Importance of visual field score and asymmetry in the detection of glaucoma

Quantification of congruence between the right and left visual fields

In the past, congruence between the right and left visual fields could only be evaluated subjectively. This study presents a congruence index to assess the similarity of the two visual fields objectively and quantitatively based on probability calculations. In 18 patients with suprachiasmal lesions of the visual pathways (cerebrovascular accident or tumor), the index found a homonymous congruence in all cases (100%). Of 26 persons with pituitary adenoma, in 22 cases (85%) the index found heteronymous congruence. The validity of the method may be even higher, because all cases with atypical indices also had atypical congruence by subjective evaluation. Using this new method in 41 patients with primary open-angle glaucoma, heteronymous congruence was detected in 73% and homonymous congruence was found in 17%. This new index may be useful for the development of computerized parametric methods of differential diagnosis.

Blue versus white stimuli in ocular hypertension with the Friedmann Mark 1 Visual Field Analyser

Fifty eyes of fifty patients with ocular hypertension had their visual fields tested on a Friedmann Mark 1 field analyser whilst wearing a Wratten 47B blue filter in a spectacle frame. All had normal visual fields to a white stimulus. Use of a scoring system with the blue field identified 11 patients (22%) with ocular hypertension as abnormal. The scores from this subgroup were indistinguishable from a group of subjects with early glaucomatous field loss, whilst the remaining scores were similar to normal subjects. These two subgroups of ocular hypertensive patients were similar in age and intraocular pressure. The use of a blue filter in front of the eye may offer a simple test to identify a subgroup of patients with ocular hypertension who are at increased risk of developing field loss.

Correlation of visual function and retinal leukocyte velocity in glaucoma

Twelve subjects with glaucoma or ocular hypertension underwent measurement of visual fields (Humphrey perimeter and the Henson CFS2000 perimeter), contrast sensitivity (Vistech wall charts), and perimacular leukocyte velocity (Oculix BFS-1000 blue field entoptic technique). Significant positive correlations were seen between asymmetry of visual function and asymmetry of retinal leukocyte velocity in the study population. The eye with the higher velocity of retinal leukocyte flow tended to have better visual function as measured by Humphrey mean deviation (P less than .05), Henson Score (P less than .06), and Vistech contrast sensitivity score at 6 cycles/degree (P less than .001). An association of borderline significance was found between the asymmetries of intraocular pressure and retinal leukocyte velocity (P = .06). No significant intraocular pressure:visual field correlations were found on asymmetry analysis, although the inverse relationship between intraocular pressure and contrast sensitivity was significant (P less than .05). Significant correlations were obtained between visual field scores derived from the Henson data and Humphrey parameters mean deviation (P less than .001) and corrected pattern standard deviation (P less than .05) on both asymmetry and single eye analysis.