Comparison of 5468 retreatments after laser in situ keratomileusis by lifting the flap or performing photorefractive keratectomy on the flap

Laser-Assisted In Situ Keratomileusis (LASIK) Enhancement for Residual Refractive Error after Primary LASIK

Background: To evaluate the safety, efficacy, and predictability of laser-assisted in situ keratomileusis (LASIK) enhancement after primary LASIK and compare to Food and Drug Administration (FDA) criteria. Methods: Patients who underwent LASIK enhancement after primary LASIK between 2002 and 2019 were compared to those who underwent LASIK without retreatment. Patient demographics, preoperative characteristics, visual outcomes, and postoperative complications were compared between groups. Epithelial ingrowth (EI) development was stratified based on duration between primary and secondary procedures. Results: We compared 901 eyes with LASIK enhancement to 1127 eyes without retreatment. Age, sex, surgical eye, sphere, cylinder, and spherical equivalent (SE) were significantly different between groups (p < 0.05). At 12 months post-enhancement, 86% of the eyes had an uncorrected distance visual acuity of 20/20 or better and 93% of eyes were within ±0.50 D of the target. Development of EI (6.1%) demonstrated an odds ratio of 16.3 in the long-term compared to the short-term (95% CI: 5.9 to 45.18; p < 0.0001). Conclusions: Older age at primary LASIK, female sex, right eye, and larger sphere, cylinder and SE were risk factors for enhancement. Risk of EI significantly increased when duration between primary and enhancement procedures exceeded five years. LASIK enhancements produce favorable outcomes and meet FDA benchmarks for safety, efficacy, and predictability.

Re-treatment in LASIK: To Flap Lift or Perform Surface Ablation

PURPOSE

To review safety and efficacy outcomes following re-treatment for residual refractive errors in eyes with prior laser in situ keratomileusis (LASIK) and determine the most appropriate course of action for patients.

METHODS

A review of all patients undergoing LASIK enhancement at a single refractive surgery center between 2012 and 2017 was undertaken. Refraction and biomicroscopy results before and after enhancement were collated and analyzed according to the method of enhancement (flap lift or surface ablation).

RESULTS

A total of 108 eyes were included in the analysis; 58 eyes underwent flap lift and 50 underwent surface ablation retreatment with mean times to enhancement of 22.3 and 53.2 months, respectively. The mean spherical equivalent prior to enhancement was -0.43 ± 0.69 and -1.03 ± 1.01 diopters (D) for the flap lift and surface ablation groups, respectively. The absolute difference from intended refraction was statistically significant (lift 0.16 ± 0.24 versus surface ablation 0.31 ± 0.35 D; P = .01). The difference was more pronounced for eyes with prior hyperopia (P = .041). The incidence of haze following re-treatment was 3.4% in the flap lift group versus 10.0% in the surface ablation group, and 8.6% of the flap lift group had evidence of epithelial ingrowth, with 1 eye requiring washout. There was no correlation between time to enhancement, refraction, and incidence of complications following the enhancement procedure.

CONCLUSIONS

There has been a trend toward treating residual LASIK refractive error through surface ablation. This review suggests that flap lift may result in a more accurate refractive outcome, albeit with an expected greater risk of epithelial ingrowth. [J Refract Surg. 2020;36(1):6-11.].

Re-Treatment by Flap Relift Versus Surface Ablation After Myopic Laser In Situ Keratomileusis

PURPOSE

To compare clinical outcomes of patients undergoing first re-treatment by flap relift with those re-treated by surface ablation on the flap after an initial myopic laser-assisted in situ keratomileusis (LASIK) procedure.

METHODS

This is a retrospective cohort analysis of consecutive patients who underwent myopic LASIK and required re-treatment between January 2007 and December 2016. Cases re-treated by flap relift were propensity score matched with cases re-treated by surface ablation, and clinical outcomes were compared. One eye from each patient was included.

RESULTS

A total of 1,234 out of 21,191 cases required re-treatment after myopic LASIK during the follow-up period. Surface ablation was performed in 75% of cases and relift in 25%. Patients re-treated by surface ablation were more commonly male (61.8% vs. 48.1%, P < 0.001), were younger (33.2 ± 7.8 vs. 35.2 ± 10 years, P = 0.005), and had thinner corneas (483 ± 46 vs. 502 ± 43 μm, P < 0.001). Propensity score matching was performed for 416 eyes (208 from each group). After matching, differences in baseline characteristics became nonsignificant (P > 0.05). Cases re-treated by surface ablation had a worse safety index (0.98 ± 0.12 vs. 1.02 ± 0.17, P = 0.049), yet better predictability (0.14 ± 0.6 vs. 0.35 ± 0.5 diopters of deviation, P = 0.009), a similar efficacy index (0.92 ± 0.2 vs. 0.93 ± 0.3, P = 0.814), higher rates of haze (5.8% vs. 0.5%, P = 0.002), and a lower risk for epithelial ingrowth (0.5% vs. 8.2%, P < 0.001).

CONCLUSIONS

Re-treatment after myopic LASIK with surface ablation resulted in worse safety and higher rates of haze, yet more predictable outcomes and reduced ingrowth rates, compared with re-treatment with flap relift.

Enhancement Options After Myopic Small-Incision Lenticule Extraction (SMILE): A Review

PURPOSE

To provide an overview of the currently available retreatment methods after myopic small-incision lenticule extraction (SMILE).

DESIGN

Systematic literature review.

METHODS

The PubMed library was searched for articles containing the terms "small-incision lenticule extraction" and "enhancement" or "retreatment". The last search was performed on May 1, 2019.

