Kohlhaas M, Draeger J, Böhm A
Universitäts-Augenklinik Hamburg.
Ophthalmologe. 1995 Aug;92(4):410-3.
The influence of corneal hydration on the precision of plano lamellas and on the precision of lenticles modified with a "non-freeze" technique was studied in pig eyes. Ten pig eyes were dissected with a rotating lamellar microkeratome, and the discs were measured with a mechanical pachymeter. The hydration of the discs was measured in BSS and in dextran solution. A total of 160 corneal discs with different degrees of hydration were modified with a "non-freeze" technique on concave anf convex vacuum cylinders and measured with a photokeratoscope TMS. The discs increased in thickness within 3 h becoming 1.7 times as thick in BSS and 1.2 times as thick in dextran. After refractive dissection minor modifications were achieved with higher precision than were larger corrections. However, we achieved an undercorrection after all refractive dissections. Plano-discs for refractive modification should be taken from dehydrated corneoscleral discs or from intact eyes. Owing to mechanical factors during cutting and tissue hydration undercorrection of the intended change was observed.
在猪眼中研究了角膜水化对平片层精度以及对采用“非冷冻”技术改良的晶状体精度的影响。用旋转板层角膜刀解剖10只猪眼，并用机械测厚仪测量切片。在平衡盐溶液（BSS）和右旋糖酐溶液中测量切片的水化程度。在凹面和凸面真空柱体上用“非冷冻”技术对总共160个不同水化程度的角膜切片进行改良，并用TMS角膜地形图仪进行测量。切片在3小时内厚度增加，在BSS中变为原来厚度的1.7倍，在右旋糖酐中变为原来厚度的1.2倍。屈光性切割后，小的矫正比大的矫正能达到更高的精度。然而，所有屈光性切割后我们都出现了欠矫。用于屈光性改良的平片应取自脱水的角膜巩膜切片或完整的眼睛。由于切割过程中的机械因素以及组织水化，观察到预期改变出现了欠矫。
