Fixed, firm, focal unyielding resistance was the most common finding when probing patients with obstructive meibomian gland dysfunction, regardless of gland expressibility, according to a study published in Cornea.
“The frequent intraductal fixed unyielding obstructions are consistent with clinical slit-lamp findings and confocal microscopy findings suggestive of periglandular fibrosis,” the authors wrote. “These probe findings offer a compelling hypothesis for the cause of ductal obstruction.”
Author Steven L. Maskin, MD, developed a meibomian gland (MG) probing technique designed especially for probing obstructed MGs that are refractory to traditional treatments.
His method consists of using stainless wire probes inserted through the natural gland orifice, into the intraductal space. Noticing fixed, firm, focal, unyielding resistance (FFFUR) in the duct, known to be associated with periductal fibrosis, increased pressure is applied to advance the probe, thus relieving resistance from the taut fibrosis bands.
In this retrospective study, researchers analyzed data from 11,776 glands of 404 lids probed using this method.
Eighty-four percent of glands showed mechanical resistance to probing, and FFFUR was seen in 79.5% of obstructed glands.
FFFUR occurred regardless of gland expressibility; however, FFFUR in occult MG obstruction was associated with an audible or tactile “firm pop” sensation, according to the study.
“Glands that are expressible have occult fixed resistance,” the authors wrote. “Expressible glands were just as likely to have occult obstruction as nonexpressible glands to have obvious obstruction. This suggests a significant incidence of obstruction proximal (deep) to at least one acinus in the case of lids with intact expressibility.”
Researchers concluded that FFFUR was the most common finding when probing obstructed meibomian glands, expressible or not.
They also noted that the upper lids showed increased resistance, FFFUR and firm gritty sensation, while the lower lids had increased expressibility and no resistance, which may indicate anatomical differences and microtrauma related to blinking.
“This study reveals significant and frequent occult fixed and unyielding blockages within the intraductal space of expressible and nonexpressible MGs in the setting of obstructive MGD,” the authors wrote. “These occult lumen changes bring together subjective and objective findings of this elusive disease that help explain the frustrating clinical experience of treating this disease.” – by Scott Buzby
Disclosure: Maskin holds patents on the use of jojoba anesthetic ointment and instrumentation and methods for intraductal diagnosis and treatment of meibomian gland disease. Alluri received an educational stipend from Ocular Surface Research and Education Foundation.