Roger H. S. Langston

Infectious Crystalline Keratopathy

In three patients (three men, 44, 67, and 83 years old) an unusual keratopathy characterized by white, branching, crystalline stromal opacities produced lesions that were insidious, that increased in size slowly, and that were clinically and histopathologically associated with little corneal inflammation. Intraocular inflammation eventually became evident in two of the patients. The keratopathy developed while the patients were using topical corticosteroids. In two cases, histopathologic studies disclosed accumulations of gram-positive cocci in the corneal stroma; a viridans streptococcus agent was isolated on culture. In one case, the viridans streptococcus was determined to be a dextran producer, which may have contributed to the pathogenesis of the keratopathy. Despite aggressive treatment with a variety of drugs, epithelial healing, and resolution of the corneal infiltrate, residual scarring persisted in two cases and neovascularization and graft edema in one case each.

Acanthamoeba keratitis: The Persistence of Cases Following a Multistate Outbreak

Purpose: To describe the trend of Acanthamoeba keratitis case reports following an outbreak and the recall of a multipurpose contact lens disinfection solution. Acanthamoeba keratitis is a serious eye infection caused by the free-living amoeba Acanthamoeba that primarily affects contact lens users. Methods: A convenience sample of 13 ophthalmology centers and laboratories in the USA, provided annual numbers of Acanthamoeba keratitis cases diagnosed between 1999–2009 and monthly numbers of cases diagnosed between 2007–2009. Data on ophthalmic preparations of anti-Acanthamoeba therapies were collected from a national compounding pharmacy. Results: Data from sentinel site ophthalmology centers and laboratories revealed that the yearly number of cases gradually increased from 22 in 1999 to 43 in 2003, with a marked increase beginning in 2004 (93 cases) that continued through 2007 (170 cases; p < 0.0001). The outbreak identified from these sentinel sites resulted in the recall of a contact lens disinfecting solution. There was a statistically significant (p ≤ 0.0001) decrease in monthly cases reported from 28 cases in June 2007 (following the recall) to seven cases in June 2008, followed by an increase (p = 0.0004) in reported cases thereafter; cases have remained higher than pre-outbreak levels. A similar trend was seen in prescriptions for Acanthamoeba keratitis chemotherapy. Cases were significantly more likely to be reported during summer than during other seasons. Conclusion: The persistently elevated number of reported cases supports the need to understand the risk factors and environmental exposures associated with Acanthamoeba keratitis. Further prevention efforts are needed to reduce the number of cases occurring among contact lens wearers.

Corneal Edema Related to Accidental Hibiclens Exposure

Five patients developed corneal edema presumably caused by accidental preoperative ocular exposure to Hibiclens. In all cases, the patients complained of ocular pain after surgery. Conjunctival inflammation and corneal epithelial defects were found in all patients. Between two and ten weeks after exposure, stromal and epithelial edema, with a predilection for the inferior cornea initially, developed in all patients. The corneal edema resolved in three patients in approximately six months, leaving mild stromal scarring and reduced endothelial cell counts. The corneal edema in the other two patients progressed to diffuse bullous keratopathy, which eventually required penetrating keratoplasty. We recommend that Hibiclens be avoided in preoperative preparation of the facial skin to prevent accidental ocular exposure.

Clinical experience with Acanthamoeba keratitis at the Cole Eye Institute, 1999-2008.

Purpose: To review the clinical presentations, risk factors, medical and surgical management, and outcomes of patients with Acanthamoeba keratitis (AK). Methods: Retrospective review of laboratory and medical records of all patients suspected of having AK from January 1999 through May 2008 at Cole Eye Institute. Results: Twenty-nine eyes of 26 patients were identified as having either culture- or tissue-proven AK or presumed AK based on clinical examination and complete response to full course of treatment. The most common risk factors identified for AK were history of contact lens wear (89.7%) and exposure to contaminated water (27.6%). Clinical presentations included early AK (superficial disease) in 37.9% of eyes or late AK (deep stromal disease with or without epithelial disease) in 62.1% of eyes. All early AK cases had best-corrected visual acuity of 20/30 or better at last follow-up, whereas only 55.6% of late AK cases achieved 20/30 or better. Eight eyes underwent penetrating keratoplasty. One patient demonstrated viable-appearing cysts in the corneal button, despite 15 months of maximum medical treatment and 5 months off all medical treatments. Over the nearly 10-year period, there was no significant increase in the number of cases seen each year. Conclusions: The most common risk factor for AK continues to be contact lens wear. AK requires prolonged and intense treatment, although good final visual acuity can be achieved. Potentially viable Acanthamoeba cysts can still persist in a noninflamed cornea after extensive medical therapy, supporting the practice that corneal transplantation after presumably resolved cases of AK should be followed with vigilance to detect the earliest signs of recurrent disease.

