Incidence, Risk, and Visual Outcomes after Repositioning of Acute Non-Traumatic Flap Dislocations Following Femtosecond-Assisted LASIK

Quantitative assessment of corneal elasticity distribution after FS-LASIK using optical coherence elastography

Quantifying corneal elasticity after femtosecond laser-assisted in situ keratomileusis (FS-LASIK) procedure plays an important role in improving surgical safety and quality, since some latent complications may occur ascribing to changes in postoperative corneal biomechanics. Nevertheless, it is suggested that current research has been severely constrained due to the lack of an accurate quantification method to obtain postoperative corneal elasticity distribution. In this paper, an acoustic radiation force optical coherence elastography system combined with the improved phase velocity algorithm was utilized to realize elasticity distribution images of the in vivo rabbit cornea after FS-LASIK under various intraocular pressure levels. As a result, elasticity variations within and between the regions of interest could be identified precisely. This is the first time that elasticity imaging of in vivo cornea after FS-LASIK surgery was demonstrated, and the results suggested that this technology may hold promise in further exploring corneal biomechanical properties after refractive surgery.

Surgical and visual outcomes of flap repositioning for various flap-related pathologies post laser in-situ keratomileusis (LASIK)

To evaluate the surgical and visual outcomes of flap repositioning for various post-laser-assisted in-situ keratomileusis (LASIK) flap pathologies. Retrospective review of consecutive cases between April 1, 2017 and February 28, 2022, where surgical flap repositioning was performed following LASIK for various flap-related complications. Of the 6018 eyes, 31 needed flap repositioning (0.51%). Indications were flap displacement and folds in 20 eyes (64%), flap subluxation in five eyes (16%), epithelial ingrowth and interface debris in two each, and one eye each of diffuse lamellar keratitis and incomplete flap. Final best spectacle-corrected visual acuity of ≥ 20/25 was obtained in 25/31 (80%) eyes. The efficacy index pre to post repositioning showed significant improvement (0.86 ± 0.39 vs. 0.63 ± 0.29 preop, P = 0.011). Flap repositioning incidence was significantly higher (7/602 (1.16%)) during the COVID lockdown phases compared to the non-COVID lockdown phase (24/5416 (0.44%, P = 0.019)). The COVID group had lower efficacy (0.72 ± 0.36 vs. 0.90 ± 0.39, P = 0.300) and safety indices (0.85 ± 0.24 vs. 1.06 ± 0.35, P = 0.144) compared to the non-COVID group; however, the results were not statistically significant. The flap displacement rate was statistically higher in nasal hinged (microkeratome) flaps (18/2013, 0.89%) compared to superior hinged (Femto) flaps (13/4005, 0.32%) (0.32%, P = 0.003). Our study shows that flap repositioning has a low incidence in LASIK, with the most common indication being flap displacement/folds. The outcome post flap repositioning was poorer during the lockdown period, perhaps due to the inability to follow up early. Early identification and surgical repositioning are successful in both anatomical and visual restoration.

A Literature Review of the Incidence, Management, and Prognosis of Corneal Epithelial-Related Complications After Laser-Assisted In Situ Keratomileusis (LASIK), Photorefractive Keratectomy (PRK), and Small Incision Lenticule Extraction (SMILE)

Our purpose is to provide a comprehensive investigation into the incidence, treatment modalities, and visual prognosis of epithelial-related complications in corneal refractive surgeries, including laser-assisted in situ keratomileusis (LASIK), photorefractive keratectomy (PRK), and small incision lenticule extraction (SMILE). A systematic search of multiple databases was conducted by two independent examiners using various search terms related to epithelial-related complications and corneal refractive surgeries. A total of 91 research articles were included, encompassing a sample size of 66,751 eyes across the three types of surgeries. The average incidence of epithelial-related complications varied across the different types of corneal refractive surgeries. LASIK had an average incidence of 4.9% for epithelial defects, while PRK and SMILE had lower rates of 3.3% and 3.9%, respectively. Our findings indicate that SMILE has a lower incidence of epithelial defects compared to LASIK, potentially due to the less invasive nature of lenticule incision in SMILE. Visual prognosis after epithelial complications (EC) is generally favorable, with various supportive care and surgical interventions leading to significant improvements in postoperative visual acuity and full recovery. Understanding the incidence rates and management approaches for epithelial-related complications can guide clinicians in enhancing patient safety, refining surgical techniques, and optimizing postoperative outcomes in corneal refractive surgeries.

Multicenter survey on implantable collamer lens dislocation

This study aimed to investigate the incidence, patient background, and postoperative prognosis of implantable collamer lens (ICL) dislocation. We retrospectively reviewed all cases of ICL dislocation at four major refractive surgery centers in Japan until December 2019. The incidence, patient background, cause of dislocation, complications of repositioning surgery, and postoperative visual function were investigated. Seven ICL dislocations [0.072% of total ICL-implanted eyes (9775 eyes)] occurred at an average of 28.6 months (11–82 months) postoperatively. All patients were male. Five eyes were injured during sports activities, one due to a fall from a bicycle, and another due to ocular blunt trauma caused by a mortuary tablet. Two patients had re-dislocation in the same eye. Retinal detachment occurred after repositioning surgery in one patient, and scleral buckling surgery was performed without ICL removal. ICL dislocation is a rare complication of ICL surgery; repositioning surgery is effective, but retinal complications may occur.