Change in optic disc topography associated with diurnal variation in intraocular pressure

Purpose: A case demonstrating significant changes in optic disc topography from variation in intraocular pressure (IOP) is demonstrated. Methods: Within a single 24-hour period, confocal scanning laser ophthalmos copic images were obtained in the left eye of a patient during an IOP peak (60 mmHg) and during an IOP trough (18 mmHg). Results: During an IOP trough, paired t tests showed significant reduction in cup area, cup volume, mean cup depth. and maximum cup depth, and a signi ficant increase in rim area and cup-to-disc (CD) ratio. Conclusion: Under certain conditions, optic disc topography may be affected by diurnal variations in IOP.