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The patient is a 25 year old white man with Duchenne muscular dystrophy (DMD), complicated by respiratory failure requiring ventilatory assistance and impaired cardiac function. His ocular complaints were “floaters” and decreased vision over the preceding 6 weeks. He had no history of ocular disease or trauma. The patient’s level of alertness was reported to routinely fluctuate but no new neurological findings were present. The best corrected visual acuity was count fingers in the right eye and 20/70 in the left eye. The intraocular pressures were 14 and 8 mm Hg. The anterior segment examination was unremarkable with no neovascularisation of the iris or angle. Biomicroscopy revealed bilateral vitreous haemorrhage. Indirect ophthalmoscopy showed the retinal periphery to be attached in both eyes. The optic discs and macula were partially obscured by haemorrhage. Fluorescein angiography revealed delayed filling and venous beading in both eyes, without central or branch, vascular occlusion. Hyperfluorescence, consistent with neovascularisation, was present along the temporal vascular arcades and at the optic discs. Fundus photography corroborated the angiographic findings (see figs 1 and 2).
Indirect laser with scleral depression resulted in full treatment of retina outside of the vascular arcades. Treatment appeared to have little effect on neovascular progression. Overwhelming anaesthetic risk prevented intraocular procedures. Both eyes progressed to subtotal traction retinal detachment and counting fingers vision.
The working diagnosis was retinal ischaemia secondary to hypoperfusion or pan-microvascular occlusive disease. The cardiac ejection fraction was 20% of predicted; the forced vital capacity was 14% of predicted and the forced expiratory volume in 1 second was 15% of predicted. We believe that cardiopulmonary compromise was a primary contributor to the development of retinal neovascularisation. Arterial blood gas analysis was not available. The patient was on Coumadin for cardiac indications. He was not a diabetic and finger stick blood sugars were consistently in the low to normal range. Additional normal evaluation included erythrocyte sedimentation rate, anticardiolipin, C reactive protein, C3, C4, total complement, C1q complex, and a Raji assay. The presentation, appearance, and course were not typical for Terson’s syndrome, Valsalva retinopathy, or Takayasu disease.
Duchenne muscular dystrophy is the most common X linked neuromuscular disorder. It has an incidence of one in 3500 male births.1–3 DMD results from a gene mutation that leads to altered or absent dystrophin production.4 Dystrophin is normally expressed in the retina and localises to photoreceptor terminals and around retinal vessels. Deficiency of dystrophin produces abnormal transmission between photoreceptors and optic nerve bipolar cells and a diminished electroretinogram (ERG) signal.5 Mice lacking the Dp71 isoform of dystrophin suffer greater damage to the ganglion cell layer following transient ischaemia than wild type mice.6 Therefore, dystrophin may be involved in the regulation of ischaemic processes in the retina. Cardiopulmonary assist is not routinely associated with proliferative retinopathy in adults. Retinal neovascularisation is not prevalent in the Duchenne population, suggesting that absence of dystrophin is not sufficient to induce neovascularisation alone.
In summary, rapidly progressive, bilateral proliferative retinopathy may be associated with DMD in the presence of severe cardiopulmonary compromise. Whether an absence of dystrophin contributes directly or indirectly is unknown but consideration of the possibility may lead to novel insights into the development of pathological retinal neovascularisaton. The visual prognosis with late presentation in this setting is uncertain despite full panretinal photocoagulation. Patients with advanced DMD may benefit from periodic fundus examination as it is not known whether early treatment has the potential to alter prognosis.
Supported in part by Research to Prevent Blindness, Juvenile Diabetes Foundation, Stewart Trust, NEI-KO8 (PG).