Pattern-Scan Laser System vs. Conventional Photocoagulation: Changes in Macular Thickness After Treatment

Abstract

 

Purpose:

 

To measure the difference in central macular thickness (CMT) and macular volume (MV) by optic coherence tomography (OCT), before and after panretinal photocoagulation (PRP) with Pattern Scan Laser (PaScaL) vs conventional laser, in patients with severe non-proliferative diabetic retinopathy (SNPDR) and proliferative diabetic retinopathy (PDR)

 

Methods:

 

We designed a prospective, interventional and comparative study, where we included patients with SNPDR or PDR without clinical macular edema, previous laser treatment or anti-angiogenic drug therapy. PRP was performed in two sessions of 750 burns each, with an interval of 2 weeks, always with conventional laser in the right eye and PaScaL system in the left eye. We measured best corrected visual acuity (BCVA), CMT and MV by OCT (OCT3, Carl Zeiss) at baseline and day 28. All t-paired tests were two-tailed with alpha=0.05

 

Results:

 

We included 15 patients (30 eyes), 16 eyes with PDR. All measures are summarized in Table 1. Significant differences were found in the following comparisons between baseline versus the 28th day: CMT left eye (p=0.04); MV right eye (p=0.01) and left eye (p=0.006); BCVA right eye (p=0.05) and left eye (p=0.03)

 

Conclusions:

 

Even though it is a preliminary study in which only five cases were compared, we observed that in both eyes, CMT and MV increased, while ETDRs decreased  

 

Clinical Trial:

 

www.clinicaltrials.gov NCT00563628

 

Keywords: laser • diabetic retinopathy • edema