Microbial Keratitis After Accelerated Corneal Collagen Cross-Linking in Keratoconus.

PURPOSE: To assess the pattern of microbial keratitis after accelerated corneal collagen cross-linkage (aCXL) in patients with keratoconus. METHOD: The medical records of cases of keratoconus that underwent aCXL from June 2014 to May 2017 were reviewed. Cases that developed microbial keratitis after aCXL were included in the study. The clinical, microbiological profile and the treatment outcomes were evaluated. RESULTS: Of 532 eyes that underwent aCXL, 7 cases developed microbial keratitis during the study period. Median age at presentation was 11 years (range 8-17). Association with vernal keratoconjunctivitis was noted in 57.1% of cases (n = 4/7). The median time at the onset of infection was 3 days after aCXL (range 1-4). Microbiological reports revealed mixed infection in 3 cases [coagulase-negative Staphylococcus (CoNS) + Aspergillus fumigatus, Staphylococcus aureus and Mucor spp., Staph. aureus and Acanthamoeba], Staph. aureus in 2 cases, and CoNS and Alternaria spp. in 1 case each. Resistance to fourth-generation fluoroquinolones was noted in 83.3% of cases of bacterial keratitis (n = 5/6). All cases were initially managed with empirical antibiotic treatment that was later tailored based on microbiological reports. One case eventually required therapeutic penetrating keratoplasty for corneal perforation. At 6 months, the corrected distance visual acuity was >6/60 in 3 cases while 4 cases had corrected distance visual acuity <6/60. CONCLUSIONS: Microbial keratitis after aCXL is rare; however, the infection tends to be severe with high preponderance of mixed infection and resistance to fourth-generation fluoroquinolones.

Topical ayurvedic ointment-induced chemical injury presenting as bilateral acute keratitis.

A 40-years-old female patient was referred to the cornea clinic as a probable case of bilateral keratitis. The patient had a history of headache followed by acute onset of redness, pain and discharge from both eyes for 15 days. The patient was diagnosed as bilateral keratitis by the first contact physician and was started on topical antibiotics, cycloplegics and lubricating eye-drops. At presentation, both eyes had visual acuity of perception of light, conjunctival congestion, limbal blanching, diffuse corneal oedema and epithelial defect. A detailed history revealed application of Vicks VapoRub [topical ayurvedic analgesic which contains (per 100 g of product) menthol (2.82 g), camphor (5.25 g) and eucalyptol (1.49 mL) and excipients include thymol (0.1 g), turpentine oil (5.57 mL), nutmeg oil (0.54 mL), cedar wood oil and petrolatum)] on the forehead and eyelids for headache several times over 2-3 days before the onset. The patient further confirmed the accidental application of the ointment in the eyes. A provisional diagnosis of acute chemical injury with Vicks VapoRub was made and treatment with topical antibiotic, cycloplegic, steroid, lubricant and vitamin C was started. On follow-up, both eyes showed gradual resolution of corneal oedema and epithelial defect. Visual acuity improved in the left eye to 6/60 with no change in right eye due to corneal haze.

Peripheral ulcerative keratitis associated with chronic malabsorption syndrome and miliary tuberculosis in a child.

A 16-year-old girl presented with pain, redness, watering, and blurring of vision in her right eye. Slit lamp examination revealed the presence of peripheral ulcerative keratitis (PUK) and nodular scleritis. On clinical examination, the patient had stunted growth, low body mass index, and enlarged axillary nodes. Giardia cysts were present in the stool sample and histopathology of axillary lymph nodes showed caseating necrosis suggestive of tuberculosis (TB). A diagnosis of PUK with chronic malabsorption syndrome secondary to giardiasis and miliary TB was made. Oral metronidazole, anti-tubercular treatment, high protein diet and vitamin supplements were started. Topical steroids were started for peripheral ulcerative lesions following, which the PUK resolved.

Evaluation of moxifloxacin 0.5% in treatment of nonperforated bacterial corneal ulcers: a randomized controlled trial.

PURPOSE: To compare the equivalence of moxifloxacin 0.5% with a combination of fortified cefazolin sodium 5% and tobramycin sulfate 1.3% eye drops in the treatment of moderate bacterial corneal ulcers. DESIGN: Randomized, controlled, equivalence clinical trial. PARTICIPANTS AND CONTROLS: Microbiologically proven cases of bacterial corneal ulcers were enrolled in the study and were allocated randomly to 1 of the 2 treatment groups. INTERVENTION: Group A was given combination therapy (fortified cefazolin sodium 5% and tobramycin sulfate) and group B was given monotherapy (moxifloxacin 0.5%). MAIN OUTCOME MEASURES: The primary outcome variable for the study was percentage of the ulcers healed at 3 months. The secondary outcome variables were best-corrected visual acuity and resolution of infiltrates. RESULTS: Of a total of 224 patients with bacterial keratitis, 114 patients were randomized to group A, whereas 110 patients were randomized to group B. The mean ± standard deviation ulcer size in groups A and B were 4.2 ± 2 and 4.41 ± 1.5 mm, respectively. The prevalence of coagulase-negative Staphylococcus (40.9% in group A and 48.2% in group B) was similar in both the study groups. A complete resolution of keratitis and healing of ulcers occurred in 90 patients (81.8%) in group A and 88 patients (81.4%) in group B at 3 months. The observed percentage of healing at 3 months was less than the equivalence margin of 20%. Worsening of ulcer was seen in 18.2% cases in group A and in 18.5% cases in group B. Mean time to epithelialization was similar, and there was no significant difference in the 2 groups (P = 0.065). No serious events attributable to therapy were reported. CONCLUSIONS: Corneal healing using 0.5% moxifloxacin monotherapy is equivalent to that of combination therapy using fortified cefazolin and tobramycin in the treatment of moderate bacterial corneal ulcers. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Bilateral microbial keratitis in highly active antiretroviral therapy-induced Stevens-Johnson syndrome and toxic epidermal necrolysis: a case series.

