Correlation Between Ocular Biomechanics And The Progression Of Axial And Segmental Ocular Biometric Lengths In Teenagers – A Portuguese Cohort From The Oporto Myopia Study

Published 2024 - 42nd Congress of the ESCRS

Reference: PO273 | Type: Free paper | DOI: 10.82333/r3f9-xv70

Authors: João Ramalhão* ¹ , João Heitor ¹ , Paulo Sousa ¹ , Saúl Pires ¹ , Renato Ambrósio ² , Pedro Menéres ¹ , João Beirão ¹ , Pedro Baptista ¹

¹CHUdSA,Porto,Portugal, ²UNIRIO,Rio de Janeiro,Brazil

Purpose

Our purpose is to describe corneal baseline biomechanics and progression of axial and segmental ocular biometric lengths in a cohort of portuguese teenagers and to correlate both parameters during the follow up.

Setting

Centro Hospitalar e Universitário de Santo António, Porto, Portugal

Methods

This is a prospective cohort study including 126 eyes of 63 individuals. Data was collected from 2 timepoints, spaced by 2.4(+-0.3) years.

Corneal biomechanics was assessed in the baseline visit, by means of Scheimpflug image, with Corvis ST(OCULUS, Germany).

Ocular biometric data from Axial length (AL) and segmental ocular biometric lengths (Central Corneal Thickness (CCT), Anterior Chamber Depth (ACD) and Lens Thickness (LT)) were assessed in both timepoints by means of swept source OCT with the IOL MASTER 700 (ZEISS, Germany). The variable Vitreous Cavity Length was Built [VCL=AL – (CCT + ACD + LT)]. Deltas of progression were built for AL (Δ_AL) and VCL (Δ_VCL). Correlations were addressed between ocular biomechanics and Δ_AL and Δ_VCL.

Results

Δ_AL and Δ_VCL were correlated with 8 baseline biomechanical parameters (Pearson coefficients (P)/Spearman's rank (S)): Radius [mm] (S 0.194 p<.05); Whole Eye Movement Max [ms] (P -0.206 p<.05;); HC dArc Length [mm] (S -0.236 p<.01); DA Ratio Max (2mm) (P -0.238 p<.01; S -0.228 p<.05); Integrated Radius [mm^-1] (P -0.279 p<.01; S-0.294 p<.001); TBI v1(P -0.195 p<.05; S -0.19 p<.05); TBI v2(S -0.2 p<.05); Δ_VCL correlations were Radius [mm] (P 0.193 p<.05; S 0.22 p<.05); Whole Eye Movement Max [ms] (P -0.198 p<.05); HC dArc Length [mm] (S -0.224 p<.05); DA Ratio Max (2mm) (P -0.222 p<.05; S -0.225 p<.05); Integrated Radius [mm^-1] (P -0.266 p<.01; S -0.276 p<.01); TBI v1(P -0.213 p<.05; S -0.21 p<.05); TBI v2(P -0.208 p<.05; S -0.249 p<.01).

Conclusions

The present study reports the association of ocular biomechanics analysis by means of Scheimpflug image with both axial length and vitreous cavity length growth in teenagers. Furthermore, it highlights the concept of analyzing the axial growth of the young eye from a sum of segments perspective. This could pave the way for the creation of a biomechanical algorithm that could help in the prediction of ocular axial elongation in the young. These data are important to help design effective strategies for the prevention of the global myopia epidemic in the upcoming decades.