An improved method for the delivery of artificial tears using an infusion pump.

Patients with markedly decreased or absent tear duct production require the frequent instillation of artificial tear preparations. Through animal experiments, a new method has been developed for the continuous infusion of these solutions. In this procedure, the canalicular system is intubated with fenestrated silastic tubing, which is subcutaneously tunnelled and then attached to a miniaturized and computerized pumping device. This makes it possible for a predetermined volume of solution to be automatically and continuously delivered. Using this technique, artificial tear solution was instilled at a rate of 1.75 microliter/min, a rate approximately the normal basic tear secretion rate (0.5-2.2 microliters/min). This resulted in a 14% increase in tear flow from preoperative values. This represents a 74% increase in tear secretion rates for patients with keratoconjunctivitis sicca. None of the experimental animals developed subcutaneous infections, dacryocystitis, or corneal ulcers. By utilizing the normal anatomy of the lacrimal drainage system, this new technique: does not compromise the conjunctival cul-de-sac or the salivary system, avoids the inconvenience of previous external devices, and allows for the automatic instillation of predetermined volumes of artificial tear solutions.

Decorin and biglycan of normal and pathologic human corneas.

PURPOSE: Corneas with scars and certain chronic pathologic conditions contain highly sulfated dermatan sulfate, but little is known of the core proteins that carry these atypical glycosaminoglycans. In this study the proteoglycan proteins attached to dermatan sulfate in normal and pathologic human corneas were examined to identify primary genes involved in the pathobiology of corneal scarring. METHODS: Proteoglycans from human corneas with chronic edema, bullous keratopathy, and keratoconus and from normal corneas were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), quantitative immunoblotting, and immunohistology with peptide antibodies to decorin and biglycan. RESULTS: Proteoglycans from pathologic corneas exhibit increased size heterogeneity and binding of the cationic dye alcian blue compared with those in normal corneas. Decorin and biglycan extracted from normal and diseased corneas exhibited similar molecular size distribution patterns. In approximately half of the pathologic corneas, the level of biglycan was elevated an average of seven times above normal, and decorin was elevated approximately three times above normal. The increases were associated with highly charged molecular forms of decorin and biglycan, indicating modification of the proteins with dermatan sulfate chains of increased sulfation. Immunostaining of corneal sections showed an abnormal stromal localization of biglycan in pathologic corneas. CONCLUSIONS: The increased dermatan sulfate associated with chronic corneal pathologic conditions results from stromal accumulation of decorin and particularly of biglycan in the affected corneas. These proteins bear dermatan sulfate chains with increased sulfation compared with normal stromal proteoglycans.

Streptococcal endophthalmitis from contaminated donor corneas after keratoplasty. Clinical and laboratory investigations.

We report three cases of Streptococcus viridans endophthalmitis following penetrating keratoplasty in which S viridans was cultured from the recipient eye, McCarey-Kaufman (M-K) media, and corneoscleral rims. As a laboratory correlation, we investigated the ability of S viridans to survive in M-K medium supplemented with gentamicin. After M-K medium was inoculated with S viridans, it was stored overnight at 4 degrees C, after which the temperature was raised to 23 degrees C. Periodic colony counts were performed for up to 24 hours after warming. No killing occurred in the cold. Ten hours passed before there was one log reduction in the bacterial colony count. Organisms could still be cultured at 24 hours. We conclude that gentamicin alone may be inadequate prophlyaxis against S viridans contamination of donor corneas.

Photocoagulation-induced lens opacity.

Lens opacities secondary to argon laser photocoagulation were seen in six eyes of four patients undergoing treatment for subretinal neovascular membrane and diabetic retinopathy. Laser-induced lens opacities were multiple, grayish-white, and localized at the junction of the nucleus and anterior cortex of the lens. These lens opacities were stable and nonprogressive. Laser-induced lens opacities are a potential complication of photocoagulation treatment in patients with nuclear sclerosis.

Superoxide radical scavenging agents in treatment of alkali burns. An experimental study.

To test the hypothesis that superoxide radicals are involved in tissue destruction after alkali burns, superoxide dismutase, ascorbic acid, and glutathione were used as superoxide radical scavenging agents. Daily subconjunctival injections were given in rabbit eyes after alkali burns. Both superoxide dismutase and ascorbic acid were effective in preventing corneal perforations. Glutathione did not show any beneficial effect. These experiments suggest that superoxide radical scavenging agents may be useful in the treatment of ocular alkali burns.

Deep stromal vascularization associated with cosmetic, daily-wear contact lenses.

