Findings from the Collaborative Initial Glaucoma Treatment Study, published in Ocular Surgery News, show that the estimated loss of visual field was significantly lower in patients who reported zero missed medication doses than in patients who reported missing doses.*

What they did

Of the 607 study participants, 307 were randomly assigned to the medication group. These participants self-reported their medication adherence, which was analyzed alongside their visual field loss measurements, which were measured in decibels (dB), a unit of power quantity used for light intensity. Both forms of data were noted at six-month intervals for up to 10 years. 

According to available follow-up for 306 of the 307 participants:

• 142 reported never missing a dose of medication, 
• 112 reported a missed dose at up to ⅓ of follow-up visits, 
• 31 reported a missed dose at between ⅓ and ⅔ of follow-up visits, and 
• 21 reported a missed dose at more than ⅔ of follow-up visits.

What they found

Over a period of eight years, the findings showed a significant difference between the relatively minor visual field loss of people who didn’t miss any doses and those who did, and the greater the number of missed doses, the greater the loss of visual field. 

• Those who missed 0 doses had a visual field loss of 0.62 dB.
• Those who reported having missed a dose at ⅓ of their follow-up visits had a visual field loss of 1.42 dB.
• Those who reported having missed a dose at ⅓ to ⅔ of their follow-up visits had a visual field loss of 1.82 dB.
• Those who reported having missed a dose at more than ⅔ of their follow-up visits had a visual field loss of 2.23 dB.

Patients who didn’t miss any doses of their glaucoma medication demonstrated similar visual field loss numbers as people whose glaucoma is considered stable. 

What it means

Visual field loss still occurred whether or not doses of glaucoma medication were missed; however, the amount by which visual field loss worsened notably increased with an increase in the number of doses missed.

*Linnehan, R. (2020, May 28). Medication adherence, visual field loss significantly associated. Healio. https://www.healio.com/news/ophthalmology/20200528/medication-adherence-visual-field-loss-significantly-associated

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