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