Development of conjunctival goblet cells and their neuroreceptor subtype expression.

PURPOSE: To investigate expression of muscarinic, cholinergic, and adrenergic receptors on developing conjunctival goblet cells. METHODS: Eyes were removed from rats 9 to 60 days old, fixed, and used for microscopy. For glycoconjugate expression, sections were stained with Alcian blue/periodic acid-Schiffs reagent (AB/PAS) and with the lectins Ulex europeus agglutinin I (UEA-I) and Helix pomatia agglutinin (HPA). Goblet cell bodies were identified using anti-cytokeratin 7 (CK7). Nerve fibers were localized using anti-protein gene product 9.5. Location of muscarinic and adrenergic receptors was investigated using anti-muscarinic and beta-adrenergic receptors. RESULTS: At days 9 and 13, single apical cells in conjunctival epithelium stained with AB/PAS, UEA-I, and CK7. At days 17 and 60, increasing numbers of goblet cells were identified by AB/PAS, UEA-I, HPA, and CK7. Nerve fibers were localized around stratified squamous cells and at the epithelial base at days 9 and 13, and around goblet cells and at the epithelial base at days 17 and 60. At days 9 and 13, M2- and M3-muscarinic and beta2-adrenergic receptors were found in stratified squamous cells, but M1-muscarinic and beta1-adrenergic receptors were not detected. At days 17 and 60, M2- and M3-muscarinic receptors were found in goblet cells, whereas M1-muscarinic receptors were in stratified squamous cells. Beta1- and beta2-adrenergic receptors were found on both cell types. Beta3-adrenergic receptors were not detected. CONCLUSIONS: In conjunctiva, nerves, M2- and M3-muscarinic, and beta1- and beta2-adrenergic receptors are present on developing goblet cells and could regulate secretion as eyelids open.

Corneal topography of posterior keratoconus.

Posterior keratoconus is an unusual abnormality of the cornea generally classified as one of the anterior chamber cleavage anomalies. It is characterized clinically by the presence of a circumscribed or generalized corneal thinning with posterior depression of the cornea and is considered distinct from keratoconus. Although patients with posterior keratoconus may have visual complaints clearly related to their abnormal corneas, the surface topography of these corneas has not been studied in detail. Keratometry and photokeratoscopy provide an incomplete picture of the surface geometry of posterior keratoconus. We utilized computer assisted topographic analysis to study the cornea of a patient with posterior keratoconus. The Topographic Modeling System demonstrated that the patient's cornea showed a central steepened "cone" coincident with the area of circumscribed posterior keratoconus as well as paracentral flattening. This report documents the topographic abnormality in this rare disorder.

Geriatric optometry questionnaire.

A national survey of American Optometric Association Low Vision Section members was conducted by the newly formed Geriatrics and Low Vision Committee during the fall of 1989. The "Geriatric Optometry Questionnaire" was designed to establish a greater understanding of the nature of comprehensive professional services for the unique needs of visually impaired older persons. Of the 481 surveys mailed, 289 were returned for a response rate of 60 percent. Seventy-eight percent of the respondents had completed their formal optometric education after 1970. Results indicated that geriatric optometric care is predominantly delivered in private practices and in low vision agencies. Approximately 69 percent of the patients are above the age of 65, with the majority of those being under 85. Although the average initial low vision appointment lasts 60-90 minutes, this generally represents the low vision examination and evaluation of low vision devices only. Complete ocular health assessments combined with low vision evaluations are provided by only 33.5 percent. While 80 percent of the optometrists responding take psychosocial histories, only 60 percent routinely refer patients for social services and rehabilitative training. Similarly, 57 percent of those responding referred patients for independent daily living skills instruction and only 53 percent for orientation and mobility training. These data suggest that optometrists have not yet completely incorporated the multidisciplinary approach to geriatric health care and that continuing education in this area is needed.

Clinical evaluation of back optic radius and power determination by age in pediatric aphakia due to congenital cataract fitted with a Silicone Elaster contact lens.

The purpose of this study was to provide optometrists with suggested base curves and powers for initial lens choice based on the infant's age. A retrospective chart review of 16 congenital cataract patients fitted at U.C. Davis Eye Clinic between July 1987 and May 1993 was performed. Patients with associated ocular pathologies were excluded. All patients were fitted with a Bausch & Lomb Silsoft lens, a Silicone Elastomer, set at a 3.00 D myopic posture, which was decreased with the child's increasing age and activity. This study provides a graphical approach to pediatric aphakic silicone elastomer contact lens fitting. Best-fit regression lines for both graphs have an r squared value better than 0.9. Optometrists will now be able to reference the Base Curve vs. Age and Power vs. Age graphs to determine the initial lens choice when keratometry is unachievable. Furthermore, the data suggest a need for an increased range of powers provided by the Silicone elastomer lens in order to approximate normal visual development.

Ocular effects of second generation oral hypoglycemic agents.

Second generation oral hypoglycemic agents, such as glyburide and glipizide, are often the treatment of choice in non-insulin dependent diabetes mellitus. These sulfonylureas are more potent osmotic agents than their predecessors and may give rise to crystalline lens changes and refractive error shifts in the absence of blood glucose variation. Such a case is presented, as is a detailed description of the mechanism of action of commonly prescribed oral hypoglycemic agents.