Ocular dominance and patient satisfaction after monovision induced by intraocular lens implantation.

PURPOSE: To elucidate the relationship between ocular dominance and patient satisfaction with monovision induced by intraocular lens implantation. SETTING: Eye Clinic, Kitasato University School of Medicine Hospital, Sagamihara, Kanagawa, Japan. METHODS: The durations of exclusive visibility of dominant- and nondominant-eye targets were measured in 16 patients with successful monovision and 4 patients with unsuccessful monovision to determine the characteristics of ocular dominance. The dominant eye was determined using the hole-in-card test (sighting dominance). The contrast of target in nondominant eye was fixed at 100%; the contrast of target in the dominant eye varied (ie, 100% to 80% to 60% to 40% to 20%) using rectangular gratings of 2 cycles per degree that were 4 degrees in size. RESULTS: In the successful monovision group, the reversal thresholds (ie, exclusive visibility of the nondominant eye crosses over that of the dominant eye) were displayed only at low decreasing contrast (80% and 60%). However, in the unsuccessful monovision group, the reversal thresholds were at high decreasing contrast (20%) or not at all. The reversal thresholds in patients with unsuccessful monovision were at a significantly lower contrast than in patients with successful monovision (P<.05). CONCLUSIONS: Success and patient satisfaction in monovision patients were significantly influenced by the magnitude of ocular dominance. The balance technique seems to be a good method to evaluate the quantity of ocular dominance and prospectively evaluate the monovision technique.

Effects of a new excitotoxic amino acid, dysiherbaine, on cultured Müller cells.

PURPOSE: To determine the pharmacological response when dysiherbaine acts on cultured Müller cells, considering the glutamate receptor functions. Dysiherbaine is a new excitotoxic amino acid, which was recently isolated from the liquid extract of a certain sponge. METHODS: Retinas of adult rabbits were used to culture the Müller cells. Intracellular calcium ion concentration ([Ca(2+)](i)) analysis was done by fluorophotometry with the calcium indicator, acetoxymethyl ester fura-2 (Fura-2 AM). RESULTS: A transient increase of [Ca(2+)](i) was observed following the administration of dysiherbaine (2.5 microM-2.5 mM) to Müller cells, but no [Ca(2+)](i) increase was observed in the extracellular calcium-free solution. This increase was blocked by the non-N-methyl-D-aspartate (NMDA) glutamate receptor antagonist, 6-cyano-7 nitroquinoxaline-2,3-dione (CNQX). A dysiherbaine-induced increase in [Ca(2+)](i) following preincubation of the NMDA glutamate receptor antagonist, (5R,10S)-(+)-5-methyl-10,11-dyhydro-5H-dibenzo [a,d] cyclohepten-5, 10-imine hydrogen maleate (MK 801) was seen in the same number of Müller cells with and without the antagonist. CONCLUSIONS: Dysiherbaine appears to act primarily as a non-NMDA glutamate receptor agonist, having a secondary action as a NMDA glutamate receptor agonist.