Comparison of Optic Nerve Head Topography and Visual Field in Eyes with Open-angle and Angle-closure Glaucoma
Presented at: Association for Research in Vision and Ophthalmology Annual Meeting, May 2007, Fort Lauderdale, Florida.
Received 23 January 2007; received in revised form 6 March 2007; accepted 23 March 2007. published online 17 December 2007.
Objective
To compare the optic disc and visual field (VF) alterations in primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG).
Design
Observational case series.
Participants
A total of 146 persons (217 eyes), 110 with POAG and 36 with PACG, recruited from a university glaucoma service.
Methods
Each subject underwent visual acuity measurement, applanation tonometry, gonioscopy, slit-lamp examination, dilated optic disc and retinal examination, axial eye length measurement, central corneal pachymetry, automated perimetry, optical coherence tomography (OCT) nerve fiber layer (NFL) examination, and Heidelberg Retina Tomograph (HRT) optic disc evaluation. Parameters of interest were studied by multivariate regression models.
Main Outcome Measures
Heidelberg Retina Tomograph parameters compared between POAG and PACG.
Results
Primary open-angle glaucoma and PACG groups were similar in age, ethnic background, and treated intraocular pressure, but the PACG group had significantly more women, shorter eye length, more hyperopia, and a larger disc area (all Ps < 0.001). The VF average mean deviation (MD) did not significantly differ between POAG and PACG, but the PACG group had lower pattern standard deviation (PSD) for a given MD (P = 0.001). Although 3 HRT parameters differed somewhat between POAG and PACG (cup area, rim area, and cup-to-disc area ratio), they did not significantly differ after correction for multiple comparisons. Mean deviation and disc area were much more significant predictors of the HRT measures than was diagnosis. Similar results were obtained when using OCT NFL thickness as a structural measure of damage as opposed to MD as a functional measure. When controlling for MD, current IOP was not significantly associated with disc parameters in POAG.
Conclusions
When the amount of optic nerve damage is taken into account by adjusting for VF MD or OCT NFL thickness, those with POAG and PACG have no significant differences in optic disc topography. Visual field damage in PACG was more diffuse than that in POAG, as measured by a lower PSD for a given level of MD. There was no corresponding difference in the uniformity of structural damage as measured by OCT NFL thickness.
Available online: December 17, 2007.
1Dana Center for Preventive Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland.
2Glaucoma Service, Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland.
Correspondence and reprint requests to Michael V. Boland, Johns Hopkins University, Wilmer 119, 600 North Wolfe Street, Baltimore, MD 21287.
Manuscript no. 2007-100.
Supported by the National Eye Institute, Bethesda, Maryland (grant nos. EY015025, EY012295, EY001765); Research to Prevent Blindness, New York, New York; and Saranne and Livingston Kosberg.
The authors have no commercial or proprietary interest in the products or companies mentioned in the article.
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