Potential of Spectral Domain Optical Coherence Tomography in assessing new vessel activity in proliferative diabetic retinopathy

Abstract

 

Purpose

 

To characterize active and inactive new vessels at the disc (NVD) or elsewhere (NVE) and its associated vitreoretinal features in diabetic patients with proliferative diabetic retinopathy using Spectral Domain Optical Coherence Tomography (SD-OCT).

 

Methods

 

Retrospective cross-sectional study of 20 non-consecutive patients with proliferative diabetic retinopathy that were assessed in the Medical Retina Department of Moorfields Eye Hospital, London, UK, between July and November 2012. SD-OCT (SPECTRALIS®, Heidelberg Engineering, Heidelberg, Germany) was performed in areas of active or inactive NVE and NVD. New vessel activity was assessed using clinical and angiographic criteria.

 

Results

 

A total of 38 SD-OCT scans of new vessel complexes were analysed from 28 eyes of 20 patients. The mean age was 56 (SD:25-73), and 11 (55%) were male. 6 patients had type 1 and 14 type 2 diabetes. 13 scans were of NVD and 25 of NVE. 5 eyes had both NVD and NVE and 4 eyes had more than one foci of NVE. 20 scans (52,6%) had active neovascularization (NV) and 18 (47,4%) were quiescent. In SD-OCT scans across the new vessels, tissue contracture was noted in 18 scans (47,3%). Similarly, intraretinal fluid was noted in 7 scans (18,4%) and hyperreflective dots within the NV complex in 9 scans (23,7%). (Table 1) (Figure 1). The presence of tissue contracture was significantly greater in quiescent vs active NV (p<0.01). Although the presence of intraretinal fluid and hyperreflective dots was more frequent in active NV, this was not statistically significant (p=0.878 and p=0.560, respectively). The presence of hyperreflectivity within the NV complex or vitreous invasion did not differ between groups (p=0.898 and p=0.068, respectively).

 

Conclusions

 

SD-OCT can be used to assess retinal neovascularization and associated vitreoretinal features. Tissue contracture was significantly different between active and quiescent disease. Such parameters may be useful in differentiating active from quiescent disease.

 

 

Table 1- SD-OCT features of active and quiescent NV.

 

 

Figure 1 - Examples of the SD-OCT. A - NVE with intraretinal fluid (*) and features of tissue contracture (arrow). B - NVE with vitreous invasion and tissue contracture (arrow). C - NVE with hyperreflective dots (*). D - NVD with hyperreflective changes (*) and vitreous invasion.

 

Keywords: 499 diabetic retinopathy • 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • 700 retinal neovascularization