An Experimental And Clinical Study On The Operative Therapy For Mycotic Keratitis

Objective By systemically summarizing the rule of the occurrence and development for mycotic keretitis (MK), comparing the recurrence ratio of MK after lamellar keratoplasty (LKP), to explore the scientific methods of operative therapy for MK.Methods 1. 24 Mk models were made for fusarium solaui (FS), aspergillus fumigutus (AF) and candida albicans (CA) by New Zealand white rabbit (NZW). Light and electric microscopic observation were did at early, middle and late period (3, 5～8, 12 days) of the disease. The fungal (various kind) growth mode and responses of the corneal tissue were demonstrated. 2. Deep LKP was performed in 60 cases of MK at the period of middle corneal stromal in NZW (20 cases for FS, AF, and CA respectively ). The diameter of the trephine was 1.5 more than that of the disease .The recurrence ratio of the three kinds of MK after LKP were compared.3. The fungal kind identify and LKP were performed in 11 patients with MK (5,4 and 2 cases for FS, AF, and CA respectively ). The recurrent situation of the patients after LKP was studied.Results1. The light and electric microscopic observation showed that: FS grow parallel to the corneal stromal collagen lamellae. The new hyphae have 45o angle with the trunk. AF grow vertical to thecorneal stromal collagen lamellae. It can traverse the Descemet membrane in so much as 5 day. CA grow parallel or vertical to the stromal collagen lamellae, it growth slowly.2. The experimental LKP showed that: after LKP 5% (1/20),35% (7/2), 10%(2/20) were recurred for FS, AF and CA respectively. FA recurred from the edge of the graft-host .AF and CA were recurred from the graft-host interbed.3. The result of fungal kind identification showed that the 11 patients include 5, 4 and 2 patients of FS, AF, CA respectively. The clinical LKP showed that no recurrence was discovered after the operation for Fs and CA. But 2 cases of AF were recurred from graft-host interbed.Conclusions The light and electron microscopic observation demonstrated that the different fungi grew in the corneal tissue with different growth mode and different corneal tissue responses. It indicated that the operative method (LKP or PKP) would be determined upon the fungal kind and the disease phases. LKP is adapted to FS and some CA.PKP is more safety for AF. The results of experimental LKP confirmed the above conclusions. The results of clinical LKP are also accordant to the above-mentioned principles for the operative methods choice.