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Primary ocular lymphomas are typically confined to either the eye or the orbit. Rarely, in immune-competent patients, lymphomas affect both the eye and the orbit simultaneously. Mucosa-associated lymphoid tissue (MALT) lymphomas are the most common ocular lymphomas. They usually present primarily in the orbit but sometimes can present primarily in intraocular tissue. MALT lymphomas that occur initially in the uvea can sometimes spread to the adjacent orbit. We report a case of progressively enlarging MALT lymphoma in a 62-year-old immune-competent patient causing a severe mass effect in the orbit and simultaneously presenting with intraocular involvement. There was radiographic evidence of lymphoma confined to the orbit with intraocular involvement. The simultaneous presentation makes it difficult to determine if the lymphoma initially presented in the orbit or intraocular tissue, although the orbital component was more impressive. The case also includes a literature review of simultaneous orbital and intraocular MALT lymphomas. The patient responded to systemic chemotherapy with regression in size of the lymphoma, relief of the mass effect seen in the orbit, and the regression of the intraocular involvement. [ABSTRACT FROM AUTHOR]

Basal encephaloceles are uncommon malformations that are usually congenital in nature, although, occasionally, they can be traumatic. When they are congenital, they are associated with skull and facial midline defects, central nervous system abnormalities, and possible ocular and visual problems. The authors present a case of an adult male with a basal encephalocele who presented with a bitemporal hemianopsia. Ocular abnormalities, visual loss, and visual field deficits have previously been reported in patients with basal encephalocele; however, there does not appear to be any reported cases with formal visual field testing to demonstrate specific defects such as a bitemporal hemianopsia. [ABSTRACT FROM AUTHOR]

Purpose: To develop a three-dimensional optical model of the anterior segment which will provide a basis for understanding the effects of corneal and adnexal problems on vision. Methods: A three-dimensional optical model of the anterior segment was developed to calculate the effective corneal refractive surface (ECRS), which is a specific area of cornea that refracts incident light rays arising from an object in visual space through the physical pupil (PP); light rays refracted by cornea outside the ECRS do not traverse the PP. This model incorporated the patient variables of central anterior chamber depth ( A) and central corneal curvature ( K). A vector analysis was combined with three-dimensional analytic geometry to create a unified solution for all object locations in visual space. A computer program in BASIC on a PC was developed to perform the calculations. Results: The ECRS was circular for objects on the line of sight, but with increasing displacement from the fixation point it became oval and eventually crescent shaped. The size of the ECRS increased as the distance of the object from the eye increased, but it rapidly reached a limiting value at about 200 mm. The size of the ECRS increased with PP diameter, but showed only a small dependence on A and minimal dependence on K. Conclusion: This comprehensive optical model of object space and the anterior segment of the eye allows clinicians to better understand the effects of corneal light transmission on vision. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether the currently accepted method of selecting a minimum optical zone diameter for laser refractive surgery that is equal to or slightly greater than the dark-adapted pupil diameter provides a sufficient diameter of corneal surface to focus light arising from objects in the paracentral and peripheral visual field. Setting: Department of Ophthalmology and Visual Sciences, Texas Tech University Health Sciences Center, Lubbock, Texas, USA. Methods: An optical model of the anterior segment was developed to calculate the effective corneal refractive diameter (ECRD), which is the diameter of the area of cornea that refracts all incident light rays arising from an object through the physical pupil (PP). This model incorporates the patient variables of central anterior chamber depth (ACD), central corneal curvature (K c), and the diameter of the apparent entrance pupil (EP). The model was expanded to incorporate distant objects off the line of sight (LOS), described by their angular displacement from the fixation object in visual space (the object tangent angle δob). Results were calculated for the 360 meridian degree visual field (ie, for all objects in visual space perceptually displaced from the fixation object by angle δob). The effect of the prolate nature of the cornea was also investigated. Results: The ECRD expanded rapidly as a function of PP and δob but was minimally influenced by K c. Beyond a critical object tangent angle δc, light rays striking the corneal vertex were not refracted through the PP, and the ECRD became an annular surface centered on the corneal vertex. The δc was not a function of K, but increased as the PP increased and decreased as the ACD increased. The prolate nature of the cornea had little influence on the ECRD, even for very peripheral light rays. Conclusions: The ECRD expands rapidly when considering distant objects only slightly displaced from the LOS. A patient treated with an optical zone equal to or slightly greater than the dark-adapted pupil diameter may experience vision quality loss for paracentral and midperipheral objects even under conditions of ambient indoor lighting. [Copyright &y& Elsevier]

