The effect of an eyelid-warming device (Blephasteam) on intraocular pressure in patients with meibomian gland dysfunction

Background: This randomized cross-over study focused on the use of an eyelid-warming device (Blephasteam^®) which can monitor heat therapy during a period of time in an enclosed environment as a treatment of Meibomian Gland Dysfunction (MGD). According to the inconclusive association between Intraocular Pressure (IOP) and heat, we aim to find the safety of Blephasteam^® for MGD patients, especially when corresponding with glaucoma.

Purpose: To study the effect of an eyelid-warming device (Blephasteam^®) on intraocular pressure in patients with MGD patients.

Methods: One hundred participants with MGD were randomized between group A( n = 48) and B ( n = 52) using stratified permuted block method. Participants in Group A received Blephasteam^® treatment followed by an observation phase, while Group B underwent the reverse sequence. IOP measurements were taken during both phases in Groups A and B using a rebound tonometer (iCare^®) at four time points: before the procedure, and at 0, 5, and 10 minutes post-procedure. The primary outcome was the mean IOP differences between the Blephasteam^® and observation phases at each time point. Equivalence testing was performed by comparing IOP differences at each time point against a predefined clinical threshold of ±0.5 mmHg.

Results: Mean IOP differences between Blephasteam^® phase and observation phase at 0, 5,10 minutes were 0.62 mmHg (95%CI 0.56-0.69), 0.47 mmHg (95%CI 0.41-0.54), 0.34 mmHg (95%CI 0.28-0.40) respectively. A test for equivalence at each time point showed an interpretation of not equivalent (p value* 0.999) at 0 min, inconclusive (p-value*= 0.233) at 5 mins and equivalent (p-value* = <0.001) at 10 mins. Subgroup analysis in glaucoma group (n = 22) showed a corresponding result with slightly higher mean IOP difference of 0.71mmHg (95%CI 0.58-0.84) at 0 min, 0.53 mmHg (95%CI 0.40-0.66) at 5 mins and 0.40 mmHg (95%CI 0.27-0.54) at10 mins after procedure.

Conclusions: Eyelid-warming device (Blephasteam^®) use resulted in a clinically and statistically significant increase in IOP immediately after use (0 minutes), with a slightly greater effect observed in glaucoma patients. IOP returned to within the clinical threshold by 10 minutes post-procedure.

Keywords: Meibomian Gland Dysfunction, Blephasteam, Eyelid-Warming Device, Intraocular Pressure.

p-value* = p-value of test for equivalence

Dr. Patima is currently an Ophthalmology resident at Maharaj Nakorn Chiangmai hospital, Faculty of Medicine, Chiang Mai University, Thailand. She graduated as MD from Chulalongkorn University, Bangkok, Thailand in 2022. She has been the membership of Asia Pacific Glaucoma Society – APGS since 2022.