Abstract
Purpose: :
Retinal Cotton Wool spots are a common finding in diabetic retinopathy, hypertension and HIV disease. Histologically they appear as areas of cytoid bodies due to pre retinal arteriolar occlusion. We have previously shown that localized SD OCT scans can demonstrate permanent damage to the retina in eyes with HIV related CWS. The purpose of this study is to evaluate the hypothesis that resolved retinal CWS, regardless of disease etiology, leave focal areas of ganglion cell and retinal nerve fiber layer loss and that these can be quantified thus showing the potential for using DS-OCT to determine the total lifelong burden of systemic disease.
Methods: :
24 eyes of 20 patients with photographically documented retinal CWS (total 54 CWS) were imaged between 8 months and 16 years after photographic documentation of resolution. Underlying disease included diabetes (n=28 lesions), hypertension (n=7 lesions) and HIV (n=19 lesions). Two masked observers determined the thickness of the retinal nerve fiber layer, ganglion cell layer, IPL, INL, OPL and Outer nuclear layers.
Results: :
Evidence of permanent inner retinal damage with thinning of the retinal nerve fiber layer could be seen in all lesions. Damage to the GCL was also apparent in all lesions. This was shown by determining thickness of the layers in comparison to control non-involved areas within 1.5 mm of the lesion. Loss of median loss of NFL was between 22 and 7 microns. Median loss of GCL was between 4 and 6 microns. There was displacement of the ONL into the inner retina with a pseudo thickening between 8 and 16 microns. The inner retinal tissue loss was different across the different disease entities p=0.03 using GEE.
Conclusions: :
Chronic diseases such as HIV, diabetes and hypertension can result in focal retinal damage due to retinal cotton wool spots. The focal absence of certain retinal layers can be seen and appears to be permanent (up to 17 years) when analyzed by SD OCT using SLO localization (Spectralis, Heidelberg engineering). The ability to detect these changes opens the possibility to scan the retina to look for and document retinal damage which may be a marker for total body disease burden.
Keywords: AIDS/HIV • diabetic retinopathy • imaging/image analysis: clinical