The International Workshop on Meibomian Gland Dysfunction: Report of the Clinical Trials Subcommittee

Abstract

T he objective of this subcommittee was to summarize the evidence in clinical trials on meibomian gland dysfunction (MGD) and to use this information to make recommendations for best-practice clinical trial design for this condition.We conducted a PubMed and Medline literature review (through the end of 2009) to identify treatment or observational trials. Our search terms were those commonly used interchangeably with MGD, including (in addition to MGD) posterior blepharitis, meibomian gland disease, and tarsal gland disease. The level of evidence for each study was classified (Table 1) according to American Academy of Ophthalmology (AAO) Classification Scheme. In short, level I evidence includes evidence obtained from at least one properly conducted, well-designed randomized controlled trial. It could include meta-analyses of randomized controlled trials. Level II includes evidence obtained from welldesigned controlled trials without randomization, well-designed cohort or case-control analytic studies, preferably from more than one clinical center or from multiple-time series with or without the intervention. Level III includes evidence obtained from descriptive studies, case reports, or reports of expert committees/organizations (e.g., panel consensus with external peer review). Additional information on levels of evidence is found in Table 1 of The Report on Management and Therapy. In some cases, the trial designs were not sufficiently described to have more than a tentative grading. Further, recent publications (August 2009 and later) were purposely excluded from Table 1.Articles were reviewed according to the key components that are necessary for protocol design in determining safety and efficacy of a new treatment: objectives, trial design and methodology, patient group, inclusion criteria, exclusion criteria, outcome measures, treatment, and statistical considerations. We also evaluated clinical trials that had been registered at ClinicalTrials.gov if they included a summary of key trial design features. Further, a summary of key design features of the registered trials plus recommendations for future trials are suggested.The review and summary were also based on the committee's personal expertise, including experience in clinical trials in ocular disease and in MGD. The initial search was performed in March 2009 and updated in July 2009. Twenty-six eligible papers 1-26 were identified and reviewed.During the review, committee members found that the study investigators in the published papers often had not been explicit in describing their methods. As a result, the members, who conducted their reviews independently of one another, often interpreted the available data differently. The various interpretations are included in this summary.Few publications qualify as well-designed randomized controlled trials. Aside from the three studies graded level I, there are additional trials that were randomized and controlled. Some were open-label with very small sample sizes and seemed to be lacking information on the ...

Assessment of meibomian glands and tear film in post‐refractive surgery patients

“…The prevalence of MGD appears to be much higher in Asian populations; it is has been reported to be greater than 60% in many Asian population‐based studies, compared with a lower prevalence in Caucasians (3.5% to 19.9%) . There are several potential reasons why Asian populations have a greater predisposition to MGD, as follows: different lid morphological characteristics, lipid profile of meibum, environmental factors such as geographic factors (temperature, humidity and air quality) and increased near vision activities . Recently, 18.95% of normal Chinese myopic teenagers performing strenuous near vision tasks have been diagnosed with DED, in which MGD played an important role …”

“…12 There are several potential reasons why Asian populations have a greater predisposition to MGD, as follows: different lid morphological characteristics, 32 lipid profile of meibum, 33 environmental factors such as geographic factors (temperature, humidity and air quality) and increased near vision activities. 34 Recently, 18.95% of normal Chinese myopic teenagers performing strenuous near vision tasks have been diagnosed with DED, in which MGD played an important role. 35 Corneal refractive surgery has been shown to affect the ocular surface by reducing corneal sensation, 36 tear secretion, tear quality, corneal and conjunctival epithelial integrity and conjunctival goblet cell density.…”

Total cholesterol and lipoprotein composition are associated with dry eye disease in Korean women

“…However, the International Workshop on Meibomian Gland Dysfunction has reported a striking feature that the prevalence of MGD appeared to be higher in studies on Asian populations [23]: 46.2% in a Bangkok study [24], 60.8% in the Shipai Eye Study [25], 61.9% in a Japanese study [26], and 69.3% in the Beijing Eye study [27]. Although the nationwide prevalence of MGD has not yet been reported in Korea, we assume that more than half of the patients who report having clinically diagnosed DED also have MGD, considering the previous epidemiologic studies in Asia.…”

A novel noninvasive ocular surface analyzer for the assessment of dry eye with Meibomian gland dysfunction

“…The MGD group was comprised of subjects with clinical symptoms and/or signs of dry eye, clinical signs of MGD, terminal duct obstructions, clogging of the MG, turbid secretions or turbid secretions with clumps, inflammation and swelling of the eyelid margin, posterior lid margin hyperemia or symptoms of MGD for at least 3 months (15). The control group did not have any clinical signs and/or symptoms of MGD, posterior blepharitis, dry eye, or significant ocular surface disease, and were not using eye drops or eye medications.…”