Transscleral Cyclophotocoagulation for Refractory Intraocular Pressure Elevation After Penetrating Keratoplasty

Transscleral cyclophotocoagulation significantly reduces intraocular pressure and anti-glaucomatous medication use post-penetrating keratoplasty, with low hypotony risk, particularly if delayed. Safe reintervention is feasible for intraocular pressure recurrence.

Transscleral cyclophotocoagulation (TSCPC) is an established procedure for lowering intraocular pressure (IOP). We aimed to evaluate the therapeutic efficacy and the safety of TSCPC in patients with refractory IOP elevation after penetrating keratoplasty (PK), as well as to identify risk factors associated with postoperative hypotony.

TSCPC was performed in 52 eyes with inadequate pressure regulation despite maximal conservative therapy after PK. All the patients were reviewed on day 1, 1 month, 6 months, and 1 year after the TSCPC. A diagnosis of hypotony was considered if the IOP was <6 mm Hg at any time postoperatively. Multivariate analysis was applied to identify risk factors for hypotony and elevated IOP recurrence.

The IOP value decreased significantly from the median baseline of 29.1±0.7 mm Hg to 15.1±0.8 mm Hg at 1-year follow-up. The number of anti-glaucomatous medications was significantly reduced 1 year after TSCPC (2.9±0.1 vs. 2.4±0.2; P <0.01). Only 6 (11.5%) patients developed transitory hypotony. The mean time between PK and TSCPC was significantly lower ( P <0.01) in patients who developed hypotony (5.8±2.2 vs. 28.9±5.7 mo). A total of 53.8% of cases had a relapse of IOP increase at any time point during the follow-up. Reintervention with TSCPC was performed in 42.4% of patients.

TSCPC after PK significantly reduces IOP and the number of anti-glaucomatous medications. The rate of postoperative hypotony is low. Patients with shorter time intervals between PK and TSCPC are at higher risk of developing hypotony. TSCPC can be safely reperformed in patients after PK.