CULTURE POSITIVITY RATES OF DEEP VITREOUS BIOPSY UNDER AIR VIS-À-VIS CONVENTIONAL ANTERIOR VITREOUS BIOPSY IN ENDOGENOUS ENDOPHTHALMITIS.

Purpose: To describe the comparison of the culture positivity rates of deep vitreous biopsy under air and conventional anterior vitreous biopsy in endogenous endophthalmitis.

Materials: A retrospective, consecutive, comparative series including cases of endogenous endophthalmitis from January 2014 to January 2021. They were divided into those where conventional anterior vitreous biopsy was taken and those where a deep biopsy was taken under air (DBA group). The culture positivity rate among the two groups was compared, and factors affecting the same were analyzed by a regression analysis.

Results: There were 140 eyes in the conventional anterior vitreous biopsy group and 44 eyes in the DBA group. Sex, age, duration of symptoms, underlying systemic illness, presenting vision in logMAR, and total number of vitreous interventions were comparable between the two groups. Visual outcome was better in patients undergoing DBA as compared with those who underwent conventional anterior vitreous biopsy , (1.28 ± 1.01 logMAR, 20/380 vs. 1.88 ± 1.33 logMAR, 20/1,500, P = 0.03). No case in the DBA group developed retinal detachment or any complication attributable to the technique. In the conventional anterior vitreous biopsy group, the culture positivity was seen in 43/140 samples (30.71%), and in the DBA group, it was noted in 29/44 samples (65.9%). Taking a DBA was the only factor that was significant both in bivariate (odds ratio 4.36, 95% confidence interval 2.12-8.95, P < 0.0001) and multivariate analysis (odds ratio 4.02, 95% confidence interval 3.1-7.43, P < 0.0001).

Conclusion: Vitreous sampling can be performed from the deep vitreous cavity in endogenous endophthalmitis safely and effectively under air infusion, improving the culture positivity rates.