Development Of Corneal Ulcers Research Articles

Microvascular submandibular gland transfer for the management of xerophthalmia; an experimental study

Free submandibular salivary gland transfer was investigated as a method of treatment for xerophthalmia. Xerophthalmia was created in rabbits by surgical removal of the lacrimal gland and the incidence of corneal ulceration was seen to correlate with the decrease in tear secretion. Microvascular transfer of the submandibular salivary gland to drain saliva into the conjunctival fornix prevented the development of corneal ulceration in 63% of the cases.

Keratoconjunctivitis Sicca and Corneal Ulcers

We reviewed the records of 56 patients (109 eyes) who satisfied our criteria for keratoconjunctivitis sicca (KCS) to determine factors associated with the development of sterile corneal ulcers. The patient's age, sex, and associated local ocular surface and/or systemic disease were studied. We found a statistically significant association between the development of corneal ulceration and the presence of an underlying condition or disease state, especially chronic rheumatoid arthritis. Patient sex and age were not significantly associated with the development of corneal ulceration. We present three case histories that illustrate the complications that arise in managing KCS plus an associated disease and methods of management.

Post‐keratoplasty corneal ulcers and bandage lenses

285 cases of penetrating keratoplasty in whom hydrophilic bandage lenses were fitted were analyzed for the occurrence of corneal ulcers. Of these eyes 26 developed culture-proven bacterial ulcers. No correlation could be made between any particular type of contact lens and the development of corneal ulcer. Although no single factor could be delineated which may be responsible for this problem, this risk appears to be escalated where host defense mechanisms are impaired. The clinician should recognize the potential risk in using bandage lenses when the cornea is immunosuppressed and completely denervated.

Corneal Ulcers Associated with Daily-Wear and Extended-Wear Contact Lenses

Over a 21-month period, we treated corneal ulcers in 11 patients using daily-wear contact lenses and 29 patients using extended-wear contact lenses. Since more patients use daily-wear than extended-wear lenses, this suggests that patients using extended-wear lenses are at greater risk for the development of corneal ulcers. Positive bacterial cultures were obtained from the corneal scrapings of nine of 11 patients using daily-wear lenses and 20 of 29 patients using extended-wear lenses. In the daily-wear group, all 11 patients failed to exercise satisfactory care in using and disinfecting their contact lenses: three did not wash their hands before manipulating the contact lenses, eight wore them overnight, two did not use any disinfecting system, and four had contaminated contact lens cases, solutions, or drops. In the extended-wear group, 17 patients failed to exercise satisfactory care in using and disinfecting their contact lenses: 12 had contaminated contact lens care systems, two did not use any disinfection system, five reported not washing their hands before contact lens manipulation, and two disinfected their contact lenses at intervals of more than a month. We were unable to identify any defect in the way 12 patients took care of their extended-wear lenses, suggesting that there may be a problem with these contact lenses even when care is satisfactory.

Corneal ulcers associated with contact lens wear.

We reviewed the experience with ulcerative keratitis associated with contact lens wear at Wills Eye Hospital, Philadelphia, from Jan 1, 1978 through July 1, 1983. Of the 322 cases of ulcerative keratitis, 56 cases (17%) were associated with the use of contact lenses. Twenty-nine (52%) of the 56 cases of contact lens-associated ulcers were culture positive. Pseudomonas was the most common isolate, occurring in 13 (23%) of the 56 cases. Staphylococcus species were the second most common, occurring in 11 (20%) of the 56 cases. In this series, contact lens-associated ulcers were seen frequently in those wearing soft lenses (48/56 cases or 86%) and in those wearing aphakic lenses (32/56 cases or 57%). Contact lens use is an increasingly important risk factor for the development of corneal ulcers. Prompt, appropriate, and intensive treatment is necessary to prevent visual loss.

Corneal Ulcers Associated with Extended-Wear Soft Contact Lenses

We treated nine myopic and nine aphakic eyes in patients who developed corneal ulcers while wearing extended-wear soft contact lenses. Bacteria were recovered from the corneal ulcers of 13 of 18 patients with Pseudomonas aeruginosa being the pathogen most frequently isolated. Chemical disinfection was used by seven of the nine patients with myopia and eight of the nine with aphakia. Two of nine patients in the myopic group had visual loss to 20/200 and hand movements; five of nine patients in the aphakic group had visual loss to 20/50 or worse. Invasion of the corneal stroma by bacteria may occur after breakdown of the epithelial barrier by contact lens manipulation or after chronic overnight anoxic stress. Thus, the use of soft contact lenses on an extended-wear basis may be complicated by the development of corneal ulcers. Both aphakic and myopic eyes are at risk.

Ascorbic Acid in the Treatment of Alkali Burns of the Eye

Severe ocular alkali burns in rabbits result in a decrease in aqueous humor ascorbate levels to one-third normal levels. If this deficiency is reversed by immediate treatment with parenteral or topical ascorbate, there is a significantly decreased incidence of subsequent corneal ulceration and perforation. The morphologic changes in these ulcerating corneas are typical of those noted in scorbutus (scurvy). It is concluded that alkali injury to the ciliary epithelial transport processes or ciliary body vasculature results in localized deficiency of ascorbic acid in the aqueous humor and cornea. The development of corneal ulceration is thought to be based on this deficiency which results in the failure of fibroblasts to produce sufficient collagen for repair. A randomized clinical trial of ascorbic acid in the treatment of human alkali burned eyes is now underway.

Endocrine Influences on Ulceration and Regeneration in the Alkali-Burned Cornea

Subconjunctival dibutyryl 3',5' cyclic adenosine monophosphoric acid (DBcAMP) produced a statistically significant reduction of ulceration in the alkaliburned rabbit cornea. No effect on epithelial cell growth was observed. DBcAMP also caused a statistically significant acceleration of corneal neovascularization in the first two weeks postburn. Medroxyprogesterone acetate also affected the development of corneal ulcers postalkali burn, but in a less well-defined manner. Dinoprost and indomethacin did not seem to influence this lesion. Cyclic adenosine monophosphoric acid may therefore possess a potential for use in the alkali-burned human eye.

Demographic and Aetiological Profile of Microbial Corneal Ulcer in a Hill State in North India

Aim: To ascertain the demographic and aetiological profile of microbial corneal ulcer in Uttarakhand, a predominantly hilly state of North India.Methods: In this prospective non-randomized study, 180 consecutive patients with suspected microbial corneal ulcer attending the ophthalmology outpatient department of the Himalayan Institute of Medical Sciences, Dehradun, India, were evaluated. Corneal scrapings were taken and subjected to microbiological analysis, including Gram stain, potassium hydroxide wet mount, and bacterial and fungal culture.Results: Among 180 patients, male sex, prior history of ocular trauma with vegetative materials,and occupation involving outdoor activity, especially agricultural work, were the major risk factors for development of corneal ulcer in the population studied. Forty percent of the ulcers were fungal, 28% were bacterial, 10% showed mixed bacterial and fungal growth, and 5% were viral. The aetiology could not be determined in 17% of patients. Fusarium spp was the most common fungal isolate (87.5%) while Staphylococcus aureus was the commonest bacterial isolate (53%).Conclusions: Fungal ulcers, especially due to Fusarium spp, were the most common type, followed by bacterial ulcers due to Gram-positive bacteria, especially S aureus. This information may be useful for empirical treatment of patients with corneal ulcer in remote areas, where microbiological diagnostic facilities are often not available.