Thermoelectric warming therapy beneficial in MGD-related dry eye disease

A device that applies consistent emissive heat to the meibomian glandular apparatus appears to produce significant improvements in the signs and symptoms of dry eye disease (DED) in patients with meibomian gland dysfunction (MGD), with the benefits sustained over 6 months following treatment initiation, as shown in a study.

Named the MiBoFlo Thermoflo treatment system, the device consists of a handheld probe that delivers thermoelectric heat at a constant temperature of 108 degrees Fahrenheit or 42.2 degrees Celsius for the duration of the treatment. The heat, coupled with a gentle ocular massage, facilitates softening and clearance of thickened secretions clogging the meibum.

At the end of the procedure, meibomian glands are manually expressed under direct slit-lamp visualization using forceps, allowing flow of meibum lipids that help coat the aqueous tear film, thereby enhancing tear film stability and corneal surface wettability, according to the investigators. [Clin Ophthalmol 2009;3:405-412; Ocul Surf 2017;15:179-192]

The MiBoFlo thermoelectric probe is said to be carefully regulated to consistently deliver the preset temperature. In case the temperature rises, the device will automatically shut off.

The device was tested in 203 eyes of 102 patients with DED (mean age 65.8 years, 79.3 percent female). Of the eyes, 46.8 percent had an aqueous component (Schirmer’s I <10 mm) associated with MGD, 65 percent were partial blinkers, 72.41 percent had blepharitis, and 42.35 percent had nocturnal lagophthalmos.

All patients received three 10-minute per eye thermoelectric warming therapy with MiBoFlo, performed at a 2-week interval. Ultrasound gel was applied to the tip of the probe to permit heat through the lid to the meibomian glands. During the treatment, the probe was used to gently massage the lids with an alternating circular and back-and-forth motion.

Increased liquid secretion

At month 6 after the intervention, DED symptoms decreased by 35 percent from baseline, with total Standard Patient Evaluation of Eye Dryness (SPEED) score dropping from 16.09 to 10.36 (p<0.0001) and the Ocular Surface Disease Index (OSDI) score decreasing from 46.64 to 30.30 (p<0.0001). [Am J Ophthalmol 2022;doi:10.1016/j.ajo.2022.06.013]

MiBoFlo also produced significant improvements in lissamine green conjunctival staining (from 5.32 to 1.20; p=0.0001), corneal fluorescein staining (from 1.37 to 0.28; p=0.0001), tear film breakup time (from 3.13 to 6.37 seconds; p=0.0001), and osmolarity (from 304.58 to 300.16; p=0.006). These improvements were observed across subgroups defined by age, gender, or race.

Finally, the total number of functional meibomian glands yielding any liquid secretion improved from 11.05 at baseline to 19.1 at 6 months (p<0.0001). The quality of the meibum obtained after MiBoFlo treatment was clear in 64 percent of the glands expressed as opposed to only 11.7 percent at baseline (p<0.00001).

None of the patients experienced ocular or systemic adverse events, change in visual acuity, or intraocular pressure elevation during any of the MiBoFlo treatments.

“In general, our patient population had failed conventional topical therapy with lubricants and in many cases topical immunomodulatory therapy (cyclosporine, lifitegrast) prior to the MiBoFlo treatment… MiBoFlo was the primary intervention so the use of other concurrent medications such as lubricants, anti-inflammatory drugs, topical immunomodulatory medications, or punctum plugs was neither instituted nor changed from the preprocedure patient treatment regimen,” the investigators said.

“Improvement of symptoms was negatively correlated with certain comorbidities, particularly autoimmune disease and pretreatment blepharitis, but was not affected by a history of age-related macular disease, glaucoma, or other patient or ocular factors. Thus, the device seems to be effective in a broad spectrum of patients with DED,” they added.

MiBoFlo vs available treatments

Currently approved topical therapies, such as lifitegrast and cyclosporine eye drops, address the inflammatory component of DED but not the blockage of the meibomian glands in eyes with MGD. This is somewhat of a disadvantage, according to the investigators, as MGD is present in most of the cases of DED with an estimated prevalence of 3.5–70.0 percent in the adult population and 42 percent in the paediatric population. [Ocul Surf 2017;15:179-192; Cornea 2012;31:472-478; Invest Ophthalmol Vis Sci 2011;52:1994-2005; Cornea 2018;37:426-430]

Meanwhile, most instruments used for treating MGD (ie, LipiFlow, iLUX MGD, IPL, and TearCare) function to liquify meibum and permit expression of lipids. A downside is that these devices are expensive or require expensive activators, which add cost to the treatment, the investigators said.

The MiBoFlo system, in comparison, is an “inexpensive and customizable treatment [that] is highly effective on multiple symptomatic and ocular surface objective outcomes. Customization is a potential advantage of MiBoFlo as it permits the operator to provide the proper duration of contact of the heated probe, pressure, and massage for meibum expression,” they pointed out.

“Some might consider the requirement of a skilled doctor to perform the [MiBoFlo] procedure a negative. We cannot comment upon treatment outcomes if a technician or other ancillary person does the treatment,” the investigators acknowledged.