Extended targeted retinal photocoagulation versus conventional pan-retinal photocoagulation for proliferative diabetic retinopathy in a randomized clinical trial
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To determine the clinical efficacy of extended targeted retinal photocoagulation (ETRP) compared to conventional panretinal photocoagulation (CPRP) in proliferative diabetic retinopathy (PDR).
In a single-masked randomized clinical trial, 270 eyes of 234 patients with naïve early or high-risk PDR were randomly assigned to receive either CPRP or ETRP (135 eyes, each treatment arm). Best-corrected visual acuity (BCVA) measurement, fundus examination, wide-field fluorescein angiography (WFFA) and optical coherence tomography were carried out before and 3 months after retinal photocoagulation. Primary outcome was early PDR regression, specified as reduction in retinal neovascularization based on WFFA at 3 months. Secondary outcomes were BCVA and central macular thickness (CMT) changes.
There were significantly more high-risk PDR eyes in ETRP group compared to CPRP (109 and 94 eyes, respectively, P = 0.04). Early PDR regression occurred in 71.9 and 64.4% of eyes in the ETRP and CPRP groups, respectively (P = 0.19). The mean number of applied laser spots in the ETRP was significantly fewer than CPRP (1202 vs. 1360, respectively, P < 0.001). Mean BCVA at baseline and 3 months post-laser were 0.37 ± 0.26 and 0.47 ± 0.19 logMAR in the ETRP arm, respectively. In the CPRP arm these values were 0.40 ± 0.27 and 0.47 ± 0.24 logMAR, respectively. Although mean BCVA decreased significantly in both treatment arms (ETRP P < 0.001, CPRP P = 0.009), the difference was not significant between arms (P = 0.68). CMT increased significantly in both groups (ETRP 41.08 μm, P < 0.001, CPRP 33.31 μm, P < 0.001). Nevertheless, the difference between the groups was not significant (P = 0.26).
ETRP with fewer number of laser spots may be an appropriate alternative to CPRP in PDR regression at least through 3 months.
Clinical trial.gov registration number
KeywordsExtended targeted retinal photocoagulation Panretinal photocoagulation Proliferative diabetic retinopathy
Compliance with ethical standards
Conflict of interest
The authors declare that they have no financial interest in the subject matter or materials discussed in this manuscript.
The study was carried out after receiving the approval of the research ethics committee of Shahid Beheshti University of Medical Sciences and followed the tenets of the Declaration of Helsinki.
Informed consent was obtained from all individual participants included in the study.
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