Association Between Demodex Blepharitis And Anti-Inflammatory Agent Use After Cataract Surgery. A Retrospective Case Control Study.

We had conducted a retrospective case control study using data collected from Chang-Gung Memorial hospital, Linkou branch from 2018 to 2022.

 Patient with demodex blepharitis diagnosed under direct light microscope (40x~100x)  either before or within three months after receiving cataract surgery were included. Electronic medical records were reviewed; medication history, demographic data, ocular examination result was viewed and recorded. A total of 78 patient (104 eye) were included and 48 of them (72 eye) with significant symptom, including foreign body sensation, itchy or even pain, had receive anti-demodectic treatment before cataract surgery (either lid scrub or OUST ^TM) , and 30 of them (32 eye) recieve anti-demodectic treatment after the operation.

A total of 78 patient (104 eye) was reviewed. Demographic data are shown in Table 1. All patient had blepharitis before cataract surgery, and was proven to have demodex infestation either before the cataract surgery, or within 3 month after the operation. There are no significant different of the interval of shifting from high potency steroid  to low potency steroid between patient using anti-demodectic treatment and those whose don’t ( p=0.667) . However, in subgroup analysis of the anti-demodectic treatment group, the interval of using anti-demodectic treatment before cataract surgery is negatively correlated with the interval of shifting from high to low potency steroid (rho=-0.486, p=0.039) (Table 3, figure 2)

Demodex blepharitis is a disease easily overlooked and under treatment especially in patient without significant symptoms. Our study demonstrated that patient with symptomatic demodex blepharitis without adequate management might result in prolong inflammation after cataract surgery, demonstrated by the significant negative correlation between the interval of using anti-demodectic treatment and the interval shifting from high to low potency steroid. These result indicated that proper treatment in symptomatic patient with demodex blepharitis before surgery can potentially lower excessive inflammatory response after the operation. However, a prospective randomized controlled trial should be initiated to further consolidate our result.