Study: Scleral lenses, corneal thickness, and intraocular pressure

Does intraocular pressure rise from wearing scleral lenses?

This has been an ongoing question playing out over the past few years in the medical literature. Can scleral lens use raise IOP, and if so, how? Under what circumstances is it most likely to? with

Below is the latest study on the subject, which found NO significant relationship between scleral lens wear and intraocular pressure, but did find that people with ocular surface disease (a/k/a dry eye disease) have increased central corneal thickness.

Effect of Scleral Lens Wear on Central Corneal Thickness and Intraocular Pressure in Patients With Ocular Surface Disease. Shahnazi KC, Isozaki VL, Chiu GB. Eye Contact Lens. 2019 Oct 24.

OBJECTIVES:

To determine the effect of scleral lens wear on central corneal thickness (CCT) and intraocular pressure (IOP).

METHODS:

Twenty-five subjects (46 eyes), fit with scleral lenses that ranged in diameter from 17.0 to 18.0 mm, were included in this retrospective study at the University of Southern California, Department of Ophthalmology. All subjects had ocular surface disease and were categorized into the following groups based on etiology of their dry eye: chronic graft versus host disease, Stevens-Johnson syndrome, Sjögren syndrome, or general dry eye syndrome. Measurements of CCT and IOP were obtained at the initial scleral lens consultation (pre-CCT and pre-IOP) and at follow-up visits (post-CCT and post-IOP) immediately after lens removal.

RESULTS:

The total average difference between pre-CCT and post-CCT was 7.19 μm (544.90±31.29 vs. 552.09±30.30 μm), which was a statistically significant increase of 1.01% (P≤0.05). On the other hand, the total average difference between pre-IOP and post-IOP was -0.89 mm Hg (14.47±3.63 vs. 13.58±3.61 mm Hg), which was not statistically significant (P≥0.05). There were no statistically significant correlations between change in CCT (ΔCCT) and visual acuity (P≥0.05), between ΔCCT or change in IOP (ΔIOP) in relation to lens diameter (P≥0.05), between etiology of dry eye affecting ΔCCT or ΔIOP (P≥0.05), between wearing time today and ΔCCT or ΔIOP (P≥0.05), and between average wearing time (AWT) and ΔCCT (P≥0.05). In addition, there was no statistically significant correlation between AWT and ΔIOP (R=0.0796) over a range of wear time hours.

CONCLUSION:

There was a statistically significant increase in CCT after scleral lens wear in subjects with ocular surface disease, which may be attributed to subclinical hypoxic conditions created by scleral lens wear. No significant relationship was found between scleral lens wear and IOP.