Abstract
Purpose: :
To evaluate the retinal vascular changes in patients treated with intravitreal pegaptanib compared to the untreated fellow eye using a novel software.
Methods: :
Patients with ischaemic diabetic macula edema resistant to treatment with laser and / or intravitreal steroids have been recruited since January 2011. Patients were seen every 6 weeks for assessment and treatment, receiving a total of 5 injections of pegaptanib sodium. Fluorescein angiogram was carried out at baseline and at the final visit (week 30).The central retinal arteriolar (CRAE) and venular equivalence (CRVE) on baseline angiogram and at week 30 were measured using a new software. In this software, the CRAE and CRVE can be calculated in patients with only the temporal part of the optic disc included in the colour fundus image and in fluorescein angiogram images. Student t-test was used.
Results: :
Twenty seven patients have been recruited between January 2011 and November 2011. Sixteen patients have to be excluded from the study. 2 patients had received less than 3 injections, 3 patients had an early termination, 11 patients had poor quality images in either eye on fluorescein angiogram examination. In many cases we managed to analyse the data in 3 out of 4 images but these were excluded for this analysis. The mean CRAE unit were 5.07 (SD 1.22) and 5.04 (SD 0.93) before and after treatment while the mean CRVE unit were 6.83 (SD 1.02) and 7.11 (SD 0.83) before and after treatment. There were no significant changes in CRAE (p=0.83) whilst CRVE is increased significantly (p=0.025). There were no significant changes in the untreated eye either on CRAE or CRVE. The mean CRAE unit in the untreated group were 4.86 (SD 0.68) and 5.07 (SD 1.70) before and after treatment. The mean CRVE were 7.37 (SD 1.08) and 7.31 (SD 2.03) before and after treatment. There was no significant change in the CRAE (p=0.72) and CRVE (p=0.91) units in the untreated eyes.
Conclusions: :
This novel software appears to be able to measure retinal vascular changes reliably in an angiogram. We were able to demonstrate, pegaptanib, a selective anti-VEGF agent, has retinal venular dilatation effect. Our findings are in keeping with previous studies that showed retinal venular dilation after non-selective anti-VEGF therapies.
Clinical Trial: :
http://www.clinicaltrials.gov NCT01175070
Keywords: diabetic retinopathy • imaging/image analysis: clinical • retina