Risk factors for early flap misalignment following microkeratome-assisted laser in situ keratomileusis: A retrospective large database analysis.

PURPOSE: To determine factors associated with early flap misalignment following microkeratome-assisted laser in situ keratomileusis. MATERIALS AND METHODS: This retrospective study included the right eyes of consecutive patients who underwent laser in situ keratomileusis procedure between 2005 and 2016 at Care-Vision Laser Centers, Tel-Aviv, Israel. Patients were divided into two groups according to whether or not they subsequently developed early flap misalignment. RESULTS: A total of 14,582 eyes (mean age of patients: 32.4 ± 10.3 years) were included. Post-laser in situ keratomileusis early flap misalignment developed in 158 eyes (1.1%). Misalignment was more frequent during the spring (32.3% vs 22.8%, p = 0.003) and in a higher operating room temperature (23.34 ± 1.06 vs 22.98 ± 1.26, p < 0.001). In addition, in the misalignment group, there was a higher rate with the of use of the a Moria M2 microkeratome (rather than sub-Bowman's keratomileusis microkeratome) head (55.2% vs 40.5%, respectively, p < 0.001). In a multivariable analysis adjusted for surgeon and year of surgery, high operating room temperature (odds ratio = 1.22, p = 0.006), treatment zone of 9.0 mm (as opposed to smaller treatment zones, odds ratio = 1.54, p = 0.04), and springtime (odds ratio = 1.58, p = 0.02) were associated with flap misalignment. There was a significant difference in misalignment rates between surgeons (p = 0.02). CONCLUSION: This study found that larger treatment zones, higher operating room temperature, operating during the spring, and the use of Moria M2 microkeratome were associated with increased flap misalignment rates. The association with operating room temperature and seasonal variation is of interest and merits further research.

Post laser-assisted in-situ keratomileusis dry eye disease and temporary punctal plugs.

PURPOSE: The aim of this study was to compare the incidence of post laser in situ keratomileusis (LASIK) dry eye with and without intraoperative extended duration temporary punctal plug placement. METHODS: This retrospective study included myopicastigmatic eyes without a preoperative diagnosis of dry eye disease that underwent LASIK surgery between January 2017, and March 2018. Patients who received punctal plugs during surgery in addition to usual postoperative care were compared to a control group who received usual postoperative care alone. Visual acuity, safety and efficacy indices, as well as predictability and presence of dry eye disease were assessed 3-6 months after surgery. RESULTS: A total of 345 eyes of 345 patients were included, 172 eyes received punctal plugs and 173 did not. The mean age was 30.4 ± 10 years (range: 17-60 years) and 46.1% (N = 159) were female. Both groups were similar in terms of preoperative parameters, including age, gender, spherical equivalent, pachymetry or contact lens use. Patients treated with punctal plugs had significantly less postoperative dry eye complaints (N = 37 vs. 58, 21.5% vs. 34.1% respectively, P = 0.001). Patients treated with plugs that did develop dry eye disease did so later (51.2 ± 77.64 days' vs. 20.78 ± 26.9 days, P = 0.009). Postoperative visual acuities were similar between groups (P > 0.05) at all postoperative follow-up visits as were safety (0.95 ± 0.16 vs. 0.99 ± 0.09, P = 0.30) and efficacy (1.01 ± 0.13 vs. 1.00 ± 0.11, P = 0.52) indices. CONCLUSION: Preventative temporary punctal plug placement during LASIK appears to reduce dry eye disease in the short term, without affecting visual acuity outcomes.

Incidence, Indications, and Outcomes of Eyes Needing Early Flap Lifting After LASIK.

PURPOSE: To analyze the incidence, indications, and outcomes associated with early flap relifting after uncomplicated laser in situ keratomileusis (LASIK). METHODS: All LASIK cases from a single surgical center between 2007 and 2015 were reviewed. Early postoperative flap lift cases (<15 d after surgery) were identified. RESULTS: Overall, 25,712 eyes were included, of which 366 (1.42%) underwent early postoperative flap lifting. There was a significant reduction in early postoperative flap lifting rates from 2006 (2.46%) to 2015 (0.92%) (P = 0.001). Reasons for early flap lifting included striae (n = 301, 1.17%), diffuse lamellar keratitis (n = 62, 0.24%), flap dislocation (n = 20, 0.08%), epithelial ingrowth (n = 18, 0.07%), and interface debris (n = 15, 0.06%). There was a significant difference in rates and outcomes of flap relifting among high-volume surgeons (P < 0.001). The flap lift group had a significantly lower final safety index (0.95 ± 0.16 vs. 1.01 ± 0.15, P < 0.001), efficacy index (0.85 ± 0.26 vs. 0.94 ± 0.26, P < 0.001), and a higher distance from target refraction (0.39 ± 0.61 vs. 0.21 ± 0.46 D). In unilateral cases, the study eye had a lower safety index (P < 0.001), efficacy index (P < 0.001), and greater distance from target refraction (P = 0.003) compared with the fellow eye. After intervention, 81.1% of cases achieved full resolution, 10.1% achieved partial resolution, 4.1% required additional flap relifting, and 4.7% were nonresolved by the end of follow-up. CONCLUSIONS: The main indication for early flap relifting after LASIK was striae, and most cases achieved full resolution. Although refractive and visual outcomes are lower in this group, they are, nevertheless, satisfactory.