Relationship Between Sleep Position and Glaucoma Progression

Kevin Kaplowitz; Justin Dredge; Robert Honkanen

Disclosures

Curr Opin Ophthalmol. 2019;30(6):484-490. 

In This Article

Relationship Between Sleep Position and Glaucoma Progression

As discussed above, studies have shown that certain sleep positions lead to higher immediate IOP measurements, which may persist and lead to progressive nerve damage. For instance, one study on NTG found that the correlation between rate of change of mean deviation as a marker of glaucomatous progression and IOP was only significant when analyzing IOPs measured in the supine position, but not in the sitting position.[23] Other studies have found associations between latent asymmetry (similar bilateral IOP while sitting but asymmetric IOP in the laying position) and worsening visual field, with latent asymmetry appearing in 30% of 53 consecutively enrolled open-angle patients.[24] A study observing for unilateral disc hemorrhages in normal tension glaucoma surveyed the patients about the favored sleeping position, but could find no significant relationship between the dependent eye and disc hemorrhages.[25]

Although it has been proposed that the dependent eye in the LDP often has a higher IOP and so might more commonly show glaucomatous progression, the early data is conflicting. One study included only patients with C/D asymmetry of at least 0.1 and who also favored a sleeping position that maintained one eye in the dependent position (sleeping either on one side or prone with face turn to one side) and analyzed them as one group.[26] They found that the dependent eye had more cupping than the nondependent eye in 78% of cases. Kim et al.[27] surveyed 692 glaucoma patients, 62% of whom had asymmetric visual fields. Twice as many patients with asymmetric visual fields favored sleeping with the worse eye dependent than nondependent.[27] One study included NFL measurements and found that the side with a greater positional increase had a mean deviation that was 27% worse and a nerve fiber layer 6% lower compared to the fellow eye.[28] Meanwhile, at least three studies failed to show that the dependent eye has earlier or more severe glaucomatous progression. One study showed a small increase (0.5 mmHg) in the mean IOP for the dependent eye versus nondependent eye, but only 39% of patients had more progression in the eye which was dependent in the favored sleeping position.[29] Another study found a 0.8 mmHg higher positional increase from supine to LDP in the eyes with worse mean deviation, although that finding failed to reach statistical significance.[12] A similar study also failed to find any significant difference in positional increases in the eye with the better versus worse visual field.[9]

The main drawback to analyzing the relationship between inter-eye asymmetrical positional increases and visual field progression may be the poor understanding of the cause. For instance, one study sought to compare positional increase in only healthy cases.[15] The investigators report initially screening 34 healthy study participants but only included data on 19. The most common reason for exclusion (60%) was inter-eye asymmetry of the positional increase in these healthy cases with no suspicion for glaucoma. Much more study is needed on the frequency and degree of positional increase in both healthy and glaucomatous eyes before an association with glaucoma progression can be solidified. If more studies find a significant relationship between greater positional increases and greater nerve loss in certain cases, testing the positional change in clinic could help identify patients more likely to progress or who might benefit more from maintaining certain sleep positions.

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