RESULTS

In contrast to laser in-situ keratomileusis (LASIK), which can be retreated by a flap relift, repeat SMILE retreatment is currently not approved and only seldomly performed. As substitutes, surface ablation, cap-to-flap conversion using the CIRCLE program in the VisuMax platform, and thin-flap LASIK have been recently established. While all options offer safety and efficacy comparable to LASIK retreatments, each has its patient-specific advantages and disadvantages. While surface ablation preserves the flap-free approach of the primary procedure, the aspect of pain and a slow visual recovery might render it less attractive as compared with CIRCLE and thin-flap LASIK which offer quick recovery, however at the price of flap creation. Besides, each retreatment method generates specific tissue responses and has a different impact on corneal biomechanics, which is strongly dependent on the previous SMILE parameters, especially the cap thickness.

CONCLUSIONS

Refractive enhancement after SMILE is currently mostly performed by surface ablation, CIRCLE cap-to-flap conversion or thin-flap LASIK, which all offer safety and efficacy comparable to LASIK retreatments. In this review, a detailed overview over each method, its technical aspects, and specific advantages and disadvantages is given.

Early Surface Ablation on Aborted LASIK Flaps

PURPOSE

To report the outcomes of a series of 16 patients who had secondary surface ablation within 4 weeks of an aborted femtosecond laser-assisted in situ keratomileusis (FS-LASIK) procedure.

METHODS

A retrospective chart review of electronic medical record data from 2011 to 2015 was performed to identify eyes of patients who had an aborted FS-LASIK procedure followed by secondary surface ablation (photorefractive keratectomy or laser epithelial keratomileusis) within 4 weeks of the primary procedure. Patients were required to have at least three postoperative visits to be included in the study.

RESULTS

The review identified 20 aborted FS-LASIK procedures of 7,142 eyes (0.003%), of which 16 met the inclusion criteria. The most common reasons for abortion were incomplete (10) and decentered (3) flaps. Thirteen of 16 eyes were treated within 2 weeks. A total of 11 of 16 eyes achieved uncorrected distance visual acuity (UDVA) of 20/20, 13 of 16 achieved UDVA of 20/25 or better, and 15 of 16 had a corrected distance visual acuity (CDVA) of 20/20. There were no intraoperative complications during the second procedure and there were no cases of diffuse lamellar keratitis. One patient developed postoperative haze with a CDVA of 20/25 and was lost to follow-up.

CONCLUSIONS

This case series indicates that early surface ablation (within 4 weeks) after an aborted FS-LASIK procedure may be performed with good visual outcomes. [J Refract Surg. 2019;35(2):121-125.].

Flap-Lift LASIK 10 or More Years After Primary LASIK

PURPOSE

To evaluate the safety and efficacy of flap-lift LASIK performed 10 or more years after the original LASIK procedure.

METHODS

All patients who were treated with flap-lift LASIK 10 or more years after primary LASIK for whom records of the primary treatment could be obtained and at least 45-day follow-up refractions after re-treatment were available were included in this study. A total of 23 eyes of 20 patients were identified. The median time between primary LASIK and flap-lift LASIK was 13.9 years (range: 10 to 18.7 years).

RESULTS

A total of 22 of 23 eyes (96%) retained the same corrected distance visual acuity (CDVA) postoperatively that was present preoperatively. One of 23 eyes (4%) experienced a loss of CDVA from 20/20 to 20/25 as the result of clinically significant epithelial ingrowth requiring multiple treatments followed by photorefractive keratectomy (PRK) treatment. One additional eye experienced clinically significant epithelial ingrowth that required a single surgical treatment. Fourteen of 20 eyes with a goal of plano achieved uncorrected distance visual acuity (UDVA) of 20/20 or better and 6 eyes achieved UDVA of 20/25 (2 of these eyes had preoperative CDVA of 20/25). For the eyes with a goal of plano, 16 of 20 eyes (80%) achieved UDVA equal to the preoperative CDVA.

CONCLUSIONS

Flap-lift LASIK is an effective treatment for refractive error when performed between 10 and 18.7 years after the initial flap was created. Epithelial ingrowth is the major complication, occurring to a clinically significant degree in 9% of the eyes. [J Refract Surg. 2018;34(9):604-609.].

Epithelial ingrowth following laser in situ keratomileusis (LASIK): prevalence, risk factors, management and visual outcomes

The number of laser in situ keratomileusis (LASIK) procedures is continuing to rise. Since its first application for correcting simple refractive errors over 25 years ago, the role of LASIK has extended to treat other conditions, including postkeratoplasty astigmatism/ametropia, postcataract surgery refractive error and presbyopia, among others. The long-term effectiveness, predictability and safety have been well established by many large studies. However, due to the creation of a potential interface between the flap and the underlying stroma, interface complications such as infectious keratitis, diffuse lamellar keratitis and epithelial ingrowth may occur. Post-LASIK epithelial ingrowth (PLEI) is an uncommon complication that usually arises during the early postoperative period. The reported incidence of PLEI ranged from 0%–3.9% in primary treatment to 10%–20% in retreatment cases. It can cause a wide spectrum of clinical presentations, ranging from asymptomatic interface changes to severe visual impairment and flap melt requiring keratoplasty. PLEI can usually be treated with mechanical debridement of the affected interface; however, additional interventions, such as alcohol, mitomycin C, fibrin glue, ocular hydrogel sealant, neodymium:yttriumaluminum garnet laser and amniotic membrane graft, may be required for recurrent or refractory cases. The aims of this review are to determine the prevalence and risk factors of PLEI; to describe its pathogenesis and clinical features and to summarise the therapeutic armamentarium and the visual outcome of PLEI.