Traumatic Flap Striae 6 Years After LASIK: Case Report and Literature Review

Efficacy and Safety of Surgically Managed Late Traumatic LASIK Flap Displacements in a Study of 66 Cases

PURPOSE

To evaluate safety and efficacy in the management of flap displacement after laser in situ keratomileusis (LASIK) and subsequent complications.

METHODS

This was a retrospective study performed using data recorded at the center's database from October 2002 to August 2021. Efficacy and safety were both converted to binary outcomes (loss of one or more lines and no change or gain in lines of visual acuity). The effects of time from surgery to complication and from complication to repair were assessed and the odds ratios and probabilities were calculated. The same procedure was applied to investigate the effect of these temporal variables on complications.

RESULTS

A total of 66 eyes with late traumatic LASIK flap displacements were studied. Efficacy remained unchanged in 48 patients (64 eyes, 75%), and safety remained unchanged in 53 patients (59 eyes, 90%). Sixty-six patients (64 eyes, 100%) achieved visual acuity values of 20/40 and 45 patients (64 eyes, 70.3%) achieved values of 20/20. The flap displacement was resolved in the first 24 hours (SD ± 0.1 days). Surgery was performed in 58 patients (65 eyes, 90%). Epithelial ingrowth was the most frequent complication. Patients who underwent surgery tended not to lose lines (P = .05). The risk of developing epithelial ingrowth increases with time after LASIK surgery until traumatic flap displacement (odds ratio: 1.001; P < .001). The prevalence of dislocation during the study period was 0.012%.

CONCLUSIONS

Visual safety values were favorable after resolution of the flap complication. Immediate surgical management leads to better visual efficacy, and the time between LASIK and trauma increases the risk of epithelial ingrowth after flap displacement. [J Refract Surg. 2022;38(4):270-276.].

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.

Flap Sliding Technique for Managing Flap Striae following Laser In Situ Keratomileusis

Purpose

To assess the efficacy and safety of a simple, noninvasive, "flap-sliding" technique for managing flap striae following laser in situ keratomileusis (LASIK).

Methods

This prospective, interventional study included eyes with post-LASIK flap striae. All eyes underwent flap sliding 1-2 days after surgery. Following flap edge epithelialisation, a cellulose sponge was used to gently slide the flap perpendicular to the striae direction. This technique allows for flap striae treatment without flap lifting, avoiding any associated lifting complications. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and refractive error were monitored one day after the flap-sliding procedure.

Results

Fifteen eyes (15 patients) with post-LASIK flap striae were managed using the flap-sliding technique. The procedure did not successfully relocate the flap striae in 1 eye, and flap elevation and floating (using a balanced salt solution) were required. Therefore, 14 eyes were included in post-flap-sliding analyses. The UDVA improved in all patients the first day after the flap-sliding procedure was performed, with 11 of 14 eyes (78.57%) reaching an UDVA of 20/25 or better. Complications following flap sliding occurred in 2 eyes (14.29%). One eye had intraoperative epithelial abrasion, and 1 eye had residual postoperative striae outside of the optical zone.

Conclusion

The flap-sliding technique is a simple, noninvasive, efficient, and safe technique for managing post-LASIK flap striae that develop after epithelial healing in the early post-LASIK period. This trial is registered with NCT04055337.

LASIK flap stability after severe ocular injury

Purpose

To report two cases of LASIK flap stability after severe ocular trauma.

Observations: Two patients suffered open globe injuries several years after undergoing uneventful LASIK with femtosecond laser corneal flap. Both underwent primary ruptured globe repair, during which no LASIK flap dislocation was identified. Histopathologic examination of one of the cornea specimens confirmed an intact LASIK flap.

Conclusion and Importance

In these cases, the femtosecond LASIK flap remained in place despite significant injury to the cornea. The presence of a femtosecond LASIK flap did not complicate surgical management of the injury, and did not contribute to the patient's loss of BCVA.

Comparison of the efficiency of femtoLASIK and ReLEx SMILE in terms of dioptric error reduction

BACKGROUND AND AIMS

Refractive eye surgery is a rapidly expanding field of ophthalmology and corneal surgery is undergoing constant development leading to less invasive technologies. The goal of this study was to compare the most common femtoLASIK surgery with the newer ReLEx SMILE surgery which is gentler to the cornea. The comparison was made in terms of dioptric error reduction.

METHODS

The studied cohort of patients consisted of two major groups: 30 patients who underwent femtoLASIK surgery and 30 who underwent ReLEx SMILE surgery. -30 patients, 60 eyes. All patients were aged 18-45 years with moderate myopia or astigmatism ranging from -3.25 to -6.0 spherical diopters and from 0 to -1.0 cylindrical diopters. In all, the best corrected visual acuity measured prior to surgery was 1.0. Pachymetry was not comparable because each surgical method was performed at a different time point and the introduction of an innovative method into practice led to a change in selection criteria.

RESULTS

During postsurgical check-ups, the ReLEx SMILE method (0.74) led to lower values of non-corrected visual acuity compared to the femtoLASIK method (0.88), (P<0.001). However, the results changed at the one-year post-surgery check-up, when ReLEX SMILE patients achieved non-corrected visual acuity of 0.97 compared to femtoLASIK patients, who scored 0.83, (P=0.007). Based on data analysis from the automatic refractometer, the average spherical diopters of the femtoLASIK (-0.32 D) were higher than those of the ReLEx SMILE (-0.07 D), (P<0.001). The results for the cylindrical diopters were also significant, (P=0.021). When we compared the spherical equivalent one year after surgery, the difference between methods was significant. The FemtoLASIK method resulted in an average SE -0.55 D compared to -0.09 D for the ReLEx SMILE method, (P<0.001).

