Peripheral refraction of myopic eyes with spectacle lenses correction and lens free emmetropes during accommodation

Purpose To measure axial and off-axis refraction patterns in myopic eyes with spectacle lenses correction and lens free emmetropes in young healthy subjects at different target distances from 2.00 m (0.50 D) to 0.20 m (5.00 D) in terms of sphere, astigmatism, and spherical equivalent refraction. Methods Refraction was measured at the center, 20 and 40 degrees from the line of sight both nasally and temporally in 15 emmetropic and 25 myopic young healthy subjects with an open field, binocular, infrared autorefractor (Grand Seiko WAM-5500, Hiroshima, Japan). Fixation target was a Maltese cross set at 2.00, 0.50, 0.33 and 0.20 m from the corneal plane. Changes in off-axis refraction with accommodation level were normalized with respect to distance axial values and compared between myopic eyes with spectacle lenses correction and lens free emmetropes. Results Off-axis refraction in myopic eyes with spectacle lenses correction was significantly more myopic in the temporal retina compared to lens free emmetropes except for the closest target distance. Relative off-axis refractive error changed significantly with accommodation when compared to axial refraction particularly in the myopic group. This change in the negative direction was due to changes in the spherical component of refraction that became more myopic relative to the center at the 0.20 m distance as the J0 component of astigmatism was significantly reduced in both emmetropes and myopes for the closest target. Conclusion Accommodation to very near targets (up to 0.20 m) makes the off-axis refraction of myopes wearing their spectacle correction similar to that of lens free emmetropes. A significant reduction in off-axis astigmatism was also observed for the 0.20 m distance.

Possibilities of scleral lenses for visual rehabilitation of patients with corneal scars

Purpose. To analyze the efficacy and safety of SCL in patients with corneal cicatricial changes and other concomitant conditions. Material and мethods. The study included 19 patients (20 eyes) with cicatricial deformity of the cornea of various etiology, who were fitted with scleral contact lenses. Results and discussions. The use of SCL is possible in post-traumatic pathology, such as corneoscleral scars with or without aphakia, as well as after keratitis with an outcome in cicatricial deformity, cicatricial changes after a burn. A significant increase in visual acuity compared with spectacle correction has been proven. Depending on the topography of the scar, it is possible to select scleral lenses such as Oblate and Prolate, as well as with different versions of the support zone: both toric and quadratic. Conclusion. Scleral lenses can be successfully used for optical correction in patients with cicatricial changes in the cornea and other concomitant post-traumatic conditions of ineffectiveness of other methods of visual rehabilitation. Key words: cornea, lenses, vision correction, contact lenses, visual rehabilitation, scleral lenses, corneal scars, post-traumatic astigmatism, aphakia, keratitis, toric lenses, quadratic lenses, astigmatism, irregular cornea, regular cornea, regular astigmatism, irregular cornea, irregular astigmatism, prolate, oblate.

Corneal collagen crosslinking in a child with keratoconus

This clinical case describes medical history of the patient who came to the clinic with complaints of progressive decrease in visual acuity and intolerance of spectacle correction. In the following article all methods of diagnostic are fully described. We are also mentioning and discuss aspects of modern methods of diagnostic and treatment of keratoconus in children such as corneal collagen crosslinking. Key words: keratoconus, keratoconus in children, corneal collagen crosslinking.

Successful Combination Therapy for Amblyopia Secondary to Micro-Esotropia And Anisometropia

Background: Micro-esotropia is a small-angle esodeviation typically less than nine prism diopters. Patients with this ocular condition often develop amblyopia due to the presence of a constant unilateral strabismus and an anisometropic refractive error in the deviated eye. Current treatment methods for strabismic and refractive amblyopia include spectacle correction, patching, and vision therapy (VT). Case Summary: A 9-year-old Asian female presented with a constant left primary micro-esotropia with unsteady eccentric fixation, contributing to mild amblyopia and frequent suppression in the left eye. She also had a hyperopic anisometropic refractive error. Combination treatment of in-office VT with short-term patching therapy (two hours per day) was administered, with the goal of improving her binocularity, fixation, and visual acuity. Conclusions: Amblyopia results from binocular dysfunction, therefore monocular patching therapy alone will not improve the underlying issue. VT is necessary to actively treat binocularity and subsequently improve visual acuity, while short-term patching can be used in combination to effectively target monocular accommodation and fixation.

Cause of amblyopia in adult patients: a cross-sectional study

Background: Amblyopia has been defined as a decrease of visual acuity for which no causes can be detected by the physical examination of the eye, caused by vision deprivation or abnormal binocular interaction. This study aims to determine the cause of amblyopia in adult patients at HAHC hospital South Delhi.Methods: This is a cross-sectional study conducted over a period from January 2018 till March 2018 among the patients in HAHC hospital. A comprehensive eye examination was used to analyse the visual condition.Results: Amblyopia was diagnosed in 42 participants, with age-and gender-adjusted prevalence of 3.2%. Of these, 1.9% were unilateral cases, and 1.3% were bilateral cases. A major cause of amblyopia in this population was a refractive error, hence using spectacle correction and vision therapy for its initial management.Conclusions: This study has provided causes of amblyopia in an adult population. Amblyopia is a frequent cause of lifelong unilateral visual impairment.

