[Unified classification of conditions united by the notion of 'diffusive lamellar keratitis (D.L.K.)' in the corneal refractive surgery]

A total of 4810 laser keratomilase surgeries (LASIK) in myopia and hypermetropia were analyzed. The spherical equivalent of clinical refraction in myopia amounted to -6.56 +/- 1.34 diopters, in hypermetropia it amounted to +3.97 +/- 1.74 diopters. The refraction parameters in myopia ranged from 1.5 diopters to 12.0 diopters; in case of astigmatism they ranged from 0.5 diopters to 2.75 diopters, and in hypermetropia they varied from 1.5 to 6.25 diopters. The age of patients ranged from 18.5 to 52; there were 49.3% male patients and 50.7% female patients. The observation period was up to 2 years. The lamellar corneal incision was implemented by three types of microkeratomes: "Hansatome" (Germany), "Moria" (France) and "Nidek" (Japan). Photoablation was carried out by Keracor Techlas 217 (Germany) of the "flying dot" scanning type and by "Profil 500" (Russia). The primary DLK reaction of the dystrophic nature amounted, during the first year of using the method, to 1:75 cases, during the second year it was 1:350 cases. The share of secondary DLK manifestations ranged from 0.1 to 17% with regard for a type of complications. DLK can be characterized by various forms, phases and stages. The reaction can be primary (early) and secondary (delayed). Basically, it is a universal inflammatory response of keratocytes to a prolonged malfunction of lamellar flap due to disadaptation. It is described as a complication of the lamellar surgery as a whole and is, most probably, a response to the sutureless surgery. There are factors, which diminish the frequency of such complication. A new working classification of the DLK response is presented. A new clinical classification of DLK and DLK-like conditions in the corneal lamellar surgery is offered. Finally, notion "lamellar malfunction" is offered for a comprehensive usage in refraction surgery.