Author: Alireza Ramezani (Iran, Islamic Republic of)
Co-authors: Toktam Shahraki, Ramin Nourinia, Amir Arabi, Morteza Entezari, Nazanin Fatemeh Beheshtizadeh, Homayoun Nikkhah
Purpose
To compare the safety and therapeutic effect of panretinal photocoagulation (PRP) alone versus intravitreal bevacizumab (IVB) alone versus a modified combination of IVB and laser photocoagulation on naïve proliferative diabetic retinopathy (PDR).
Setting/Venue
Ophthalmic Epidemiology Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Methods
In this randomized 3-armed clinical trial, 153 eyes with PDR were included and divided randomly into 3 groups: PRP group (51 eyes) that underwent full PRP in 2 or 3 sessions and then rescue IVB; IVB group (52 eyes) that received 4 monthly IVB injections and then rescue IVB, and modified combination group (50 eyes) that received 2 bimonthly IVB injections and a modified laser (1 session anterior to the equator) and then rescue IVB or laser. Diabetic macular edema (DME) was treated independently. Primary outcome was best corrected visual acuity (BCVA) at 1-year follow-up. Additionally, area of neovascularization leakage on retinal angiography, central macular thickness (CMT), mean deviation (MD) of visual field (VF) sensitivity on 30-2 pattern test, and the number of examinations and injections were compared.
Results
The difference of final BCVA was not significant between the groups. Modified combination group had lower final leakage area compared with PRP (P=0.003) and IVB group (P=0.001). Eyes in IVB group experienced the lowest decrease of neovascularization (P=0.006). The difference of MD of VF was insignificant between IVB and modified combination groups, while PRP group had lower final MD of VF compared to IVB (P=0.001) and modified combination group (P=0.001). The rate of new-onset DME was the highest in RPP group (P=0.01). There was no difference in the rate of new-onset DME between IVB and modified combination groups. The difference of final CMT was insignificant between the groups. The median of total IVB injections were 3.5, 7.5, and 6 for PRP, IVB, and modified combination group, respectively (P=0.002). The median of IVB injections for DME were 3, 2.5, and 2.5 for PRP, IVB, and modified combination group, respectively (P=0.11). Patients in IVB group underwent more visits (P=0.001). For the eyes with baseline DME, final leakage was the lowest in modified combination group (P=0.005). In final BCVA and CMT, however, the difference was not significant. For the eyes without baseline DME, there were no difference in final BCVA and leakage area.
Conlusions
This trial showed that all treatment protocols were similarly effective in improving BCVA and CMT. However, modified combination protocol was more effective in PDR regression, overall and in the presence of baseline DME. Since the numbers of intravitreal injections and laser adverse effects were fewer in modified combination protocol, this protocol would be recommended for PDR treatment, especially in cases with baseline DME.
Financial Disclosure
There is no financial interest to declare.
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