Molecular, clinical, and pathologic comparison of two distinct strains of Haemobartonella felis in domestic cats

PURPOSE: To evaluate the long-term effect of photoastigmatic refractive keratectomy (PARK) on mild keratoconus. SETTING: Laser Unit, Ein Tal Eye Center, Tel Aviv, Israel. METHODS: Eight eyes of 6 patients with stable compound myopic astigmatism and topography features of keratoconus were treated with a VISX Twenty-Twenty excimer laser. The laser beam slit width ranged between 4.8 and 5.0 mm according to the degree of cylinder. Preoperative slitlamp examination did not reveal significant thinning, ectasia, or scarring. Astigmatism ranged between -2.00 and -7.50 diopters and follow-up, between 36 and 48 months. RESULTS: In 7 of 8 eyes, uncorrected visual acuity (UCVA) before PARK ranged between 6/30 and finger counting. After PARK, it ranged between 6/9(-) and 6/15, and patients could manage in most of their daily activities without using spectacles. In 2 eyes, the final UCVA was 6/15(-) and 6/15. In 1 eye, treatment failed to improve UCVA and corneal topography revealed progression of the keratoconus. CONCLUSIONS: Photoastigmatic keratectomy was partially effective in eyes with mild stable keratoconus. However, the long-term results may be altered by progression of corneal thinning and ecstatic disease. In addition to the mild nature of the keratoconus, this is a small series and further studies are needed to confirm these results.