Abstract
Abstract: :
Purpose: To evaluate accuracy of full automatic cell analysis system KC-3309 (ver. 1.05) (using both automated and manual methods) compared to the center method in measuring endothelial cell count (ECC). Method: Non contact specular microscopy (NONCON ROBO) of the cornea of 17 eyes from 9 normal subjects was performed. Each image was analyzed for endothelial cell density by: the center method (CM) in which the center of 100 contiguous cells was marked manually, the automated method (AM) which automatically analyzes the endothelial image and the manual method (MM) which allows for correction of automatic analysis by erasing or adding lines in order to determine the exact edges of the cells. The same person (GC) obtained all measurements. The length of time it took to perform each of these analysis was also measured. Results: Balanced repeated measures ANOVA based analysis showed that there was no statistical difference in ECC when comparing the AM to the CM. However, there was a statistical difference between AM and MM as well as between the CM and MM.The mean ECC for AM was 2611 cells/mm 2 with 95% CI 2549-2674; CM 2616 cells/mm 2 with 95% CI 2554-2678; MM 2352 cells/mm 2 with 95% 2290-2415. The difference between the means of AM and CM is -4.82 with 95% CI 92.87-83.23, t value= -0.11 and p= 0.91. The difference between the means of AM and MM is 259.0 with 95% CI 170.9-347.1, t value=5.99, p<0.0001. The difference between the means of CM and MM is 263.8 with 95% CI 175.8-351.9, t value 6.1, p<0.0001. The average time to obtain ECC for each method was CM 1.24 min, AM 0.08 min, MM 2.63 min. Conclusions: Specular microscopy is a useful tool for evaluation of endothelial cell densities. Clinical applications of ECC include: the evaluation of prospective corneal donor material, ability of a host cornea to tolerate cell loss and detection of posterior corneal pathology. Therefore, having a time efficient and reliable method of obtaining ECC is extremely valuable. Our study showed that there was a significant difference between the manual method compared to the other methods (AM and CM) and thus the manual method does not offer reliable ECC. However, there was no statistical difference in ECC when using the AM compared to the CM. Therefore, the AM offers physicians the ability to perform ECC as accurately as the CM in a fraction of the time.
Keywords: 371 cornea: endothelium • 430 imaging/image analysis: clinical • 356 clinical (human) or epidemiologic studies: systems/equipment/techniques