Purpose. To evaluate the appearance and potential occludability of narrow anterior chamber angles in total darkness. Methods. 11 eyes of 11 patients suspected of having angle closure were evaluated with a four mirror contact gonioscopy lens, without indentation. Images were obtained with a high-resolution infrared video camera attached to a Zeiss photographic slit-lamp biomicroscope modified with an infrared transmission filter. Angles were graded by Scheie's method, with Schwalbe's line identified by the corneal parallelopiped. Angles were evaluated with maximal pupillary dilation and then with pupillary constriction induced by light directed into the contralateral eye. Visible light video goniography was performed for comparison. Eyes were reevaluated after laser iridectomy. Results. Infrared goniography demonstrated angle closure in all 11 eyes, with appositional closure in 11/11 inferior and 9/11 superior angles. In contrast, 7/11 eyes appeared to have narrow but open angles with visible light goniography and with infrared goniography when the pupil was constricted. After laser iridectomy, Scheie's classification of the angle was the same with both infrared and visible light goniography. Conclusions. Infrared goniography permits visualization of the anterior chamber angle in total darkness, with maximal pupillary dilation. It provides a full view of the angle with no visible illumination, thereby clarifying whether a narrow angle, which appears open even with minimal visible illumination, is actually closed. It is therefore a useful diagnostic technique and teaching tool for the identification of occludable angles.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Feb 15 1996|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience