Experimental Study on the Prevention of Anterior Segment Ischemia by Preservation of Anterior Ciliary Vessels

Purpose: To observe the effect of preserving anterior ciliary vessels (ACVs) on anterior segments of rabbit eyes undergoing tenotomy of extraocular muscles. Methods: Thirty-two adult New Zealand white rabbits were divided into four groups. Same procedures were done in both eyes in each group except that left eyes underwent preservation of ACVs. In the first group medial and lateral recti, in the second group, superior and inferior recti, in the third group, medial, lateral and superior or inferior recti and in the fourth group, all four recti, underwent tenotomy. Slit-lamp examination, intraocular pressure (IOP) measurement, total protein and lactic acid quantification in aqueous humor were done in all eyes pre- and post-operatively. By four weeks after operation, the eyes were enucleated for histological examination and electron microscopy. All data were analyzed using SPSS version 10.Results: In the left eyes of both group 1 and group 2, no inflammatory response was observed. In the left eyes of group

Experimental Study on the Prevention of Anterior Segment Ischemia by Preservation of Anterior Ciliary Vessels

Purpose: To observe the effect of preserving anterior ciliary vessels (ACVs) on anterior segments of rabbit eyes undergoing tenotomy of extraocular muscles. Methods: Thirty-two adult New Zealand white rabbits were divided into four groups. Same procedures were done in both eyes in each group except that left eyes underwent preservation of ACVs. In the first group medial and lateral recti, in the second group, superior and inferior recti, in the third group, medial, lateral and superior or inferior recti and in the fourth group, all four recti, underwent tenotomy. Slit-lamp examination, intraocular pressure (IOP) measurement, total protein and lactic acid quantification in aqueous humor were done in all eyes pre- and post-operatively. By four weeks after operation, the eyes were enucleated for histological examination and electron microscopy. All data were analyzed using SPSS version 10.Results: In the left eyes of both group 1 and group 2, no inflammatory response was observed. In the left eyes of group 3 and 4, we observed mild inflammatory response with slit-lamp examination, which disappeared in one wk. However, we did not find significant changes in IOP, total protein and lactic acid of aqueous humor, histology and electron microscopic examination in these groups. In the right eyes in group 2, 3 and 4, we observed moderate to severe inflammatory changes, a few even developed anterior segment ischemia, appeared as decreased IOP, increased total protein and lactic acid in aqueous humor, along with pathological and electron-microscopic changes. Conclusion: Simultaneous tenotomy of three or four recti or two vertical recti on one eye may decrease anterior segment blood flow even lead to ischemia. ACVs preservation may protect the blood circulation in anterior segment. Our study suggests that ACVs preservation in strabismus surgeries especially those involving multi-recti tenotomies may prevent potential anterior segment ischemia. Eye Science, 2003; 19: 25 - 32.