Eyeworld

SEPTEMBER 2022 | EYEWORLD | 25 continued on page 26 References 1. Moshirfar M, et al. LASIK enhance- ment: clinical and surgical manage- ment. J Refract Surg. 2017;33:116–127. 2. Cagil N, et al. Effectiveness of laser-assisted subepithelial keratectomy to treat residual refractive errors after laser in situ keratomileusis. J Cataract Refract Surg. 2007;33:642–647. 3. Carones F, et al. Evaluation of photorefractive keratectomy retreat- ments after regressed myopic laser in situ keratomileusis. Ophthalmolo- gy. 2001;108:1732–1737. 4. de Rojas V, et al. Infectious kera- titis in 18,651 laser surface ablation procedures. J Cataract Refract Surg. 2011;37:1822–1831. 5. Schallhorn SC, et al. Flap lift and photorefractive keratectomy enhancements after primary laser in situ keratomileusis using a wavefront-guided ablation profile: Refractive and visual outcomes. J Cataract Refract Surg. 2015;41:2501– 2512. 6. Caster AI. Flap-lift LASIK 10 or more years after primary LASIK. J Refract Surg. 2018;34:604–609. 7. Davis EA, et al. Lasik enhance- ments: a comparison of lifting to recutting the flap. Ophthalmology. 2002;109:2308–2314. 8. Rubinfeld RS, et al. To lift or recut: changing trends in LASIK enhancement. J Cataract Refract Surg. 2003;29:2306–2317. 9. Vaddavalli PK, et al. Complica- tions of femtosecond laser-assisted re-treatment for residual refractive errors after LASIK. J Refract Surg. 2013;29:577–580. 10. Domniz Y, et al. Recutting the cornea versus lifting the flap: comparison of two enhancement techniques following laser in situ keratomileusis. J Refract Surg. 2001;17:505–510. 11. Alió Del Barrio JL, et al. Laser flap enhancement 5 to 9 years and 10 or more years after laser in situ keratomileusis: Safety and efficacy. J Cataract Refract Surg. 2019;45:1463–1469. 12. Santhiago MR, et al. Flap relift for retreatment after femtosecond laser-assisted LASIK. J Refract Surg. 2012;28:482–487. more than 15 years after the initial proce- dure. 6,11 Nevertheless, relifting can be techni- cally challenging and complicated by epithelial ingrowth (EI). 12,13 Prior studies have suggested pre-enhancement time interval, microkeratome use, loose epithelium, and advanced age to be possible post-relifting EI risk factors. 14,15,16,17,18 With this current study, Chang et al. seek not only to confirm the viability of flap relifting years after LASIK but also to assess the rela- tionship between relifting success and EI with pre-enhancement time interval, age during relift, sex, and primary LASIK flap creation method. Methods The authors retrospectively reviewed all LASIK relifting enhancement cases performed by one surgeon at the Hong Kong Sanatorium & Hospi- tal between 1997 and 2019. They included data only on the first relift procedure if a patient had multiple. They excluded patients with second flap-related procedures within 75 days of the first relift, less than 75 days of follow-up in the absence of epithelial ingrowth, macular disease, insufficient stromal bed, evidence or suspicion of keratectasia, hypertension, history or risk of retinal vessel occlusion, glaucoma, and oth- er procedures like corneal crosslinking. Their primary outcomes were relifting success, EI development, intraoperative complications, and postoperative corrected distance visual acuity (CDVA). They defined clinically significant EI as distance visual acuity (corrected or uncorrected) loss, foreign body sensation, keratolysis, epithe- lial irregularity, or flap revision desired by either the surgeon or the patient. The study performed statistical analysis with R, especially using bina- ry logistic regression to evaluate the association between relifting success and EI with pre-en- hancement time interval, age during relift, sex, and primary LASIK flap creation method. These associations were presented as odds ratios. The authors described the relifting proce- dure used in the study. In summary, the previ- ous flap edge was visualized under a slit lamp, anesthetized by 0.5% proparacaine, and initially lifted by a 25-gauge needle bent 2 mm from the tip that extended 1.5 mm inward. The needle created a 2–3-mm long flap lift that was pressed back on the stromal bed. The Seibel II IntraLase flap lifter and retreatment spatula short end extended the incision along the old flap's circumference, after which the long end lifted the flap. The stromal bed was then treated by an excimer laser and scrubbed by a Merocel sponge. A feeding tube connected to suction removed residual fluid under the flap, and a bandage contact lens was placed. Results The authors included 73 eyes from 68 patients. The mean follow-up periods were 4.3±4.7 years. The mean time interval between LASIK and relift was 8.6±6.4 years. Relifting was successfully performed in 46 eyes (63%) >5 years and in 34 eyes (47%) >10 years after pri- mary LASIK. Relifting was successful in 71 eyes (97.3%). The 2 eyes with failed relifting had successful recutting procedures without com- plications. Of the successfully relifted flaps, 12 (16.9%) developed EI. Of these, 3 (4.2%) were clinically significant. None of these lost CDVA after EI removal. EI only recurred in 1 of those 3 eyes but was clinically insignificant. Seven eyes (9%) lost one line of CDVA but no eyes lost >1 line. The association between pre-en- hancement time intervals with relift success or EI development was not statistically significant, even after adjusting for patient characteristics like primary LASIK flap creation method, year of relift, or age at relift. There were also no direct associations found between relift success or EI development with sex, patient age at relift, year of relift, and primary LASIK flap creation method (microkeratome vs. femtosecond laser). Discussion Various studies have advised against relifting a LASIK flap after the 1-year postop mark. 12,19 However, conflicting reports have demonstrated successful flap relifting after this time period, even up to 15–20 years after surgery. 6,11 Before considering LASIK enhancement complications, the flap must first be successfully mobilized and lifted. This study reported a success rate of 97% with half of its cases occurring more than 10 years after primary LASIK surgery at a maxi- mum of 22 years later. The feared complication of EI occurred in roughly 17% of patients, which is consis- tent with previously reported numbers of 0 to 18%. 17,20 However, clinically significant EI occurred in only 4.2% of relifted flaps, none continued from page 22

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