Management of a traumatic flap dislocation seven years after LASIK

Corneal foreign body post laser in-situ keratomileusis: Diagnosis, management, outcome and review of literature

Purpose

To report a case of metallic corneal foreign-body (CFB) penetrating the Laser in situ keratomileusis (LASIK) flap and its successful outcome. To highlight usefulness of Anterior Segment Optical Coherence Tomography (ASOCT) in diagnosis and management of post-LASIK CFB. To enumerate other similar cases published in literature.

Method

A 30-year-old male presented to the emergency department of a tertiary eye care centre with a metallic CFB. He had undergone uneventful LASIK elsewhere 4-years back. He was unaware of any trauma. CFB removal was attempted elsewhere but abandoned as CFB appeared deeply embedded. ASOCT showed CFB had penetrated LASIK flap and lodged into midstroma, 207 μm deep. CFB was successfully removed in operation theatre along with the application of cyanoacrylate glue and bandage contact lens. A review of literature for CFB in post-LASIK patients was done through PubMed search.

Result

Postoperative course was uncomplicated and there was a follow up period of 4 months. Vision improved to unaided 20/20 and N/6 from preoperative 20/60 and N/10. Review of literature of 24 patients showed Post-LASIK FB was more common in males (79%). None of the patients except for one had protective eye-wear. Metallic FB was most common followed by organic FB. Flap complications were present in seven patients. Diffuse lamellar keratitis (DLK) and epithelial ingrowth were the most common post-FB removal complications occurring in six (25%) and four (16.6%) patients respectively.

Conclusion

Post-LASIK patients with CFB need to be inspected for flap related complications. CFB can be successfully removed, although DLK, epithelial ingrowth, microbial keratitis, astigmatism, can occur post-CFB removal. ASOCT can delineate CFB and flap related details and thus is an additional useful imaging tool in such scenarios.

Traumatic displacement of laser in situ keratomileusis flaps: an integrated clinical case presentation

Background

Traumatic dislocation of laser-assisted in situ keratomileusis (LASIK) corneal flaps is an uncommon postoperative complication that could occur any time after LASIK, and could be visually devastating. We evaluated the visual outcomes, corneal sensation, tear function, and dry eye questionnaire results of patients with traumatic dislocation of LASIK flaps, including one LASIK flap amputation.

Methods

This is a retrospective case series. Seven patients who were diagnosed with traumatic displacement of the LASIK flap and underwent flap replacement surgery between August 2014 and January 2019 were included.Patient’s visual acuity, refraction, corneal sensitivity, non-invasive tear breakup time (NIBUT), tear meniscus height (TMH), and ocular surface disease index (OSDI) results were evaluated.

Results

The patients’ mean age was 35.86 ± 5.84 years, and 42.9 % (3/7) were male. The mean duration from LASIK to trauma was 8.86 ± 2.48 years.The mean preoperative and postoperative six-month corrected distance visual acuity (CDVA) were 0.55 ± 0.34 and 0.02 ± 0.03, respectively. The mean spherical equivalent and astigmatism at six months postoperatively was − 1.0 ± 0.95 D and − 0.5 ± 0.25 D, respectively. The corneal flap was clear and well-positioned at the final follow-up (mean: 28.57 ± 6.9 months). 85.71 % (6/7) of the patients showed worse corneal sensation in the injured eye. Interocular OSDI discrepancy was less in those whose last visit was more than 30 months after the trauma.

Conclusions

Postoperative CDVAat six months was improved, and the refractive data also showed some improvement. The corneal nerve and tear function recovery peaked before 30 months, while the OSDI continued to show a strong trend of improvement beyond 30 months.

Calzone-Like Traumatic Flap Dislocation Four Years after Laser in situ Keratomileusis

A 46-year-old patient presented with a flip-folded partially dislocated flap after trauma caused by a sheet of paper, four years after a reportedly uneventful laser in situ keratomileusis procedure using microkeratome. Flap re-lift, mechanical debridement, and flap stretching were performed in a first interventional approach. Due to epithelial ingrowth two month after the first intervention, a flap re-lift and mechanical removal of epithelial cells from the stroma bed and flap were performed. In addition, triamcinolone was applied subconjunctivally. Thereafter, best corrected visual acuity of 20/20 was regained and no more epithelial ingrowth was observed. Only few cases of flap dislocation with epithelial ingrowth have been described in the literature following trauma, though none of a permanently inward folded flap. The use of subconjunctival triamcinolone is a new approach to prevent recurrent epithelial ingrowth.

Effect of fibrin glue on corneal lamellar healing and how it correlates to biomechanical properties: biomechanical wavefront analysis and confocal study

Background

To evaluate, using a rabbit model, the influence of the wound healing process at the flap edge on corneal biomechanics after sutured, glued, and non-augmented microkeratome flaps.

Methods

Unilateral 160 μm thick laser in situ keratomileusis (LASIK) flaps using a mechanical microkeratome were performed on the corneas of the left eyes of 36 rabbits. Animals were then divided into 3 groups of 12 rabbits each: A: the flaps were glued with human fibrin tissue adhesive (Tisseel); B: the flaps were sutured; and C: the flaps were allowed to heal without the use of sutures or glue (non-augmented). The contralateral eyes served as controls. Reichert ocular response analyzer (ORA) was used to measure corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg) and cornea-compensated IOP (IOPcc) at 6 weeks and 3 months postoperatively. In vivo confocal microscopy (IVCM) was also used to study the corneal wound healing process in all groups.

Results

Both mean CH and mean CRF were significantly higher in sutured and glued groups compared with the non-augmented group at 6 weeks and 3 months postoperatively (P  < 0.0001). No statistically significant difference in corneal biomechanics was found between controls and groups A and B at any time points. Activated keratocytes were detected at the wound edge and peripheral flap interface in sutured and glued groups.

Conclusion

The healing process at the wound edge is critical for optimal corneal integrity. Fibrin glue may serve as a safe and effective substitute to sutures in enhancing the corneal flap edge healing response and in increasing its mechanical strength.