This case shows the potential risks of retreatments after refractive surgery, including insufficiently treated astigmatism, a hyperopic outcome, and epithelial ingrowth.
Given the patient’s medical history, and before beginning a treatment regimen, it is important to discuss at length the options for treatment and their related outcomes. The patient’s motivation for wearing a contact lens after developing a contact lens–related Pseudomonas ulcer, and in view of his profession, is understandably low and underlines the necessity for a more definite solution.
If flap amputation is considered, one has to be aware of a more hyperopic outcome, worse UDVA, and a flat cornea. Fitting a contact lens on a central flat cornea, even when performed by an experienced technician or optometrist, is difficult and the patient’s motivation for contact lens wear will be low.
I would avoid treating the stromal scar. Retreating a stromal scar with a topography-guided excimer laser treatment, possibly in combination with removal of the epithelial ingrowth, will lead to more flattening of the cornea and another unpredictable outcome. The amount of tissue that will have to be removed will lead to thinning of the stromal bed, and the irregularity may remain the same or become worse.
I would discuss the possibility of anterior lamellar graft excision in combination with the use of lamellar donor tissue. I would advise creating a deep lamellar cut using a big-bubble technique or a femtosecond laser. The diameter must be at least the size of the flap (approximately 9.0 mm overall). The goal must be to restore the curvature of the cornea and create a translucent cornea without a scar. The depth of removal of the anterior stroma must be more than 70% of the central thickness.
Among the things that have to be discussed with the patient are the visual and refractive outcomes, interface-related problems, and refractive correction after the surgery. Once the sutures are removed, the final refractive outcome can be managed by performing a refractive lens exchange.
The last suggested option, a (penetrating) mushroom-shaped keratoplasty, is not yet necessary because the endothelial cell count remains the same after excimer laser surgery. The visual outcomes of a penetrating procedure are potentially better than those of a lamellar procedure; however, the wound architecture, graft rejection period, and long period of topical medication use make this treatment less preferable than lamellar grafting.