Subfoveal And Parafoveal Choroidal Thickening In Patients With Keratoconus Using The Etdrs Grid On Swept-Source Oct
Published 2024 - 42nd Congress of the ESCRS
Reference: PO805 | Type: Poster | DOI: 10.82333/085g-p273
Authors: Neus Burguera Giménez 1 , Celeste Briceno-Lopez 1 , María Amparo Díez-Ajenjo 2 , Noemí Burguera 3 , María Josefa Luque-Cobija 4 , María del Carmen García-Domene 4 , Cristina Peris-Martínez* 5
1Anterior Segment and Cornea and External Eye Diseases Unit,Foundation Ophthalmological Medical Hospital (FOM),Valencia,Spain;Department of Optics and Optometry and Vision Science,University of Valencia,Burjassot,Spain, 2Department of Optics and Optometry and Vision Science,University of Valencia,Burjassot,Spain;Anterior Segment and Cornea and External Eye Diseases Unit,Foundation Ophthalmological Medical Hospital (FOM),Valencia,Spain, 3Ophthalmology Department,Q Vision Vithas Virgen del Mar Hospital,Almeria,Spain, 4Department of Optics and Optometry and Vision Science,University of Valencia,Burjassot,Spain, 5Anterior Segment and Cornea and External Eye Diseases Unit,Foundation Ophthalmological Medical Hospital (FOM),Valencia,Spain;Surgery Department, Ophthalmology,University of Valencia,Valencia,Spain
Purpose
There is growing evidence that confirms morphological changes in the posterior structures in patients with keratoconus (KC); however, isolated alterations could have been missed. This study assesses choroidal thickness (CT) in the fovea and beyond in KC eyes.
Setting
Anterior Segment and Cornea and External Eye Diseases Unit, Fundación de Oftalmología Médica (FOM)
Methods
This prospective case-control and non-randomized study enrolled 107 eyes, 62 eyes of 62 patients with KC, and 45 age-matched eyes of 45 control subjects with axial length in the range of 22–26 mm. Swept-source optical coherence tomography (SS-OCT) was performed to manually measure the subfoveal choroidal thickness (SCT) using a single-line scan. CT was obtained automatically from the Early Treatment Diabetic Retinopathy Study (ETDRS) grid using the 12-lines radial scan pattern. A two-way repeated-measures analysis of variance (ANOVA) was conducted to evaluate CT variations among macular eccentricity, parafoveal area, and the interaction between both factors. CT was compared in all parafoveal areas between groups and subgroups of KC.
Results
SCT was significantly thicker in KC eyes (357 ± 57 lm) than in healthy eyes (325 ± 63 lm) (p<0.001). Significant choroidal thickening was observed in the central ring and outer and inner rings of the temporal, superior, and inferior parafoveal macular areas (p<0.001), except in the outer ring of the nasal macular zone (p>0.05) of KC compared to healthy eyes. The CT significantly decreased from the center to the outer ring regardless of the presence of KC (p<0.001). The choroid in the nasal macular zone was significantly thinner than that in the temporal, superior, and inferior parafoveal areas (p<0.001).
Conclusions
The choroidal structure increased its thickness not only in the subfoveal area, but also in eight parafoveal areas of the ETDRS grid encompassing a wider area of macular examination.These findings demonstrate and corroborate that keratoconus is not a purely corneal disease. Furthermore, it confirms the role that the choroidal structure has in the pathophysiology of keratoconus.