Escalating treatment for glaucoma increases the risk of PK graft failure, study finds

Escalating treatment for glaucoma in patients who had undergone penetrating keratoplasty significantly increases the risk of graft failure and a poor final visual outcome, according to a retrospective study by researchers in Saudi Arabia.

Mansour Al-Mohaimeed, MD, and colleagues reviewed data for 715 eyes in 678 patients who underwent PK at King Khaled Eye Specialist Hospital in Riyadh over a 2-year period. The investigators evaluated the prevalence and risk factors of escalation of glaucoma therapy as well as the effects on graft survival.

Over 32.2 months mean follow-up, treatment for glaucoma escalated in 89 eyes (12.4%). "Medical escalation accounted for 73 (82%) cases, whereas surgical escalation occurred in 16 (18%) eyes," the authors reported.

The researchers found that the surgical indication for PK (P < .001), increasing patient age (P < .001), pre-existing glaucoma (P < .001), recipient trephination (P = .02) and being either pseudophakic or aphakic (P < .001) were all significantly associated with an increased risk of glaucoma therapy escalation, according to the study.

Eyes in which glaucoma therapy escalated also had a significant reduction in graft survival, with 52.8% of grafts surviving among these eyes compared with 82.9% of eyes without treatment escalation.

Additionally, increased treatment for glaucoma significantly affected final visual acuity. Only 9% of eyes in the escalated treatment group achieved a visual acuity of 20/40 or better compared with 42.1% of eyes that did not require an increase in treatment (P < .001), and 70.8% of eyes in the escalated treatment group achieved a visual acuity of 20/200 or worse compared with 26.7% of non-escalated cases (P < .001), according to the study, published in the December issue of Ophthalmology.