Changes in the corneal thickness and limbus after 1 year of scleral contact lens use

Abstract

Purpose To assess the physiological changes in the cornea over time in patients with irregular cornea fitted with Rose K2 XL gas-permeable scleral contact lenses. Methods Prospective study of 16 eyes of patients who did not tolerate gas-permeable corneal contact lenses and were fitted with Rose K2 XL scleral lenses. We assessed the central vault and the corneal thickness centrally and at peripheral regions (2 to 5 mm annulus). All these measures were obtained by anterior segment optical coherence tomography. The measurements were taken immediately after fitting the lenses and 1, 6 and 12 months later. Prior to the study and at 1 year, we performed an objective test for diagnosing limbal stem cell deficiency (Limbokit). Results The mean vault was 201.7 ± 82.3 µm 20 min after fitting the contact lens; 189.4 ± 94.0 µm at 1 month; 165.1 ± 75.9 µm at 6 months and 142.1 ± 76.8 µm at 1 year, the values at 6 and 12 months being significantly different to baseline. After 1 year, the central corneal thickness had increased by 2.3% (IQR = 5.6), but the changes were only significant for the superior thickness. There is no limbal stem cell deficiency after 1 year of scleral contact lens use. Conclusions After use of Rose K2 XL scleral contact lenses, the corneal physiology of patients with an irregular cornea remains unchanged, as assessed by corneal thickness measurements and the Limbokit test. In all cases, however, the vault decreased over time.

Keratoconus: An updated review

“…Limbal compression must be avoided in corneoscleral designs since any insult at this anatomical location can potentially trigger a neovascular response [276]. Limited long-term data is available on corneoscleral lens designs in the management of keratoconus; however, significant improvements in higher order aberrations and visual acuity [277] compared to spectacles or habitual contact lens corrections have been reported for a range of corneal irregularities [272,[277][278][279], with no apparent alteration in corneal biomechanics [280] or limbal stem cell health (based impression cytology and DNA analysis), after 12 months of lens wear [281].…”

BCLA CLEAR - Scleral lenses

“…Following the evolution of rigid lens materials from glass to PMMA to low Dk [13] and then hyper-oxygen permeable rigid lens materials (Dk ≥ 100), a number of short-term studies have shown that on average modern scleral lenses induce ~2 % corneal oedema in healthy [173,224,226,[246][247][248] or keratoconic eyes [107,176,229,249], and approximately double (up to 4 % on average) in post-graft corneas [107,250]. This oedema is primarily stromal in nature [173], although, microcystic epithelial oedema (and neovascularisation) may also arise due to mechanical irritation (e.g.…”

Current Trends in Scleral Lens Prescription, Management, and Evaluation

“…Questions on whether these metrics were evaluated in patients using SLs were not even included in the 2015 SCOPE survey. Since then, several publications have described the interplay between the SL and the cornea 2,26–30 and the SL's effects on IOP 9,30–34 and the eyelids. 35 According to the current study, virtually all practitioners reported routinely assessing for corneal and conjunctival staining after lens removal; however, just over one-third of practitioners reported assessing corneal thickness, almost half reported measuring IOP, and just over half of practitioners reported that they evert the upper eyelids to evaluate the superior tarsal conjunctiva during routine SL evaluation.…”

“…US practitioners reported fitting a significantly higher percentage (67%634%) of lenses 16.0 mm or more in diameter compared with their non-US counterparts (57%635%) (P¼0.001), but no significant differences in the percentages of large-diameter and small-diameter SLs were noted between academic and community practitioners or between established and new practitioners. Countries represented included the following: Italy (32 participants); Canada (27); India, Spain, and Sweden (14 participants each); United Kingdom (12); Mexico (11); Switzerland (10); France, New Zealand, and South Africa (7 participants each); Columbia, Greece, Netherlands, Norway, and Portugal (6 participants each); Australia and Israel (5 participants each); Brazil, Germany, and Nigeria (4 participants each); Belgium, Denmark, Ecuador, Guatemala, and Saudi Arabia (3 participants each); Algeria, Argentina, China, Costa Rica, Cyprus, Philippines, Poland, Serbia, Taiwan, Trinidad and Tobago, and Uruguay (2 participants each); and Bahrain, Chile, Finland, Iran, Ireland, Japan, Jordan, Kazakhstan, Lebanon, Malaysia, Malta, Morocco, Nepal, Pakistan, Peru, Russian Federation, Singapore, Slovenia, and Venezuela (1 participant each).…”