Abstract
Purpose :
Normal corneas have high endothelial cell density (ECD) and abnormal corneas have very low ECD leading to endothelial decompensation (700 to 400 cells/mm2) during lifetime. Subnormal corneas have progressive endothelial deterioration of its cell density and morphology, characterized by large ECD range with different clinical status. To characterize if cornea can decompensate during lifetime, long term endothelial status must be analyzed according to corneal transparency and life expectancy. The purpose of this study is to describe different types of Subnormal Corneal Endothelium (SnCE) within theoretical average life expectancy of 100 years old.
Methods :
Cross-sectional study performed using 10-year corneal specular microscope (SM) database during December 2007 through November 2016. Non-contact SM (CSO, Italy) and a contact SM (BiOptics, USA) was used. All ECD data was plotted in a Statistical-Analytical Ruler (Fig.1) of a reliability index software (Cells Analyzer USA Patent, Technicall, Brazil) to identify if data were within the range of corneal decompensation during lifetime. Each CSMe data (blue area in Figure1) were classified in one of the 3 proposed nomina for subnormal corneal endothelium (SnCE) according to age and ECD: (1) SnCE with Transparent Cornea within Life Expectancy (TCLE); (2) SnCE with No Transparent Cornea within life Expectancy (No TCLE) (3) Decompensation due to Corneal Endothelium Failure (DCEF)(edema and symptoms). SnCE No TCLE subdivides as (a) Imminent Risk of Corneal Decompensation within Life Expectancy (Imminent DRisk) (1000-700 cells/mm2); (b) Immediate Risk of Corneal Decompensation within Life Expectancy (Immediate DRisk) (700-500 cells/mm2). Data for normal cornea was not used in study.
Results :
Within 9,399 eyes examined, 7326 were normal (77.94%) and 2073 SnCE (22.05%) were identified. 1387 eyes were SnCE TCLE (66.92%), 619 were SnCE No TCLE (29.85%); and 67 was DCEF (3.23%). Within SnCE No TCLE, 412 eyes were Imminent DRisk (19.87%); 207 eyes were Immediate DRisk (9.98%) (Figure 2). For the total populational analysis, SNCE LECT was 14.76%; Imminent DRisk was 4.38%; Immediate No TCLE was 2.20%; and DCEF was 0.71%.
Conclusions :
Within 9,399 eyes studied during 10 years, the risk for corneal transparency abnormality is approximately 7.29%. SnCE prevalence was 22.05%. The presented nomina is useful to describe different patterns of SnCE.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.