The progression of retinal pigment epithelial failure with development and progression of geographic neuronal and RPE atrophy or development of choroidal neovascularization have been recognized to now represent major causes of central vision loss worldwide due to the inherited ocular complication of macular degeneration. Subthreshold diode micropulse laser has been demonstrated to delay both the progression of geographic atrophy as well as choroidal neovascularization. While the method of this photodynamic treatment has been thought to be through the restoration of oxidant/antioxidant balance and modulated of apoptotic/autophagy protein expression, termed “Reset to default” the effect on retinal function has been examined only in a pilot trial examining the short term course following diode panmacular subthreshold diode micorpulse laser in which chart visual acuity was unchanged with a small, barely significant improvement in automated contrast sensitivity. However, these measurements detect only the most marked abnormalities of photopic cone function at fixation while the person with macular disease scans the chart to detect the limited clear areas within the field and are not correlated with functional vision.
Sinclair Technologies, LLC has collaborated with Jeff Luttrull, MD, a retina specialist in Ventura, California in a study of 361 eyes of 292 patients, atrophic AMD that had undergone SMD treatment, compared with 224 normal eyes of 115 patients utilized as controls. Baseline Omnifield indices of acuity at fixation, best acuity within the central field, global macular acuity and the visual field areas of vision better than or equal to 20/40 and better than or equal to 20/80 for each of the AREDS category subgroups, AREDS 1-2, AREDS 3, and AREDS 4 were evaluated in comparison with the values of the age matched normal controls. All indices of visual function except for best corrected chart acuity were significantly worse in the atrophic AMD eyes than among the controls (p<0.0001 for all comparisons) with progressive significant worsening noted among the progressive AREDS groups prior to treatment.
For the normal controls, comparison of the first and second Omnfiield indices showed minimal changes. For treated AMD eyes all indices were significantly improved at one month following the first SDM treatment, from 0.06 to 0.1 logMAR among all AREDS groups, but still significantly below the results of the normal controls. The visual field area with acuity better than 20/40 was improved a significant 26% in the AREDS 1-2 group resulting in near normal values, while the visual field area 20/80 or better was improved, but less and only poorly in the AREDS 3 and 4 groups. Between the first and second treatment episodes (6-8 months) all Omnifield indices improved among the AREDS 1-2 group but declined slightly in the AREDS 3 and 4 groups. Following the second treatment episode all Omnifield indices again improved but with significant variation in the AREDS 1-2 and AREDS 3 groups. The visual field areas >20/40 or >20/80 either remained very stable or worsened slightly but overall remained restricted in relation to normal values.
Among the eyes with reticular pseudodrusen, a group with known severe risk of progression, significantly worse Omnifield measurements were recorded than among the eyes without the PSD among all AREDS categories. However, the eyes without and without RPD both showed significant improvements in Omnifield indices following SDM, without differences between the groups. These results have demonstrated for the first time the previously unrecognized preservation of functional vision in these eyes at risk of severe vision loss, but indicate that the treatments should be administered early in the course with studies that will follow to evaluate the longer term consequences.