Glaucoma treatment increases graft failure risk

Escalating treatment for glaucoma patients who have undergone penetrating keratoplasty (PK) significantly increases the risk of graft failure and poor visual outcomes, according to a report published in the December 2007 issue of Ophthalmology.

Mansour Al-Mohaimeed, MD and colleagues from the King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia and the University of Iowa Hospitals and Clinics, Iowa City, USA reviewed the data for 715 eyes of 678 patients who had undergone PK at the King Khaled Eye Specialist Hospital over a two-year period. The prevalence and risk factors of escalation of glaucoma therapy and the effects on graft survival were evaluated.

Over a mean follow-up period of 32.2 months, treatment for glaucoma escalated in 89 eyes (12.4%). Medical escalation accounted for 73 (82%) cases and surgical escalation occurred in 16 (15%) eyes. The surgical indication for PK (p<0.001), increasing patient age (p<0.001), pre-existing glaucoma (p<0.001), recipient trephination (p=0.02) and being either pseudophakic or aphakic (p<0.001) were all significantly associated with an increased risk of glaucoma therapy escalation.

Eyes in which glaucoma therapy did escalate also had a significant reduction in graft survival, with 52.8% of grafts surviving among these eyes compared with 82.9% of eyes with treatment escalation. Furthermore, increased treatment for glaucoma significantly affected final visual acuity (VA). Just 9% of eyes in the escalated treatment group achieved a VA of 20/40 or better compared with 42.1% of eyes that did not require an increase in treatment.

The results of this study suggest that escalating treatment for glaucoma patients who have undergone PK, can significantly increase the risk of poor visual outcomes and graft failure.