Abstract
Purpose: :
To demonstrate that some patients with non–vascular retinal disorders have glaucoma–like arcuate visual field defects.
Methods: :
We performed a retrospective review of 50 patients with non–vascular retinal disorders affecting photoreceptor function. Diseases included tapetoretinal degenerative disorders, hereditary macular disease and retinal pigment epitheliopathies. Threshold Humphrey visual field testing results and retinal nerve fiber layer (RNFL) results measured by either the GDxVCC or optical coherence tomography (OCT3) were analyzed.
Results: :
Eleven patients (22%) had arcuate visual field defects that mimicked glaucoma. These included patients with retinitis pigmentosa (RP), RP sine pigmento, Stargardt's disease, acute zonal occult outer retinopathy (AZOOR), multiple evanescent white dot syndrome (MEWDS) and autosomal dominant peripapillary retinochoroidal degeneration. Nine of these eleven patients (81%) had completely normal RNFL measurements. The two exceptions were a patient with Stargardt's disease, who also had glaucoma ,and a patient with MEWDS.
Conclusions: :
This study demonstrated that some patients with photoreceptor disease can exhibit glaucomatous–type visual field loss with normal RNFL thickness. Not all patients with arcuate field loss have RNFL impairment due to glaucoma or due to non–glaucomatous optic neuropathy. In this small study, arcuate–type field loss in patients with photoreceptor disease was not rare. Interpretation of visual fields in such patients when the photoreceptor disease may be occult and especially when accompanied by family history, elevated intraocular pressures, thin corneas and/or suspicious cupping may erroneously make the patient suspect for glaucoma. RNFL measurements with either the GDxVCC or OCT3 can tease apart the retina and thereby aid in the differential diagnosis of arcuate–type visual field defects.
Keywords: visual fields • retinal degenerations: hereditary • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)