The practical value of preoperative intraocular lens power calculations in "normal" eyes with less than 4.50 diopters (D) of myopia or hyperopia was evaluated in a consecutive series of 520 eyes that underwent cataract extraction and lens implantation by four experienced surgeons at The Wilmer Ophthalmological Institute. The observed postoperative results with the lenses selected by the surgeons were compared with results calculated for the measurement-predicted emmetropic power lens and for a standard 20-D lens. The need for postoperative spectacle correction of residual refractive errors was comparable for all three choices of lens. Only two eyes (0.4%) would have developed greater than 4.00 D of refractive error with either the "implanted" or "predicted-emmetropic" lenses, as would 11 eyes (2.1%) with the "standard" 20-D lens. The surgeons' deviation from the calculated emmetropic lens did not reduce postoperative refractive error.

Aged↗

PubMed1986

Methacholine sensitivity and cAMP protein kinase in tracheal smooth muscle.

We studied regional variation in canine trachealis smooth muscle sensitivity and responsiveness to methacholine as well as basal and methacholine-stimulated adenosine 3',5'-cyclic monophosphate (cAMP) and cAMP-dependent protein kinase activity. The trachea between the cricoid cartilage and the carina was divided into three segments of equal length (designated cervical, middle, and thoracic regions), each consisting of approximately 12-14 cartilage rings. Smooth muscle strips from each of the three regions were exposed to cumulative half-log increments of methacholine chloride. The sensitivity (-log EC50) and responsiveness (force per cross-sectional area and force per milligram protein) of the smooth muscle to methacholine in each region was determined from these data. Smooth muscle strips from cervical and thoracic regions were frozen before and after exposure to cumulative half-log increments of methacholine up to each region's previously determined EC50. Frozen samples were assayed for cAMP content or cAMP-dependent protein kinase activity. The relationship between resting tension and methacholine sensitivity and responsiveness were studied. For the size strips we used, 4 g resting tension set the average cervical and thoracic strips at 96 and 101% of their optimal length, respectively. The methacholine EC50 was not affected by a variation in resting tension. Sensitivity to methacholine was 7.1, 6.8, and 6.5 for cervical, middle, and thoracic regions, respectively. The responsiveness of the cervical and thoracic smooth muscle to methacholine was 16.4 and 16.3 g force/mm2, respectively, at an EC50 methacholine. Basal cAMP was lower in cervical smooth muscle than in thoracic. cAMP-dependent protein kinase activity ratios under both basal and EC50 methacholine-stimulated conditions were lower in cervical smooth muscle than in thoracic. We have observed in trachealis smooth muscle an inverse relationship between methacholine sensitivity and either cAMP or cAMP-dependent protein kinase activity. We suggest that cAMP and cAMP-dependent protein kinase play a role in the regulation of airway smooth muscle sensitivity to cholinergic agonists.

Animals↗

PubMed1985

Topical retinoid treatment for various dry-eye disorders.

We evaluated the clinical efficacy of treating various dry-eye disorders using 0.01% and 0.1% (weight/weight) topical all-trans retinoic acid ointment. Twenty-two patients were selected and classified into four major groups: keratoconjunctivitis sicca (6 patients; 11 eyes), Stevens-Johnson syndrome (9 patients; 17 eyes), ocular pemphigoid or drug-induced pseudopemphigoid (3 patients; 6 eyes), and surgery or radiation-induced dry eye (4 patients; 4 eyes), based on the criterion that they remained symptomatic even under maximum tolerable conventional medical and/or surgical therapies. The results indicated that squamous metaplasia with mucin deficiency secondary to goblet cell loss and keratinization may be the basis for the development of clinical symptoms and morbidities, as these epithelial abnormalities were invariably present before treatment. After treatment, all patients demonstrated clinical improvements in symptoms, visual acuity, rose Bengal staining, or Schirmer test. Most importantly, this topical vitamin A treatment caused the reversal of squamous metaplasia as evidenced by impression cytology. Therefore, this treatment may represent the first nonsurgical attempt to treat these disorders by reversing diseased ocular surface epithelium.

Administration, Topical↗

PubMed1985

Expulsive hemorrhage: its incidence in cataract surgery and a report of four bilateral cases.

Between 1978 and 1983, 13,890 cataract extractions were performed in Baltimore at JHH and the GBMC with 14 expulsive hemorrhages for an incidence of 0.10%. In the years 1963 through 1983, 180,690 cataract extractions were performed in Taxila, Pakistan with 87 expulsive hemorrhages for an incidence of 0.05%. Reasons for the significant differences in incidence are presented. The six reported cases of bilateral expulsive hemorrhage are reviewed. Four more cases are added. A classification of choroidal hemorrhage is presented.

Aged↗

PubMed1979

Tissue adhesives: new perspectives in corneal perforations.

In corneal perforations associated with extensive progressive corneal disease, a technique using tissue adhesive closure of the perforation site and reformation of the anterior chamber before penetrating keratoplasty or conjunctival flap mobilization has been described. Over the past year, six eyes have been successfully treated in this manner. This method allows reformation of the eye under local anesthesia as an emergency procedure without incarceration or injury of the intraocular contents and without pain to the patient. The definitive surgical procedure can then be performed safely under retrobulbar anesthesia.

Adult↗

PubMed1978

Penetration routes of topically applied eye medications.

Tritium-labeled hydrocortisone acetate and pilcarpine hydrochloride solutions were topically applied to the eyes of rabbits. In one group of animals, the drugs were excluded from contact with the cornea by a cylindrical well glued to the eye surface. In another group, the drug solutions were allowed contact with the entire anterior surface of the eye. Total application time in all cases was five minutes, then the eyes were flushed with saline. Samples of aqueous humor, stroma, and iris-ciliary body were taken after five, 20, 35, 65, and 125 minutes and counted in a liquid scintillation counter. With hydrocortisone, up to 70 times more drug reached the stroma when the cornea was exposed; 40 times more reached the iris. Peak stromal levels occurred by 20 minutes, dropping to one third of peak value by two hours. With pilocarpine, about five times more drug reached the iris-ciliary body when corneal access was allowed; the level peaked in about five minutes. These results illustrate the important role of tear film distribution and blinking in delivering remotely applied drugs over the cornea with subsequent entry to interior sites.

Administration, Topical↗

PubMed1975

Comparison of suturing techniques in keratoplasty for keratoconus.

The results of 48 consecutive penetrating keratoplasties for keratoconus were analyzed. The overall success rate was 93% clear grafts and there was no significant difference in the percentage of success, the amount of the spherical equivalent of the myopia, or the types of complications between the technique using 9-0 interrupted virgin silk sutures and 10-0 monofilament nylon running suture. The average astigmatic error was 25% less in the series employing the running suture.

Adolescent↗

PubMed1974