Posters

Comparison of 3 non-contact specular microscopy

Poster Details

First Author: H.Bayramlar TURKEY

Co Author(s):    R. Karadag   O. Cakici   E. Koyun        

Abstract Details

Purpose:

To investigate and compare specular microscopy and pachymeter measurements of 3 different non-contact specular microscopy devices in healthy subjects.

Setting:

Istanbul Medeniyet University, School of Medicine, Department of Ophthalmolgy, Istanbul, Turkiye Huseyin Bayramlar, Department of Ophthalmolgy, School of Medicine, Istanbul Medeniyet University, Istanbul, Turkiye

Methods:

Fifteen eyes of 15 healthy subjects (9 women) aged over 20 years old were included into the study. The mean age was 37.9±15.1. Non-contact specular microscopic measurement was performed in the right eyes of the subjects. Central corneal thickness (CCT) and endothelial parameters including, endothel cell count, maximum, minimum and mean cell size and hexagonality rates were investigated. Three non-contact specular microscopy devices that we used in the study were Nidek CEM-530 (Nidek Co., Japan), Topcon SP-3000P (Topcon Corp., Tokyo, Japan) and Tomey EM 3000 (Nagoya, Japan). All measurements were performed by same examiner. For statistical analysis, SPSS 16 package program were used. Because the data distributed normally, parametric tests were used and p<0.05 was accepted as significant.

Results:

With Nidek SM, endothelial cell count, CCT, maximum, minimum and mean endothelial cell size and hexogonality rate were 2448.5±388.03 per mm2, 543.2±36.8, 1123.9±277.07, 148.5±24.3, 417.6±68.17 µm and 71.5±6.9, respectively. Same parameteres were found as 2582±420.8 per mm2, 527.0±36.41, 811.1±121.6, 163.8±69.6, 398.7±73.7 µm and 58.2±7.8 with Topcon SM; 2556.27±341.8 per mm2, 533.13±38.9, 944.7±302.5, 94.2±17.0, 397.5±52.4 µm and 44.13±7.8 with Tomey SM, respectively. Endothelial cell count, CCT and mean endothel cell size measurements were not differed from each other between 3 devices (p>0.05 for all). Maximum endothelial cell size measurements taken by Nidek was significantly higher than that of Topcon (p=0.001), while there was no significant difference between Nidek and Tomey (p=0.058) and between Tomey and Topcon (p=0.081). Minimum endothelial cell size measurements taken by Tomey was significantly lower than that of Topcon (p<0.001) and Nidek (p<0.001), while there was no significant difference between Nidek and Topcon (p=0.794). The highest rate of hexagonality was found in Nidek measurements and in comparison of 3 devices, each of three paired comparison of 3 devices showed significant difference (p<0.001).

Conclusions:

Endothelial cells have vital importance in maintaining corneal clarity. When endothelial cell counts markedly decrease, cornea began to lose its transparency. Endothelial cell count can diminish due to several reasons such as trauma. Bullous keratopathy is one of the most frequent causes of keratoplasty. Determining the endothelial cell count is important in follow-up of the patients and in deciding what type of surgery will be done. Today, the phakic lens implantation which is performed in young ages, increase the importance of the endothelial cell counting and morphology. Low endothelial cell number may facilitate the endothelial failure especially in the eyes with an anterior chamber phakic intraocular lenses. Endothelial cells may count with various methods. One of them is non-contact specular microscopy. These are very quick and practical devices. In this study, we found similar results for endothelial cell count, CCT and mean endothelial cell size with 3 devices, though hexagonality values are different from each other. While Nidek, Tomey and Topcon showed good correlation for endothelial cell count, CCT and mean endothelial cell size, they did not show a correlation in terms of hexagonality. In terms of endothelial cell morphology, there are significant differences and no correlation between these 3 devices, according to our study. So, it does not seem to be appropriate to use those 3 devices instead of each other. FINANCIAL INTEREST: NONE