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Biomedical subjects

A A Kashani

Publications and source records attributed to A A Kashani.

15 recordsLinked to original sources
PubMed1997

Central nervous system malignant B-cell lymphoma identified with standardized echography of the optic nerve.

Ocular-central nervous system malignant B-cell lymphoma initially caused diplopia and morning headaches in a 10-year-old boy. After initial diagnosis of pseudotumor cerebri was made, based on normal findings from magnetic resonance imaging and magnetic resonance angiography elsewhere, he was treated with acetazolamide. Standardized echography demonstrated a combination of solid infiltration and fluid within the optic nerve sheaths. Lumbar puncture showed elevated opening pressure and cerebrospinal diagnostic of central nervous system (CNS) B-cell lymphoma, which was confirmed by gene rearrangement. Results of peripheral blood study were negative. Aggressive treatment with chemotherapy and external-beam radiation produced complete resolution of solid optic nerve sheath infiltration in both eyes. This report discusses the clinical and ultrasonographic characteristics of CNS malignant B-cell lymphoma with ocular involvement and its differentiation from pseudotumor cerebri.

Brain Neoplasms↗
PubMed1993

The triplex hypothesis of vision.

The duplex theory of vision is concerned with the light level and dual retinal function and refers only to the rod and cone photoreceptor cell systems. There are some visual functions that are not represented by the duplex theory, visual field, or the dark-adaptation curve. There is some confusion as to whether the relationship between visual threshold and bleached pigment is logarithmic or linear. I do not know how many photopigments exist and which pigment and what circuit plays a role in the photoperiod. The complexity of the retina appears to exceed its known functions. Finally, I wonder how the rate of eye growth is regulated. To clarify these concerns, I propose a new cell type and a third mechanism of vision, which has not been described previously to my knowledge. On the basis of this study and the data from the literature, it appears that early retinal ganglion cells cannot project into the visual cortex because the latter has not been formed. Therefore, their axons may progress into the diencephalic centers that are developing and are differentiating. So, there is a novel photoreceptive system with its associated ganglion cells that is the basis for the visual foundation. These are the first photoreceptors to form and are not engaged directly in the visual process, but they play a significant role in nutrition, function, and the well-being of the other parts of the visual apparatus. This, of course, requires much investigation and research. I believe there are three classes of photoreceptors and submit the following triplex hypothesis.

Axons↗
PubMed1990

Pathogenesis of age-related macular degeneration: embryologic concept.

Age-related macular degeneration (ARMD) is a bilateral progressive process which deprives millions of elderly individuals of central vision. Although numerous risk factors have been enumerated, embryonic implication, in relation to ARMD is an area that has been neglected to my knowledge. I address this new issue for the first time.

Aging↗
PubMed1977

Ocular manifestations of Wilson's disease in Iran.

Within the last 5 years, 25 proved cases of hepato-lenticular degeneration (Wilson's disease) have been seen at the Children's Hospital Medical Center affiliated to Tehran University. The disease manifested abnormal copper metabolism in the following respects: (1) Hypoceruloplasminaemia was present: (2) 24-hr urinary copper excretion was low; (3) Tissue concentration of copper was high; (4) Treatment with penicillamine led to increased copper excretion in the urine and usually to relief of symptoms. The ophthalmologist cannot always assist the paediatrician in diagnosis, but fourteen of the 25 patients showed a Kayser-Fleischer ring and these were all in the older age groups. The following conclusions were drawn: (1) The incidence of Wilson's disease in Iran is high; (2) Penicillamine treatment may be successful; (3) Any young person with kidney, liver, or neurological disease of uncertain aetiology should have a detailed ophthalmological examination.

Adolescent↗
PubMedDate not supplied

Congenital aphakia.

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Anterior Eye Segment↗