BARELY VISIBLE AND SUBTHRESHOLD 577NM (YELLOW) PASCAL® LASER WITH AND WITHOUT ENDPOINT MANAGEMENT® IN PROLIFERATIVE DIABETIC RETINOPATHY AND DIABETIC MACULAR OEDEMA

Abstract

 

Purpose

 

The semi automated Pascal® laser system delivers a single or a pattern-array of sequential burns utilising either a Green (532nm) or a Yellow (577nm) (YW-PL) wavelength laser source. Endpoint Management® (EpM®) allows accurate laser power titration by the clinician to a barely visible or subthreshold burn: the clinician selects the percentage of laser energy to be delivered to certain burns within the pattern-array of burns. The aim of this study is to report on safe and effective laser treatment parameters for YW-PL with and without EpM® in clinical practice and in patients with Proliferative Diabetic Retinopathy (PDR) and/or Diabetic Macular Oedema (DMO).

 

Methods

 

Retrospective Observational Case Series of 44 YW-PL procedures in 34 patients:10 Females (29%) and 24 males (71%). Patients were categorised into three treatment groups: 1-Single-session Panretinal Photocoagulation (PRP); 2-Focal or Modified Macular Grid; 3- Single-session PRP with Macular Grid. All patients underwent pre and post laser Fourier-Domain Optical Coherence Tomography (FD-OCT) (3D OCT-2000 FA plus®, Topcon Corp.) and post laser macular (3D OCT-2000 FA plus®, Topcon Corp.) and wide-field Fundus Autofluorescence (FAF) (200Tx®, Optos plc.). See Table.

 

Results

 

No increase in OCT central retinal thickness (CRT) after PRP was found in Group 1 patients (p=0.941 t-Student). Diminished or unchanged CRT was found in Group 2 patients coincident with the reporting of these results (p=0.03 t-Student). Significantly reduced CRT was found in group 3 patients (p=0.014 t-Student). Burns could be partially visualized on biomicroscopy and were confirmed with FAF within one hour from treatment. No peri-treatment laser-associated adverse effects associated with the PRP or macular YW-PL array treatments were found.

 

Conclusions

 

Yellow 577nm wavelength Pascal® with and without EpM® was found to be safe and effective. Fundus Autofluorescence allows the identification and documentation of areas treated with barely visible or non-visible subthreshold laser.

 

 

Keywords: 499 diabetic retinopathy • 578 laser • 688 retina