Evaluation Of Changes In Intraocular Pressure And Incidence Of Glaucoma Following Endothelial Keratoplasty

C. Robinson, MD
S. Pramanik, MD, K.M. Goins, MD, J.E. Sutphin, MD, W.L. Alward, MD, E.C. Greenlee, MD, Y.H. Kwon, MD, PhD, sponsors

Purpose: To report the changes in intraocular pressure (IOP) and incidence of new or worsened ocular hypertension (OHTN) or glaucoma following endothelial keratoplasty. Secondary measures included BSCVA and central corneal pachymetry (CCT).

Methods: A retrospective, consecutive review of all patients undergoing DLEK and DSEK between 12/03 and 9/05, with a minimum of 3 months of postoperative follow-up was done. Baseline data included age, gender, BSCVA, preoperative IOP, preoperative CCT, preoperative diagnosis of OHTN or glaucoma, preoperative IOP medication regimen and preoperative glaucoma surgical history. IOP and other clinical outcome measures were collected at 1, 3, 6 and approximately 12 months postoperatively. All IOP measurements were collected with a Tono-pen. The development or worsening of OHTN or glaucoma was defined as the need for medical or surgical intervention for the treatment of elevated IOP.

Results: 57 eyes of 57 consecutive patients were evaluated with a mean age of 70.0±10.4 years. 34 (59.6%) were female and the average follow-up time was 8.0±4.0 months with a range of 3 to 16 months. Preoperatively, the mean BSCVA was 0.70±0.47 LogMAR (20/100), mean IOP was 15.7±4.0 mmHg, and mean CCT was 736.1±113.7µm. 13 (23%) of patients carried a diagnosis of OHTN or glaucoma: 9 required preoperative glaucoma medication and 6 had prior filtering surgery. There were 39 endothelial keratoplasties (38 DLEK, 1 DSEK) and 18 combined phacoemulsification cataract surgery with IOL and DLEK. The mean IOP difference from preoperative measurements was -0.6±5.1 mmHg at 1 month, 1.9±6.6 mmHg at 3 months, 1.2±7.5 mmHg at 6 months and -0.3±5.3 mmHg at 1 year. The mean CCT was 573.8±124.1 µm, 559.9±122.4 µm, 578.0±115.0 µm, and 587.4±143.0 µm at 1, 3, 6 and 12 months. The mean BSCVA was 0.55±0.29 LogMAR (20/70) at 1 month, 0.41±0.22 LogMAR (20/50) at 3 months, 0.34±0.19 LogMAR (20/44) at 6 months and 0.29±0.15 LogMAR (20/40) at 12 months. 16 (28%) patients developed or worsened pre-existing OHTN or glaucoma at the time of last followup; 7 out of 13 patients with a pre-existing diagnosis worsened and 9 out of 44 patients without a pre-existing diagnosis required treatment. Only 12 (23%) patients required an increased number of glaucoma medications from baseline or surgical intervention at the time of last follow-up.

Conclusions: Although endothelial keratoplasty results in a minimal change in IOP there is a moderate risk of the development of OHTN or glaucoma and worsening of pre-existing disease. This risk appears to be lower than the published risk for penetrating keratoplasty.

Support: Research to Prevention Blindness, University of Iowa Department of Ophthalmology Resident Research Fund