Minimum Image Gain in the follow up of endophthalmitis

Abstract

Purpose : To determine Minimum Image Gain (MIG) in patients with endophthalmitis, and to compare the changes in MIG throughout time in patients treated with intravitreal antibiotic injections.

Methods : Retrospective, observational and comparative study. Patients with diagnosis of endophthalmitis treated from March 2018 to October 2018 were included. Patients had baseline and follow-up ultrasound examinations where a 10 mega Hz B-scan probe was used to obtain a longitudinal image at the 9 o'clock position for right eye, and 3 o'clock position for left eye.To obtain MIG: The longitudinal image is observed without any additional zoom, and with the highest amount of gain (db). The scan’s gain is then lowered in order to obtain a completely echo-silent vitreous cavity. This point is termed MIG, and the dBs are registered.
Comparison of baseline versus final MIG was performed using a paired samples t-test.

Results : 8 eyes were analysed, baseline MIG mean is 73.62dB (Range 54dB - 84 dB), final MIG mean is 80.37 dB (Range 69 dB - 94 dB), having a diference between baseline and final MIG of 6.75 dB. Stadistic t = -2.3513, P (one tailed) = 0.025, critic value for t (one tailed) = 1.89, P (two tailed) = 0.05, critic value for t (two tailed) = 2.36

Conclusions : MIG can be obtained in patients with endophtalmitis to determine in an objective way the density of the inflammation. MIG can also be used to compare the response in patients with endophtalmitis that were treated with intravitreal antibiotic injections

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.