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Daily fluctuations in visual function, epithelial mapping and corneal tomography in patients with mild form of Fuchs’ endothelial corneal dystrophy

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First Author: I.Krolo CROATIA

Co Author(s):    A. Kasumović   I. Radman   I. Sabol   K. Lončarić   I. Petric Vicković   Z. Vatavuk     

Abstract Details

Purpose:

To investigate the functional and structural daily variations in eyes with mild form of Fuchs' endothelial corneal dystrophy (FECD).

Setting:

University Department of Ophthalmology, University Hospital Center „Sestre milosrdnice“, Vinogradska 29, Zagreb, Croatia

Methods:

Study included 40 eyes of patients with beginning stage of FECD. Patients' subjective visual disability was assesed with the V-FUCHS instrument. All eyes underwent three daily measurements (8AM, 2PM, 8PM) of visual acuity and function; twilight vision (TV) and spatial frequency contrast sensitivity (CS) testing (Vista Vision Far-Pola, DMD MedTech charts). We also measured daily structural changes using endothelial microscopy (Tomey EM-4000), anterior segment optical coherent tomography (Optovue Avanti Widefield AS-OCT) and corneal tomography (Pentacam, OCULUS). Epithelial and corneal thickness parameters were analysed, as well as corneal tomography changes with an aim of determining the daily diversity of results.

Results:

Statistical analysis did not show any significant change in SM measurements (cell density, hexagonality, coefficient of variation and central corneal thickness) during the day. Uncorrected distance visual acuity was significantly lowest in the morning and showed gradual improvement during the day (0.429-0.492-0.529); P<0,001. TV showed the best results in the afternoon (0.738-0.788-0.775); P=0,017, while CS showed the best results in the evening measurements, most prominent in low spatial frequencies (P<0,001). Morning Pentacam measurements showed significantly higher central corneal thickness (567.1 µm-563.1 µm-563.5 µm; P<0,001) and Thinnest Location (TL) values (562.2 µm-557.2 µm-557.5 µm; P<0,001), as well as flatter values of K1 and K2 (P=0,015 and P=0,04 respectively) and EKR65 K1 and EKR65 K2 (P<0,001). AS OCT epithelial mapping showed the greatest CCT 5mm (554.0 µm-550.5 µm-550.4 µm; P<0,001) and CCT 7mm (553.6 µm-550.3 µm-551.0 µm; P=0,025) values in the morning. Epithelial thickness was also highest in the morning on both maps (CET 5mm and CET 7 mm). Comparing CCT measurements by three different methods (SM, AS OCT and Pentacam), Pentacam showed the greatest values and greatest variability at 8PM (+21 µm comparing to SM and +8 µm to AS OCT); P<0,0001.

Conclusions:

Structural corneal changes correlated well with visual performances. Morning measurements in patients with mild FECD demonstrated significantly thicker epithelial and corneal thickness mapping and flattest keratometry measurements on both anterior corneal surface and EKR65 Pentacam measurements. AS OCT epithelial mapping could be a very useful tool for monitoring patients even at the onset stages of FECD in clinical practice and research.

Financial Disclosure:

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