COMPARISON OF CHOROIDAL AND MACULAR SUBFOVEAL THICKNESS IN HEALTHY AND KERATOCONUS EYES OF DIFFERENT STAGES.

Published 2022 - 26th ESCRS Winter Meeting

Reference: P131 | Type: Abstracts | DOI: 10.82333/x6n1-jh36

Authors: Neus Burguera-Giménez* ¹ , Celeste Briceno-Lopez ¹ , Mª Amparo Díez-Ajenjo ² , Mª José Luque-Cobija ² , Mª Carmen García-Domene ² , Noemi Burguera ³ , Cristina Peris-Martínez ⁴

¹Cornea and anterior segment unit,FISABIO Oftalmología Médica,Valencia,Spain;Department of Optics and Vision Sciences,University of Valencia,Burjassot, Valencia,Spain, ²Department of Optics and Vision Sciences,University of Valencia,Burjassot, Valencia,Spain;Cornea and anterior segment unit,FISABIO Oftalmología Médica,Valencia,Spain, ³Ophthalmology department,Q vision, Vithas Virgen del Mar Hospital,Almeria,Spain, ⁴Cornea and anterior segment unit,FISABIO Oftalmología Médica,Valencia,Spain;Surgery department, Faculty of Medicine,University of Valencia,Valencia,Spain

Purpose

To compare subfoveal choroidal thickness (SCT) and subfoveal macular thickness (SMT) measurements of healthy and keratoconic eyes depending on keratoconus (KC) severity.

Setting

FISABIO Ophtalmological Medical Centre (FOM), University of Valencia, Catedra Alcon-FISABIO-UVEG

Methods

Cross-sectional and prospective case-control study with 80 eyes of 60 KC and 20 control patients aged between 18 and 50 years recruited from FISABIO Ophthalmological Medical centre. All patients underwent a comprehensive ophthalmological exam including subjective refractive error, slit lamp biomicroscopy, axial length (AL) measurement with IOL Master 700 (Carl Zeiss Meditec, Jena, Germany) and corneal analysis with Pentacam HR (Oculus Optikgeräte GmbH, Wetzlar, Germany). SMT and SCT were automatically obtained from Swept Source OCT (DRI-1 Atlantis SS-OCT, Topcon Medical System, Japan) using the 12 mm line scan pattern. Only eyes with AL between 22 and 26 mm and spherical equivalent (SE) less than -6.00 D were included. KC eyes were stratified in 4 groups considering the topographic KC classification (TKC): TKC0 (TKC= possible and fellow eye with diagnosed KC, n= 18), TKC1 (n=17), TKC2 (n=17) and TKC3 (n=8). Shapiro-Wilk test showed that SMT was not normally distributed, hence, Mann-Whitney test was used to compare the two main groups whereas Kruskal-Wallis test was run to explore SMT variations between all subgroups. SCT was normally distributed, thus, T-test was used to compare KC and healthy while one-way analysis of variance (ANOVA) with Tukey post hoc was used for assessing SCT differences between control and KC subgroups.

Results

Mean age (28.70±7.50 vs. 30.67±9.90 years, U=551.5, p=0.59), mean SE (-2.15±1.90 vs. -1.80±1.70 D, U=492.5, p=0.23) and mean AL (24.23±0.99 vs. 24.03±1.08 mm, U=661.5, p=0.49) did not show statistical differences between healthy and KC eyes. Similar SMT were observed in both groups (control 240±20 vs. KC 246±25 μm, U=543, p=0.59), whereas KC presented significant thicker SCT compared to non-KC eyes (KC 311±60 vs. control 263±88 μm, t(25.17)=2.24, p=0.034). As KC phases increased, SMT became thinner: TKC0= 254±23 μm; TKC1= 240±13 μm; TKC2= 250±33 μm; TKC3= 235±25μm; Nevertheless, multiple comparisons manifested not statistical differences among all groups (H(4), p=0.34). The choroid suffered a slight thickening in early KC stages (TKC0= 300±65 μm; TKC1= 320±73 μm). However, SCT remains unchanged in advanced KC grades (TKC2= 310±54 μm; TKC3= 316±33 μm). One-way analysis of variance revealed non statically significant SCT variations between healthy and KC subgroups (F(5,75)=1.96, p=0.11).

Conclusion

Choroidal thickness seems to be increased in early KC stages remaining stable in advanced phases. Macular thickness decreased as the KC phase increased. Although a choroidal thickening could be expected in KC eyes, further investigations are needed to confirm the role of the choroids in the KC activity due to the non-statistical differences among healthy and KC subgroups.