Abstract
Purpose: :
To investigate the efficacy and safety profile of Pascal targeted retinal laser photocoagulation (TRP) and reduced fluence/minimally-traumatic panretinal laser (MT-PRP) compared to standard-intensity PRP (SI-PRP) in treatment-naive diabetic retinopathy (PDR).
Methods: :
Three-arm randomized clinical trial (10 eyes per arm). PDR was treated with single-session 2,500 burns using 4*4/5*5 arrays. ETDRS visual acuity (VA),central retinal thickness (CRT),24-2 SITA-Std (VF),nerve fibre layer thickness (NFLT),optic disc rim volume (ODRV), multispectral imaging (MSI), and Oxymap retinal oximetry were recorded at baseline,4 and 12-weeks post-laser. Changes in each parameter were analyzed over time (TRP vs. SI-PRP; MT-PRP vs. SI-PRP) using masked graders.
Results: :
Clinical and safety results reported for 29 eyes (16 males, 7 female). There were no significant differences in baseline HBA1C (range 8.4-8.6) or baseline PDR (moderate Airlie House grade). Laser fluence was significantly lower in TRP (4J/cm2) and MT-PRP (2.7J/cm2) compared to SI-PRP (4.8J/cm2,p<0.05). VA increased after TRP (+4 letters,p=0.1) and MT-PRP (+2 letters, p=0.012), versus SI-PRP. There were reductions in CRT after TRP (-10µm, p=0.092) and MT-PRP (-16µm,p=0.008), versus SI-PRP (+0.25 µm). No significant changes in ODRV and NFLT developed between groups. Mean Deviation VF values improved over time (TRP-1.06dB; MTPRP-0.72dB; SI-PRP-1dB; p<0.05). There were no significant differences between treatment groups for temporal change in tissue oxygenation using MSI (n=27). Clinical PDR regression was similar between groups (TRP 67%, MT-PRP 78%, SI-PRP 89%;p=058). There were no laser-related ocular complications.
Conclusions: :
This pilot study reports that 20ms-Pascal TRP and MT-PRP using 2,500 burns may be as effective as SI-PRP with no ocular adverse events observed in the short-term.
Clinical Trial: :
Central Manchester University Hospitals NHS Foundation Trust, R01007
Keywords: laser • diabetic retinopathy • imaging/image analysis: clinical