Deep stromal vascularization and corneal opacification occurred in three patients with normal eyes who wore hard and soft contact lenses on a daily basis. To our knowledge, this complication has not been reported in association with daily-wear contact lenses.

Streptococcus sanguis survival in K-Sol. Comparison of gentamicin and the fluoroquinolone antibiotics.

Viridans streptococci are poorly covered by gentamicin sulfate in corneal storage medium. To evaluate possible antibiotic alternatives among the newer broad-spectrum fluoroquinolone antibiotics, we compared the survival of the viridans representative Streptococcus sanguis in K-Sol with gentamicin sulfate (100 mg/L), norfloxacin (250 mg/L), ciprofloxacin lactate (250 mg/L), ofloxacin (250 mg/L), or no antibiotic. At 23 degrees C, K-Sol with gentamicin produced a 2-log kill by 80 minutes. By comparison, only one of the others (norfloxacin) had achieved a 2-log kill by 4 hours. At 4 degrees C, all antibiotics differed little from the control, and none was superior to gentamicin.

Factors associated with glaucoma after penetrating keratoplasty.

We conducted a retrospective analysis of 80 eyes that underwent penetrating keratoplasties to determine the factors associated with early (less than three months) and late (more than three months) postoperative increases in intraocular pressure. The patients ranged in age from 14 to 91 years (mean age, 58.5 years). The 56 patients with aphakic eyes had a mean age of 64 years and the 24 patients whose eyes had lenses had a mean age of 48 years. In the 17 eyes with preoperative glaucoma, the intraocular pressure was controlled with medication (mean intraocular pressure, 17.6 mm Hg; range, 10 to 21 mm Hg). The follow-up periods ranged from 12 to 26 months (mean, 22 months). Of the 80 eyes, 25 had early increases in intraocular pressure and 23 had late increases. Twenty eyes showed increases during both periods. Of the 17 eyes with preoperative glaucoma, 14 had early increases and 15 had late increases (P less than .001). Of the 57 aphakic eyes, 24 had early increases (P less than .001) and 21 had late increases (P less than .025). Other factors (whether vitrectomy was done, suture technique, and graft size) were not statistically significant.

Persistent corneal edema in aphakic eyes from daily-wear and extended-wear contact lenses.

Corneal edema developed in seven aphakic eyes of six patients (three men and three women ranging in age from 60 to 88 years) who used daily- or extended-wear hydrophilic and silicone contact lenses. This edema, which developed suddenly, persisted despite discontinuation of contact lens wear and treatment with topical corticosteroids. The onset of the edema occurred in two patterns. In three eyes, edema occurred soon (30 minutes to 30 days) after the contact lens was first worn and persisted during follow-up periods averaging 15 months. In the other four eyes, the edema developed late, after 20 to 66 months. In three of these eyes, edema resolved after follow-up periods averaging seven months. In the fourth eye, it was still present after 18 months. Of the affected eyes in which peripheral endothelial cell densities could be measured, all but one had fewer than 800 cells/mm2. Central cell densities in the five uninvolved fellow eyes averaged 1,964 cells/mm2. Marked polymegathism and cornea guttata were present in all affected and fellow eyes. We believe this condition is a complication of aphakic contact lens wear, distinct from contact-lens-intolerance syndrome and aphakic bullous keratopathy.

Clindamycin in the treatment of toxoplasmic retinochoroiditis.

We treated 26 patients with acute toxoplasmic retinochoroiditis with clindamycin between 1974 and 1982. Four patients were treated with clindamycin alone and 17 with clindamycin and prednisolone. Five patients received clindamycin and prednisolone, sulfadiazine, pyrimethamine, or cryocoagulation, or a combination of these. All patients with the acute disease had the characteristic foci and a positive titer on the Sabin-Feldman dye test of at least 1:16. Other causes of retinochoroiditis were excluded. All but two patients, who developed diarrhea after two weeks, received clindamycin for a minimum of three weeks. All patients improved after two weeks of treatment, but two patients with lesions larger than 2 disk diameters required an additional six weeks of treatment to heal completely. During follow-up periods ranging from 18 months to seven years (mean, three years) there have been only two recurrences (7.7%). Complications with clindamycin treatment were limited to gastrointestinal upsets, diarrhea, and skin rash. There were no cases of pseudomembranous colitis, the most serious reported complication of clindamycin use.

Complications of exposed monofilament sutures.

