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Biomedical subjects

L F Rich

Publications and source records attributed to L F Rich.

28 records · Page 2Linked to original sources
PubMed1979

Stimulation of corneal wound healing with mesodermal growth factor.

Mesodermal growth factor (MGF) from mouse submaxillary glands was tested in vivo for stimulating effects on corneal wounds in rabbits. Intrastromal injection of 5 microgram of MGF induced widespread fibroblast activity and stromal cell division, and markedly stimulated stromal healing. At high doses (greater than 25 microgram), corneal destruction was indicated by extensive necrosis and perforation. When low doses (1 to 5 microgram) of MGF were applied to the lip of nonperforating knife wounds of the cornea, three major differences were noted between control and experimental wounds. In wounds treated with MGF, the depth of stromal healing was greater, as was the intensity of the fibroblast activity, and the width and depth of the epithelial plug were significantly decreased. These results establish that MGF is an effective growth-stimulating agent in vivo and that the initial stages of corneal wound healing may be accelerated in vivo.

Animals↗
PubMedDate not supplied

Long-term effects of radial keratotomy on the corneal endothelium.

BACKGROUND: The long-term effects of radial keratotomy on the corneal endothelium are not well understood. We evaluated the effects of radial keratotomy on the corneal endothelium on the central and midperipheral corneal endothelium. METHODS: Anterior radial keratotomy in 25 eyes was performed and patients were followed for a duration of 4 to 10 years after surgery. Eleven non- contact lens wearing control eyes did not have surgery and were followed for the same period. Morphometric analysis of specular microscopic images was performed with regard to cell density, percent hexagonality, and coefficient of variation. RESULTS: Mean corneal endothelial cell loss rates were 0.4% per year in the radial keratotomy group and 0.9% in the untreated control group over the study duration (mean 7 yr). Morphometric analysis of the cells failed to show a significant change in hexagonality and coefficient of variation. Evaluation of the midperipheral corneal cell counts demonstrated a 1% per year cell loss rate. The cell loss rates in radial keratotomy patients followed over this period were consistent with that noted for normal aging (0.5 to 2.5% per year). CONCLUSION: Radial keratotomy does not cause accelerated endothelial cell loss over 4 to 10 years.

Adult↗
PubMedDate not supplied

Sterile interface keratitis after laser in situ keratomileusis: three episodes in one patient with concomitant contact dermatitis of the eyelids.

PURPOSE: To illustrate a case in which sterile interface keratitis after laser in situ keratomileusis (LASIK) occurred concomitantly with an allergic contact dermatitis of the eyelids. METHODS: Retrospective case review. RESULTS: Resolution of the interface keratitis and dermatitis occurred following an intense course of topical corticosteroids and brief course of oral corticosteroids. Despite an attempt to eliminate potential causes, the same patient developed interface keratitis in the fellow eye following both the initial LASIK and an enhancement, in which no microkeratome was used. Intense treatment with both topical and oral corticosteroids led to a final uncorrected visual acuity of 20/20 in the right eye and 20/25+2 in the left eye. CONCLUSION: The etiology and mechanism of sterile interface keratitis after LASIK are unknown, but are probably multifactorial. The concomitant contact dermatitis reaction may indicate a common immune mechanism.

Adult↗
PubMedDate not supplied

Photoastigmatic refractive keratectomy in myopes. Nidek US Investigators Group.

PURPOSE: Photoastigmatic refractive keratectomy (PARK) was studied in a multi-center clinical trial. The Nidek EC-5000 excimer laser was evaluated for its effect on refraction, visual acuity, and safety measures as part of a U.S. Food and Drug Administration (FDA) regulated study. METHODS: Eight U.S. centers enrolled adults with eyes having refractive astigmatism up to 4.00 D and a myopic spherical equivalent refraction up to -8.00 D. Results are reported for 749 eyes of 486 patients with at least 6 months follow-up. The rectangular beam scanning Nidek EC-5000 used a 5.5-mm-diameter treatment zone, a 7.0-mm-diameter peripheral blend zone, and a 40 Hz pulse rate for surface treatment of myopic astigmatism. Nomogram corrections to machine settings were required to achieve the desired results. RESULTS: Preoperative average spherical equivalent refraction of -4.90+/-1.74 D was reduced to -0.02+/-0.79 D at 6 months. Refractive stability was established at 3 months. Over 62% of eyes were within +/-0.50 D of desired correction at 6 months, with over 86% within +/-1.00 D. Uncorrected visual acuity improved by an average of 10 Snellen lines; over 64% of eyes saw 20/20 or better uncorrected and over 93% saw 20/40 or better uncorrected at 6 and 12 months. PARK treatment effectively reduced astigmatism with little average axis error or magnitude error. Corneal haze and safety concerns were minimal. CONCLUSIONS: Photoastigmatic refractive keratectomy using the Nidek EC-5000 excimer laser provided significant reduction of myopia and astigmatism, with minimal complications.

Adult↗
PubMedDate not supplied

Survival of streptococcus in optisol-GS medium.

BACKGROUND: Donor cornea contamination as a cause of endophthalmitis is one of the most serious complications of penetrating keratoplasty. Optisol-GS corneal storage medium with the combination of gentamicin and streptomycin was designed to provide wider antibiotic coverage, most notably against streptococcal species. However, many enterococci are resistant to streptomycin and genta micin. METHODS/RESULTS: We report a case in which Enterococcus faecium was isolated from cultures of the donor limbus prior to corneal excision and again from preoperative cultures of the donor corneal rim despite 5 days of preservation in Optisol-GS. The isolate was found to be resistant to both gentamicin and streptomycin. CONCLUSIONS: This case illustrates the need to raise awareness that streptococcus can remain a viable contaminant of donor corneas despite storage in Optisol-GS medium.

Chondroitin Sulfates↗
PubMedDate not supplied

The treatment of persistent wound leak after radial keratotomy.

BACKGROUND: Macroperforation of the cornea during refractive keratotomy can result in persistent wound leak and may need treatment by suturing. METHODS: We describe two eyes that developed a macroperforation during radial keratotomy with persistent leakage of aqueous. The wounds were sutured with 10-0 and 11-0 nylon sutures. RESULTS: The sutures induced irregular astigmatism as shown by corneal topography. Removal of sutures improved the topography and led to an acceptable outcome. CONCLUSION: Macroperforations with persistent aqueous leaks should be sutured. Suture removal within a few weeks after surgery can avoid persistent irregular astigmatism and lead to a good refractive result.

Adult↗