The tear turnover and tear clearance tests - a review.

Introduction: The aim is to provide a summary of methods available for the assessment of tear turnover and tear clearance rates. The review defines tear clearance and tear turnover and describes their implication for ocular surface health. Additionally, it describes main types of techniques for measuring tear turnover, including fluorescein tear clearance tests, techniques utilizing electromagnetic spectrum and tracer molecule and novel experimental techniques utilizing optical coherence tomography and fluorescein profilometry.

Evaluating tear clearance rate with optical coherence tomography.

Purpose: To assess the early-phase of tear clearance rate (TCR) with anterior segment optical coherence tomography (OCT) and to determine the association between TCR and other clinical measures of the tear film in a group of young subjects with different levels of tear film quality.

Methods: TCR was classified as the percentage decrease of subject's inferior tear meniscus height 30s after instillation of 5μl 0.9% saline solution.

Objective assessment of the effect of pupil size upon the power distribution of multifocal contact lenses.

Aim: To analytically assess the effect of pupil size upon the refractive power distributions of different designs of multifocal contact lenses.

Methods: Two multifocal contact lenses of center-near design and one multifocal contact lens of center-distance design were used in this study. Their power profiles were measured using the NIMO TR1504 device (LAMBDA-X, Belgium).

Simulated prototype of posterior chamber phakic intraocular lens for presbyopia correction.

Purpose: To evaluate the visual impact of adding different spherical aberration values to an Implantable Collamer Lens phakic intraocular lens (pIOL) to increase the depth of focus using an adaptive optics visual simulator.

Setting: University of Valencia, Valencia, Spain.

Design: Experimental study.

Fixed mydriatic pupil associated with an intraocular pressure rise as a complication of the implant of a Phakic Refractive Lens (PRL).

We describe a case report of a patient that was implanted with a posterior chamber phakic intraocular lens (Phakic Refractive Lens, PRL) for the correction of moderate myopia and who developed postoperatively a fixed mydriasis compatible with an Urrets-Zavalia Syndrome (UZS). Specifically, a sudden acute increase of IOP in the left eye was observed in the immediate postoperative period. After IOP stabilization, the refractive result was good, but a fixed and mydriatic pupil appeared.

Long-term comparison of corneal aberration changes after laser in situ keratomileusis: mechanical microkeratome versus femtosecond laser flap creation.

Purpose: To compute and compare visual acuity, refractive outcomes, and anterior corneal aberration changes after myopic laser in situ keratomileusis (LASIK) with flap creation by a mechanical microkeratome and by a femtosecond laser.

Setting: Private practice refractive surgery center, Valencia, Spain.

Design: Comparative case series.

Clinical evaluation of the new TGDc-01 "PRA" palpebral tonometer: comparison with contact and non-contact tonometry.

Purpose: The TGDc-01 "PRA" (Ryazan State Instrument, Ryazan, Russia) tonometer is a new portable small-sized tonometer that measures intraocular pressure (IOP) through the eyelid. The purpose of this study is to assess the repeatability of the TGDc-01 IOP measurements by comparing them against those obtained with Goldmann tonometer and with those from Perkins applanation tonometer, Xpert (Reichert, Depew, NY) noncontact tonometer, and Tono-Pen XL (Medtronic Solan, Jacksonville, FL) digital tonometer.

Methods: Fifty-eight right eyes of 58 young subjects were measured with each of the tonometers.