Contact vs. Non-contact Specular Microscopy after Cataract Surgery

Abstract

OBJECTIVE: Quantitative assessments of in vivo endothelial cell density, size and shape after cataract surgery provide an important tool for control of surgical quality. To investigate reproducibility, quality and advantages or disadvantages of individual specular micrographs obtained with a non-contact microscope, endothelial cell parameters were compared with micrographs obtained with a contact specular microscope. STUDY DESIGN: Five photographs of the central cornea of 24 eyes (17 patients) 6 months after clear-corneal cataract surgery were assessed by non-contact, using the zoom mode, and contact specular microscopy, respectively. After qualitative morphological and quantitative morphometric analysis of the 240 photographs, data of both methods were compared. SETTING: Department of Ophthalmology, Giessen, Germany. MAIN OUTCOME: Image analysis of different cell parameters showed a few significant differences in both methods: Intraphotographic analysis showed no significant coefficient variation of mean cell parameters, while interphotographic analysis detected a significantly higher spread of many values, such as cell density and area in non-contact specular microscopy. The rate of obtaining endothelial images was very successful. CONCLUSIONS: The clinical advantages of the non-contact instrument are the high successful rate of taking images with safety and useful reproducibility. The smaller field obtained with the noncontact system allows estimation of endothelial morphological and quantitative parameters. More detailed information and precision of the posterior endothelial surface was provided by the contact specular microscope.