Orthokeratology associated microbial keratitis.

PURPOSE: To report the clinical course, microbiologic findings, treatment, and outcomes of overnight orthokeratology associated microbial keratitis. METHODS: Four cases of overnight orthokeratology associated microbial keratitis are reported. RESULTS: Four patients aged 14-23 years (mean 18 years) who had central or paracentral corneal ulcers were included. Visual acuity at presentation ranged from 20/30 to hand motion. In all cases Pseudomonas aeruginosa was cultured from corneal scrapings or storage solution. In all patients the infection resolved with intensive topical antimicrobial treatment. Final best-corrected visual acuity ranged from 20/25 to 20/200 according to the location, size, and density of the corneal scar, which complicated all cases. CONCLUSIONS: Infectious keratitis is a significant, visual threatening complication of overnight orthokeratology. Eye care practitioners should be aware of this complication and educate their patients of the importance of lens hygiene and prompt medical care when symptoms or signs of keratitis appear.

[Therapeutic penetrating keratoplasty for microbial keratitis].

BACKGROUND: Microbial keratitis is a potentially sight threatening disease. Most cases respond well to antimicrobial therapy. However, in cases that progress despite intensive medical therapy, an urgent therapeutic penetrating keratoplasty (TPKP) is required. AIM: To evaluate the indications and results of TPKP in Israel. METHODS: A retrospective study reviewed the TPKP performed at the Goldschleger Eye Institute, Sheba Medical Center, between 1990-2003. The study included 18 cases of at least one-year follow-up. RESULTS: The indications for TPKP included severe infectious keratitis unresponsive to medical treatment in 33% of the patients and severe corneal destruction in 66% of them. The infectious keratitis was diagnosed as bacterial keratitis in 44% of the patients, unidentified pathogen in 39%, mycotic in 11% and acanthamoeba in 6% of the patients. Risk factors in the patients with microbial keratitis requiring TPKP included: previous ocular disease in 39%, previous ocular surgery in 66%, systemic disorders in 28% and ocular risk factors in 28% patients. TPKP was successful in bacterial and acanthamoeba keratitis as far as the transparency of the graft and elimination of the infection and improvement of visual acuity. However, TPKP failed in mycotic and unidentified keratitis. The risk factors for failure included: previous ocular disease or surgeries, systemic disorders or large corneal grafts. CONCLUSIONS: Therapeutic penetrating keratoplasty is an important and effective therapeutic tool for intractable bacterial and acanthamoeba keratitis. Prognostic factors for graft success include lack of ocular disease or previous surgeries, lack of systemic disorders or small corneal graft size.

Human corneal stromal tissue concentration after consecutive doses of topically applied 3.3% vancomycin.

AIMS: To evaluate vancomycin penetration into human corneal stromal tissue in patients treated with topical vancomycin eyedrops before penetrating keratoplasty (PKP). METHODS: Twenty four patients who underwent PKP, seven patients with keratoconus (group 1) and 17 patients with corneal scar or corneal decompensation (group 2). All patients received topical application of vancomycin eyedrops (concentration: 33 mg/ml) 10, 3, 2, 1 hour, and 15 minutes before the operation. Corneal cumulative vancomycin levels were assessed by bioassay. RESULTS: Mean vancomycin corneal stromal tissue concentration was 46.7 (SE 4.11) microg/g tissue. This value was four to 20-fold in excess of the MIC90 of vancomycin in Staphylococcus aureus (2-10 microg/ml). CONCLUSIONS: Vancomycin reached high corneal tissue concentrations that significantly exceeded the MIC90 (2-10 microg/ml) for most key Gram positive corneal pathogens. The ratio of vancomycin stromal concentration to protein concentration was statistically higher in group 2 (non-keratoconus).

Perioperative microbiologic profile of the conjunctiva in photorefractive keratectomy.

PURPOSE: Therapeutic soft contact lenses are used commonly as an adjunctive treatment after photorefractive keratectomy (PRK) to decrease postoperative pain caused by the movement of lids over the corneal epithelial defect and to facilitate epithelial healing. We assessed the microbiological profile of the conjunctiva of patients undergoing PRK for myopia, before and after the concurrent use of a therapeutic soft contact lens, and compared the effect on ocular bacterial colonization of prophylactic administration of topical tobramycin 0.3% versus ofloxacin 0.3%. METHODS: Forty-three consecutive eyes from 37 patients underwent PRK for myopia or myopic astigmatism. Eyes were assigned randomly to prophylactic antibacterial treatment with either topical ofloxacin 0.3% or tobramycin 0.3%, applied prior to surgery and three times daily after surgery until therapeutic soft contact lens removal. Material from the conjunctival sac was obtained for bacteriologic cultures prior to surgery. Clinical evaluation of all eyes was conducted prospectively. Three days after PRK, the therapeutic soft contact lenses were removed and cultured. Cultures from the conjunctival sac were then repeated. RESULTS: No statistically significant differences were observed in culture positivity between the two groups of eyes, in spite of some positive preoperative and postoperative cultures. Only one out of 43 eyes (assigned to the ofloxacin group) developed a peripheral corneal infiltrate. The corneal infiltrate healed completely without sequelae using antibiotic and corticosteroid therapy. CONCLUSIONS: The use of therapeutic soft contact lenses after PRK with either topical tobramycin 0.3% or ofloxacin 0.3% were well tolerated. However, perioperative positive conjunctival cultures were relatively frequent and prophylactic antibiotics should be used in the setting of an epithelial defect and therapeutic soft contact lens following PRK.

