Correlation of optic nerve head tomography with visual field sensitivity in papilledema.

PURPOSE: To quantify the relationship between optic nerve head tomography and perimetric sensitivity in patients with papilledema. METHODS: Eight patients with variable degrees of recently diagnosed papilledema associated with idiopathic intracranial hypertension (IIH) were evaluated with confocal scanning laser ophthalmoscopy (CSLO) and automated perimetry. Patients were followed up with serial measurements over a period of 5 to 30 months (mean +/- SD, 17.1 +/- 9), while under medical treatment (acetazolamide). The tomographic parameters, volume above reference (VAR), volume above surface (VAS), effective mean height (EMH), and maximum height in contour (MxHC), were obtained by tomography, either globally or from predefined disc sectors. The perimetric indices, mean deviation (MD) and pattern SD (PSD), were evaluated. The results from patients' right eyes and the individual intereye differences in both tomographic and perimetric parameters, were statistically evaluated by nonparametric correlational (Spearman) and repeated measures (Wilcoxon) analyses. RESULTS: At baseline, all tomographic parameters were negatively correlated with MD in global (r = -0.8) and sectorial (r = -0.6) evaluations. The interocular differences in overall tomographic parameters were correlated with corresponding differences in perimetric MD (r = -0.8) and PSD (r = 0.6). During the follow-up period, volumetric disc parameters decreased (P < 0.02), whereas perimetric MD increased (P = 0.02) at comparable times. CONCLUSIONS: In patients with recently diagnosed papilledema, optic nerve head tomographic abnormalities are quantitatively correlated with visual field sensitivity losses. Therapeutic improvement of volumetric parameters may be paralleled by recovery in perimetric sensitivity. The data support the possible use of both techniques in combination to monitor the amount of papilledema and the effectiveness of treatments designed to reduce intracranial hypertension.

Photopic negative response of the human ERG: losses associated with glaucomatous damage.

PURPOSE: To evaluate in glaucomatous eyes the photopic electroretinogram (ERG) negative response (PhNR), a component that follows the b-wave peak and is thought to be correlated with inner retinal activity. METHODS: Eleven patients with open-angle glaucoma (OAG) and moderate field loss (Humphrey 30-2 [Humphrey Instruments, San Leandro, CA] mean deviation < or = -6 dB), eight with ocular hypertension (OHT), and eight age-matched normal subjects were tested. Optic discs of patients and control subjects were evaluated by confocal scanning laser ophthalmoscopy. ERGs were recorded to long-duration stimuli (250 msec) of photopic luminance (78 candelas [cd] /m2), presented in the macular region (12 degrees x 12 degrees field size) on a steady, adapting background. Amplitudes of the a-wave and b-wave and the PhNR were measured. Pattern reversal ERGs to 30-minute checkerboards were also recorded from patients and control subjects. RESULTS: Compared with control subjects, patients with OAG showed reduced PhNR (average reduction: 62%, P < 0.01), but normal a- and b-wave amplitudes. In patients with OHT, PhNR and a- and b-wave amplitudes did not differ from control values. In individual patients with OAG, PhNR amplitudes were correlated positively with pattern ERG amplitudes (r = 0.80; P < 0.01) and central (12 degrees) perimetric mean deviations (r = 0.68; P < 0.05) and negatively with cup-to-disc area ratios (r = -0.79; P < 0.01) and cup shape measures (r = -0.78; P < 0.01). CONCLUSIONS: Similar to that found in monkeys with experimentally induced glaucoma, the PhNR is selectively altered in human glaucoma. The correlation between PhNR losses and clinical parameter abnormalities suggests that this component depends on inner retina integrity and may be of clinical value for detecting glaucomatous damage.