Rakhshanda Baqai  ( PMRC Research Center, Karachi. )
Amtul Hafiz  ( Dept. of Microbiology, Basic Medical Sciences, Karachi. )
T,H. Kirmani  ( Dept. of Ophthamology, Jinnah Postgraduate Medical Center, Karachi. )

Seventy-five per cent of the patients undergoing cataract operation harboured microorganisms in their conjunctiva, out of which 40 per cent were pathogenic species. Preponderance of Moraxella was encountered. One third of the pathogenic microorganisms were found to be resistant to most of the antibiotics except Gentamycin. Positive conjunctival cultures were also obtained from 70% controls and 50% staff members. Pathogens were isolated in 25% controls and 8% staff members.
Preoperative determination of conjunctival microorganisms and administration of appropriate antibiotics may reduce post operative complications(JPMA 31:10,1981).

The presence of both pathogenic and non pathogenic microorganisms have been observed in conjunctival cultures in patients admitted for cataract operation (Winkler and Cason, 1954).
The present study was conducted to evaluate the importance of preoperative cultures from the conjunctival sac of patients admitted for cataract surgery and their response to antibiotics.

Conjunctival swabs were taken at bedside from 100 patients admitted for cataract operation in the Eye ward of Jinnah Postgraduate Medical Centre. These patients were between 30 to 90 years of age and were admitted to the hospital 48 hours prior to surgery. Twenty healthy adults and 12 staff members of the Eye Ward were also included in the study as controls. None of them were using any antibiotics.
Collection of Material
For culture a sterile cotton swab was rubbed on the lower conjunctiva and inoculated on blood agar plates. Incubation of the plates was done aerobically at 37°C for 24 hours to 48 hours. Organisms grown were identified on the basis of colony morphology, gram staining and biochemical reactions. Antibiotic sensitivity test of all potentially pathogenic organisms isolated in pure culture was performed by disc diffusion method.

Table I shows the result of cultural studies on conjunctival swabs. Pathogenic bacteria were more often present in patients than in the two control groups.
The organisms isolated from conjunctival swabs are shown in table II.

Moraxella was found more frequently than the other organisms in the patients group.
Bacterial flora from the conjunctival swab in the present study was compared with that of Winkler and Cason (1954). The increase in the percentage of cultures of Moraxella and a decrease in the percentage of Staph albus and Dip-theroids was most striking (Table III).

Strept. pyogenes was detected in 3% in this series while this organism was infrequently reported by Winkler and Cason (1954).
Gentamycin was found to be the most effective antibiotic against all pathogenic organisms isolated followed by Cloxacillin, Erythromycin, Ampicillin, Tetracycline and Chloramphenicol. Polymyxin B was only effective against gram negative organisms (Table IV).

Bacteriological study on conjunctival cultures of cataract patients and two control groups revealed simultaneous occurrences of both pathogenic and non pathogenic microorganisms. Observations in patients and healthy subjects were similar to those reported in other studies (Burns, 1959; Smith, 1954). Moraxclla was most frequently encountered here and Staph albus in England (Winkler and Cason, 1954). The difference in the microorganisms isolated from conjunctival sac from different countries may be due to varying climatic and hygienic conditions (Hardy et al., 1967).
Gentamycin was the most effective antibiotic against pathogenic microorganisms isolated from cultures of conjunctival swabs. The efficacy of this antibiotic was also observed by Halasa (1967) in bacterial conjunctivities.
If preoperative cultures are done and sensitivity determined the chances of post operative complications and emergency of drug resistant strains may decrease significantly by giving proper antibiotics prior to surgery.

1. Burns, R.P. (1959) Postoperative infections, in an ophthalmologic hospital with comments upon bacteriophage typing of staphylococci as preventative tool. Am. J. Ophthal., 48:519.
2. Halasa, A.H. (1967) Gentamycin in the treatment of bacterial conjunctivitis. Am. J. Ophthal., 63:1699.
3. Hardy, D., Surman, P.G. and Howarth, W.H. (1967) The cytology of conjunctival smears from aboriginal school children at Yalata, South Australia. Am. J. Ophthal., 63: Suppl: 1538.
4. Smith, C.H. (1954) Bacteriology of the healthy conjunctiva Br. F. Ophthal., 38:719.
5. Winkler, C.H. Jr. and Cason, L. (1954) Bacteriology of the eye. II. Role of gram-negative bacilli in infections following cataract extraction. Arch. Ophthal., 51:200.