Features associated with vision in eyes with sub foveal fibrosis from neovascular AMD: Determinants of vision in eyes with subfoveal fibrosis

Purpose
To report the characteristics and correlation of visual acuity in eyes treated for neovascular AMD (nAMD) and developed fibrosis.

Design
Case-control study

Methods
356 treatment naive nAMD eyes that were treated for 12 months were included. Fibrosis was defined as present if well-defined hyperreflective material (HRM) between the neurosensory retina and the Bruchs’ membrane (BM) on optical coherence tomography (OCT) which correlated with well-defined regions of yellowish pallor on fundus photography and/or staining on fluorescence angiography were present. OCT features of sub foveal fibrosis and the overlying retina were correlated with visual acuity at month 12.

Results
20.3% developed incident fibrosis at month 12. Compared to eyes that did not develop fibrosis these eyes had lower baseline vision (49 vs 54 letters, p=0.02), more had type II macular neovascularisation (15.0 vs 8.8%, p=0.03), larger lesion area (29.6 vs 15.1 mm2, p=0.02) and sub-retinal haemorrhage ≥4 disc diameters (44.4% vs 19.8%, p<0.01). Visual acuity was worse in the incident fibrosis compared to the group that never developed fibrosis by month 12. (-1.4±17.1 versus +6.0±17.4 letters, p<0.01). In 83 eyes that had sub foveal fibrosis, better vision was associated with intact EZ/ELM complex (β coefficient (95% CI) 29.4 (14.2 to 44.6, p<0.01) while worse vision was associated with RPE-involving HRM, HRM above the RPE and width of HRM. (β coefficient (95% CI) -25.4 (-36.3 to -14.6, p<0.01), -23.5 (-39.0 to -7.9, p<0.01) and -3.8 (-7.2 to -0.4, p=0.03) respectively).

Conclusion
While fibrosis is associated with poorer visual outcome, preservation of ELM and level of fibrosis relative to the RPE are associated with visual outcomes.