Subthreshold Grid Laser Treatment of Macular Edema Secondary to Branch Retinal Vein Occlusion with Micropulse Infrared (810 Nanometer) Diode Laser

doi:10.1016/j.ophtha.2006.05.056

Ophthalmology

Volume 113, Issue 12, December 2006, Pages 2237-2242

Presented in part as a poster at: Association for Research in Vision and Ophthalmology meeting, May 2005, Fort Lauderdale, Florida.

https://doi.org/10.1016/j.ophtha.2006.05.056 Get rights and content

Purpose

To compare the effectiveness of subthreshold grid laser treatment (SGLT) with an infrared micropulse diode laser with that of threshold grid laser treatment (TGLT) for macular edema secondary to branch retinal vein occlusion (BRVO).

Design

Randomized clinical trial.

Participants

Thirty-six patients (36 eyes) were randomized either to infrared SGLT (17 eyes) or to krypton TGLT (19 eyes).

Methods

Complete ophthalmic examinations, including determination of visual acuity (VA) with Early Treatment Diabetic Retinopathy Study charts, optical coherence tomography (OCT), and fluorescein angiography, were performed at the time of the study entry and at 6-month intervals, with a planned follow-up of 24 months.

Main Outcome Measures

Primary: decrease in mean foveal thickness (FT) on OCT. Secondary: changes of the total macular volume (TMV) over the follow-up, proportion of eyes that gained at least 10 letters (approximately ≥2 lines of VA gain) at the 12- and 24-month examinations, and timing of macular edema resolution.

Results

Changes in mean FT and TMV from the initial values were statistically significant for TGLT from the 6-month examination (P<0.001) and for SGLT from the 12-month examination (P<0.001). After 1 year, there was no difference in mean FT and TMV between the 2 groups. At the 12-month examination, 10 patients of the SGLT group (59%) and 11 of the TGLT group (58%) gained at least 10 letters (2 lines) in VA. At the 24-month examination, this gain was achieved by 11 patients (65%) of the SGLT group and 11 (58%) of the TGLT group. Moreover, at the 24-month examination 59% and 26% gained 3 lines in the SGLT and TGLT groups, respectively.

Conclusions

Resolution of macular edema and VA improvement are similar to those obtained with conventional TGLT, but SGLT is not associated with biomicroscopic and angiographic signs. A multicenter randomized clinical trial would be needed to ascertain the real efficacy and the most appropriate settings of SGLT for macular edema secondary to BRVO.

Section snippets

Materials and Methods

A prospective randomized clinical pilot trial was planned to compare the effects of SGLT performed by infrared micropulse diode laser and of TGLT delivered with krypton laser. Patients affected by BRVO observed in the outpatient department of Trieste Eye Clinic between June 2001 and December 2002 were identified and invited to enroll prospectively. The research adhered to the tenets of the Declaration of Helsinki, and investigational review board approval was obtained. Each patient was

Results

Forty-four patients with macular edema secondary to BRVO were considered for the study. Three of them were excluded from the study because they had undergone previous photocoagulation, and 5 patients declined to take part in the study. No patient showed sensory retinal detachment on OCT, either at baseline or over the follow-up. Overall, 36 patients (36 eyes) fulfilling the inclusion and exclusion criteria were randomized either to SGLT (17 eyes) or to TGLT (19 eyes).

Complete demographic

Discussion

The Branch Vein Occlusion Study Group has demonstrated that grid laser treatment performed using argon laser is effective both in promoting macular edema resolution and in improving VA.² Unfortunately, conventional grid laser treatment delivered with a visible ophthalmoscopic end point may bring about several complications over the long-term follow-up (i.e., scar enlargement, subretinal fibrosis, choroidal neovascularization, and perimetric sensitivity deterioration) that can severely affect

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Original ArticleSubthreshold Grid Laser Treatment of Macular Edema Secondary to Branch Retinal Vein Occlusion with Micropulse Infrared (810 Nanometer) Diode Laser

Purpose

Design

Participants

Methods

Main Outcome Measures

Results

Conclusions

Section snippets

Materials and Methods

Results

Discussion

Ophthalmology

Am J Ophthalmol

Ophthalmology

Ophthalmology

Ophthalmology

Macular oedema and retinal branch vein occlusion

Aust J Ophthalmol

Argon laser photocoagulation for macular edema in branch vein occlusion

Am J Ophthalmol

Progressive enlargement of laser scars following grid laser photocoagulation for diffuse diabetic macular edema

Arch Ophthalmol

Focal photocoagulation treatment of diabetic macular edemaRelationship of treatment effect to fluorescein angiographic and other retinal characteristics at baseline: ETDRS report no 19

Arch Ophthalmol

Subretinal neovascularization complicating laser photocoagulation of diabetic maculopathy

Ophthalmic Surg

Choroidal neovascularization after laser photocoagulation for diabetic macular edema

Ophthalmology

Subretinal fibrosis after laser photocoagulation for diabetic macular edema

Am J Ophthalmol

Sub-pigment epithelial membranes after photocoagulation for diabetic macular edema

Arch Ophthalmol

Subretinal fibrosis in diabetic macular edemaETDRS report 23

Arch Ophthalmol

Influence of laser photocoagulation for clinically significant diabetic macular oedema (DMO) on short-wavelength and conventional automated perimetry

Diabetologia

Short-wavelength sensitive visual field loss in patients with clinically significant diabetic macular oedema

Diabetologia

The use of scanning laser ophthalmoscope microperimetry to detect visual impairment caused by macular photocoagulation

Ophthalmic Surg Lasers

Automatic static threshold perimetry is useful for estimating the effects of laser photocoagulation on diabetic maculopathy

Ophthalmic Res

Original Article
Subthreshold Grid Laser Treatment of Macular Edema Secondary to Branch Retinal Vein Occlusion with Micropulse Infrared (810 Nanometer) Diode Laser