Congenital Night Blindness Research Articles

Retinal Pigmentation in a Case of Congenital Night Blindness

Retinal Pigmentation in a Case of Congenital Night Blindness

Acquired unilateral loss of dark adaptation.

Poor dark adaptation is a not uncommon symptom and may occur in a wide variety of diseases but its occurrence in one eye only is far less frequent. When it occurs unilaterally, an obvious ocular disease is generally present to account for it and visual functions other than that of dark adaptation are also depressed. Some subjects with poor dark adaptation may have no demonstrable ocular lesion nor any other defect of visual function. Almost always they have one of the forms of congenital night blindness but sometimes the trouble is the first evidence of a progressive tapeto-retinal degeneration. Electrophysiological studies of the retinal function of these patients have proved to be useful, and Armington and Schwab (I954) have shown that by using electroretinography patients with a non-progressive night blindness can be differentiated from those with a progressive tapeto-retinal degeneration. Auerbach, Godel, and Rowe (i969) have similarly studied a large series of patients with night blindness. They have shown that patients with an apparently stationary night blindness fall into two main groups, but they also note that progression of the condition may occur. An acquired form of night blindness without obvious ocular defects and without disturbance of any other ocular function was described by Kelsey and Arden (I969) in which electrophysiological tests of retinal function suggested a lesion at the level of the bipolar cell layer. Two patients with similar acquired changes which were strictly uniocular are described below.

A New Pedigree of Idiopathic Congenital Night-Blindness : Transmitted as a Dominant Hereditary Trait

A New Pedigree of Idiopathic Congenital Night-Blindness : Transmitted as a Dominant Hereditary Trait

PHOTOPIC FLICKER ERG IN CASES OF CONGENITAL NIGHT BLINDNESS AND TOTAL COLOR BLINDNESS.

The photopic flicker ERG in response to intense intermittent light of fixed brief duration has been investigated in normal subjects and those with some specific congenital deficiencies of the retina.

Area and luminance of test object as variables in projection perimetry

Abstract The relationship between area and threshold luminance of the projected test object was measured for the standard background of the Goldmann perimeter, in normal eyes and in eyes with field defects associated with various forms of ocular disease or anomaly. Photometric dysharmony, characterized by a significantly greater increase in threshold for small than for large test objects, was noted in some cases. The findings do not support the hypothesis that photometric dysharmony is produced by retinal edema, since it was absent or slight in all patients with central serous retinopathy and was marked in some patients with achromatopsia. Its absence in congenital night blindness and in pigmentary degeneration of the retina suggests that photometric dysharmony occurs only when there is impairment of the cone receptor mechanism. When it is present, early field defects should be more easily detected by a decrease in size than by a decrease in luminance of the test object.

Comparative electroretinographic studies in congenital night blindness and total color blindness.

In the analysis of the human electroretinogram, the study of subjects with congenital night blindness and total color blindness is of great value. The absence of specific electroretinographic components in these anomalies simplifies the complex pattern of response, allows a more detailed investigation of the remaining components, and aids in the analysis of the photopicscotopic nature of the different waves. However, the few investigations which deal with the electroretinogram in congenital night blindness and total color blindness have studied each condition separately; therefore, no direct comparison has been made between their electroretinographic responses. The purpose of this study is to investigate quantitatively the influence of dark-adaptation and stimulus intensity on the electroretinogram of normal, congenitally night-blind, and totally color-blind subjects,* examined under identical experimental conditions. <h3>Subjects</h3> The night-blind subject is a 28-year-old married white woman. She has been aware of poor night vision in both eyes since childhood, nonprogressive in

Electroretinography in night blindness and other vitamin A deficiencies.

