Corneal Biomechanical Changes in Patients with Inherited Retinal Diseases

Abstract

Ana Marta,1,2 André Ferreira,1,3,4 Inês Couto,1 Miguel Mesquita Neves,1 Miguel Gomes,1 Luis Oliveira,1 Celia Azevedo Soares,5– 8 Maria João Menéres,1,2 Carolina Lemos,2,8 João Melo Beirão1,2 1Department of Ophthalmology, Centro Hospitalar Universitário de Santo António, Unidade Local de Saúde de Santo António, Porto, Portugal; 2Instituto Ciências Biomédicas Abel Salazar (ICBAS), Porto, Portugal; 3Department of Biomedicine - Unit of Anatomy, Faculty of Medicine of University of Porto, Porto, Portugal; 4Centre for Health Technology and Services Research, Health Research Network (CINTESIS@RISE), Faculty of Medicine of the University of Porto, Porto, Portugal; 5Medical Genetics Department, Centro Hospitalar Universitário de Santo António, Unidade Local de Saúde de Santo António, Porto, Portugal; 6Unit for Multidisciplinary Research in Biomedicine, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal; 7Medical Science Department, Universidade de Aveiro, Aveiro, Portugal; 8i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, PortugalCorrespondence: Ana Marta, Centro Hospitalar Universitário de Santo António, Unidade Saúde Local de Santo António, EPE (ULSSA), Largo do Prof. Abel Salazar, Porto, 4099-001, Portugal, Email [email protected]: Inherited retinal diseases (IRDs) are a group of degenerative disorders of the retina, that can be potentially associated with changes in the anterior segment, but their prevalence and impact are not known. Exploring these concomitant ophthalmologic changes with biomechanical assessment may help identify other non-retina causes of vision loss in these patients, such as corneal ectasia or susceptibility to glaucoma. This study aimed to measure and compare corneal biomechanics in patients with and without IRDs.Methods: A total of 77 patients (154 eyes) with IRD were recruited as the study group. The control group consisted of 77 healthy adults (154 eyes) with matched age and sphere equivalents. All participants underwent a comprehensive assessment including corneal tomography (Pentacam®) and biomechanical assessment (Corvis ST®). A total of 4 second-generation biomechanical parameters and 3 indexes were collected: Ambrosio Relational Thickness (ARTh), Deflection Amplitude Ratio Max (DARM), Integrated Radius (IR) and Stiffness Parameter at Applanation (SP-A1), the final deviation value D of the Belin/Ambrosio Enhanced Ectasia Display (BAD-D), Corvis Biomechanical Index (CBI) and Tomographic Biomechanical Index (TBI).Results: For IRD patients, there was a higher DARM (p < 0.001), lower ARTh (p < 0.001), higher CBI (p < 0.001), higher TBI (p< 0.001), and higher BAD-D (p < 0.001) compared to the control group. Regarding discrimination of healthy subjects and IRD patients, ARTh was the most sensitive parameter.Conclusion: The results showed that IRD patients tend to have softer corneal behaviour, compared to eyes without pathology, which may predispose patients to corneal ectasia or glaucoma development. ARTh could be used to screen IRD patients if a non-retina cause of vision loss is suspected.Keywords: IRD, corneal biomechanics, corneal tomography

Keywords

• ird
• corneal biomechanics
• corneal tomography