Ophthalmic observations in lecithin cholesterol acyltransferase deficiency.

Lecithin cholesterol acyltransferase is an enzyme that esterifies free cholesterol. A complete deficiency of this enzyme results in a diffusely cloudy cornea. This deficiency is thought to be transmitted as an autosomal recessive trait. We studied a family in which four members were homozygote recessive. In the homozygote recessive condition, a central corneal haze caused by deposition of numerous minute gray dots was consistently present. In the heterozygote condition, arcuslike changes were present in some of the patients studied. We found the corneal change in the recessive state to be sensitive and specific as a marker of this condition. Heterozygotes appear to have a higher incidence of arcuslike corneal changes.

Human excimer laser keratectomy. Immunohistochemical analysis of healing.

OBJECTIVE: To analyze human corneal responses to excimer laser by immunohistochemistry. METHODS: Corneas cultured for 3 weeks after laser ablation or taken from patients 5 to 16 months after laser treatment were exposed to antibodies to beta, integrin; types VII, IV, and III collagen; fibronectin; type I procollagen; and prolyl 4-hydroxylase. Antibody distributions were compared with those of normal corneas and unablated regions of treated corneas. RESULTS: After 3 weeks, distribution of beta, integrin, and types VII and IV collagen was patchy; heavy deposits of fibronectin appeared subepithelially. Keratocytes stained for prolyl-4-hydroxylase and type I procollagen. With increasing postoperative time, fibronectin diminished, and beta 4 integrin and type VII collagen became linear, stromal staining of types III and IV collagen increased and their diminished. CONCLUSIONS: Components of basement membrane, attachment complexes, and stromal matrix are synthesized shortly after laser treatment. Changes in these elements persist for 16 months in the human cornea.

Elevated corneal epithelial lines in Acanthamoeba keratitis.

Elevated corneal epithelial lines are another clinical sign in Acanthamoeba corneal infection. In this report, one patient wore extended wear soft contact lenses, and another wore daily wear soft contact lenses. Both patients used distilled water and salt tablets in their lens care. Histopathologic examination of these lines revealed trophozoites and cysts. In one of the patients following penetrating keratoplasty, Acanthamoeba castellani and Acanthamoeba polyphaga were cultured by impression cytology of an epithelial line, as well as from the bulbar and tarsal conjunctiva. In the other patient who did not undergo penetrating keratoplasty, these lines appeared in the cornea one month after initial symptoms.

A prospective, randomized comparison of thermal cautery and argon laser for permanent punctal occlusion.

Permanent punctal occlusion was performed by two techniques on 27 patients (73 puncta). Patients were randomly assigned to be treated with either thermal cautery or argon laser for keratitis sicca. Follow-up assessment disclosed that the puncta to which thermal cautery was applied remained closed significantly longer than those to which laser treatment was applied (P < .05, log-rank test). Using time to recanalization of a punctum as the end point, we found a long-term advantage of thermal cautery over argon laser treatment.

Oculocardiac reflex during manipulation of adjustable sutures after strabismus surgery.

We studied 44 patients who underwent strabismus surgery with the use of adjustable sutures to determine the occurrence of the oculocardiac reflex during the postoperative adjustment process. We defined the reflex as at least a 10% decrease in the baseline heart rate. Only two patients (4.5%) displayed an oculocardiac reflex during the adjustment. We did not identify any preadjustment factors that would increase the susceptibility to develop the reflex.

Cholesterol localization in ultrathin frozen sections in Schnyder's corneal crystalline dystrophy.

We examined a 57-year-old woman who had bilateral corneal crystalline deposits associated with xanthelasma. The patient's son had bilateral stromal haze. Plasma cholesterol and apolipoprotein A-I and B levels were normal. Histopathologic examination disclosed lipid deposits, particularly in the superficial stroma and Bowman's layer. These deposits stained with oil red O and filipin, a fluorescent probe that specifically detects unesterified cholesterol. Cryoultramicrotomy disclosed more specific ultrastructural localization of unesterified cholesterol with an array of crystals resembling multiple plates in extracellular corneal tissue.

A new scleral suction trephine for retrieval of corneoscleral donor tissue.

BACKGROUND: Removal of donor corneo-scleral shell from a cadaver, leaving the remainder of the eye in place, has become a popular technique. Manual removal can result in excessive trauma to the corneal endothelium or an uneven scleral rim. METHODS: We describe a new technique for corneal retrieval using a sceral suction trephine. RESULTS: The scleral suction trephine was cut evenly in our eyebank study. There was no additional trauma to the endothelium and the scleral rim was regular. CONCLUSION: Suction trephination of the sclera in retrieval of corneal donor tissue appears to be safe and effective.

