The temporal dynamics of miniscleral contact lenses: Central corneal clearance and centration

Abstract

For the miniscleral contact lens studied, horizontal and vertical lens decentration followed an exponential decay over 8h that plateaued approximately 2h after lens insertion, while central post-lens tear layer thinning plateaued after 4h of lens wear.

Anterior Eye Profilometry-guided Scleral Contact Lens Fitting in Keratoconus

“…For the type of CL used, when it is well-fitted, horizontal and vertical lens decentration has been demonstrated to follow an exponential decay over 8 hours that plateaus approximately at 2 hours after lens insertion, while central postlens tear layer thinning plateaus after 4 hours of lens wear. 11 In our case, the behavior of the lens was different and potentially compatible with the high level of asymmetry of the scleral geometric profile. After this, we performed a refitting using the toric model of the same scleral CL in order to check if better stability and visual performance were achieved.…”

Optical coherence tomography and scleral contact lenses: clinical and research applications

“…Figure displays the mean change in central corneal clearance over an eight hour period for five different scleral lens designs, presented as the percentage reduction in the initial clearance since larger diameter lenses (with greater sagittal depths) typically provide a greater initial corneal vault . The viscosity of the fluid used to fill the scleral bowl does not appear to impact lens settling in the short term and while the reduction in the post‐lens tear layer thickness over the course of the day does influence the optics of the combined contact lens–tear layer system, the effect is minimal (about a 0.25 D myopic shift in eyes with flat or normal corneal curvature) . However, this change in optical power is more pronounced for thicker post‐lens tear layers, steeper corneae, steeper lens fits and higher plus powers.…”

“…The change in central corneal clearance for five different diameter miniscleral contact lenses over an eight hour period in normal healthy eyes measured with anterior segment OCT . The majority of lens settling occurs within the first two hours of lens wear, with minimal changes between two and eight hours.…”

“…Due to the large variation in scleral lens settling over time between individuals and lens designs (Table ), the end of day corneal vault should be monitored in all patients during the initial fitting and aftercare visits, noting the duration of lens wear for that day. Ideally, this should be quantified using OCT (which allows the lens to remain on the eye) since reinserting a scleral contact lens following removal for slitlamp examination to check for corneal staining or to add sodium fluorescein to the bowl may not result in the lens returning to the same settled position.…”

Anterior eye surface changes following miniscleral contact lens wear

“…If a potential participant was unable to wear the described miniscleral lens, the participant withdrew the study. Corneal clearance was assessed immediately after lens insertion and after 2 h of lens settling [20], using an anterior spectral domain OCT (RTVue, Optovue Inc., Fremont, CA, USA). The callipers within the analysis software were used to determine the distance between the back surface of the miniscleral contact lens and the anterior surface of the cornea to provide a measure of the central corneal clearance at the position of the corneal reflex.…”