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104. Jahrestagung der Deutschen Ophthalmologischen Gesellschaft 2006
Abstract
Abstract
FR.07.10 Accommodative IOL's Pro & Con Auffarth G. U.1, Guthoff R. F.2
1Universitäts-Augenklinik Heidelberg, 2Universitäts-Augenklinik Rostock Accommodative IOL’s Con
True pseudophakic accommodation is caused by ciliary muscle contraction. The only currently available lens models of attaining pseudophakic accommodation are based on the principle of effecting refractive change by shifting the optical system of the artificial lens along the optical axis, induced by angulated flexible haptic designs.
So called “accommodative” artificial lenses are commercially available today. Clinical and experimental investigations show that an accommodative ciliary muscle contraction causes in slight changes in haptic angulation and axial shift of these lens models. No statistically significant differences however have been found in some studies between these IOL generation and standard IOL’s concerning change in anterior chamber depth and accommodative amplitude.
The application of objective accommodation measurements is mandatory to objectively assess the accommodative capacity of so-called accommodative intraocular lenses. Available methods, especially for measuring near vision, tend to depend on subjective patient information and a variety of influences that are difficult to objectify, such as the type of eyeglass correction, target illumination, distance, and the specification of reading tests. Objectively measurable parameters include changes of the anterior chamber depth as well as objective refraction measurements obtained, for instance, by coincidence refractometry according to ScheinerÂ’s principle and streak retinoscopy. Future studies regarding accommodative lenses should also consider the IOL properties, astigmatism, pupillary diameter, and the test conditions with regard to their standardization. Factors presently not fully clarified but objectively limiting the function of currently available accommodative IOLÂ’s are the maximal available space and the influence of capsular bag shrinkage. Factors known but in publications not always properly addressed are true axial shift of the implant and change of the refractive power of the complete optical system of the eye.
The proof of principle for axial shift driven IOLÂ’s in the human eye according to literature and own experimental as well as clinical results is still lacking.
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