Ophthalmology
Journal Scan is the clinician's guide to the latest clinical research findings in the Archives of Ophthalmology, Ophthalmology, and other important journals of interest in ophthalmology. Short summaries of feature articles include links to the article abstracts. (Access to full-text articles usually requires registration at the specific journal's Web site.)
Detection and Prognostic Significance of Optic Disc Hemorrhages During the Ocular Hypertension Treatment Study
Budenz DL, Anderson DR, Feuer WJ, et al; Ocular Hypertension Treatment Study Group
Ophthalmology. 2006:113;2137-2143
The presence of an optic disc hemorrhage has traditionally been thought to be related to the progression of ganglion cell loss in glaucoma. The Ocular Hypertension Treatment Study (OHTS), a multi-institutional study that assessed whether lowering intraocular pressure (IOP) in patients with ocular hypertension delays or prevents visual loss from primary open-angle glaucoma (POAG) and excluded patients with baseline optic disc hemorrhages, provided researchers with an opportunity to evaluate factors related to the development of an optic disc hemorrhage. In this cohort study, the investigators reviewed the records of 1618 patients from the OHTS to:
Determine the rate of detection of optic disc hemorrhages by clinical examination vs optic disc photographs;
Determine the incidence of optic disc hemorrhages before and after the development of POAG;
Identify factors associated with the development of an optic disc hemorrhage; and
Determine whether optic disc hemorrhages predict the development of POAG.
Both eyes were examined every 6 months for the presence of optic disc hemorrhage. Stereoscopic funduscopic images were reviewed annually for the presence of an optic disc hemorrhage. Photographs demonstrated an optic disc hemorrhage in 128 eyes of 123 patients before the development of POAG. Of these, only 21 cases were noted during funduscopy. Older age, thinner corneas, a larger vertical cup-to-disc ratio, larger pattern standard deviation index on automated perimetry, a personal history of smoking, and a family history of glaucoma were all associated with the development of an optic disc hemorrhage. The development of an optic disc hemorrhage in patients enrolled in the OHTS increased the risk for the development of POAG by 6 times. The incidence of POAG in patients with an optic disc hemorrhage was 14%, compared with 5% in those without an optic disc hemorrhage.
These data suggest that the presence of an optic disc hemorrhage is predictive of the development of POAG, and support prior notions that an optic disc hemorrhage is an important finding in patients with POAG or ocular hypertension. Unfortunately, the rate of detection of an optic disc hemorrhage by clinical examination was only one fifth the rate of detection with optic disc photographs -- and this was despite the fact that clinical examinations were performed every 6 months and fundus photography was performed yearly. It appears that detection still poses a challenge.
Reference
Kass MA, Heuer DK, Higginbotham EJ, et al. The Ocular Hypertension Treatment Study: a randomized trial determines that topical ocular hypotensive medication delays or prevents the onset of primary open-angle glaucoma. Arch Ophthalmol. 2002;120:701-713.
Abstract
http://www.medscape.com/medline/abstract/16996592
Occurrence of Cerebral Venous Sinus Thrombosis in Patients With Presumed Idiopathic Intracranial Hypertension
Lin A, Foroozan R, Danesh-Meyer HV, De Salvo G, Savino PJ, Sergott RC
Ophthalmology. 2006:113;2281-2284
Optic disc edema secondary to elevated intracranial pressure can result from a variety of mechanisms. In the absence of a mass lesion, and in patients with normal cerebrospinal fluid consistency, the most common cause of papilledema is idiopathic intracranial hypertension (IIH, also known as pseudotumor cerebri). Criteria for the diagnosis of IIH have been published and include no evidence of a mass lesion on neuroimaging. Apart from visual loss from optic neuropathy, other symptoms of IIH include diplopia, headaches, and pulsatile tinnitus. Cerebral venous sinus thrombosis (CVST) results from clotting within the intracranial dural venous sinuses and may produce a clinically identical syndrome to IIH. Dural venous sinus thrombosis may go undetected in patients who only undergo computed tomography (CT) or magnetic resonance imaging (MRI) of the brain. The diagnosis of CVST may require catheter venography, but can be made with magnetic resonance venography (MRV) or computed tomographic venography (CTV).
The authors of this retrospective study reviewed the records of 131 patients with papilledema from 3 neuroophthalmic centers. All patients with papilledema were required to undergo both MRI and MRV of the head to be included in the study. Of the 106 patients who were included in the study, 10 (9.4%) were diagnosed with CVST as the cause of papilledema. In only 1 of 10 patients was CVST detected with MRI alone; the other 9 cases were detected with both MRI and MRV. In 9 of 10 patients, underlying risk factors for thrombosis were determined.
The treatment of IIH and CVST is generally different because IIH is treated with diuretics and CVST with anticoagulation. Therefore, distinguishing these 2 conditions is important. The study authors did not attempt to determine the optimal method of diagnosis of CVST. However, from the data in this study, they suggested that CVST should be excluded in all patients with elevated intracranial pressure and MRV considered for this subgroup of patients with papilledema.
Abstract
http://www.medscape.com/medline/abstract/17157135