Restoration of retinal ganglion cell function in early glaucoma after intraocular pressure reduction: a pilot study.
OBJECTIVE
To investigate the changes of pattern electroretinogram (PERG) after intraocular pressure lowering in glaucoma patients and normal controls.


METHODS
Interventional retrospective cross-sectional study.


METHODS
Twenty-five patients (49 eyes) with ocular hypertension or glaucoma undergoing topical treatment to lower IOP served as a study group; 22 patients (44 eyes) with ocular hypertension or glaucoma observed without treatment served as a control group for treated glaucoma patients; 9 normal subjects (18 eyes) receiving a 250-mg acetazolamide tablet served as a second study group; and 17 normal subjects (34 eyes) from a previous study served as a second control group for treated normal subjects.


METHODS
Pattern electroretinograms were recorded simultaneously from both eyes using skin electrodes and automated analysis. Visual field (VF) analyses were performed with white-on-white standard automated perimetry (SAP). Intraocular pressure was measured with Goldmann applanation tonometry; central corneal thickness was measured with pachymetry.


METHODS
Pattern electroretinogram amplitude (microvolts), phase (pi rads), and test-retest variability (test 2-to-test 1 ratio, in decibels), SAP mean deviation (decibels), and IOP (millimeters of mercury).


RESULTS
In 56% of right eyes and 21% of left eyes of the treated glaucoma subgroup, the PERG amplitude and/or phase improved beyond the 95% confidence intervals of the test-retest variability of the untreated glaucoma control group. Pattern electroretinogram improvement with IOP lowering occurred in both high- and low-tension glaucoma eyes. Eyes with severely impaired VFs showed little improvement in PERG; however, eyes of normal subjects treated with acetazolamide did not show significant PERG changes relative to the test-retest variability of normal controls.


CONCLUSIONS
Retinal ganglion cell function can be at least partially restored after IOP reduction in glaucomatous eyes with early VF impairment.
Ventura
Lori M
LM
Bascom Palmer Eye Institute, Miami, Florida 33136, USA.
Porciatti
Vittorio
V
D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D003430:Cross-Sectional Studies; D004596:Electroretinography; D005901:Glaucoma / Q000188:drug therapy / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D009798:Ocular Hypertension / Q000188:drug therapy / Q000503:physiopathology; D010364:Pattern Recognition, Visual; D010865:Pilot Projects; D020127:Recovery of Function / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000502:physiology*; D012189:Retrospective Studies; D014065:Tonometry, Ocular; D058609:Visual Field Tests; D014794:Visual Fields
D000959:Antihypertensive Agents