| OCR Text |
Show Reply-Optic Disc Doubling or Pseudo-Optic Disc in Colobomatous Retinal Abnormality? We thank Gerth-Kahlert and Wildberger for their com-ments on our article dealing with optic disc doubling (1). In their case, the blood vessels that appear to arise from the coloboma inferior to the disc are actually a continuation of the blood vessels emerging from the optic disc. This is an example of a lesion simulating the optic disc or pseudo-disc doubling. In contrast, in our patient, there is no connection on the surface of retina between the 2 groups of vessels. The emerging retinal vasculature from the optic disc has a normal configuration except for an absent inferotemporal venous trunk. The superonasal part of the inferior disc is occupied by the cup, and the inferonasal portion shows the origin of another independent but incomplete retinal vascular sys-tem. It consists of superotemporal and inferotemporal venous and superotemporal and inferonasal arterial arcades, converging at one point. There is a single foveal avascular zone corresponding to the true optic disc at a level slightly lower than its normal position. The inferotemporal portion of the perifoveal capillary net is formed by the tributaries from the superotemporal vascular arcade from the second disc. Fundus fluorescein angiography shows simultaneous and similar filling patterns of both vascular systems. The arcuate visual field defect in our patient demon-strates that the inferior optic disc is nonfunctioning. The hypopigmented bridging track possibly indicates an embryological relationship between the 2 discs. The 2 separate vascular systems, the presence of 2 blind spots on visual field testing, and the crater-like depression over the inferior disc in optical coherence tomography (OCT) suggest that our patient has true doubling of the optic disc. With regard to our OCT findings, unfortunately we do not have a horizontal line scan passing across the inferior disc to show nasotemporal asymmetry of the nerve fiber layer. We agree with Gerth-Kahlert and Wildberger that discontinuation of the junction of the inner and outer photoreceptor segment is difficult to assess because of the quality and angulation in the scan. Ultrahigh resolution OCT passing across both optic discs would give better delineation of the adjacent retinal architecture. Tapas R. Padhi, MS Consultant, Department of Retina and Vitreous, LV Prasad Eye Institute, Bhubaneswar, India drtapasranjan@yahoo.co.in The authors report no conflicts of interest. REFERENCE 1. Padhi TR, Samal B, Kesarwani S, Basu S, Das T. Optic disc doubling. J Neurophthalmol. 2012;32:238-239. Idiopathic Intracranial Hypertension in a Child With Obstructive Sleep Apnea Cured by Tonsillectomy/Adenoidectomy We read with interest Dr Michael Wall's editorial on idiopathic intracranial hypertension (IIH) (1). We describe a surgically treatable case of IIH associated with obstructive sleep apnea (OSA). A 9-year-old girl presented to our emergency department with complaints of diplopia, headaches, nausea, and vomit-ing for 5 days associated with mild neck stiffness. She was taking no medications. Her height was 62 inches, weight 159 lbs for a body mass index of 29, (over the 95th percentile for girls her age and height). Visual acuity was 20/40, right eye and 20/25, left eye. Pupillary reactions, color vision, and confrontation visual fields were normal. Extra-ocular motility demonstrated limited abduction bilaterally. Funduscopic examination revealed mild bilateral optic disc swelling with dilated retinal vessels without hemorrhage or exudate. Neurological examination was normal. Automated visual fields performed 3 days later showed superior arcuate scotomas in each eye and a nasal step in the right eye. Magnetic resonance imaging of the brain was normal as was magnetic resonance venography. Opening pressure on lumbar puncture was greater than 50 cm H2O, and cerebro-spinal fluid analysis was normal. The patient was diagnosed with IIH and prescribed 500 mg of acetazolamide 4 times a day. This was eventually reduced to 500 mg twice a day. Her diplopia resolved, but 6 months later, she complained of Letters to the Editor: J Neuro-Ophthalmol 2013; 33: 412-423 413 Letters to the Editor Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. |
