Frequency doubling technology and scanning laser tomography in eyes with generalized enlargement of optic disc cupping.

PURPOSE: To characterize functional and structural changes in eyes with generalized enlargement of optic disc cupping (vertical cup/disc ratio > or = 0.8), normal intraocular pressure, normal standard achromatic automated perimetry (SAP) results, and no other ophthalmoscopic findings suggesting glaucoma (large C/D eyes) using frequency doubling technology (FDT) and the Heidelberg Retina Tomograph (HRT). METHODS: This comparative observational case series included 30 large C/D eyes (30 subjects), 17 eyes (17 patients) with early-stage normal tension glaucoma with generalized enlargement of optic disc cupping (NTG eyes), and 25 eyes from 25 normal subjects (normal eyes). Results with Humphrey 30-2, FDT N-30 threshold programs, and HRT were compared among these groups. Large C/D eyes were subdivided into FDT-normal and -abnormal eyes according to the predetermined criteria and HRT parameters were compared among them. RESULTS: No significant difference was seen in HRT parameters between the large C/D and NTG eyes. In the large C/D eyes, FDT mean deviation was lower than in the normal eyes and higher than in the NTG eyes, whereas FDT pattern standard deviation was smaller than in the NTG eyes (P = 0.02-0.03). Among HRT parameters, only cup shape measure (CSM) showed significant negative correlation with FDT mean deviation in the large C/D eyes. Between FDT-normal and -abnormal subgroups, only CSM showed significant difference (P < 0.01). CONCLUSION: Frequency doubling technology showed abnormalities in large C/D eyes. Only CSM showed significant correlation with FDT result and difference between those with normal and abnormal FDT results. In management of large C/D eyes, FDT and CSM will be useful to detect functional and structural change.

Orbital varix rupture during cataract surgery.

We report a case of orbital varix rupture during cataract surgery with retrobulbar anesthesia. No remarkable changes were observed 10 minutes after retrobulbar anesthesia was administered, but a rise in intraocular and intraorbital pressure was noted about 10 minutes after phacoemulsification began. The eyelid could not be closed at the end of surgery because of severe proptosis. Follow-up by magnetic resonance imaging and color Doppler imaging revealed orbital hemorrhage and varix. Based on the time of its appearance, the hemorrhage was thought to be the result of venous congestion caused by anesthetic agent in the muscle cone. Although intermittent exophthalmos is a symptom of orbital varix, silent orbital varix should be considered when selecting the method of anesthesia for ocular surgery.

Molecular identification of nicotinic acid receptor.

Nicotinic acid and its derivative, Acipimox, have been widely used in the treatment of hyperlipidemia. Pharmacological studies have demonstrated that they exert the beneficial effect through the activation of a Gi-protein-coupled receptor on adipocyte, which has remained elusive to date. Here we show that a novel GPCR, designated HM74b because of its high similarity to HM74, is a receptor for nicotinic acid. HM74b mRNA is found in human, murine, and rat adipose tissues. Nicotinic acid and Acipimox inhibit forskolin-stimulated intracellular cAMP accumulation in human HM74b-expressing cells and activate GTP gamma S binding in a dose-dependent manner. [3H]Nicotinic acid specifically binds to HM74b-expressing membrane and its binding is replaced by Acipimox. This finding will open a new phase of research on the physiological role of nicotinic acid and will be a clue to develop novel antihyperlipidemic drugs.