An extinguished electroretinogram in cases of retinitis pigmentosa has been demonstrated by Prof. G. Karpe, of Sweden. Lorrin A. Riggs (1954) and Armington and Schwab (1954) have reported similar electroretinographic responses in cases of congenital night blindness and retinitis pigmentosa. This paper deals with yet another form of night blindness and its effects on the human electroretinogram. As is well known, an adequate vitamin A level in the blood is mainly responsible for the normal functioning capacity of the rods. Similarly, the scotopic electroretinographic tracing represents the electrical response of the rods. A direct relationship may thus exist between the clinical manifestations of vitamin A deficiency and the electroretinogram. The height of the b-wave of an electroretinogram of a dark-adapted eye represents directly the functioning capacity of the rods and indirectly the grade of vitamin A deficiency in the blood. This paper indicates the relationship between (1) clinical manifestations of

Electroretinogram in nyctalopia.

THE PRESENCE of distinct defects in the electroretinogram (ERG) in the varying forms of night blindness has been well documented in recent reports. The most conspicuous changes have been recorded from frank cases of primary pigmentary degeneration of the retina. In these cases the tracings are usually extinguished or greatly reduced in amplitude.* A recent article in the Japanese literature 4 describes similar but less marked changes in Oguchi's disease. Bornschein and Vukovich 5 have observed subnormal recordings with avitaminosis A, and definite changes have also been seen in cases of congenital night blindness without fundus change.† This latter form of nyctalopia appears to us to be of more interest than other forms. The existence of clear-cut alterations is of pertinent significance when clinically evaluating alleged night blindness—especially in the military service. In the past such patients have been frequently looked upon as psychiatric problems, if not actually designated as

Two cases of congenital night-blindness

In the recent communication of my paper on a “Fourth Sensation in Colour Vision,” in April last, attention was called to the case of night-blind eyes as throwing light on the question of the functions of the rods and cones in the retina in regard to colour and colourless vision. I cited two cases of congenital stationary night-blindness, which, through the kindness of Mr. Nettleship, were brought to my laboratory for examination in view of certain researches in which Prof. (now Colonel) Watson and myself were together interested. As Colonel Watson has been long at the Front in France, and as he conducted a principal part of the only partially completed examination, I hesitated to give the details without his collaboration. I have now obtained his acquiescence in my request that I should communicate the results obtained to the Royal Society. I now do so. As a matter of fact, I had worked out the observations before my colleague left me for the Front some 2½ years ago, and these results I have put in the following com­munication: I may say that any other form of night-blindness than those to which the late Mr. E. Nettleship introduced us would have been useless for the investigation on which we were engaged, as, if it were not so, night-blindness due to disease might call in question some of the deductions to be made. Mr. Nettleship’s investigations of the family to which they belonged, and its history, left no doubt that we were dealing in our two cases with genuine cases of congenital stationary types.

Two cases of congenital night-blindness

In the recent communication of my paper on a “Fourth Sensation in Colour Vision,” in April last, attention was called to the case of night-blind eyes as throwing light on the question of the functions of the rods and cones in the retina in regard to colour and colourless vision. I cited two cases of congenital stationary night-blindness, which, through the kindness of Mr. Nettleship, were brought to my laboratory for examination in view of certain researches in which Prof, (now Colonel) Watson and myself were together interested. As Colonel Watson has been long at the Front in France, and as he conducted a principal part of the only partially completed examination, I hesitated to give the details without his collaboration. I have now obtained his acquiescence in my request that I should communicate the results obtained to the Royal Society. I now do so. As a matter of fact, I had worked out the observations before my colleague left me for the Front some 2½ years ago, and these results I have put in the following communication: I may say that any other form of night-blindness than those to which the late Mr. E. Nettleship introduced us would have been useless for the investigation on which we were engaged, as, if it were not so, night-blindness due to disease might call in question some of the deductions to be made. Mr. Nettleship’s investigations of the family to which they belonged, and its history, left no doubt that we were dealing in our two cases with genuine cases of congenital stationary types.

Societies and Academies

Societies and Academies

Review of Congenital Night-Blindness and Pigmentary Degeneration.

Review of Congenital Night-Blindness and Pigmentary Degeneration.