Dados do Trabalho

Título

CORNEAL ENDOTHELIAL SEVERITY SCORING SYSTEM (CESSS) FOR FUCHS ENDOTHELIAL DYSTROPHY (FED) BY SPECULAR MICROSCOPY AND POSSIBLE CORNEAL ZONES TO CALCULATE ENDOTHELIAL CELL DENSITY (ECD

Fundamentação/Introdução

Morphologically, the cornea has 3 zones: Central (CZ), Mid Peripheral (MPZ), and Peripheral (PZ). Excrescences of Descemet's membrane (EDM) characterize FED, and with their progression increase in quantity and size and initially affect the CZ endothelial mosaic (EM) to later the MPZ and PZ. Different profiles of EM involvement at different corneal zones indicate the need to grade these areas, from most to least affected. Non-contact specular microscopes (SM) evaluate the CZ, the central part of the MPZ, and never the PZ.

Objetivos

To study EM deterioration using an objective CESSS for FED with SM to confirm previous studies showing that exposed cornea areas can show worse endothelial patterns; Identify EM zones where it is possible and not calculate corneal endothelial density.

Delineamento e Métodos

Retrospective cross-sectional study, 372 eyes, 186 patients with FED. Age range 25-88 years old and an average of 59±12 years old, Female 140 (75.26%) and males 46 (24.76%).
Contact specular microscopy (2013-2022) - Corneal Endothelium Lab - DANAT UFPR, Curitiba, Brazil with a BioOptics CSM, Oregon, USA, and Cells Analyzer – Corneal Endothelial Lab, Technical, Brazil.
EM involvement by EDM was scored into six categories (G1 to G6) to describe the studied zones: Central (CZ), superior mid-periphery (SMPZ), superior (SZ), temporal (TZ), inferior (IZ), and nasal (NZ), and determine which EM zones can be included in a sampling process to calculate the corneal endothelial density (CED). Results are presented by descriptive statistics.

Resultados

The percentages of EM involvement in FED:
CZ: G6 30%, G5 24%, G4 8%, G3 13%, G2 15%, G1 10%;
SMPZ: G6 10%, G 8%, G4 5%, G3 10%, G2 22%, G1 32%;
SZ: G6 3%, G5 1%, G4 1%, G3 2%, G2 6%, G1 85%;
TZ: G6 6%, G5 6%, G4 4%, G3 9%, G2 18%, G1 57%;
IZ: G6 7%, G5 7%, G4 6%, G3 6%, G2 18%, G1 56%;
NZ: G6 3%, G5 8%, G4 2%, G3 6%, G2 19%, G1 62%;
Corneas with zones that can be used to integrate the EM sampling process for calculating the ECD were classified as grades 1, 2, and 3: CZ 141 (37.9%), SMPZ 243 (65.32%), SZ 350 (94.08%), TZ 312 (83.87%), IZ 298 (80.1%), and NZ 323 (86.82).

Conclusões/Considerações Finais

The most affected EM zone in the FED was the central one, and the least affected were the peripheral ones. However, the superior peripheral zone was much less affected than all other zones.
Examining the central zone only 38% of exams be able to calculate ECD, including peripheral zones, calculate until 80 to 94% of exams. Unfortunately, non-contact specular microscopes don’t examine corneal peripheral zones.