PURPOSE: To report three cases of bilateral microbial keratitis in eyes with Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) induced by highly active antiretroviral therapy (HAART) in patients of acquired immune deficiency syndrome (AIDS). METHODS: A case series. RESULTS: A detailed clinical examination and systemic review of all the three patients on HAART was performed. While one manifested with the more severe variant of TEN, two of these patients presented with SJS with ocular involvement. Despite withdrawal of nevirapine, the ocular surface disorder persisted. The entailing chronic epitheliopathy along with the compromised immune status led to the development of secondary microbial keratitis in all these cases. CONCLUSIONS: The immune reconstitution occurring as a response to the antiretroviral therapy may potentially increase immunologically mediated diseases like SJS and TEN, which in turn may predispose the eye to develop corneal ulcer.

Randomized clinical study for comparative evaluation of fourth-generation fluoroquinolones with the combination of fortified antibiotics in the treatment of bacterial corneal ulcers.

PURPOSE: Comparative evaluation of efficacy of monotherapy with moxifloxacin (0.5%) or gatifloxacin (0.3%) with combination therapy of cefazolin (5%) and tobramycin (1.3%) in treatment of bacterial corneal ulcers. METHODS: Patients diagnosed with bacterial keratitis (ulcer diameter 2-8 mm) were randomized to 1 of the 3 treatment groups (tobramycin 1.3% and cefazolin 5%, gatifloxacin 0.3%, or moxifloxacin 0.5%). After obtaining corneal scrapings, assigned study medication was instilled hourly for 48 hours and tapered as per clinical response. Healing of ulcer, duration to cure, adverse reactions, antibiogram profile, treatment failures, final visual acuity, and corneal opacity size were evaluated. RESULTS: A total of 61 patients were enrolled [cefazolin and tobramycin (n = 20), gatifloxacin (n = 21), and moxifloxacin (n = 20)]. Overall, 57 patients (93%) healed on treatment. On comparison of the mean time taken to heal, no statistically significant difference was found among all the 3 treatment groups (P = 0.98). Positive bacterial culture was obtained in only 38 patients (62%). There was no significant difference in the bacterial isolates in each treatment group. There were 4 (7%) treatment failures (perforation or nonhealing ulcer): 1 (5%) each in moxifloxacin and gatifloxacin group and 2 (10%) in fortified antibiotics group. All regimens were well tolerated. CONCLUSION: The study failed to find a difference in the efficacy of monotherapy with fourth-generation fluoroquinolones in the treatment of bacterial corneal ulcers of 2-8 mm size when compared with combination therapy of fortified antibiotics.

In vitro susceptibility of bacterial keratitis isolates to fourth-generation fluoroquinolones.

PURPOSE: To study the microbiological profile of bacterial keratitis in Northern India and to determine the antibiotic sensitivity pattern of bacterial keratitis isolates to fourth-generation fluoroquinolones. METHODS: Laboratory records of all consecutive cases of clinically suspected bacterial corneal ulcers were retrospectively reviewed. Data noted included microorganism isolated and antibiotic culture sensitivity to cefazolin, tobramycin, gatifloxacin, and moxifloxacin. In vitro susceptibility toward individual antibiotics was determined and compared with the potential in vitro susceptibilities to cefazolin-tobramycin, cefazolin-gatifloxacin, and cefazolin-moxifloxacin combinations. RESULTS: A total of 292 bacterial isolates were identified. Of these, 255 (87.3%) were Gram-positive and 37 (12.7%) were Gram-negative. Staphylococcus epidermidis (n=227, 77.7%) was the most common organism. Overall susceptibility of isolates was 95.52% to gatifloxacin, 92.83% to moxifloxacin, 90.07% to tobramycin, and 83.56% to cefazolin (p<0.000). Organisms which showed resistance to fourth-generation fluoroquinolones included Staphylococcus epidermidis, Pseudomonas aeruginosa, viridans streptococci, Streptococcus pneumoniae, Staphylococcus aureus, and Escherichia coli. Susceptibilities to gatifloxacin and moxifloxacin were comparable with each other (p=0.312) and with potential susceptibilities to cefazolin-tobramycin (p=0.479), gatifloxacin-cefazolin (p=0.134), and moxifloxacin-cefazolin (p=0.412) combinations. CONCLUSIONS: Monotherapy with moxifloxacin or gatifloxacin can be an effective alternative to cefazolin-tobramycin combination as a first-line empirical therapy for bacterial keratitis. The addition of cefazolin to a fourth-generation fluoroquinolone is of limited value.