Bacteriological Study of The Conjunctival Sac in Aquired Anophthalmic Patients Fitted with Ocular Prosthesis

Abstract

SUMMARY N ormally, conjunctiva is colonized by small number of bacteria that causes no harm called normal commensals or normal conjunctival flora.. This flora is important in maintaining the surface homeostasis and competing the pathogenic bacteria out for their nutrition, thus inhibiting their growth. A balanced relation between the host defense mechanisms and the potential pathogenic organisms mechanisms is what keeps infection away. Several factors can alter the normal conjunctival flora such as age, gender, dry eye, contact lens wearing, immunosuppression, previous eye surgeries and anophthalmic state. After enucleation or evisceration, an ocular prosthesis should be considered to preserve the conjunctival socket from contraction, improving cosmeses and hence, preventing the bad psychological impact of loosing an eye. There are two types of prostheses, ocular made of glass, acrylic or silicone and orbital that is always made of silicone. Ideal socket with deep fornices should be fitted with ideal prosthetic device that achieves an acceptable look and acceptable range of movment. Care and hygiene of the prosthetic device is a crucial element in reducing infection and the mucoid discharge that seems to be the most common complaint of anophthalmic patients. Twenty (20) patients, (40 eyes), were recruited in this study. Anophthalmic eyes (20) constituted the study group, while the contralateral sound eyes (20) served as the control group. All patients were subjected to conjunctival swab and bacteriological examination. The mean age at time of presentation was 25.2 ± 25.4 years with no gender predilection. Enucleation and evisceration served mostly equally in being the cause of anophthalmia (55% and 45% respectively) with the most common indication of the surgery was intraocular tumors (Retinoblastoma 55%) , followed by ruptured globe (30%), inflammations (10%) and absolute glaucoma (5%). Previous application of local antibiotic eye drops and duration of wearing the ocular prosthesis seemed non contributory factors in positivity of the cultures. Cultures from the sound eyes revealed presence of positive growth of coagulase negative Staphylococci in three eyes (10.0%) out of twenty. MRSA and Pseudomonas species were the most common isolated organisms from the anophthalmic socket in the present study (35.3%), followed by MLS and Klebsiella species (17.6%). α- Hemolytic Streptococcus viridans and non hemolytic Streptococcus each accounted for 11.5% of the positive cultures, Proteous and α-hemolytic Streptococcus pnemoniae each appeared once in the cultures. The commonly prescribed antimicrobials were tested for their susceptibility pattern, 75.0% of bacteria were sensitive to each of Linzolide and Vancomycin, 62.5% to Levofloxavin, 50.0% to each of Ciprofloxacin and Meropenem. Regarding resistance of microorganisms to antibiotics; (42.8%) were resistant to Penicillin, (28.5%) to each of Cefoxitin, Cefotaxime, Gentamycin and Doxycycline, (14.2 %) to each of Ampicillin, Amoxacillin, Oxacillin, Cefotriaxone, Ciprofloxacin, Ofloxacin and Erythromycin.