Prosthetic Replacement of the Ocular Surface Ecosystem Improves Acuity

A prosthetic ocular surface scleral lens treatment significantly improves vision for patients with distorted corneal surfaces and ocular surface disease (OSDs), according to research published in Eye & Contact Lens.

The investigators sought to inform doctors about the impact of the Prosthetic Replacement of the Ocular Surface Ecosystem (PROSETM, BostonSight) treatment and to support the continuation of related programs to improve access for patients with complex corneal conditions that have not responded to other treatments.

They retrospectively reviewed charts of 78 patients (39 women, 126 eyes) who presented to the Kensington Eye Institute PROSE clinic from March 2018 to March 2020 for new fittings. Patients were divided into subgroups of distorted corneal surface or OSD diagnoses.

The most common conditions in the distorted cornea group were keratoconus (n=39), post corneal graft (n=15), and corneal scar (n=11). In the OSD group, they were limbal stem cell deficiency (LSCD)(n=17), ocular graft versus host disease (GVHD) (n=15), and Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) (n=14). Fourteen eyes had glaucoma and 7 had corneal grafts older than 10 years.

The most frequent presenting symptoms included blurry vision, photophobia, and pain. The distorted cornea group more frequently reported glare/rainbow around lights while the OSD group reported more pain, injection, and grittiness symptoms. Conventional scleral contact lenses, glasses, and corneal gas permeable lenses were the most common previously attempted modalities.

The mean best-corrected visual acuity (BCVA) pre-PROSE was 0.58±0.54 logMAR. It was significantly worse in the distorted cornea group (0.68±0.47 logMAR) compared with the OSD group (0.48±0.58 logMAR, P =.04). Both groups experienced significant improvement in mean BCVA after fitting with the devices. The distorted cornea group improved to 0.14±0.18 logMAR, P <.0001). The OSD group improved to 0.19±0.29 logMAR, (P <.0001).

Post-PROSE, 108 eyes achieved 20/50 BCVA or better and 91 eyes achieved a BCVA of at least 20/30. Pre-PROSE, only 64 eyes had achieved 20/50 BCVA or better (P <.0001). 

Final customized lenses had a mean diameter of 18.2±0.60 mm, meridians of toricity of 4 in 75.4% of lenses and 8 in 24.6%, and eccentricity measurements of 0.6 in 97.6% of lenses, and 0.8 in 2.4%. The devices were also able to use channels to improve fluid ventilation and oxygen exchange if haptics fit too tightly over the conjunctiva, and Hydra-PEG coating was used in 8.7% of lenses to improve surface wettability.

Ten eyes of 6 patients were lost to follow-up, and 3 eyes of 2 patients failed PROSE treatment. The average time to failure was 7.29±4.70 weeks. Reasons for failure were disease progression requiring surgery, lens discomfort, and difficulty with insertion and removal.

Limitations of the study include its retrospective nature, lack of data regarding quality of life, lack of data regarding previous fitting attempts for scleral lenses, and limited follow-up time.

Disclosure: Several study authors declared affiliations with the biotech or pharmaceutical industries. Please see the original reference for a full list of authors’ disclosures.

Reference

Wong BM, Garg A, Trinh T, et al. Diagnoses and outcomes of prosthetic replacement of the ocular surface ecosystem treatment — a Canadian experience. Eye & Contact Lens. Published online March 16, 2021. doi:10.1097/ICL.0000000000000779