: PurposeTo determine whether the currently accepted method of selecting a minimum ablation zone size for refractive surgery based on dark-adapted pupil diameter is substantiated by geometric optical analysis.: SettingDepartment of Ophthalmology and Visual Sciences, Texas Tech University Health Sciences Center, Lubbock, Texas, USA.: MethodsAn optical model of the anterior segment was developed to calculate the effective corneal refractive diameter (ECRD), which is the diameter of the area of cornea that refracts all incident light rays arising from objects along the line of sight though the physical pupil (PP). The concept of the entrance pupil (EP) was reexamined and developed, and the ECRD was calculated over a range of corneal curvatures (K), anterior chamber depths (ACDs), and EP sizes. The model was generalized to include oblique light rays. Calculations were performed using MatLab Optimization Toolbox® software (The MathWorks).: ResultsFor a given EP size, the ECRD was significantly influenced by K and slightly influenced by ACD. For objects on the line of sight, the ECRD was smaller than the EP in all cases. Regarding rays from objects in the periphery, the ECRD expanded rapidly as the angle of oblique incidence increased.: ConclusionsFor objects on the line of sight, the ECRD is always smaller than the clinically measured pupil (EP) because the EP is substantially magnified relative to the PP. Ablation zones larger than the EP should, in theory, prevent scattered or defocused light rays from contributing to the foveal image. When considering objects in the periphery, the increase in ECRD is sufficiently rapid that current refractive procedures cannot stop scattered light from these objects from contributing to the retinal image. [Copyright &y& Elsevier]

Purpose: To report a case of a transient homonymous hemianopia in a patient with nonketotic hyperglycemia with negative magnetic resonance imaging (MRI) scans.Design: Case report.Method: A 72-year-old woman with diabetes mellitus was referred to the neuro-ophthalmology service with hyperglycemia and multiple visual complaints.Results: The patient was found to have a dense left homonymous hemianopia on examination. An MRI scan of the brain was negative for a lesion affecting the visual pathways. Resolution of the homonymous hemianopia and the patient''s symptoms came with normalization of her blood glucose levels.Conclusion: Nonketotic hyperglycemia is an important diagnostic consideration in patients who present with homonymous visual field defects but have negative neuroimaging studies. [Copyright &y& Elsevier]

Purpose: To report a case of Gorham disease, also known as vanishing bone disease, of the orbit.Design: Interventional case report.Methods: A 43-year-old Caucasian woman developed a depression in her left temple, pulsation in her left upper eyelid and temple, and bulging of the left upper eyelid and headache. Computerized tomography revealed a lytic lesion in the roof of the left orbit.Results: Intraoperative examination of the lesion revealed a bony defect in the left orbital roof. Surgical intervention resulted in improvement of her symptoms, and pathology failed to reveal evidence of malignancy or other benign neoplastic process.Conclusion: Gorham disease should be considered in the differential diagnosis of lytic bony lesions of the orbit. [ABSTRACT FROM AUTHOR]

A 37-year-old woman experienced painless, progressive vision loss to no light perception in the left eye over the course of 3 days. The right eye was unaffected. On examination, the only other abnormal finding was a +4 left afferent pupillary defect. She was initially diagnosed with retrobulbar optic neuritis and admitted for treatment with intravenous methylprednisolone. Neuro-imaging revealed a large right anterior cerebral artery aneurysm that crossed the midline to compress the left optic nerve. The aneurysm was treated with coil embolization, which was technically successful but which did not lead to significant improvement in vision. [Copyright &y& Elsevier]