Study demonstrates value of MicroPulse technology for diabetic macular edema treatment

IRIDEX Corporation (Nasdaq: IRIX) today announced that leading clinicians have performed and published the results of a new study that compares the benefits of MicroPulse photocoagulation technology, similar to that used in the new generation IRIDEX lasers, over the standard-of-care protocol for the treatment of eyes with diabetic macular edema (DME). The results indicated that treating using MicroPulse mode was as effective as the standard-of-care protocol in treating DME but with the added advantages of causing no localized laser scars and significantly improving visual acuity. DME is damage to the retina caused by diabetes, and is the leading cause of blindness in persons under 50 years of age in the developed world. DME affects an estimated 2 million in the U.S. alone.

"This study is another important step in demonstrating the value of MicroPulse technology for the treatment of DME," said Theodore A. Boutacoff, President and CEO. "The prevailing wisdom has been that it was necessary to cause localized damage to the retinal tissue in order to achieve the desired therapeutic effect.  In recent years, this view has been challenged by evidence that using a MicroPulse dosing mode can achieve a treatment outcome for DME, which is comparable to the current standard-of-care laser therapy without producing damage and resulting scarring.  This study confirms those findings and, in fact, shows an improvement in visual acuity following treatment.  We believe this is another step towards what could be a paradigm shift in ophthalmic laser eye treatment."

The recent online publication of the peer-reviewed clinical study compared results obtained in the treatment of DME with a subthreshold diode laser MicroPulse photocoagulation treatment protocol to those obtained using modified Early Treatment of Diabetic Retinopathy Study (mETDRS) laser protocol, the currently recognized standard-of-care. At one year, the prospective, randomized, controlled, double-masked clinical study demonstrated that a subthreshold diode laser MicroPulse protocol was as effective as the mETDRS protocol in the treatment of DME. Moreover, visual acuity significantly improved in eyes in the subthreshold diode laser MicroPulse treated group compared to the mETDRS group. All eyes in the mETDRS group developed localized laser scars, which were rarely found in eyes treated in the subthreshold diode laser MicroPulse group.

The authors conclude:

• At one year, the clinical performance of high-density subthreshold diode laser MicroPulse photocoagulation was superior to that of the modified ETDRS photocoagulation technique based on the anatomic and functional measures of improvement used in this investigation.
• The fact that a significant outcome can be obtained with less damaging laser treatments is an encouraging and a highly desirable clinical achievement.
• Overall, the superior therapeutic response of high-density subthreshold diode laser MicroPulse may constitute the "proof of principle" that more destructive laser lesions would be unnecessary in macular laser photocoagulation for DME.
• The benefits of this selective retina-sparing treatment, raises the possibility of improving the gold standard.

"This is the first randomized study to demonstrate a significant improvement in best corrected visual acuity using subthreshold diode laser MicroPulse treatment compared to the standard mETDRS laser photocoagulation treatment of DME and it is the second randomized study which has demonstrated a significant improvement in visual function," continued Boutacoff. "This study is important as it also makes a significant milestone contribution towards optimizing the laser treatment technique by validating the superiority of the high-density subthreshold diode laser MicroPulse protocol."

The study, conducted at the Hospital de Olhos de Araraquara and at the Federal University of Sao Paulo, Brazil, prospectively randomized 123 patients with previously untreated DME and best corrected visual acuity worse than 20/40 and better than 20/400 into one of three treatment arms: an mETDRS treatment arm using a standard green laser photocoagulator, a standard-density subthreshold diode laser MicroPulse treatment arm and a high-density subthreshold diode laser MicroPulse treatment arm. At one year, the mETDRS and the high-density subthreshold diode laser MicroPulse treatment groups demonstrated statistically significant improvements in central retinal thickness measurement and visual acuity from baseline. The improvement in visual acuity was significantly higher in the high-density subthreshold diode laser MicroPulse treatment group (+12 letters) compared to the conventional mETDRS treatment group (+4 letters). The percentage of eyes that improved 3 or more lines (15 letters) was 48% in the high-density subthreshold diode laser MicroPulse treated group compared to 23% in the mETDRS treated group.