Key parameters identified for improved visual outcomes in post-keratoplasty astigmatism surgery
Femtosecond laser-assisted arcuate keratotomy (FSAK) shows promise in improving visual outcomes for individuals with post-keratoplasty astigmatism, according to a study.
The retrospective analysis included 106 eyes from 104 patients. The majority of cases (89.4%) were attributed to keratoconus (KC), with other conditions such as scar, granular dystrophy, post-LASIK ectasia, and macular dystrophy also represented.
Key findings from the study demonstrated an improvement in uncorrected visual acuity (UCVA) from 1.02±0. to 0.87±0.49 at 3 months and to 0.92±1.08 at 17 months. Best spectacle-corrected visual acuity (BSCVA) also saw improvement from 0.41±0.30 to 0.31±0.19 at 3 months and to 0.23±0.27 at 17 months.
The success rate, defined as an improvement of ≥3 lines on the Early Treatment Diabetic Retinopathy Study (ETDRS) chart, was achieved in 50% (n = 53) at the 3-month follow-up and 49% (n = 52) at the 17-month follow-up. The success group exhibited worse preoperative UCVA (1.21±0.56 vs 0.83±0.44) and worse preoperative BSCVA (0.50±0.36 vs 0.33±0.19).
The study identified a preoperative UCVA cutoff point of 0.90 (equivalent Snellen 20/159) as optimal for predicting success, with 76.9% sensitivity and 35.2% specificity.
The analysis of tomographic parameters revealed a flattening index (FI) of 87% in deep anterior lamellar keratoplasty (DALK) compared to 73% in penetrating keratoplasty (PKP). The correction index was 99% for DALK and 86% for PKP. The success rates for astigmatic surgery in DALK and PKP were 44% and 42%, respectively.
Reference
Alsaif BA, Al Somali A, Banaji SH, Alshaibani AK. Vector Analysis and Prognostic Factors for Femtosecond Arcuate Keratotomy in Post-Keratoplasty Astigmatism. Clin Ophthalmol. 2023;17:3747-3759. doi: 10.2147/OPTH.S429264. PMID: 38089650; PMCID: PMC10712245.
