Ultrasound biomicroscopy in opaque grafts with post-penetrating keratoplasty glaucoma

To evaluate the anterior segment in opaque grafts with post-penetrating keratoplasty glaucoma (PPKG) by using ultrasound biomicroscopy (UBM).

An observational clinical case series of patients with opaque corneal grafts with PPKG who underwent UBM examination of the anterior chamber is reported. Indication for keratoplasty, lens status, intraocular pressure at the time of presentation, and the time of diagnosis of glaucoma were noted. Examination included slit-lamp biomicroscopy, posterior-segment ultrasound evaluation, and UBM evaluation of the anterior segment.

Thirty-one eyes of 31 patients with PPKG were recruited into the study. The mean intraocular pressure was 35.5 +/- 5.8 mm Hg (range, 26-52 mm Hg). The mean time of follow-up after penetrating keratoplasty was 6.97 +/- 2.98 months (range, 2-16 months). Of the 31 patients, 11 had undergone penetrating keratoplasty for therapeutic purposes (infectious keratitis), whereas the remaining 20 had undergone keratoplasty for optical reasons. Fourteen (45.1%) patients were pseudophakic, 13 (41.9%) were aphakic, and 4 (12.9%) were phakic. The types of synechiae noted on the UBM included peripheral anterior synechiae in 30/31 (96.7%) eyes, synechiae at the graft-host junction in 13/31 (41.93%) eyes, both peripheral anterior synechiae and graft-host junction synechiae in 12/31 (38.7%) eyes, central iridocorneal synechiae in 6/31 (19.3%) eyes, and intraocular lens iris synechiae in 3/31 (9.6%) eyes.

Secondary angle closure caused by anterior synechiae formation is one of the important causes of PPKG in eyes with opaque grafts. UBM serves as a useful tool for anterior-segment evaluation in such cases and can help in planning the site for glaucoma filtering surgeries and drainage devices.