CLEAR - Scleral lenses.

Scleral lenses were the first type of contact lens, developed in the late nineteenth century to restore vision and protect the ocular surface. With the advent of rigid corneal lenses in the middle of the twentieth century and soft lenses in the 1970's, the use of scleral lenses diminished; in recent times there has been a resurgence in their use driven by advances in manufacturing and ocular imaging technology. Scleral lenses are often the only viable form of contact lens wear across a range of clinical indications and can potentially delay the need for corneal surgery. This report provides a brief historical review of scleral lenses and a detailed account of contemporary scleral lens practice including common indications and recommended terminology. Recent research on ocular surface shape is presented, in addition to a comprehensive account of modern scleral lens fitting and on-eye evaluation. A range of optical and physiological challenges associated with scleral lenses are presented, including options for the clinical management of a range of ocular conditions. Future applications which take advantage of the stability of scleral lenses are also discussed. In summary, this report presents evidence-based recommendations to optimise patient outcomes in modern scleral lens practice.

Variation of clearance considering viscosity of the solution used in the reservoir and following scleral lens wear over time.

PURPOSE: This study aims to evaluate the settling of a scleral lens and if this process is influenced by the nature of the fluid layer. METHODS: A prospective, non-randomized control study was performed using an 18mm scleral lens. They were fitted with a central clearance of 400 um at insertion. One eye was randomly assigned to be fitted with a non-preserved gel solution of carboxymethylcellulose, while the other was inserted with non-preserved saline. Measurements of clearance in 3 locations were taken (OCT) at baseline, every 30min up to 1h30 post insertion and every 2h thereafter up to 6h00 of wear. A two-way repeated measure analysis of variance (liquids×times) was used to test central, nasal and temporal fluid thickness. RESULTS: Following 6h of wear, the 18mm lens had a mean central settling of 70.0±9.8µm, 36.7±9.8µm of which occurred within the first 30min of wear. There was no significant difference between lenses filled with non-preserved saline to those with non-preserved gel. However, a paired comparison concluded to a significant difference between mean nasal settling (41.4µm) and temporal settling (20.4µm). CONCLUSION: With respect to the lens studied, current results suggest that practitioners can evaluate the lens 30min post insertion and can estimate the amount of fluid that will remain after lens stabilization by doubling the value obtained initially. The use of non-preserved saline or non-preserved more viscous solution to fill the lens does not influence its settling.

Effects of LATISSE (bimatoprost 0.03 per cent topical solution) on the ocular surface.

PURPOSE: LATISSE is marketed for the treatment of hypotrichosis (loss of eyelashes), using a prostamide analogue and preserved with benzalkonium chloride, which is an effective preservative; however, it also causes irritation to the ocular surface. LATISSE is applied to the lid margin; however, with the blink, some solution may fall onto the ocular surface. The objective of this study was to assess the effects of LATISSE on the ocular surface over two months. METHODS: Non-dry eye participants interested in eyelash lengthening were invited to a prospective uncontrolled, open-label clinical study using LATISSE for two months. Eyelash length, subjective symptoms, tear film stability, osmolarity, ocular redness and intraocular pressure were evaluated at baseline (T0) and at one (T1) and two months (T2). RESULTS: Twenty-eight women (ages 18 to 29) entered the study. Fifteen completed the study with five who discontinued due to burning upon instillation and eight were lost to follow-up. Average eyelash length increased at each time (p < 0.001). Dryness, burning and grittiness remained low (less than 25/100) throughout the trial with dryness showing a significant change between T0 and T1 (p = 0.04), but not between T1 and T2 (p > 0.05). No difference (p > 0.05) was noted for the non-invasive break-up time, photochromametry or tear osmolarity. Intraocular pressure showed a decrease with time but translated to only a one to two mmHg change, which was not clinically relevant. CONCLUSIONS: LATISSE increases eyelash length within a short time (less than two months). Patients seeking eyelash enhancement options should be educated as to the use, precautions and any secondary effects, including the potential for discomfort upon instillation.