As the epidemic of diabetes mellitus continues throughout the developed world, diabetic macular edema (DME) will remain one of the pathologies most frequently seen by retina specialists.
Laser photocoagulation has been the gold standard of treatment for DME since the ETDRS. The anatomical and visual benefits have been shown to be sustainable over the long term; however, the treatment is associated with risks and side effects due to the iatrogenic damage to retinal tissue.
A major advancement to laser photocoagulation is subthreshold MicroPulse Laser Therapy (MPLT). MPLT is therapeutically effective without producing discernible signs of laser-induced damage during treatment or at any time postoperatively, offering a more attractive option for patients and specialists.
In more recent years, pharmacotherapy has been advocated for the treatment of DME. Its widespread adoption, largely prompted by compelling acute effects, has been tempered by the realizations that its benefits require multiple intraocular injections and many patients do not respond adequately.
In selected cases, the addition of laser treatment to anti-VEGF therapy can achieve a sustained therapeutic effect while reducing the need for injections. MicroPulse laser appears to be the most logical choice for laser therapy because it has been shown to be less destructive to tissue while achieving the desired biological effect. Recently, Vujosevic et al1 showed that MicroPulse laser treatment appears to be as effective as modified-ETDRS laser photocoagulation for treating DME, but it causes far less damage to the retinal pigment epithelium, as judged by microperimetry and fundus autofluorescence. Having the option of a laser therapy that produces little to no collateral damage is quite attractive in the setting of patients with severe disease and difficult access to ophthalmic care. We believe that combination therapy of pharmacotherapy and non-damaging laser is a particularly useful approach for DME in these cases.
UMDNJ-University Hospital in Newark, NJ is a tertiary referral center. As a result, we care for many patients in whom the severity of diabetic retinopathy is high. We first started using subthreshold MPLT for these patients with clinically significant macular edema. MPLT protocols employ low intensity/high density laser applications in envelopes of repetitive short pulses to induce beneficial intracellular antiangiogenic and restorative biological factors without photodestruction.
We performed a study over 10 years ago to evaluate whether diode MPLT reduced the side effects that have been noted with argon thermal laser for macular edema. We started the study in 2001 and followed patients through to 2004, and in that time period, we noted that the edema was reduced for patients treated with MPLT with less visual loss, fewer retinal scars, less subretinal fibrosis, and lower risk of choroidal neovascular membranes and scotomata, as compared to conventional continuous-wave laser photocoagulation.2
Pairing MPLT with 577 nm
Our MicroPulse experience has been with 810 nm lasers. This same technology has been paired with the new 577 nm lasers, providing similar tissue-sparing capabilities and clinical outcomes. In the following pages, 3 retina specialists who have used 577 nm MPLT for treating disease, including DME and central serous chorioretinopathy, will discuss the effects of MPLT on achieving successful clinical outcomes, increasing patient satisfaction, and its positive impact to their practices.
Neelakshi Bhagat, MD, MPH, is Associate Professor of Ophthalmology at UMDNJ and Director, Vitreoretinal and Macular Surgery at Institute of Ophthalmology and Visual Science at University of Medicine and Dentistry (UMDNJ). Dr. Bhagat may be reached at email@example.com.
Marco A. Zarbin, MD, PhD, FACS, is Professor and Chair at the Institute of Ophthalmology and Visual Science and Professor of Neurosciences at UMDNJ. He is also Chief of the Department of Ophthalmology at University Hospital in Newark, NJ. Dr. Zarbin may be reached at firstname.lastname@example.org.
- Vujosevic S, Bottega E, Casciano M, Pilotto E, Convento E, Midena E. Microperimetry and fundus autofluorescence in diabetic macular edema: Subthreshold micropulse diode laser versus modified early treatment diabetic retinopathy study laser photocoagulation. Retina. 2010;30(6):908-916.
- Bhagat N, Zarbin MA. Use of diode subthreshold micropulse laser for treating diabetic macular edema. Contemp Ophthalmol. 2004;3(13):1-6.