Pupil perimetry demonstrates hemifield pupillary hypokinesia in a patient with a pretectal lesion causing a relative afferent pupil defect but no visual field loss

Relative Afferent Pupillary Defect with Normal Vision: Unique Localisation to the Contralateral Brachium of the Superior Colliculus

A relative afferent pupillary defect (RAPD) is a very important clinical finding in neuro-ophthalmology, and is almost always accompanied by other signs of afferent visual pathway dysfunction including visual field defect, decreased acuity and abnormal colour vision. We present a case of isolated RAPD and describe the anatomic localisation of the lesion with a review of the literature for similar cases.

Relative Afferent Pupillary Defects in Homonymous Visual Field Defects Caused by Stroke of the Occipital Lobe Using Pupillometer

Relative afferent pupillary defects (RAPD) may be detected in patients with occipital lobe lesions. However, no previous report has used an objective technique to record the abnormal pupillary light reflex in such cases. Therefore, we measured the pupillary light reflex objectively in 15 patients with homonymous visual field defects (HVFD) due to occipital stroke using a new pupillometer. This study detected significantly smaller and slower pupillary light reflexes in the contralateral eyes than in the other eyes, which is equivalent to the presence of RAPD in patients with HVFDs caused by retrogeniculate lesions using an objective technique. Our results confirmed those of the previous reports using the swinging flashlight test more objectively.

Educating the blind brain: a panorama of neural bases of vision and of training programs in organic neurovisual deficits

Vision is a complex function, which is achieved by movements of the eyes to properly foveate targets at any location in 3D space and to continuously refresh neural information in the different visual pathways. The visual system involves five main routes originating in the retinas but varying in their destination within the brain: the occipital cortex, but also the superior colliculus (SC), the pretectum, the supra-chiasmatic nucleus, the nucleus of the optic tract and terminal dorsal, medial and lateral nuclei. Visual pathway architecture obeys systematization in sagittal and transversal planes so that visual information from left/right and upper/lower hemi-retinas, corresponding respectively to right/left and lower/upper visual fields, is processed ipsilaterally and ipsialtitudinally to hemi-retinas in left/right hemispheres and upper/lower fibers. Organic neurovisual deficits may occur at any level of this circuitry from the optic nerve to subcortical and cortical destinations, resulting in low or high-level visual deficits. In this didactic review article, we provide a panorama of the neural bases of eye movements and visual systems, and of related neurovisual deficits. Additionally, we briefly review the different schools of rehabilitation of organic neurovisual deficits, and show that whatever the emphasis is put on action or perception, benefits may be observed at both motor and perceptual levels. Given the extent of its neural bases in the brain, vision in its motor and perceptual aspects is also a useful tool to assess and modulate central nervous system (CNS) in general.

New approach for the glaucoma detection with pupil perimetry

OBJECTIVE

To calculate the pattern deviation for identifying abnormal points of pupil perimetry, and also to evaluate the grayscale display for distinguishing glaucomatous pupil field loss (abnormal test points) from normal pupil field (normal test points).

METHODS

Fourteen patients ranging in age from 51 to 80 years, who had normal-tension glaucoma (6 eyes) and primary open-angle glaucoma (8 eyes) were tested. Pupil perimetry (Kowa & Hamamatsu, Japan) was used to objectively measure the visual field. Also, to obtain a subjective visual field, the analysis was performed with a Humphrey Field Analyzer (30-2, Full threshold program, Carl Zeiss Meditec, Dublin). Of the 76 test points, the 22 surrounding points and the 3 points corresponding to the blind spot are excluded; and among the remaining 51 points, the 85th percentile value of pupil perimetry was calculated. The abnormal and normal test points were recorded, and the amount of positive or negative deviation of each test point from the normal median value for the corresponding test points was determined. We also used this technique to identify the value for distinguishing glaucomatous pupil field loss from the normal pupil field.

RESULTS

This study could be improved by calculating the sensitivity and specificity of a certain cut-off value between the normative data and the glaucoma patients. The value for identifying both abnormal and normal test points was a negative deviation of -4. Based on these results, pupil perimetry gray scales were determined: white (< -3), 25% gray (from -4 to -8), 50% gray (from -9 to -13), 75% gray (from -14 to -18) and black (> -19). Glaucomatous pupil field losses were generally distinguished from the normal pupil field by use of a gray scale.

CONCLUSION

Our studies demonstrated that, when a deviation of > -4 was regarded as an abnormal value, the detection of pupil perimetry exhibited improvement in glaucoma patients.