Subthreshold microsecond laser for proliferative diabetic retinopathy: a randomized pilot study

Abstract

AimTo compare the outcomes of subthreshold microsecond (STM) and continuous-wave laser (CWL) panretinal photocoagulation (PRP).MethodsIn this randomized, prospective, pilot study, 20 eyes of 10 subjects with symmetric severe non-proliferative (NPDR) or low-risk proliferative diabetic retinopathy (PDR) were included. Each eye of the subject was randomized into either CWL or STM PRP group. Patients were evaluated at baseline and at months 3, 6, and 9 with color fundus photographs and visual field tests at each visit; however, electroretinography (ERG) was conducted at baseline and at month 9. The primary outcome measure was the difference in disease progression between the groups. Secondary outcome measures included change in visual acuity, contrast visual acuity, retinal sensitivity on visual field test, and change in ERG parameters.ResultsDuring the 9-month follow-up, one eye of the STM group progressed to vitreous hemorrhage at the month 6 follow-up and required rescue conventional laser. The CWL group showed a drop in low-contrast visual acuity, visual field index, and scotopic b/a ratio in comparison to the STM group, although the difference was statistically insignificant (p>0.05).ConclusionThis prospective pilot study proposes microsecond PRP is non-inferior to CWL PRP and could be an alternative to CWL PRP to avoid associated complications in cases of severe NPDR and early PDR.

Micropulse Laser Treatment of Retinal Diseases

“…After 12 months, the risk for progression to vitreal haemorrhage was assessed at 12.5% and risk for pars plana vitrectomy at 14.6 %. A second study by Jhingan et al included 10 patients (20 eyes) with severe NPDR or low-risk PDR [85]. Each eye was randomized to receive either classic PRP or SMPLT PRP.…”

Ginsenoside Rb1 attenuates diabetic retinopathy in streptozotocin-induced diabetic rats

“…In non-proliferative DR, the intra-retinal microvasculature is associated with diabetic macular edema 3 . Proliferative DR is implicated in the formation and growth of new blood vessels in low-oxygen environments 4 . DR is also characterized by increased vascular permeability, which leads to fluid accumulation and retinal hemorrhage in the macula 5 .…”

Transient Increase and Delay of Multifocal Electroretinograms Following Laser Photocoagulations for Diabetic Macular Edema

“…We had hypothesized that recording the mfERGs immediately after the PC would reveal the early physiological changes in the retina. Earlier studies using full-field ERGs [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 19 , 24 , 29 , 30 , 31 ] could not determine the functional alterations produced by a small PC spot. Therefore, investigators typically examined subjects who had hundreds of coagulation spots as in panretinal PC.…”

“…For decades, electroretinograms (ERGs) have been used to assess the alterations of retinal function caused by PC [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ] to treat diabetic retinopathy (DR) or diabetic macular edema (DME) [ 2 , 3 , 4 , 5 , 6 , 7 , 13 , 14 , 15 , 16 , 19 , 21 , 23 , 24 , 25 , 27 , 29 , 30 , 31 ], central serous chorioretinopathy (CSC) [ 20 , 22 ] and animal models [ 8 , 10 , 11 , 12 , 17 , 18 , 26 , 28 ].…”

“…However, most of these ERG studies recorded ERGs after several to 24 h after PC, which is long after the acute changes had occurred [ 4 , 9 , 11 , 12 , 28 , 31 ]. ERGs have also been recorded at even longer intervals after PC [ 3 , 5 , 6 , 7 , 8 , 9 , 10 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 31 ] to assess the therapeutic effects of PCs.…”