# Characterising microstructural retinal changes in children with inherited retinal dystrophies – a retrospective observational cross-sectional study

## TL;DR

This study found that children with inherited retinal diseases show distinct retinal microstructural changes compared to healthy controls, suggesting early retinal remodelling.

## Contribution

The study provides the first detailed characterisation of retinal microstructural changes in children with inherited retinal diseases using OCT.

## Key findings

- Inner retinal layer thickness was significantly increased in IRD groups compared to controls.
- Photoreceptor complex thinning was observed in cone-rod disorders but not in other IRD types.
- Total retinal thickness was reduced in cone and cone-rod groups but not in other IRD types.

## Abstract

Trials exploring novel treatments for inherited retinal diseases (IRDs) have utilised microstructural retinal changes for outcome measures, but such changes in children are incompletely described. We aimed to characterise the retinal microstructural in children with IRDs versus controls using optical coherence tomography (OCT).

Cross-sectional study of retrospective OCT data from 51 children (91 eyes) with IRDs attending the Melbourne Children’s Eye Clinic and 64 controls (126 eyes) recruited prospectively at Australian College of Optometry clinics.

OCT was performed using a Nidek RS-3000 with volume scans in each participant eye. Image quality was manually reviewed. Semi-automated layer segmentation was performed and thickness based on eccentricity relative to the central fovea position was calculated to standardise measurements between participants.

Inner retinal layer thickness was significantly increased in IRD groups versus controls (rod-cone p < 0.0001; cone-rod p < 0.0001; macula p < 0.0001; cone p < 0.0001). This was not observed for photoreceptor complex thickness where instead thinning versus controls was seen in cone-rod disorders (rod-cone p = 0.89; cone-rod p < 0.0001; macula p = 0.21; cone p = 0.17).

Total thickness was significantly reduced in cone and cone-rod group versus controls, but not in other IRD types (rod-cone p = 0.25; cone-rod p < 0.0001; macula p = 0.74; cones p = 0.004).

Our findings suggest retinal remodelling takes place in childhood-onset IRDs. Clinical trials in IRDs should consider remodelling when evaluating treatment effects. Future studies on the longitudinal natural history of retinal microstructural changes in childhood IRDs are required to address the impact of factors including IRD type, sex, age and disease duration.

The online version contains supplementary material available at 10.1007/s00417-025-06983-7.

Inherited retinal disease (IRD) trials have employed optical coherence tomography (OCT) based outcomes; however, microstructural OCT changes in childhood IRDs are less studied.

Inherited retinal disease (IRD) trials have employed optical coherence tomography (OCT) based outcomes; however, microstructural OCT changes in childhood IRDs are less studied.

We found the retinal microstructure of children with IRDs differed from controls, with different IRD types demonstrating different patterns of change.This may indicate potential early retinal remodelling in these conditions.Our findings highlight a need for greater understanding of retinal microstructural changes in childhood IRDs, to successfully develop OCT-based clinical trial outcome measures.

We found the retinal microstructure of children with IRDs differed from controls, with different IRD types demonstrating different patterns of change.

This may indicate potential early retinal remodelling in these conditions.

Our findings highlight a need for greater understanding of retinal microstructural changes in childhood IRDs, to successfully develop OCT-based clinical trial outcome measures.

The online version contains supplementary material available at 10.1007/s00417-025-06983-7.