CONCLUSION

This study showed that there was a significant difference in results between the two surgical methods of treatment of moderate myopia and astigmatism, in terms of regression of dioptric error, as well as in achievement and maintenance of visual acuity during the observed period. The ReLEx SMILE had better results.

Traumatic corneal flap displacement after laser in situ keratomileusis (LASIK)

Background

Laser in situ keratomileusis (LASIK) is the most common and popular procedure performed for the correction of refractive errors in the last two decades. We report a case of traumatic flap displacement with flap folding which occurred 3 years after LASIK was performed. Previous literature suggests that vision prognosis would be closely related to proper and prompt management of traumatic flap displacement with flap folding 3 years after LASIK.

Case presentation

A 23-year-old female presented to our hospital who had undergone uneventful LASIK in both eyes 3 years prior. Unfortunately, she had suffered a blunt trauma in her right eye in a car accident. A late onset of corneal flap displacement was found with upper and lower portion of the flap being folded inside the corneal bed. Surgical intervention for debridement with subsequent reposition of corneal flap was performed as soon as possible in the operating room. A bandage contact lens was placed, and topical antibiotic and corticosteroids were given postoperatively. Two days after the operation, the displaced corneal flap was found to be well attached smoothly on the corneal bed without folds. The best-corrected visual acuity was 6/6 with refraction of −0.75 D to 1.0 D ×175° in her right eye 1 month later.

Literature review

We reviewed a total of 19 published cases of late-onset traumatic flap dislocations or displacements after LASIK with complete data from 2000 to 2014.

Conclusion

Traumatic displacement of corneal flaps after LASIK may occur after blunt injury with specific direction of force to the flap margin, especially tangential one. According to the previous literature, late-onset traumatic flap displacement may happen at any time after LASIK and be caused by various types of injuries. Fortunately, good visual function could mostly be restored with immediate and proper management.

Corneal tissue interactions of a new 345 nm ultraviolet femtosecond laser

PURPOSE

To assess the suitability of a new 345 nm ultraviolet (UV) femtosecond laser for refractive surgery.

SETTING

Department of Ophthalmology, University of Erlangen-Nürnberg, Erlangen, Germany.

DESIGN

Experimental study.

METHODS

Twenty-five porcine corneas were used for stromal flap or lamellar bed creation (stromal depth, 150 μm) and 15 rabbit corneas for lamellar bed creation near the endothelium. Ultraviolet femtosecond laser cutting-line morphology, gas formation, and keratocyte death rate were evaluated using light and electron microscopy and compared with a standard infrared (IR) femtosecond laser. Endothelial cell survival was examined after application of a laser cut near the endothelium.

RESULTS

Flaps created by the UV laser were lifted easily. Gas formation was reduced 4.2-fold compared with the IR laser (P = .001). The keratocyte death rate near the interface was almost doubled; however, the death zone was confined to a region within 38 μm ± 10 (SD) along the cutting line. Histologically and ultrastructurally, a distinct and continuous cutting line was not found after UV femtosecond laser application if flap lifting was omitted and standard energy parameters were used. Instead, a regular pattern of vertical striations, presumably representing self-focusing induced regions of optical tissue breakdown, were identified. Lamellar bed creation with standard energy parameters 50 μm from the endothelium rendered the endothelial cells intact and viable.

CONCLUSION

The new 345 nm femtosecond laser is a candidate for pending in vivo trials and future high-precision flap creation, intrastromal lenticule extraction, and ultrathin Descemet-stripping endothelial keratoplasty.

FINANCIAL DISCLOSURES

Mr. Klenke and Ms. Skerl were paid employees of Wavelight GmbH when the study was performed. Dr. Seiler is a scientific consultant to Wavelight GmbH. No other author has a financial or proprietary interest in any material or method mentioned.

When case report became case series: 45 cases of late traumatic flap complications after laser-assisted in situ keratomileusis and review of Chinese literature

OBJECTIVE

To report 45 cases of late traumatic flap complications after laser-assisted in situ keratomileusis (LASIK) and discuss the continually increasing number of cases in China.

METHODS

A multicentre retrospective survey of eye injuries was carried in 31 military hospitals from January 2006 to December 2011. Detailed information from the medical records of all 92 cases with a history of prior LASIK treatment were collected and summarised, with respect to visual acuity (VA), flap condition, treatment and final outcome. All Chinese publications relevant to late traumatic flap complications in Chinese patients were retrieved and summarised.

RESULTS

92 inpatients (92 eyes) underwent LASIK surgery; 45 of these had traumatic LASIK flap complications. Flap dislocation was the commonest and most needed surgical repair. VA after treatment was good and no statistically significant difference was observed when compared with the 47 cases without flap complications. 109 articles related to late traumatic flap complications after LASIK were retrieved from four Chinese document databases. There were 550 cases of late traumatic flap complications. From 2004, case reports became more common; 10 or more cases were reported in some case series. VA of most cases was good and there was no remarkable vision loss after treatment.

CONCLUSIONS

Late traumatic flap complications after LASIK have become more frequent in China, although the prognosis of most cases is good.