Penetrating keratoplasty for keratoconus: a long-term review of results and complications

Journal ArticlePURPOSE: To study the long-term complications of penetrating keratoplasty (PKP) to evaluate current recommendations to patients with keratoconus. SETTING: John Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Retrospective study of all PKP procedures for keratoconus performed by 4 surgeons during a 312 year period. Follow-up was 1 day and 1, 3, 6, 12, and 24 months post-PKP. Data from 93 eyes were reviewed for allograft reaction, astigmatism, visual acuity, reasons for decreased visual acuity, and other complications. RESULTS: Allograft reaction was seen in 31% of cases but no graft failure due to allograft reaction. Mean astigmatism was 2.76 diopters (D) +/- 1.99 (SD) at 24 months, with only 15% > 5.00 D. Last best corrected visual acuity was 20/25 or better in 77% of cases (87% had 20/25 or better at some time during follow-up). Complications that did not cause decreased visual acuity were noted. Punctate keratitis was noted in 20% of patients 180 days or more after surgery. CONCLUSIONS: Penetrating keratoplasty is a good treatment option for patients with keratoconus but should be reserved for those who do not tolerate contact lenses or do not get needed visual acuity with contact lenses because of complications. This procedure has become a second-line treatment for keratoconus patients and has generally good results

Pilot Study for OCT Guided Design and Fit of a Prosthetic Device for Treatment of Corneal Disease

Purpose. To assess optical coherence tomography (OCT) for guiding design and fit of a prosthetic device for corneal disease. Methods. A prototype time domain OCT scanner was used to image the anterior segment of patients fitted with large diameter (18.5–20 mm) prosthetic devices for corneal disease. OCT images were processed and analyzed to characterize corneal diameter, corneal sagittal height, scleral sagittal height, scleral toricity, and alignment of device. Within-subject variance of OCT-measured parameters was evaluated. OCT-measured parameters were compared with device parameters for each eye fitted. OCT image correspondence with ocular alignment and clinical fit was assessed. Results. Six eyes in 5 patients were studied. OCT measurement of corneal diameter (coefficient of variation, %), cornea sagittal height (%), and scleral sagittal height (%) is highly repeatable within each subject. OCT image-derived measurements reveal strong correlation between corneal sagittal height and device corneal height () and modest correlation between scleral and on-eye device toricity (). Qualitative assessment of a fitted device on OCT montages reveals correspondence with slit lamp images and clinical assessment of fit. Conclusions. OCT imaging of the anterior segment is suitable for custom design and fit of large diameter (18.5–20 mm) prosthetic devices used in the treatment of corneal disease