Cornea - I Free Papers - aioseducation

Cornea Free Papers
slit-lamp examination. Corneal scrapings were obtained from all patients as a
part of a standard protocol and subjected to direct microscopic examination
(Gram and/or Giemsa, potassium hydroxide [10.0%] with calcoflour white)
and inoculation into various culture media such as sheep blood agar (BA),
chocolate agar (CA), Sabouraud dextrose agar (SDA), non-nutrient agar (NNA),
and brain heart infusion (BHI) broth. SDA bottles were incubated at 26±1OC
to enhance the growth of fungi, and the remaining plates were incubated at
36±1OC. While CA plates were incubated with 5% carbon dioxide, BA and BHI
broth were incubated aerobically, and NNA were incubated aerobically with
an added live Escherichia coli suspension. All media were incubated for two
weeks and were examined daily. A culture was considered significant and
was reported if the smears demonstrated morphologically similar organisms
and/or if the same organism grew in more than one medium and/or if there
was growth on at least two streaks on blood agar. In vitro susceptibility of the
isolates was tested by Kirby Bauer disc diffusion method and interpreted as
per CLSI guidelines. Muller Hinton agar with blood and commercial antibiotic
discs (cefazolin, chloramphenicol, vancomycin, ciprofloxacin, ofloxacin,
moxofloxacin, gatifloxacin) from Himedia, Mumbai were used for the test.
Zones of inhibition were noted in millimeter and interpreted as resistant,
sensitive or intermediate as per the chart provided by the company.
Intensive topical medication was started on the basis of the smear result. Topical
medication was modified in some cases depending on the clinical response,
culture report, and sensitivity of the isolated organism. The retrospective
data included patient demography (age, gender, and occupation), disease
history (onset, course, predisposing factors), clinical appearance, antibiotic
susceptibility, treatment and outcome.
RESULTS
Among 990 corneal scrapings/corneal tissues from clinically diagnosed cases
of microbial keratitis at our Institute between November 2006 and December
2009, 61 (6.2%) corneal scrapings of sixty patients were culture positive for S
pneumoniae. The mean age was 45.9±21.3 years (range: 6 months to 78 years,
median: 50). The male to female ratio was 40:20. Most patients were in the age
group 41-70 years (n=36, 60%).
An ocular predisposing condition was identified in 51 eyes. Fourteen had
undergone keratoplasty and 9 had chronic dacryocystitis. Twenty five eyes
(40.9%) had a history of ocular trauma. Fourteen eyes had polymicrobial
infection. Thirty one eyes required an adjunctive procedure. Five eyes
underwent therapeutic keratoplasty, and 20 eyes underwent tissue adhesive
and bandage contact lens application. The in vitro susceptibility of the isolates
by disc diffusion method was 100% to cefazolin, 95.1% to chloramphenicol,
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