Corneal reshaping: an experiment with a type I collagen-based vitrigel for remodeling porcine corneas.

Purpose: This study aimed to report an experiment designed to determine anatomical changes in porcine corneas following placement of a novel polymer implant into the cornea.

Methods: An ex vivo porcine eye model was used. A novel type I collagen-based vitrigel implant (6 mm in diameter) was shaped with an excimer laser on the posterior surface to create three planoconcave shapes.

How Lingering Fusional Adaptation Influences the Bielschowsky Head Tilt Test in Superior Oblique Paresis.

Background: The lack of a positive Bielschowsky head tilt test (BHTT) is commonly seen as an indicator that superior oblique paresis (SOP) is not present. This study investigated the influence of fusion on the BHTT in unilateral SOP.

Patients/methods And Material: We analyzed vertical fusional vergence using our eye-tracking haploscope and the value of BHTT difference (BHTTD) in 11 patients who were diagnosed with congenital unilateral SOP and able to fuse.

Disconjugacy of Eye Movements during Attempted Fixation: A Sufficient Marker for Amblyopia?

Background: To investigate whether detection of disconjugacy of eye movements during attempted fixation, or interocular position instability, may serve as a single sensitive test for amblyopia.

Patients/methods And Material: Binocular eye movements were recorded at 500 Hz using the EyeLink 1000 eye tracker (SR Research Ltd., Kanata, Ontario, Canada) and analyzed using EyeLink software and Matlab (MathWorks, Natick, MA, USA).

Torsional incomitance after asymmetrically adjusted Harada-Ito procedures for the simultaneous correction of vertical and torsional deviations in bilateral trochlear nerve palsy.

Background: Adjustable bilateral Harada-Ito procedures have been described, sometimes with asymmetric adjustment used to correct vertical misalignment when coexisting with torsional strabismus. We investigated the causes of significant postoperative torsional incomitance noted in some patients undergoing these procedures.

Methods: The medical records of patients who underwent bilateral Harada-Ito procedures for bilateral trochlear nerve palsy between 1980 and 2018 were reviewed retrospectively.

Increasing incidence and risk factors for divergence insufficiency esotropia.

Purpose: To document the increasing incidence of divergence insufficiency (DI) esotropia and to identify risk factors for DI.

Methods: All patients with a diagnosis of esotropia seen by one provider (DLG) over 41 years were identified from the medical record. Patients with onset of strabismus before age 10 years or with prior strabismus surgery were excluded.

Inferior Oblique Muscle "Overaction" Caused by Inferior Oblique Muscle Shortening, Not by Hypertonicity.

Purpose: To determine whether fusional vergence adaptation in patients who can fuse in at least some gaze positions can cause curvature of the non-fixing eye movement paths of patients with apparent "overaction" or "underaction" of the oblique muscles, yielding possibly erroneous evidence of hypertonicity as the cause of the overaction or underaction.

Methods: The authors retrospectively studied Lancaster red-green plots of patients with oblique muscle "overaction/underaction." If fusion was present, the plot had usually been repeated after monocular occlusion for at least 30 minutes.

Meridional aniseikonia-causes, symptoms, and therapies.

Background: The term aniseikonia refers to the two eyes' appreciating different image sizes when viewing the same object. Meridional aniseikonia can occasionally cause significant distortion of the binocular spatial sense in perceptive patients.

Methods: The medical records of 3 adult patients who complained of binocular spatial distortion consistent with meridional aniseikonia were reviewed retrospectively.

Using IOLs for anterior segment photography in children.

We present a novel and convenient technique for obtaining clear, high-resolution anterior segment images using an expired intraocular lens (IOL) over the lens of a smartphone's camera. Our technique provides the means to acquire high-quality images when expensive anterior segment imaging devices are unavailable. A further advantage is decreasing the economic and environmental costs of expired IOLs, whose life can be extended through "recycling" as adjunctive camera lenses.

A Geometric Analysis of Eye Dominance Suggesting That Rembrandt and Leonardo da Vinci Had Straight Eyes After All.

This study theorizes about the straightness of the eyes of Rembrandt Harmenszoon van Rijn and Leonardo da Vinci through diagrams and images.

Adjustable suture strabismus surgery in infants and children: a 19-year experience.

Purpose: To evaluate the success rate of adjustable suture techniques in horizontal eye muscle surgery in children ≤15 years of age over a 19-year period by a single surgeon.

Methods: The medical records of all consecutive patients in this age group who underwent horizontal eye muscle surgery from 1989 through 2012 were reviewed retrospectively. Patients were divided into two groups: those in whom a nonadjustable suture technique was used and those in whom adjustable sutures were used.

A no-moving-parts sensor for the detection of eye fixation using polarised light and retinal birefringence information.

