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Dynamics of Retinal Photocoagulation Since
its introduction nearly 40 years ago, laser photocoagulation remains the
standard of care for long-term therapy of several retinopathies. Pan-retinal
photocoagulation (PRP), for example, is highly effective to reverse angiogenesis,
and focal laser therapy is effective for treating macular edema.
Unfortunately, multiple adverse effects often follow these treatments,
including decreased peripheral, color, and night vision and retinal scars
that can enlarge postoperatively and cause choroidal neo-vascularization,
sub-retinal fibrosis and additional visual field loss. Despite
widespread use of lasers in retinal therapy, a systematic
clinico-pathological analysis of laser-induced retinal lesions and their
evolution over time is largely lacking. Moreover, it remains largely unknown
how the benefits of PRP or its many deleterious side effects relate to
parameters of laser treatment and subsequent retinal healing. Thus strategies
to reduce untoward effects of PRP while maintaining clinical benefit are
highly desirable.
We
recently discovered that dynamics of retinal healing of highly confined laser
lesions is very different from that of conventional retinal burns. For these
lighter lesions, not only can the inner retina be spared, but photoreceptor
migration into damaged areas restore photoreceptor continuity over time, as
opposed to formation of permanent scars in the conventional visible lesions.
This way retinal scotomas and scarring can be avoided, thereby ameliorating
many side effects of PRP, and allowing for re-treatment. We study this new minimally-traumatic approach to
the retinal laser therapy and associated retinal plasticity. We also develop
a numeric model of retinal photocoagulation and rupture to help us optimize
the laser treatment parameters for enhancement of the safe therapeutic range
of the short-pulse retinal photocoagulation. |
