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At least 19 recordsLinked to original sources
PubMed2001

Nyctalopia in antiquity: a review of the ancient Greek, Latin, and Byzantine literature.

OBJECTIVE: To investigate the original definition and use of the term nyctalopia in ancient medical literature in view of the controversy between the English and some continental European literatures. DESIGN: Historical manuscript. METHODS: We review the use of the term in ancient Greek, Roman, and early Byzantine medical literature (5th century BC-7th century AD) and include a quick reference to the theories on its etymology. RESULTS: Physicians of antiquity defined as nyctalopia the symptom of defective dark adaptation, most commonly in the clinical setting of vitamin A deficiency. An alternative definition, the improvement of vision at night, is not recorded before the 2nd century AD and seems to result from a broader interpretation of the word, lacking medical acceptance at that time. CONCLUSIONS: We propose to the ophthalmic community the use of the term nyctalopia exclusively for the description of defective dark adaptation.

Byzantium↗
PubMed1999

An electrophysiological follow-up study on acquired unilateral nyctalopia.

PURPOSE: To describe the clinical picture and electrophysiological findings in acquired unilateral nyctalopia. METHODS: A patient who had acquired unilateral visual loss with normal fundus was followed for a period of 2.5 years with basic ophthalmological examinations including standard electroretinogram and photopic on and off responses. RESULTS: A 46-year-old woman suffered from acquired unilateral nyctalopia. She complained of photopsia and blurred vision in her left eye. The initial examination of the left eye showed 1+ cells in the anterior chamber and a granular appearance in the fovea. After 1 month of treatment she still complained of photopsia in her left eye. Ophthalmoscopy and fluorescein angiography revealed no abnormality in either eye. A bright flash electroretinogram (ERG) in the left eye was a negative shape. Photopic ERG elicited by a 150 ms stimulus showed a depressed b-wave and enhanced a- and d-waves in the left eye. CONCLUSIONS: This ERG waveform suggested that the transmission between photoreceptor and on-bipolar cell might be affected by idiopathic retinal disease.

Electroretinography↗
PubMed1996

Mastocytosis-induced nyctalopia.

Systemic mastocytosis is characterized by an increased number of mast cells in multiple organs particularly skin. A 55-year-old man with mastocytosis presented with nyctalopia caused by malabsorption of vitamin A. Diagnosis was made by documenting a low vitamin A level and an ERG that showed rod-cone deficiency with rods affected more than cones. Vitamin A therapy led to return of good visual function. To our knowledge, this is the first reported case of mastocytosis induced nyctalopia. Vitamin A deficiency should be considered as a potential cause of visual loss in patients with sudden onset of night blindness.

Electroretinography↗
PubMed1983

Cone dystrophy, nyctalopia, and supernormal rod responses. A new retinal degeneration.

An unusual retinal degeneration considered to be inherited as an autosomal recessive trait occurred in two of four children in a Hispanic family. The abnormality causes a progressive and generalized loss of cone vision, including decreased acuity, decreased color vision, central scotomas to small test objects, photo-phobia, and a profound diminution of the cone-mediated electroretinographic (ERG) pattern. A loss of the foveal reflex and an increased granularity of the macula is seen funduscopically. In addition, there is a most unusual alteration of the rod system detectable in the rod-mediated ERG pattern. This rod response is supernormal in amplitude (greater than 1,000 microV, extrapolated), delayed in time course, and insensitive to dim stimuli, ie, the function relating response to light intensity has been drastically altered. The insensitivity to dim stimuli is accompanied by a mild nyctalopia. Some of these abnormalities could be caused by a defect in the retinal enzyme, cyclic nucleotide phosphodiesterase.

Adolescent↗
PubMed1987

Cone function in congenital nyctalopia.

A patient with congenital stationary night blindness (CSNB) (Schubert-Bornschein type) transmitted as an autosomal recessive trait was studied with several tests of electrical function as well as a variety of psychophysical procedures. Comparison of the patient's present findings with those obtained 23 years earlier showed that while rod thresholds have remained the same, cone sensitivity has decreased. Subjective flicker thresholds obtained following a bleach were unchanged during the course of dark adaptation. The absence of rod-cone interaction, together with an absent scotopic b-wave, implies that the defect is in the mid-retinal layers. Further, the absence of oscillatory potentials in the photopic electroretinogram (ERG) suggests that the interplexiform cell may be implicated in some manner. The focal ERG of the CSNB patient showed normal amplitude and normal phase delays, supporting the idea that the focal ERG samples primarily cone photoreceptor activity.

Adult↗
PubMed1989

Nyctalopia and conjunctival xerosis indicating vitamin A deficiency in cystic fibrosis.

Thirty-one Cystic Fibrosis patients were investigated for clinical and biochemical evidence of Vitamin A deficiency. All had been prescribed oral pancreatic enzyme replacements and twice the recommended daily requirement of Vitamin A (5000IU). None were aware of any ocular symptoms, but 3 out of 31 (10 per cent) were found to have frank conjunctival xerosis and six (19 per cent) to have abnormal dark adaptation. There was no correlation between the above findings and abnormal liver function or clinical disease severity. All patients with cystic fibrosis should have regular Vitamin A estimations with ophthalmological assessment if serum levels fall below 30 microgram/dl.

Adolescent↗
PubMed1991

Nyctalopia with normal rod function: a suppression of cones by rods.

Twenty-nine patients with exaggerated rod-cone interaction are described. All were referred because they appeared to suffer from night blindness. ERG and EOGs were performed but were normal. However, investigation with a modified dark-adaptometry technique showed that in these patients cone flicker thresholds rise considerably more during dark adaptation than is normal, and this is sufficient to explain the symptoms. In one case, the condition appears familial. Many patients report their symptoms begin in early adult life and slowly get worse, but we have no objective evidence of progression.

Adult↗
PubMedDate not supplied

X-linked congenital stationary night blindness with myopia and nystagmus without clinical complaints of nyctalopia.

Seven of eight patients presented initially or were followed for decreased acuity and nystagmus without complaints of night blindness. The diagnosis of congenital stationary night blindness was established with electroretinogram and dark adaptation testing. Careful electrodiagnostic testing is needed to provide accurate genetic counseling. Two patients showed pupillary constriction to darkness which is a sign of retinal disease in young patients.

Adolescent↗