Polarised near-infra-red light is reflected from the foveal area in a detectable bow-tie pattern of polarisation states, offering the opportunity for eye tracking. A coaxial optical transducer was developed, consisting of a laser diode, a polariser, a filter, and a photodetector. Several such transducers may be used to interrogate different spots on the retina, thus eliminating the requirement for scanning systems with moving parts.

Attention attraction in an ophthalmic diagnostic device using sound-modulated fixation targets.

This study relates to eye fixation systems with combined optical and audio systems. Many devices for eye diagnostics and some devices for eye therapeutics require the patient to fixate on a small target for a certain period of time, during which the eyes do not move and data from substructures of one or both eyes are acquired and analyzed. With young pediatric patients, a monotonously blinking target is not sufficient to retain attention steadily.

Nonabsorbable versus absorbable sutures in large, hang-back medial rectus muscle recessions.

Purpose: To investigate the value of nonabsorbable sutures in reducing the incidence of consecutive exotropia after large, "hang-back" medial rectus recessions.

Methods: The medical records of patients who underwent medial rectus recession of ≥6.5 mm in individuals ≤2 years of age, or ≥7.

Deficiency of depression in adduction: clinical characteristics and surgical management of the "inverted Brown pattern".

Purpose: To evaluate the clinical characteristics and surgical management of patients with an "inverted Brown pattern," which is defined clinically as a hypertropia with greatest deviation in down-and-in gaze of the higher eye, having the appearance of superior oblique muscle underaction but without significant inferior oblique muscle overaction.

Methods: The medical records of patients with this misalignment pattern who had cyclovertical muscle surgery at our institution from 2003 through 2015 were retrospectively reviewed; medical records were analyzed for pre- and postoperative motility patterns, fundus torsion, intraoperative findings, and type of strabismus surgery.

Results: A total of 45 patients presenting with a hyperdeviation worse in down-and-in gaze of the higher eye were included in the study.

New pediatric vision screener, part II: electronics, software, signal processing and validation.

Background: We have developed an improved pediatric vision screener (PVS) that can reliably detect central fixation, eye alignment and focus. The instrument identifies risk factors for amblyopia, namely eye misalignment and defocus.

Methods: The device uses the birefringence of the human fovea (the most sensitive part of the retina).

Mechanisms of Vertical Fusional Vergence in Patients With "Congenital Superior Oblique Paresis" Investigated With an Eye-Tracking Haploscope.

Purpose: To determine the mechanisms of vertical fusional vergence in patients with "congenital unilateral superior oblique paresis" (SOP) and to discuss the implications of these mechanisms.

Methods: Eleven patients were examined with our eye-tracking haploscope.

Results: Three different fusion mechanisms were found, producing significantly different cyclovergence to vertical vergence ratios (P < 0.

Photographic simulation of off-axis blurring due to chromatic aberration in spectacle lenses.

Spectacle lens materials of high refractive index (nd) tend to have high chromatic dispersion (low Abbé number [V]), which may contribute to visual blurring with oblique viewing. A patient who noted off-axis blurring with new high-refractive-index spectacle lenses prompted us to do a photographic simulation of the off-axis aberrations in 3 readily available spectacle lens materials, CR-39 (nd = 1.50), polyurethane (nd = 1.

Children with Down syndrome benefit from bifocals as evidenced by increased compliance with spectacle wear.

Background: In our experience, children with Down syndrome were noncompliant with spectacle wear, often attributed to their inability to appreciate benefit from the glasses. Studies show that up to 80% of children with Down syndrome have reduced accommodation. The purpose of this study was to evaluate whether the use of bifocals increased compliance with spectacle wear.

DVD--a conceptual, clinical, and surgical overview.

Dissociated vertical deviation (DVD) is a slow, disconjugate hypertropic deviation of a nonfixating eye. It is usually bilateral, asymmetrical, and often associated with congenital esotropia. The deviating eye elevates, abducts, and excyclotorts.

Adjustable sutures in children.

Although adjustable sutures are considered a standard technique in adult strabismus surgery, most surgeons are hesitant to attempt the technique in children, who are believed to be unlikely to cooperate for postoperative assessment and adjustment. Interest in using adjustable sutures in pediatric patients has increased with the development of surgical techniques specific to infants and children. This workshop briefly reviews the literature supporting the use of adjustable sutures in children and presents the approaches currently used by three experienced strabismus surgeons.

New pediatric vision screener employing polarization-modulated, retinal-birefringence-scanning-based strabismus detection and bull's eye focus detection with an improved target system: opto-mechanical design and operation.

Amblyopia ("lazy eye") is a major public health problem, caused by misalignment of the eyes (strabismus) or defocus. If detected early in childhood, there is an excellent response to therapy, yet most children are detected too late to be treated effectively. Commercially available vision screening devices that test for amblyopia's primary causes can detect strabismus only indirectly and inaccurately via assessment of the positions of external light reflections from the cornea, but they cannot detect the anatomical feature of the eyes where fixation actually occurs (the fovea).