Microbial Profile of Anterior Chamber Aspirates in Cataract Surgery using Different Techniques
SV Singh, Ved Pal, Ashok Garg, CS Dhull

Cataract surgery like other surgical procedures is not devoid of complications.  Despite modern microsurgical and sterilization techniques endophthalmitis is still a devastating complication of cataract surgery.  Though its incidence has declined from 10%1 to 0.05%.2 The reaction of body to infection depends upon the virulence of organism, immunity of patient and resistance of particular tissue to organism.

Bacterial endophthalmitis is caused by staph. epidermidis, staph. aureus, pseudomonas and anaerobes.  Intraoperative sources of infection can be from conjunctival sac,3 intraocular lenses4, irrigating solutions,5 instruments and the surgeon.6 We have conducted this study to know and compare AC contamination keeping in mind the duration of surgery, type of wound and surgical technique used.

MATERIAL AND METHODS
Present study was conducted on 180 patients of senile cataract undergoing surgery. Patients having previous surgery, trauma in past, clinical evidence of local or systemic infection, malignancy, treatment with immunosuppressive and intra-operative complication were not included in this study.  Patients were randomly divided into 3 equal groups.

Group I patients underwent extra capsular cataract extraction (ECCE). Group II and Group III patients underwent ECCE with PCIOL and manual small incision cataract surgery (MSICS) with PCIOL respectively. 0.2ml of anterior chamber (AC) aspirate was taken just after completion of surgery and was sent for Gram's staining and for bacterial and fungus culture.

OBSERVATIONS
Mean age of the patients included in this study was 62.14 + 7.14 years.  There were 88 males and 92 females.  There was no statistically significant difference in the demographic profile of patients in the 3 groups.  The average duration of surgery was 17.72 minutes with a range of 8-35 minutes.  There was no statistically significant difference in the duration of surgery in all the three groups.

Gram's staining was positive in 30(16.66%) eyes.  In group 1, 10 (16.66%) patients had positive staining.  In Group II 14 (23.32%) patients were positive for gram's stain.  Group III patients showed 6(10%) Gram's smears to be positive. There was no statistically significant difference in the Gram's smear positivity rate according to age, sex and duration of surgery.

On culture, bacterial growth was seen in 22 (12.22%) eyes. Group I patients had positive culture in 8 (13.33%), group II in 10 (16.66%) and group III in 4 (6.66%) eyes only. Growth proved to be Staph. epidermidis in 14 (63.63%), Staph. aureus in 4 (18.19%), Diphtheroid in 2 (9.09%) and proteus mirabilis in (9.09%) eyes. None of the culture for fungus showed growth.

DISCUSSION
With advanced surgical technique such as Manual small incision cataract surgery with scleral tunnel incision (MSICS) and phacoemulsification employing modern asepsis, many of the complications especially endophthalmitis have been drastically reduced in incidence. But once it occurs it is devastating.  As per literature there is varying incidence of contamination of AC contents following different surgical techniques.  Duration of surgery, intra-operative complication and type of surgical wound also influence intra-operative contamination.1

In this study, we have found that Gram's smear positivity rates and growths on culture are less with MSICS using scleral tunnel incision. Thus length and type of entry would have significant role. So AC contamination is less with MSICS with PCIOL using scleral tunnel incision which is due to subsequent entry of contaminants in anterior chamber.

REFERENCES

  1. Jaffe NS, Jaffe MS, Jaffe GF. Cataract surgery and its complication. 6th ed. St. Louis: Mosby Year Book; 1997.

  2. Allen HF, Mangiaracine AB. Bacterial endophthalmitis after cataract extraction. ARch ophthalmol 1974;91:3-7.

  3. Miller SJH. Parson's diseases of the eye.  18th ed. Edinburg: Churchill Livingstone, 1990.

  4. Vafadis GC, Marsh RJ Stacey AR.  Bacterial contamination of intraocular lens surgery. Br J Ophthalmol 1984;68:520-3.

  5. Dickey JB, Thompson KD, Jay WH. Intra-ocular gentamicin and post cataract anterior chamber aspirate cultures. J Cat Ref Surg 1994;20:373-7.

  6. Allen HF, Mangiaracine AB. Bacterial endophthalmitis after cataract extraction. Arch ophthalmol 1964; 72:454-62.

Address for Correspondence
Dr. SV Singh, Deptt. of Ophthalmology,
Pt. BD Sharma, PGIMS, Rohtak