A New Method To Monitor Visual Field Defects Caused By Photoreceptor Degeneration Using Quantitative Optical Coherence Tomography
Manuel Dominik Fischer 1,
Johannes C. Fleischhauer 2,
Mark C. Gillies 3,
Florian K Sutter 4,
Horst Helbig 5,
and
Daniel Barthelmes 2*
1 Institute for Ophthalmic Research, University Eye Hospital Tuebingen, Tuebingen, Germany
2 Ophthalmology, University Hospital Bern, Bern, Switzerland
3 Department of Clinical Ophthalmology, Sydney University, Sydney, New South Wales, Australia
4 Ophthalmology, University Hospital Zurich, Zurich, ZH, Switzerland
5 Ophthalmology, University Hospital Regensburg, Regensburg, Germany
* To whom correspondence should be addressed. E-mail: daniel.barthelmes{at}gmx.ch.
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Abstract |
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Purpose
To correlate the dimension of the visual field (VF) tested by Goldman kinetic perimetry with the extent of visibility of the highly reflective layer between inner and outer segments of photoreceptors (IOS) seen in optical coherence tomography (OCT) images in patients with Retinitis Pigmentosa (RP).
Methods
In a retrospectively designed cross-sectional study, 18 eyes of 18 patients with RP were examined with OCT and Goldmann perimetry using test target I4e and compared to 18 eyes of 18 controls. A-Scans of raw scan data of Zeiss Stratus OCT ® images were quantitatively analyzed for the presence of the signal generated by the highly reflective layer between the IOS in OCT images. Starting in the fovea, the distance to which this signal was detectable was measured. Visual fields were analyzed by measuring the distance from the centerpoint to isopter I4e. OCT and visual field data were analyzed in a clockwise fashion every 30°, corresponding measures were correlated.
Results
In corresponding alignments, the distance from the centerpoint to isopter I4e and the distance to which the highly reflective signal from the IOS can be detected correlate significantly (r=0.75, p
0.0001). The greater the distance in VF, the greater the distance measured in OCT.
Conclusion
We hypothesize that the retinal structure from which the highly reflective layer between the IOS emanates is of critical importance for visual and photoreceptor function. Further research is warranted to determine whether this might be useful as an objective marker of progression of retinal degeneration in patients with RP.
Key Words:
optical coherence tomography, retinal dystrophy, retinitis pigmentosa, visual field, image analysis, outer segments
