Small Incision Lenticule Extraction for Postkeratoplasty Myopia and Astigmatism

Abstract

Purpose. To evaluate the visual and refractive outcomes after small incision lenticule extraction (SMILE) for treating myopia and myopic astigmatism after penetrating keratoplasty (PKP). Design. Case-series. Methods. Ten eyes of 10 patients with previous PKP and residual myopic astigmatism for whom pentacam imaging and thickness measurements were acceptable for laser vision correction. Manifest refraction (MR), uncorrected distance visual acuity (UDVA), and corrected distance visual acuity (CDVA) were obtained preoperatively and one day, one week, and one, 3, and 6 months postoperatively. Cases were operated on the VisuMax® femtosecond laser platform with 500 kHz repetition rate. Results. The mean correction ratio for spherical errors was 0.84 ± 0.19 D and for the mean refractive spherical equivalent (MRSE) was 0.79 ± 0.13 D. Vector analysis showed a mean astigmatism reduction at the intended axis of 67 ± 25.25%, a correction index of 0.81 ± 0.21, and an overall mean percentage of success of astigmatism surgery of 53 ± 37.9%. The postoperative MRSE was stable throughout the 6-month follow-up period. The efficacy index was 0.93 and the safety index was 1.12. Conclusion. SMILE for correction of post-PKP myopia and astigmatism is effective, safe, and stable with moderate accuracy and predictability. Centration of the treatment within the grafts was easily performed.

SMILE after DALK to reduce residual refraction: two-year results

“…The mean CDVA improved from 0.23 LogMAR to 0.13 LogMAR indicating an acceptable safety index (1.53). In the study by Massoud et al (10), CDVA reduced from 0.73 LogMAR to 0.82 LogMAR 6 months after the procedure, safety index was 1.12, but none of the cases experienced a reduction in CDVA. However, in the present study, CDVA reduced in one of the patients in the rst month, which improved gradually from the 3rd month to the 24th month.…”

“…Several surgical and non-surgical methods have been used to manage this complication, which either did not have an acceptable effectiveness or were associated with serious consequences. According to the literature, there is no standard method for treatment of post-keratoplasty refractive error (10). On the other hand, SMILE, as a safe, e cacious, predictable, and stable method for correction of myopic and astigmatic error (14-16), has raised hopes for nding a new method for correction of high residual refractive error after keratoplasty.…”

“…Although the present study had a small sample size and a single-arm design without a control group, the results provide valuable information regarding the application of this procedure for correction of post-DALK residual refractive error. Massoud et al (10) reported that the short-term (6-month) results of this procedure were acceptable in patients with a history of PK that had high myopia (mean: 6.8 D) and moderate astigmatism (mean: 3.1 D).…”

“…In these cases, although the postoperative UDVA did not reached to preoperative CDVA, it improved 1 to 4 lines. Massoud et al (10) reported a 6-month e cacy of 0.93. The difference might be due to the shorter follow-up duration.…”

“…The safety and e cacy of this procedure have been con rmed as well (8, 9). To the best of our knowledge, only one study reported the 6-month results of this procedure in post-PK patients (10).…”