre-existed in the left cornea but no treatment was administered. The patient had a history of laser in situ keratomileusis in both eyes 12 years prior. On the first postoperative day, conjunctival buttonhole was found and because leaking from the hole continued, topical steroid was discontinued on the fourth postoperative day. On the seventh postoperative day, diffuse lamellar keratitis developed on the central cornea without intraocular pressure elevation, and diffuse infiltration under the corneal flap was observed in the anterior segment on optical coherence tomography. The patient was treated with topical steroid eye drops every 3 hours for the first 2 days and the frequency was increased to every hour because the keratitis did not improve. On the ninth postoperative day, keratitis began to improve and 2 months postoperatively, subepithelial lamellar infiltration improved significantly but did not show complete remission.

Diffuse lamellar keratitis can develop in an eye with laser in situ keratomileusis after trabeculectomy if appropriate treatment with topical steroid eye drops is not administered.