Purpose:
To compare the eyelid and conjunctival flora of glaucoma patients with normal subjects.
Material and Method:
One hundred and thirty-two eyes of 83 patients were assigned to 4 groups, consisting of 33 eyes each. Group 1 consisted of eyes which underwent trabeculectomy without need for postoperative antiglaucoma drops (AGD), group 2 consisted of eyes which needed to use AGD following the trabeculectomy, group 3 consisted of eyes which did not undergo trabeculectomy but used AGD, and group 4, the control group, consisted of healthy eyes. All AGD contained benzalkonium chloride (BAC) as a preservative.
Results:
A statistically significant difference was found between the group using AGD and the control group, regarding the number of coagulase-negative staphylococci isolated from eyelid specimens (p=0.03). Although the isolation rates of Streptococcus spp. and Haemophilus spp. were higher in groups 1, 2 and 3 than in the control group for the conjunctival specimens, the difference was not statistically significant (p=0.87, p=0.29, respectively).
Discussion:
Trabeculectomy together with long-term use of AGD, or long-term use of AGD with BAC itself, seemed to decrease the number of coagulase-negative Staphylococci and to increase the number of Streptococcus spp. and Haemophilus spp. in the eyelid and conjunctival flora of the control group. As Streptococcus spp. predominate in cases of delayed-onset bleb-associated endophthalmitis, by taking eyelid and conjunctiva specimens for culture at certain intervals, their eradication might be achieved and therefore, the potentially devastating endophthalmitis might be prevented.
Keywords: Benzalkonium chloride, endophthalmitis, glaucoma, Streptococcus, trabeculectomy