Experimental studies on the treatment of NaOH burns of the eye in the rabbits.

의학과/박사[한글] [영문] There have been no definitely reliable means of treating alkali burns of the eye in the past. Herewith, the present investigation was undertaken to establish the most ideal and appropriate therapeutic regimens for alkali barns of the eye experimentally induced in the rabbits. The rabbits were anesthetized with pentobarbital sodium (30mg/kg; 1. V.) and 2 ml. of 1/10 N. NaOH solution was applied locally to the eye for 5 minutes. The eye was then irrigated with, unless stated otherwise, normal saline for 5 minutes. Immediately following the production of the burn, the fellowing therapeutic measures were applied for a period of up to 8 weeks: A. Non-surgical treatment: 48 animals were subdivided into the following 4 groups : a) Control group : No therapeutic measure was applied. b) Cortisone group: One or two drops of 0.5% cortisone acetate suspension was instilled every 2 hrs. during the daytime and 1.5% cortisone acetate ointment was locally applied at night. c) Acetic acid group : 1% acetic acid was used to irrigate the eye for 15 minutes. In this group, the washout with normal saline was omitted. d) AnMonium tartrate group : One or two drops of 10% neutral ammonium tartrate solution was instilled 4 times a day. B. Surgical treatment: 54 animals were subdivided into the following 3 groups. a) Control group : No treatment was given. b) Hemegraft group: The homograft was performed on the palpebral conjunctiva and on the bulbar conjunctiva alone or with the upper part of the cornea. Having Performed the homograft operation 1% atropine sulfate ointment and 0.5% oxytetracycline ophthalmic ointment were applied local]y twice a day. c) Heterograft group: Human amniotic membrane was used for this group and the transplantation was performed on the bulbar conjunctiva. The amniotic membrane was stored in a refrigerator (4℃) for 16-24 firs prior to the operation .The postoperative care as described for the previous group was also given. Following these treatments, the eye was enucleated at scheduled time intervals and were fixed in 10% formaline solution before the histological sections were made. These sections were stained with hematoxyline and eosin. The degree of healing was judged by histological examination. A) Non-surgical group : Severe inflammatory reaction and marked postinflammatory result such as pseudopterygium and symblepharon was formed in the control group. Cortisone was most effective in minimizing the inflammatory reaction and also in resulting sequelae such as neovascularization into cornea and symblepharon. Newly formed vessels in cornea was faint, short in length and muck less in number than other groups. The onset of vascularization in cornea was slightly delayed. Fibrous scar formation of subconjunctival tissue and symblepharon was less significant than other groups. Corneal reepithelization was not delayed or interfered by local treatment with cortisone. Neutralization with 1% acetic acid solution was bet effective but rather harmful than control group. Neutral ammonium tartrate solution did net help the clearance of corneal opacity and consequently brought similar results with control group. B) Surgical group: Regardless of the Site of transplantation the homograft with the conjunctival mucous membrane after removal of the traumatized necrotic tissue worked encellently for minimizing reaction and reducing :he resulting sequelae. Symblepharon was little or none. Pseudopterygium was not seen in these groups, although it was common in the nonsurgically treated groups. The homograft on the palpebral conjunctiva or on the bulbar conjunctiva and the upper part of cornea caused a marked fibrous scaring and extensive neovascularization of the cornea. Transplantation to a portion of the bulbar conjunctiva was most effective in minimizing the inflammatory reaction, fibrous scar formation, and neovascularizion of the cornea. The amniotic membrane had a marked tendency to shrink after the transplantation. This is a serious handicap as compared with the homograft using the conjunctiva. However, this membrane took well after the transplantation and the host conjunctival epithelium grew over this membrane. This minimized the reaction and resulting sequelae. Amniotic membrane can be used as a substitute for the homograft with relatively good results. Judging from these results, in the non-surgical group,.the ideal treatment for the alkali burn with NaOH is the immediate, thorough washing with water or saline solution and application of cortisone. Results of surgically treated group were much better than non-surgically treated group, but these groups did net work satisfactorily in clearing the corneal opacity. It is probably due to a severe primary damage of the corneal tissue by alkali.restrictio