Walter M. Jay

Effect of topical epinephrine and timolol on ocular and optic nerve blood flow in phakic and aphakic rabbit eyes

The effects of 4% epinephrine bitartrate and 0.5% timolol on ocular and optic nerve blood flow were studied in phakic and aphakic rabbit eyes using a radioactive microsphere (85Sr) technique. Either epinephrine or timolol was given topically as eight drops in the hour immediately preceding blood flow measurements (one drop every 7.5 minutes). Epinephrine decreased anterior uveal blood flow in both phakic and aphakic eyes, whereas timolol exhibited no effect. Retinal and choroidal blood flow were not affected by either timolol or epinephrine in phakic eyes. In aphakic eyes, epinephrine increased choroidal blood flow without altering retinal blood flow, whereas timolol increased both retinal and choroidal blood flow. Optic nerve blood flow was increased in epinephrine treated phakic and aphakic eyes and also in timolol treated aphakic eyes.

Opsoclonus in Hemophilus influenzae meningitis

we studied a 3-month-old boy who had opsoclonus in association with acute bacterial meningitis. The CSF IgG and IgM were elevated acutely, gradually returning to normal with clinical improvement. Correspondingly, CSF cytomorphology showed excessive plasmocytosis and a higher proportion of reactive lymphocytes than expected in an acute bacterial meningitis. These abnormalities in CSF cytology are effects of an abnormal immune response in the CNS, and provide evidence to support an immunopathic basis to opsoclonus.

Possible Relationship of Ethylene Oxide Exposure to Cataract Formation

We examined 12 men whose work involved exposure to ethylene oxide sterilizers after one sterilizer developed a leak. Only the four men who had worked on the leaking sterilizer developed neurologic abnormalities. Three of them also developed cataracts, and one required bilateral cataract extractions. Four men, two of whom had not worked on the leaking sterilizer, had increased central corneal thickness with normal endothelial cell counts.

Ocular Blood Flow and Vascular Permeability in Endotoxin-Induced Inflammation

Blood flow was measured in several tissues of the rabbit eye following intravitreal injection of a dose of endotoxin that induces an inflammatory response. In separate experiments, the vascular permeability of the inflamed eye was estimated by iris fluorescein angiography and by measuring protein influx into the aqueous humor. The effect of topical corticosteroid treatment upon blood flow and vascular permeability was also measured. Following intravitreal endotoxin injection, minor changes in blood flow occurred in retina and optic nerve head. Marked changes were observed in blood flow in iris, ciliary processes, and choroid. Steroid treatment had no effect upon the increased blood flow 24 h after the endotoxin injection, although from a clinical standpoint the steroid-treated eyes appeared less inflamed. Fluorescein angiography demonstrated a massive increase in iris vessel permeability 6 and 24 h following endotoxin injection. Topical steroid treatment reduced fluorescein entry into the anterior chamber at both time periods. On the other hand, the increase in protein influx into the aqueous humor in the endotoxin-inflamed eye was not inhibited by steroid pretreatment. It is suggested that corticosteroids have a selective effect upon the permeability of different components of the blood-aqueous barrier, namely the ciliary processes and the iris vasculature.

A revised technique for extracapsular lens extraction in the rabbit.

The surgical procedure described here for extracapsular lens extraction utilizes a bent 25 gauge needle as an irrigating cystotome , a 100 degrees superior clear corneal incision, a single clean incision of the lens capsule, a muscle hook for expression of the nucleus, no cortical cleanup, and interrupted 9-0 nylon sutures to close the incision. We have found it a simple and effective technique which utilizes inexpensive instruments commonly available in an ophthalmology department or ophthalmic research laboratory.

Effect of Applying the Honan Intraocular Pressure Reducer Before Cataract Surgery

We studied 48 patients undergoing cataract extraction with local anesthesia. In 41 patients, after administering the retrobulbar injection, we applied the Honan intraocular pressure reducer for seven to ten minutes at a pressure setting of 30 mm Hg. Of these 41 patients, 13 received 3-ml injections, 14 received 4-ml injections, and 14 received 5-ml injections. No differences in intraocular pressure related to the quantity of retrobulbar injection were noted. After retrobulbar injection, the mean intraocular pressure for the study population as a whole increased 4.4 mm Hg; after application of the Honan device, it decreased 6.2 mm Hg. In a control group of seven patients, who received 4-ml retrobulbar injections but no applications of the Honan device, mean intraocular pressure increased 6.1 mm Hg immediately after retrobulbar injection and decreased only 0.7 mm Hg after seven to ten minutes.

The effect of retrobulbar epinephrine injection on ocular and optic nerve blood flow

The effect of retrobulbar epinephrine administration on ocular and optic nerve blood flow was studied in phakic and aphakic rabbit eyes using a radioactive microsphere (85Sr) technique. One hour before blood flow determination, 10 microliter of a 0.2% (base) epinephrine bitartrate solution was administered to the right eye of each experimental rabbit by the retrobulbar route. For control rabbits, 10 microliter of saline was injected retrobubarly. Blood flow measurements were determined for the iris, scrap[ed ciliary processes, choroid, retina, and optic nerve. Neither optic nerve nor ocular blood flow was altered by this dose which is approximately the dose used in retrobulbar injections in humans.

Alterations in ocular and optic nerve blood flow during intraocular surgery in aspirin pretreated rabbits

The effect of intraocular surgery on ocular and optic nerve blood flow was determined in rabbits either untreated or pretreated with aspirin. Surgery was either extracapsular lens extraction through a 100 degrees corneal incision or a sham-operation in which a 45 degrees corneal incision was performed and the lens left in place. In both cases, the incisions were not sutured and the intraocular pressure remained zero for one hour. A (85Sr) radioactive microsphere technique was used to measure blood flow in the iris, scraped ciliary processes, retina, choroid, and optic nerve. In rabbits not receiving aspirin pretreatment, blood flow was statistically increased in all portions of the eye, except the retina and optic nerve, studied for sham-operated eyes, and in the iris and optic nerve in the lens extraction group. In rabbits pretreated with aspirin, blood flow remained at normal levels. These results are consistent with the hypothesis that prostaglandins released during ocular surgery cause increased ocular tissue blood flow.