Exposed monofilament suture ends caused a variety of symptoms and signs in 18 patients. These included foreign-body sensation, pain, contact lens intolerance, giant papillary conjunctivitis, tarsal ulceration, conjunctival granuloma, corneal infiltrate, and corneal vascularization. These changes followed cataract surgery, corneal transplantation, and pars plana vitrectomy. Diagnoses in these cases were made by careful slit-lamp examination and by eversion of the upper eyelid. In every case, removal of the sutures or trimming the suture ends resulted in the immediate relief of all symptoms with complete resolution of all signs within two months.

Spontaneous ulcerative keratitis in immunocompromised patients.

We studied the occurrence of ulcerative keratitis in five eyes of four patients who were examined at the University of Maryland Hospital ophthalmology clinic over a 12-month period. All were young women who were intravenous drug abusers, with no known predisposing factors for ulcerative keratitis. Two patients had acquired immunodeficiency syndrome (AIDS), one was human immunodeficiency virus (HIV)-positive, and the fourth refused HIV testing. One had a corneoscleral limbus to corneoscleral limbus keratitis; three had inferiorly located corneal ulcers (bilateral in one patient with AIDS). Corneal cultures disclosed Capnocytophaga species in the corneoscleral limbus to corneoscleral limbus keratitis. The remaining ulcers were polymicrobial; cultures of three grew Candida albicans, cultures of two grew alpha-hemolytic streptococci, cultures of two grew Staphylococcus aureus, and culture of one grew Pseudomonas aeruginosa. Treatment with topical fortified antibiotics and antifungal agents resulted in complete healing in all four inferiorly located ulcers. The corneal ulcer became perforated and the eye was eviscerated. Histopathologic analysis of the eviscerated specimen disclosed acute keratitis with necrosis and no microorganisms.

Corneal steepening after epikeratoplasty.

Four patients had removal of their epikeratoplasty lenticules for unsatisfactory visual results. This was out of a consecutive series of 36 eyes. Three eyes were myopic and one was aphakic. In all four eyes, there was significant corneal steepening with an average increase in myopia of 2.4 diopters and an average increase in keratometry reading of 4.8 diopters. Corneoscopy was done in three cases and showed central corneal steepening. In addition, one patient (Case 1) had significant scarring of the recipient cornea and a decrease in visual acuity to 20/100. The reasons for corneal steepening may be related to midperipheral partial trephination, annular keratectomy, and spreading of the peripheral cornea.

Bilateral iridocorneal endothelial syndrome: case report and review of the literature.

We present the case of a 47-year-old woman with bilateral iridocorneal endothelial syndrome. The iridocorneal endothelial syndrome has heretofore been considered a unilateral disorder. However, a review of the literature and examination of the patient presented in this report indicate that bilateral occurrence of the iridocorneal endothelial syndrome is not uncommon. Consequently, it may be inappropriate to include unilaterality as a feature distinguishing the iridocorneal endothelial syndrome from similar conditions, most notably posterior polymorphous endothelial dystrophy.

Survival of Streptococcus viridans in gentamicin-supplemented McCarey-Kaufman medium.

Our experience with three cases of Streptococcus viridans endophthalmitis, following penetrating keratoplasty, prompted us to investigate the ability of gentamicin-supplemented McCarey-Kaufman (M-K) medium to kill S. viridans contaminants. After inoculation of 20 cc of gentamicin-supplemented M-K with S. viridans, the M-K was exposed to temperature conditions similar to those that would be encountered by a donor cornea during storage (4 degrees C) and preoperative warming prior to keratoplasty (23 degrees C). Colony counts were performed at regular intervals. After 1 h of warming, no reduction in the initial inoculum had occurred. This is in contrast to results from similar experiments with Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa in which more than 1 log unit of killing occurred after 1 h. While previously reported clinical experience has demonstrated an overall low incidence of postkeratoplasty endophthalmitis using gentamicin-supplemented M-K, our own recent clinical and laboratory data suggest that additional or alternate antibiotic coverage for S. viridans may be prudent.

Effects of epikeratoplasty on the host cornea. An experimental study.

The effects of epikeratoplasty on the host cornea was studied using albino rabbits. Eyes underwent midperipheral partial trephination alone (group I), midperipheral partial trephination and peripheral undermining (group II), midperipheral partial trephination and circular keratectomy (group III), and trephination, peripheral undermining, and circular keratectomy (group IV). Corneal topography was assessed weekly using keratometry and photokeratoscopy. All eyes showed central corneal steepening with enhancing effects of increased surgical manipulation. Results were stable by 4 weeks in all eyes. Histopathologic evaluation revealed a constant wound depth of approximately 0.1 mm, with an increased accumulation of glycosaminoglycan material at the base of the wound. This was stained with PAS and alcian blue. Steepening of the host cornea may be another reason for lack of predictability and refractive regression following epikeratoplasty.