Retinal detachment in Marfan syndrome.

PURPOSE: To report postsurgical findings in patients with Marfan syndrome and retinal detachment (RD). METHODS: The authors identified and retrospectively reviewed the charts of one cohort of 12 patients (15 eyes) with Marfan syndrome and RD who were operated on at the Wilmer Institute and a second cohort of 16 such patients (24 eyes) who were operated several years earlier and elsewhere. RESULTS: First cohort--Final visual acuity (VA) was 20/80 or better and the retina was flat in all five phakic eyes (100%). The RD occurred after the eye had undergone lens removal in 10 eyes, 6 of which (60%) had a final VA of 20/80 or better, and 9 of which (90%) had a final VA of 5/200 or better (P = 0.20). Second cohort--The final VA was 20/80 or better and the retina was flat in 6 of the 7 phakic eyes (86%). Among 17 aphakic or pseudophakic eyes, only 5 (29%) had a flat retina and VA of 20/80 or better, whereas 12 (71%) had no light perception (P = 0.03). CONCLUSIONS: The results of RD operations done in the past in Marfan patients were worse when the eye was aphakic. In most cases operated more recently, the prognosis for successful RD repair was good regardless of whether the eye was phakic.

Herpes simplex virus DNA identification from aqueous fluid in Fuchs heterochromic iridocyclitis.

PURPOSE: To report the presence of herpes simplex virus DNA in the aqueous humor of an eye with Fuchs heterochromic iridocyclitis. METHODS: In an eye with a clinical diagnosis of Fuchs heterochromic iridocyclitis, samples of aqueous humor and anterior capsule of the lens were obtained during cataract surgery. Polymerase chain reaction was performed on the samples to detect the presence of viral DNA including herpes simplex virus, varicella-zoster virus, and cytomegalovirus. Serologic analysis was also performed for antiviral immunoglobulins. RESULTS: Herpes simplex virus DNA was identified in the aqueous humor but not in the anterior capsule. Serum immunoglobulin G was positive for herpes simplex virus, varicella-zoster virus, and cytomegalovirus. CONCLUSIONS: The presence of herpes simplex virus DNA in the aqueous humor of an eye with Fuchs heterochromic iridocyclitis suggests that herpes simplex virus infection may play a role in the pathogenesis of Fuchs heterochromic iridocyclitis.

Provision of anesthesia with single application of lidocaine 2% gel.

PURPOSE: To compare the efficacy of a single application of lidocaine 2% gel with tetracaine 0.5% drops for topical anesthesia in clear corneal cataract surgery. SETTING: The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. METHODS: A preliminary toxicity study applied lidocaine 2% gel in the conjunctival fornices of rabbit eyes (n = 9). Biomicroscopic examination was performed and then enucleation at sequential intervals after the application. Intentional intracameral injection of lidocaine gel was performed (n = 3), followed by enucleation. Histopathological analysis was performed on all eyes. A randomized clinical trial comparing topical anesthesia in clear corneal cataract surgery was performed in 25 eyes of 25 patients (12 eyes randomly assigned to lidocaine gel, 13 eyes to tetracaine drops). Corneal sensation was measured with the Cochet-Bonnet aesthesiometer before application of the topical anesthesia, 5 minutes after application, and at the conclusion of surgery. Additional intraoperative local anesthesia and systemic sedation were recorded. Patients' subjective level of comfort was reported 20 minutes after surgery, and the surgeon's perception of patients' comfort was also noted. RESULTS: In rabbits, lidocaine gel did not cause clinical or histopathological alteration of the ocular tissues. In the clinical study, median corneal sensitivity before application, after 5 minutes, and postoperatively was 6, 0, 0 (maximum sensitivity = 6), respectively, in the lidocaine gel group and 5, 0, 0, respectively, in the tetracaine drops group. Additional local anesthesia was administered in 17% and 31% of patients, respectively. Satisfactory comfort was reported by 58% in the lidocaine gel group and 62% in the tetracaine drops group. CONCLUSIONS: A single application of lidocaine 2% gel was a safe and effective alternative to multiple topical anesthetic drops for clear corneal cataract surgery. Lidocaine 2% gel was similar to tetracaine drops in provision of corneal anesthesia and patient comfort, while causing no significant toxicity to the ocular surface.