Correlation Analysis Between Tomographic, Biomechanical And Chorioretinal Changes In Keratoconus Patients
Published 2024 - 42nd Congress of the ESCRS
Reference: FP02.07 | Type: Free paper | DOI: 10.82333/yvny-ha30
Authors: Meike Katharina Pandl* 1 , Hyeck-Soo Son 1 , Victor Aristide Augustin 1
1Ophthalmology,University Hospital Heidelberg,Heidelberg,Germany
Purpose
Traditionally, keratoconus (KCN) has been viewed as a degenerative disease with effects limited to the cornea. Due to this perspective, less emphasis has been placed on investigating its potential impact on the posterior segment of the eye. It has also been classified as a non-inflammatory ectasia. However, recent studies have shown that latest evidence contradicts this theory. The aim of this study was to investigate the involvement of posterior pole structures in eyes affected by keratoconus.
Setting
In this single-center, retrospective and prospective study, we reviewed the clinical records of 296 eyes examined at the University Eye Hospital in Heidelberg, Germany, between January and October 2023. This comprised 186 eyes of 128 patients diagnosed with keratoconus (KCN), 12 eyes with forme fruste keratoconus (FFK), and 100 eyes of 53 healthy subjects (C).
Methods
The ophthalmic evaluation included BCVA assessment, slit lamp biomicroscopy, and measurements using Pentacam AXL for corneal tomography, refraction, and axial length. Corneal biomechanics and IOP were assessed using Corvis ST. OCT and OCTA were utilized for assessing RNFL, macular vasculature, and CMT. ImageJ software calculated VD and VLD in mSCP, mDCP, and mCC. Statistical analysis involved Kruskal-Wallis, Mann-Whitney U tests for group comparisons, and Spearman correlation coefficients for correlation analysis. Descriptive statistics included mean, SD, median, and min-max values. Statistically significant thresholds were set at p<0.00055 for group comparisons and <0.000089 for Spearman correlations.
Results
Statistical analysis revealed a significant difference in VD within the mSCP and mDCP between the KCN and control (C) groups (p < 0,00055). Within the mSCP, the mean VD was highest in the KCN group at 83.9 ± 4.04, followed by the FFK group at 80.02 ± 4.5, and the C group at 78.29 ± 3.79. Similarly, within the mDCP, the mean VD for the KCN group was 76.98 ± 5.5, for the FFK group it was 72.06 ± 3.21, and for the C group, it was 71.07 ± 3.84. Spearman correlation analysis revealed significant correlations of the mSCP (%) and mDCP (%) with several parameters including BCVA (logMAR), cylinder values, ARC (3mm), PRC (3mm), Kmax (D), K2, BADD, the sum of the ABCD classification, CBI, E and CBiF (all p < 0,000089).
Conclusions
Our findings suggest that in addition to corneal changes, significant changes in the macular vascular density can be observed in patients with KCN. The underlying cause of these vascular changes is yet not fully understood, but may be related to inflammatory mechanisms of the disease. Further exploration of these processes and mechanisms may contribute to a better understanding and management of the condition.