Biomedical subjects
W H Stern
Publications and source records attributed to W H Stern.
Radial buckling of posterior retinal tears.
We devised a method for safely placing mattress sutures for radial scleral buckling of posterior retinal holes. The ability to pass the needle in the anteroposterior direction, as well as the ability to tie the posterior ends of the mattress suture anteriorly where they are easily accessible, makes this method of placing the mattress suture safe and effective for posterior radial buckles.
Blepharochalasis.
The condition of blepharochalasis and its treatment are discussed. Four cases are presented which show a physical sign that may help in its diagnosis.
Vitrectomy instrumentation for surgical evacuation of total anterior chamber hyphema and control of recurrent anterior chamber hemorrhage.
A patient with recurrent bleeding during hyphema extraction with the O'Malley ocutome was treated by elevation of the intraocular pressure to 50 mm Hg for 5 minutes with fluid from the infusing needle. When intraocular pressure was returned to normal, there was cessation of bleeding and postoperatively the anterior chamber remained free of blood. Elevation of intraocular pressure is offered as an initial alternative to air injection or cyclodiathermy for control of bleeding during hyphema extraction.
Initial observations on the isolated retinal pigment epithelium-choroid of the cat.
An in vitro preparation of a mammalian retinal pigment epithelium (RPE)-choroid was developed, that of the cat, in order to study the RPE in isolation from the neural retina. The purpose of these initial experiments was to evaluate the electrical characteristics of the tissue and the ionic properties of the RPE apical membrane. They were designed so that results would be directly comparable to those previously obtained on a more extensively studied cold-blooded preparation, the bullfrog. The electrical characteristics of the best cat tissues were similar to those routinely obtained in bullfrog, whereas the average cat apical membrane potential was 20 mV more depolarized than that of frog. The apical membrane of cat resembled the frog's in having a large sensitivity to potassium, but it had a relatively smaller sensitivity to bicarbonate and a relatively larger sensitivity to sodium. The cat, like the frog, also had a ouabain-sensitive mechanism on its apical membrane that directly contributed to membrane potential. Two factors contributing to the lower apical membrane potential in cat were the higher potassium concentration of the mammalian salt solution and the sodium conductance of the apical membrane.
Listeria monocytogenes endophthalmitis.
A 62-year-old white man developed an acute anterior chamber inflammation in his left eye. Listeria monocytogenes was cultured from the vitreous aspirate. There was no evidence for ocular trauma or distant site of infection from which hematogenous spread of the organism occurred. No underlying state of immunocompromise was demonstrated. The endophthalmitis responded well to therapy.
The effect of mannitol infusion on retinal function and oxygen tension.
Mannitol administered intravenously in rhesus monkeys resulted in a temporary recovery of the visual evoked response (VER) after its decrease due to elevation of the intraocular pressure. Mannitol infusion caused an immediate, albeit transitory, increase in retinal oxygen tension. These changes were independent of the ocular hypotensive effect of mannitol, and we conclude that the drug is a far better agent for the treatment of acute glaucoma than heretofore believed.
Submacular choroidal circulation.
A neoprene latex and pigment mixture was injected into the choroidal blood vessels of human cadaver eyes. When peripheral resistence was normal, a single arteriole filled a single lobule of the choriocapillaris drained by mulitple surrounding venules. The choridal veins interconnected and an increase in the peripheral resistance caused by elevation of the venous pressure resulted in filling of contiguous lobules in a retrograde manner through the venules that normally drain them.
Intracranial ophthalmic artery aneurysm.
A 45-year old black man with a carotid-ophthalmic artery aneurysm developed sudden loss of vision in his left eye, a mid-dilated pupil, and pain on movement of the left eye. A temporal island of vision was present in the left eye and the right visual field was normal. There were no other neurologic abnormalities. The aneurysm spontaneously ruptured, resulting in the death of the patient.