Purpose: The aim was to study the outcomes and results of therapeutic penetrating keratoplasty (Th PK) at a tertiary eye care hospital in northern India.
Methods: In this retrospective interventional study, a cohort of 506 eyes that underwent a Th PK for microbial keratitis was evaluated. Th PK was performed in cases of recalcitrant microbial keratitis with impending perforation (descemetocele formation) or perforation (>3 mm). Medical records were reviewed for demographic details, risk factors, ulcer and perforation size, microbiological investigations, size of donor and recipient beds, postoperative complications, and anatomical and visual outcomes.
Results: Anatomical success was seen in 454 eyes (89.7%). Preoperatively, the corrected distance visual acuity was <3/60 in 495 eyes (97.8%); after performing the Th PK, the corrected distance visual acuity was <3/60 in 249 eyes (49.2%), 3/60 to 6/60 in 182 eyes (35.9%), and >6/60 in 75 eyes (14.8%). Eyes with smaller grafts (<9 mm) had better anatomical and visual outcomes compared with eyes with larger grafts (9-11 mm; P = 0.03 and >11 mm; P = 0.0). A higher success rate was achieved with pure bacterial or fungal organisms rather than with mixed infections. A higher incidence of secondary glaucoma was seen in eyes with perforated ulcers (29.36%; 111/378) than in eyes without perforation (11.71%; 15/128) (P <.01) and in eyes with larger graft sizes (>11 mm and 9-11 mm) than in eyes with smaller graft sizes (<9 mm) (P <0.01).
Conclusions: Th PK has a definitive role in the management of severe and refractory keratitis with a high success in restoring anatomical integrity and providing useful vision. Better outcomes may be achieved with early intervention before perforation or limbal/scleral extension.