Multistage Management Of Severe Epithelial Ingrowth And Lasik Flap Melt Using Epithelial Removal, Transepithelial Ptk And Topography-Guided Custom Ablation

To describe the multistage therapeutic refractive management and outcome in a case of unmanaged epithelial ingrowth leading to central flap melt and central corneal reticular scarring 2 years after LASIK flap lift enhancement. A 38 year-old male with history of PRK (1995), LASIK (2001), flap lift enhancement (2006) and second flap lift enhancement (2014) presented at our clinic seeking help for blurred vision, ghost imaging and poor night vision in the left eye. Examination revealed late stage epithelial ingrowth coupled with central flap melt, subepithelial scarring, reticular haze and highly irregular astigmatism. On presentation, the manifest refraction was +2.00 -5.00 x 169 achieving a corrected distance visual acuity (CDVA) of 20/40. 

London Vision Clinic, London UK

The patient’s surgeon had offered a deep anterior lamellar keratoplasty, but he wondered if vision quality could be restored without resorting to a transplant. A multistage treatment plan was derived, firstly by removing and managing the epithelial ingrowth by flap-lift of the remaining flap wings, epithelial debridement and suturing of the flap edges. A Nd:YAG interface epithelial disruption procedure was required 2 weeks following flap suturing for minor epithelial ingrowth recurrence paracentrally. Following resolution of active epithelial nests, the second stage was carried out in order to further regularise the stromal surface and reduce sub-surface irregularities being masked by epithelial compensation.

An Artemis (Insight 100) very high-frequency digital ultrasound (VHFU) guided transepithelial phototherapeutic keratectomy (AGTE-PTK) was performed using the MEL 90 excimer laser (Carl Zeiss Meditec AG, Jena, Germany). At 11 months following PTK, most of the central reticular scarring had resolved and the epithelial profile was considerably regularised. This enabled the final stage of treatment to be carried out: a topography supported custom ablation (CRS-Master TOSCA II) performed as a further surface procedure having removed the epithelium by alcohol. A target of 1.50 DS was set for this non-dominant eye. 

Seven months after topography guided surgery, the patient reported that subjective night driving vision and quality of vision was significantly improved. The cornea was clear and topography significantly more regular. The manifest refraction was -1.00/-1.00x72 (SEQ -1.50 D) with CDVA of 20/25⁺². Multistage repair required first eliminating the epithelial ingrowth, sparing remaining stromal tissue from the remnants of the flap with central melt. Reduction of central reticular haze generated by the chronic inflammatory myofibroblast drive from the epithelial ingrowth. And epithelial map guided transepithelial PTK to reduce the masking of irregularities on the stromal surface, in order to perform a topography-guided custom ablation.