A blind spot?
By Jan Tunér
Macular degeneration, often age-related macular degeneration (AMD or ARMD), is a medical condition that usually affects older adults and results in a loss of vision in the center of the visual field (the macula) because of damage to the retina. It occurs in “dry” and “wet” forms. It is a major cause of blindness and visual impairment in older adults (>50 years). Macular degeneration can make it difficult or impossible to read or recognize faces, although enough peripheral vision remains to allow other activities of daily life. Although some macular dystrophies affecting younger individuals are sometimes referred to as macular degeneration, the term generally refers to age-related macular degeneration (AMD or ARMD). In the dry (nonexudative) form, cellular debris called drusen accumulates between the retina and the choroid, and the retina can become detached. In the wet (exudative) form, which is more severe, blood vessels grow up from the choroid behind the retina, and the retina can also become detached. It can be treated with laser coagulation, and with medication that stops and sometimes reverses the growth of blood vessels. [Wikipedia 2014).
In ophthalmology, lasers have been used for decades to treat various pathological conditions in the eyes. In fact, lasers have become an indispensable tool. So far, lasers have not been used to treat macular degeneration. At least not according to chapter 60 in the new great Handbook of Photomedicne [1]. In this chapter (Therapeutic Uses of Lasers in Eye Care), a number of laser applications in ophthalmology are described. But not a word about one of the most remarkable discoveries in LPT in recent years – the use of LPT to treat macular degeneration. Ivandic [2] published a paper in 2008, showing how LPT could be used successfully and inexpensively. The abstract of the papers reads:
The objective of this study of a case series was to examine the effects of low-level laser therapy (LLLT) in patients with age-related macular degeneration (AMD). AMD affects a large proportion of the elderly population; current therapeutic options for AMD are limited, however. In total, 203 patients (90 men and 113 women; mean age 63.4 +/- 5.3 y) with beginning (“dry”) or advanced (“wet”) forms of AMD (n = 348 eyes) were included in the study. One hundred ninety-three patients (mean age 64.6 +/- 4.3 y; n = 328 eyes) with cataracts (n = 182 eyes) or without cataracts (n = 146 eyes) were treated using LLLT four times (twice per week). A semiconductor laser diode (780 nm, 7.5 mW, 292 Hz, continuous emission) was used for transconjunctival irradiation of the macula for 40 sec (0.3 J/cm2) resulting in a total dose of 1.2 J/cm2. Ten patients (n = 20 eyes) with AMD received mock treatment and served as controls. Visual acuity was measured at each visit. Data were analyzed retrospectively using a t-test. LLLT significantly improved visual acuity (p < 0.00001 versus baseline) in 162/182 (95%) of eyes with cataracts and 142/146 (97%) of eyes without cataracts. The prevalence of metamorphopsia, scotoma, and dyschromatopsia was reduced. In patients with wet AMD, edema and bleeding improved. The improved vision was maintained for 3-36 mo after treatment. Visual acuity in the control group remained unchanged. No adverse effects were observed in those undergoing therapy. In patients with AMD, LLLT significantly improved visual acuity without adverse side effects and may thus help to prevent loss of vision.
The study has a large number of patients; the method is cost-effective, safe and more successful than other therapies. One would expect a great interest from the medical profession, especially from a branch where lasers are common-place. But this observation is not even mentioned in said chapter. And it’s not that the editors are lacking knowledge about LPT. On the contrary, the book has a very large and qualified chapter on LPT.
Is LPT sometimes located in a scientific blind spot?
References
[1] Hamblin M R, Huang Y-Y, eds. Handbook of Photomedicine. CRC Press, 2013.ISBN 13:978-1-4398-8469-0.
[2] Ivandic B T, Ivandic T. Low-level laser therapy improves vision in patients with age-related macular degeneration. Photomed Laser Surg. 2008; 26 (3): 241-245.