The Algorithm of the Diagnostics and Surgical Ametropia Correction in Patients after Radial Keratotomy

Alexander Doga, Nataliya Maychuk, Olga Kondakova

Sv. Fyodorov Eye Microsurgery Federal State Institution, Moscow, Russia

Purpose: to elaborate the algorithm of the ocular surface condition evaluation and refractive surgery ametropia correction in patients after radial keratotomy (RK).

Methods: 94 patients (188 eyes) with ametropies after RK were examined with confocal microscopy (ConfoScan4, Nidek Technologies, Italy) and functional lacrymal complex parameters evaluation (Shirmer test -1, -2; break-up time test; corneal epithelium estimation in 20-points scale).

Results: The functional lacrymal complex parameters evaluation didn't detect the correlation with the different types of corneal scarring at the RK zones. Confocal microscopy revealed 2 biomechanically different types of corneal scarring at the RK zones. The first one is the linear scar contained with dense fibrous tissue (57.4% - I group), the second one represents singular fibrous elements at the incisions periphery and/or optical negative substance inside with the epithelium ingrowth (42.6% - II group). All patients were operated with conventional LASIK (excimer laser Microscan-PIC, Russia; microkeratome Zyoptix XP, Perfect Vision, Germany). In II group the intra-operative incision openings (IOOP) were detected in 78.8%, sub-flap epithelium ingrowth – 17.5%, irregular astigmatism – 28.8% compare to only 3.7% of IOOP in I group.

Conclusion. The CM II scarring type significantly increases the risk of intra- and post-op. complications and requires superficial ablation technologies or not-surgical ametropia correction. Our algorithm of the diagnostics and surgical ametropia correction in patients after RK allows to decrease the number of disregenerative complications.