1. Why did the patient become as "blind as a bat" and as "dry as a bone"?Test Yourself Part II
Atropine poisoning.2. What caused the man to see yellow?
The complete description is "hot as a hare, blind as a bat, dry as bone, red as a beet, mad as a hen".
High doses of digoxin can cause objects to appear yellow (xanthopsia). Withering reported visual side effects of digoxin in his classic paper in 1785.
3. What caused the child's eyes to look like setting suns?Hydrocephalus.
Massive enlargement of the head occurs in infants with hydrocephalus before the sutures fuse. Downward pressure on the orbital plates leads to protrusion of the eyes forwards and downwards, causing an upper rim of sclera to become visible above the iris - the so-called setting sun appearance.
4. Why does the down-and-out went blind?Ingestion of methylated spirit.
Methylated spirit contains 5% methanol and 95% ethanol. When drunk for its ehtanol content, the breakdown products of methanol are extremely toxic to the eye causing optic atrophy
5. Why does the patient who have a map of Maine develop proptosis?Fibrous dysplasia (Albright's syndrome).
It is characterized by osteitis fibrosa disseminata, areas of pigmentation and endocrine dysfunction, with precocious puberty in females. The borders of the pigmentation has an irregular or jagged edge (coast of Maine). The involvement of the orbit can lead to shallowing and proptosis.
6. Why does the patient who have a map of California develop proptosis?Neurofibromatosis.7. What is the diagnosis in a woman who complains of sudden onset of pain in the ear and who cannot shut the eye on the same side?
The pigmentation has a smooth edge (coast of California). In some patients, the congenital absence of sphenoid bone leads to encephalocele and proptosis.
Ramsey Hunt syndrome.
The involvement of the seventh cranial nerve with the herpes zoster virus. There may be an eruption in the external auditory meatus, as this area receives a sensory supply from the seventh cranial nerve.
8. What is the diagnosis in a girl who ptosis is relieved momentarily by sticking out her tongue?Marcus-Gunn jaw winking phenomenon.9. Why does the man who was blind in both eyes deny that he cannot see?
It is believed to be caused by a congenital anomaly of the central connections of the innervation of the pterygoid and levator muscle (trigemino-oculomotor synkinesis).
This uncommon syndrome classically occurs in patient who has bilateral cortical blindness. The patient denies he is blind and confabulate responses when confronted with their errors and making excuses.
10. Why does the patient who need a bigger hat develop an afferent pupillary defect?Paget's disease.
This causes enlargement of the skull due to disorganization of the bony structure. This can cause compressive optic atrophy in the optic canal.
11. A woman complains of discomfort in both arms and a transient loss of vision which occurs on exercises. What is the possible diagnosis?Visual claudication.12. What made Lewis Carroll conceive of Alice seeing things smaller than they were?
She had Takayasu's syndrome with involvement of the carotid and axillary arteries. Exercise causes a "steal" syndrome leading to retinal ischaemia
He had episodes of micropsia during his migraine attacks.
13. What caused a well-known author to have visions of quicksands?Opium.
Thomas de Quincey experienced visions of a girl sinking in quicksands while he was under the influence of opium.
14. What blood test can help the ophthalmologist to make a definitive diagnosis in the case of the youngster with bilateral cataracts and epilepsy?Serum calcium. The disease is hypoparathyroidism or psuedohypoparathyroidism.
Both these conditions are associated with epilepsy and bilateral cataracts and the blood test shows a low serum calcium and a high serum phosphate. In the former condition the parathyroid glands do not produce parathyroid hormone while in the latter, parathyroid hormone is produced but the tissues especially the kidneys are resistant to its actions. The two conditions can usually be differentiated by measuring the parathyroid hormone concentration in the serum. They are both treated with calcium supplements and vitamin D supplements.
15. Nodules near the elbow occurring in patients in the UK make the doctor think of rheumatoid arthritis. Nodules near the elbow in the blind inhabitants of West Africa should make the doctor think of what?Onchocerciasis.
Also known as river blindness, this is caused by infection with the filaria parasite Onchocerca volvulus, which is transmitted by the bite of species of Simulium flies (so-called buffalo gnats). Clinically there are skin changes, nodules and eye changes that can lead to blindness. The nodules develop in subcutaneous tissue especially near bony structures and contain living or dead adult worms.
Click here for the questions Click here for the main page Click here for MRCOphth