Photoreceptor layer imaging visualises the specific retinal layers containing rod and cone cells to assess their structure and integrity. It relies mainly on high-resolution OCT and, in specialised centres, adaptive optics.
Techniques
Standard OCT shows outer nuclear, ellipsoid, and interdigitation zones as distinct bands, while adaptive optics systems can directly resolve individual photoreceptor mosaics. En face views highlight localised disruptions or loss.
- Requires good fixation and clear ocular media for optimal detail
- Reveals subtle discontinuities not visible on routine examination
- Advanced systems can differentiate cone and rod distributions
- Data may be quantified for cell density and spacing
Clinical Use
Photoreceptor imaging is important in inherited retinal dystrophies, macular degeneration, and evaluation of central serous or traumatic damage. It helps predict visual prognosis and monitor emerging therapies.
- Structural preservation of photoreceptors often aligns with better visual outcomes
- Imaging can detect early degeneration before significant acuity loss
- Used as a sensitive outcome measure in research trials
- Interpretation should consider artefacts and normal anatomical variation