Coagulase-negative Staphylococcus Endophthalmitis After Cataract Surgery With Intraocular Vancomycin

PURPOSE We studied a case of postoperative coagulase-negative Staphylococcus endophthalmitis in a 79-year-old man who had undergone cataract extraction in which vancomycin had been used intraoperatively in the infusion fluid. METHODS The medical records were reviewed for the clinical history, ocular findings, and the vitreous and anterior chamber culture results. RESULTS Acute, postoperative coagulase-negative Staphylococcus endophthalmitis developed in the patient in whom vancomycin had been used intraoperatively in the infusion fluid. CONCLUSIONS Restraint is urged in the prophylactic use of vancomycin in the infusion fluids.

Antiviral medications and corneal wound healing

Masked controlled rabbit studies were done to determine the toxic effects on corneal wound healing of the antiviral ointments 0.5% idoxuridine, 3% Ara A, and 3% acyclovir, and the antiviral drops 0.1% idoxuridine, 3% Ara AMP, and 1% trifluridine. Ara A, acyclovir, trifluridine and idoxuridine drops had no significant effects on the rate of closure of epithelial wounds. Idoxuridine ointment given 5 times a day significantly retarded the rate of epithelial wound closure, but not when given 4 times a day. Only Ara AMP caused a retardation of epithelial healing and an actual increase in the defect after 4 days of treatment. Histopathologically all drugs, except acyclovir, showed a toxic effect on the regenerating epithelium. All drugs, except acyclovir, showed retarded stromal wound healing with reduced bursting strength and collagen content. Ara AMP had increased bursting strength and collagen content possibly because of greater inflammation. Acyclovir, in comparison to all the other medications studied, appeared to have minimal to no toxic effects on experimental epithelial and stromal wound healing, and on this basis is the agent of choice for use in herpes simplex stromal keratitis with ulceration and as a prophylactic agent for long-term use after penetrating keratoplasty.

Ophthalmic Irrigants: A Current Review and Update

The search for an ideal intraocular irrigating solution is of paramount importance to te ophthalmic surgeon. An intraocular irrigating solution, as well as surgical technique, can have deleterious effects on ocular tissues. Since an intraocular irrigating solution comes in contact with the cornea, lens, trabecular meshwork, uvea, vitreous, and retina, and ideal irrigant would be ome that ensures biological function for all of these tissues. In a practical sense, the best irrigant is one that causes the least possible damage to the structural integrity and function of the intraocular environment. This paper summarizes the development, uses, and efficacy of intraocular irrigating solutions as currently used during intraocular surgery.

Penetrating keratoplasty for herpetic keratitis: decision-making and management.

The outlook for keratoplasty in herpetic keratitis has improved significantly over the past decade. While only two out of three grafts in vascularized and regrafted eyes and in eyes with active disease are clear after two years, in quiet eyes with no significant vascularization, the success rate exceeds 80 percent. The significant factor in the improved results, in both favorable and unfavorable cases, is the improvement in surgical technique, involving the operating microscope, the 10-0 nylon suture, and the increased understanding of the pathophysiology of corneal grafting, which has resulted in more sophisticated postoperative care. In our experience, the routine use of high levels of topical steroids in the immediate postoperative period, followed by a rapid tapering of these medications, has been particularly successful.

Donor Material for Corneal Grafting

Donor material selection for corneal grafting has become increasingly important. Recently, guidelines for the exclusion of potential transplant material because of the donors medical history have been established. We present a clinicopathologic case report that supports the strict contraindication to using leukemic donor tissue proposed by the Eye Bank Association of America.

Prevention and management of corneal decompensation.

While the chances of corneal decompensation following lens implantation are low, they are greater than in nonimplant cataract surgery and increase with the passage of time postoperatively. All the factors leading to corneal decompensation are not known, but available evidence suggests the most significant is trauma at the time of surgery. The likelihood of corneal decompensation can be limited by careful patient selection and surgical techniques and by appropriate management of postoperative complications. In the event of irreversible corneal decompensation, penetrating keratoplasty, with or without removal of the implant lens, offers a substantial chance of visual rehabilitation.