BCLA CLEAR presbyopia: Mechanism and optics.

With over a billion adults worldwide currently affected, presbyopia remains a ubiquitous, global problem. Despite over a century of study, the precise mechanism of ocular accommodation and presbyopia progression remains a topic of debate. Accordingly, this narrative review outlines the lenticular and extralenticular components of accommodation together with the impact of age on the accommodative apparatus, neural control of accommodation, models of accommodation, the impact of presbyopia on retinal image quality, and both historic and contemporary theories of presbyopia.

Short- and Long-Term Effects of a Multi-Component, Artificial Tear on Preocular Tear Film Stability, Tear Evaporation and Tear Film Optical Dynamic: A Prospective Randomized Double-Phase Study.

Purpose: To evaluate the short- (within 90 min) and long-term (after 21 days of treatment) effects of an artificial tear containing carbomer, hyaluronic acid, glycerol, and medium-chain triglycerides in patients with mild-to-moderate dry eye symptoms.

Methods: Subjects received the tested artificial tears in the right eye and control artificial tears in the left eye and were assessed 10, 30, 60, and 90 min after instillation in the short-term study phase. They received the study product in both eyes in the long-term phase.

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.

Tear Film Characteristics During Wear of Daily Disposable Contact Lenses.

Purpose: To evaluate changes induced over time by three daily disposable (DD) contact lenses on tear meniscus height (TMH), pre-lens non-invasive break-up time (pre-lens NIBUT), tear film osmolarity (TO) and objective quality of vision (OQV).

Patients And Methods: Forty-six subjects enrolled in this prospective open-label unmasked non-randomized simultaneous comparative cross-over study. For the first week of the study, subjects wore a nesofilcon A lens in the right eye and a delefilcon A lens in the left eye.

Immediate effect of a tear enhancer and meibomian gland expression on the corneal surface and whole eye higher order aberrations.

Purpose: To investigate changes in higher order ocular aberrations (HOA) induced by the administration of 0.15% sodium hyaluronate tear enhancer (TE) and meibomian gland expression (ME) on the tear film of normal subjects.

Methods: HOA values were obtained from the corneal surface (CS) and whole eye (WE), using a corneal topographer and Shack-Hartmann aberrometer, from both eyes of 50 subjects (25 females, mean age±sd 32.

Myopia onset and role of peripheral refraction.

Background: To determine the peripheral refraction characteristics related to 18-month changes in refraction in Caucasian (Mediterranean) children.

Methods: Non-cycloplegic peripheral refraction at 10° intervals over the central ±30° of horizontal visual field over 18 months (baseline, 12 months, and 18 months of follow-up) was conducted in 50 healthy children who were 8 years old. Axial length (AL) was also recorded.

Intrasubject tear osmolarity changes with two different types of eyedrops.

Purpose: To analyze tear osmolarity over time after instillation of two commercially available eyedrops.

Methods: This prospective, nonrandomized, simultaneous, comparative, open-label, unmasked study included 40 eyes of 20 consecutive subjects (mean age, 34.8 ± 11.