- Home
- July 2014
July 2014
In glaucoma, regardless of its etiology, retinal ganglion cells degenerate and eventually die. Although age and elevated intraocular pressure (IOP) are the main risk factors, there are still many mysteries in the pathogenesis of glaucoma. The advent of genome-wide microarray expression screening together with the availability of animal models of the disease has allowed analysis of differential gene expression in all parts of the eye in glaucoma. This review will outline the findings of recent genome-wide expression studies and discuss their commonalities and differences. A common finding was the differential regulation of genes involved in inflammation and immunity, including the complement system and the cytokines transforming growth factor β (TGFβ) and tumor necrosis factor α (TNFα). Other genes of interest have roles in the extracellular matrix, cell-matrix interactions and adhesion, the cell cycle, and the endothelin system.
UNLABELLED: We present a case of corneal perforation secondary to an intrastromal astigmatic keratotomy performed with an optical coherence tomography-guided femtosecond laser. The keratotomy was concomitant with cataract surgery and resulted in a flat anterior chamber prior to the start of lens extraction. Interrupted nylon sutures were placed to seal the keratotomy prior to phacoemulsification. Escape of cavitation bubbles into the anterior chamber or the liquid interface can alert the surgeon to the possibility of unintended perforation of the endothelium or the epithelium, respectively. FINANCIAL DISCLOSURE: Neither author has a financial or proprietary interest in any material or method mentioned.
The aim of this study was to describe a transnasal endoscopic bimanual technique for the removal of an intraconal orbital apex cavernous hemangioma. Report of a surgical technique. A 39-year-old woman with unilateral visual loss and proptosis was found to have an intraconal orbital apex mass consistent radiographically with cavernous hemangioma. Because of its posteromedial location within the orbit, a transnasal 4-handed endoscopic technique was used with pedicled nasoseptal flap reconstruction. The tumor was excised, and the patient had no complications. The transnasal endoscopic approach to orbital apex cavernous hemangioma excision is a viable surgical approach for these difficult to access lesions. The medial orbital wall may be simultaneously reconstructed to prevent diplopia and enophthalmos.
PURPOSE: To assess whether brimonidine 0.15% alters retinal vascular autoregulation and short-term visual function in normal tension glaucoma patients who demonstrate retinal vascular dysregulation. DESIGN: Nonrandomized clinical trial. METHODS: In this prospective study, 46 normal tension glaucoma patients not previously treated with brimonidine underwent retinal vascular autoregulation testing and visual function assessment using frequency doubling technology perimetry and equivalent noise motion sensitivity testing. We measured blood flow in a major temporal retinal artery with subjects seated and then while reclined for 30 minutes. Patients having a change in retinal blood flow with posture change outside the range previously found in healthy subjects were classified as having retinal vascular dysregulation. They were treated with brimonidine 0.15% for 8 weeks and designated for retesting. RESULTS: Twenty-three patients demonstrated retinal vascular dysregulation at the initial visit. Younger age (P = .050) and diabetes (P = .055) were marginally significant risk factors for retinal vascular dysregulation. After the 8-week course with brimonidine, 14 of the 17 patients who completed the study showed a return of posture-induced retinal blood flow changes to levels consistent with normal retinal vascular autoregulation (P < .0001). We found no significant changes in frequency doubling technology perimetry or in motion detection parameters following treatment with brimondine (P > .09 for all tests performed). CONCLUSIONS: Brimonidine significantly improved impaired retinal vascular autoregulation in normal tension glaucoma patients, but short-term alteration in visual function could not be demonstrated.
BACKGROUND: Surgical management of intraconal pathology represents the next frontier in endoscopic endonasal surgery. Despite this, the medial intraconal space remains a relatively unexplored region, secondary to its variable and technically demanding anatomy. The purpose of this study is to define the neurovascular structures in this region and introduce a compartmentalized approach to enhance surgical planning. METHODS: This study was an institutional review board (IRB)-exempt endoscopic anatomic study in 10 cadaveric orbits. After dissection of the medial intraconal space, the pattern and trajectory of the oculomotor nerve and ophthalmic arterial arborizations were analyzed. The position of all vessels as well as the length of the oculomotor trunk and branches relative to the sphenoid face were calculated. RESULTS: A mean of 1.5 arterial branches were identified (n = 15; range, 1-4) at a mean of 8.8 mm from the sphenoid face (range, 4-15 mm). The majority of the arteries (n = 7) inserted adjacent to the midline of medial rectus. The oculomotor nerve inserted at the level of the sphenoid face and arborized with a large proximal trunk 5.5 ± 1.1 mm in length and multiple branches extending 13.2 ± 2.7 mm from the sphenoid face. The most anterior nerve and vascular pedicle were identified at 17.0 and 15.0 mm from the sphenoid face, respectively. CONCLUSION: The neurovascular supply to the medial rectus muscle describes a varied but predictable pattern. This data allows the compartmentalization of the medial intraconal space into 3 zones relative to the neurovascular supply. These zones inform the complexity of the dissection and provide a guideline for safe medial rectus retraction relative to the fixed landmark of the sphenoid face.