Subconjunctival fibrosis after conjunctival autograft.

While largely successful, the use of a conjunctival autograft in the exposed scleral bed following a pterygium excision can result in postoperative complications. We report two cases of a previously undescribed complication: subconjunctival fibrosis at the harvest site of the graft. In one case, the fibrosis caused an asymptomatic, purely cosmetic defect; however, in the other case, the scar tissue constricted the extraocular movement with resultant diplopia. We call attention to this complication as it can affect visual function; we discuss its management and prevention.

The effect of topically applied fluorescein on fluorescent monoclonal antibodies in the diagnosis of chlamydial conjunctivitis.

Fluorescein-conjugated monoclonal antibodies have now been developed for use in the diagnosis of chlamydial conjunctivitis. This article discusses a clinical trial involving the use of such antibodies. We found that topical application of fluorescein before obtaining a specimen did not result in a statistically significant rate of false positives in a control group of patients.

A surgical technique for the treatment of central corneal perforations.

BACKGROUND: Generally, corneal perforations of 2 mm in diameter or greater are treated using graft material for tectonic support. A surgical technique for the primary repair of such perforations without the use of any additional tissue is presented. METHODS: This procedure is demonstrated by a case report. The technique involves creation of an elliptical defect out of a circular one, thus allowing for primary closure, with the addition of glue. A definitive penetrating keratoplasty was subsequently performed with several important modifications described herein. RESULTS: A water-tight closure was obtained with this technique for 1 month while the inflammation subsided. Preoperative visual acuity was light perception. One year postoperatively, it was count fingers at 8 feet with mild irregular astigmatism. CONCLUSION: This technique is useful for perforations which are central, larger than 2 mm in diameter, and when corneal or scleral material is not readily available for patch grafting.

Arcuate keratotomy for the correction of spherical hyperopia in human cadaver eyes.

BACKGROUND: A new experimental surgical technique to correct spherical hyperopia by steepening of the central corneal curvature was performed on human cadaver eyes. METHODS: Ten eyes were used in the study. All were pretreated with glycerin to ensure a uniform corneal thickness between .55 and .65 mm on ultrasonic pachometry. A constant intraocular pressure of approximately 30 to 40 mm Hg was maintained in each eye by the injection of saline into the vitreous cavity. This was verified by pneumotonometry. A vertical blade diamond knife was set at 100% of the thinnest of four paracentral readings. Each eye underwent preoperative computed topography. One set of five eyes had 12 incisions made following a 5.75-millimeter diameter Mendez hexagonal marker that included unconnected T incisions at each junction (ie, "Hex T" pattern). The other set of five eyes had four arcuate incisions made following a 6-millimeter diameter zone marker; each incision was 60 degrees in arc. Immediately after surgery, computed topography was repeated. RESULTS: The hexagonal keratotomy set of eyes had an average steepening of the cornea of 0.80 D with a range of -1.05 to + 4.38 D. The arcuate keratotomy set had an average steepening of +2.12 D with a range of +1.27 to +3.27 D. CONCLUSIONS: This study suggests arcuate keratotomy may be a more effective procedure in the correction of spherical hyperopia when compared with hexagonal keratotomy. The amount of corneal steepening achieved in a cadaver eye model may not be the same as when performed in vivo.

Iowa PK Press for donor corneas--a comparative study of donor corneal shape.

BACKGROUND: A new cornea press for cutting donor corneal buttons from the endothelial side, the Iowa PK Press, is described. Major modifications of the Bourne Press include a spring-activated piston without lateral sway, a centering device for a Teflon cutting pad, and the ability to accommodate a wider range of trephine sizes (6.2 mm to 10.0 mm). METHODS: The Iowa PK Press was compared with the Bourne Corneal Press and trephination by hand in a series of 15 donor cornea trephinations. Measurements taken from photographs of the buttons included endothelial diameter, epithelial diameter, and edge angles. RESULTS: The Iowa PK press cut buttons that had a slightly larger epithelial and endothelial diameter when compared to hand trephination (p < .05, analysis of variance) with less undercutting of the endothelial surface. There was no statistically significant difference in epithelial and endothelial diameters, eccentricity, or edge angles between the two presses. CONCLUSIONS: The Iowa PK Press is more versatile than the Bourne Press in terms of the potential range of diameter of corneal buttons that can be created.

Lamellar keratoplasty performed with a corneal scleral button.

Tissue for lamellar corneal surgical procedures is usually harvested from whole eyes. We describe a surgical technique for the rehabilitation of corneoscleral defects with lamellar keratoplasty in which the donor tissue is obtained from a preserved corneoscleral button instead of a whole globe. This technique is illustrated with a case involving the treatment of a limbal dermoid in a 26-month-old boy.