Factors affecting non-compliance to spectacle wear in children aged six years and below with refractive errors: A hospital based cross-sectional study in India

Uncorrected refractive errors (RE) are the most common cause of preventable visual Impairment (VI) in children, which if not treated in time can lead to amblyopia. VI in early childhood interferes with their overall development affecting their future opportunities in life. Spectacles remain the most popular and effective method for correction of RE. Children unlike adults, often don’t understand the need for wearing spectacles, thus prescribing spectacles in children becomes difficult. Aim of this study was to find out proportion of spectacle wear non-compliance in children aged six years and below and identify factors associated with it. The study was conducted among 115 children aged six years and below with refractive errors who were prescribed spectacle correction. Children were selected using simple random sampling. Multivariate logistic regression was used to identify independent factors associated with spectacle wear non-compliance. Proportion of spectacle wear non-compliance was 53.04%. Children with spectacle wear non-compliance were more likely to: belong to age of two to four years (AOR = 4.3; 95%CI: 1.3-14.3); have mother with up-to primary school education (AOR = 3.7; 95%CI: 1.2-11.7); have anisometropia (AOR = 11.1; 95%CI: 3.4-36.7). Statistically significant association was observed between spectacle wear non-compliance and child’s age, mother’s education, anisometropia, astigmatism, manifest squint, intolerance to glasses, glasses lost, glasses broken, concerned teasing and cost issues. Children less than four years of age; with anisometropia and those whose mothers had up-to primary school education were more likely to be non-compliant to spectacle wear.

The Castrop formula for calculation of toric intraocular lenses

Purpose To explain the concept behind the Castrop toric lens (tIOL) power calculation formula and demonstrate its application in clinical examples. Methods The Castrop vergence formula is based on a pseudophakic model eye with four refractive surfaces and three formula constants. All four surfaces (spectacle correction, corneal front and back surface, and toric lens implant) are expressed as spherocylindrical vergences. With tomographic data for the corneal front and back surface, these data are considered to define the thick lens model for the cornea exactly. With front surface data only, the back surface is defined from the front surface and a fixed ratio of radii and corneal thickness as preset. Spectacle correction can be predicted with an inverse calculation. Results Three clinical examples are presented to show the applicability of this calculation concept. In the 1st example, we derived the tIOL power for a spherocylindrical target refraction and corneal tomography data of corneal front and back surface. In the 2nd example, we calculated the tIOL power with keratometric data from corneal front surface measurements, and considered a surgically induced astigmatism and a correction for the corneal back surface astigmatism. In the 3rd example, we predicted the spherocylindrical power of spectacle refraction after implantation of any toric lens with an inverse calculation. Conclusions The Castrop formula for toric lenses is a generalization of the Castrop formula based on spherocylindrical vergences. The application in clinical studies is needed to prove the potential of this new concept.

Tactics and timing of surgical treatment in a child with congenital essential esotropia: clinical case

Purpose. To evalute the effective of the proposed volume of surgical treatment for the progressive course of infant esotropia. Material and мethods. A premature baby with congenital esotropia, which was diagnosed at the sith month of life. The patient was assigned a spectacle correction taking into account the par of ametropia and constant alternating occlusion. In connection with the subsequent increase in horizontal esodeviation and the appearance of a paretic component, a bilateral recession of the internal rectus muscle by 5mm was carried out in combination with an injection of Botox in a volume of 2.0. IU. Results and discussion. After the first stage of surgical treatment, a stable decrease of horizontal esodeviation and an increase of the amount of abduction were achieved. Conclusion. Bilateral combined weakening of medial rectus muscles (classical recession and chemorecession) allows to achieve predicted good results in case of large strabismus angles, combined with limi of abduction. Key words: congenital esotropia, chemodenervation, chemorecession.

Monocular Diplopia: An Optical Correction Modality

Post-surgical or traumatic corectopia is among the rare causes of monocular diplopia. A 26-years-old student presented to the Institute with a complaint of monocular double vision in the left eye. He had a penetrating ocular injury in the left eye and subsequently, undergone for multiple ocular surgeries. Following the final intraocular lens implantation, he experienced a monocular double vision in his left eye. Upon contact lens clinic presentation, visual acuities were 20/20 in the right and 20/320 in the left eye (improved to 20/25 with pinhole). Slit-lamp examination on the left eye revealed scarring in the superior nasal quadrant of the cornea, irregular mid-dilated pupil with exposed aphakic and pseudophakic portions. A range of different optical management options were implemented to eliminate monocular diplopia and to correct refractive error. Finally, a combination of prosthetic soft contact lens and spectacle correction was able to remove diplopia and provide binocular single vision.

Phakic intraocular lens implantation in a case of Tourette syndrome exacerbated by wearing glasses and contact lenses

A 25-year-old longsighted woman presented with a history of spectacle and contact lens induced exacerbation of Tourette syndrome symptoms. Preoperatively, she had very poor unaided vision (6/60), achieving good (6/9) vision in both eyes with spectacle correction. The patient underwent bilateral simultaneous implantation of phakic implantable collamer lens (ICL) implants (STAAR, USA) which sit in front of the natural lens. Postoperatively, her uncorrected visual acuity was markedly improved as were her manifestations of Tourette syndrome. She achieved her full potential of unaided vision (6/9). This is the first documented case of Tourette syndrome triggered by glasses and contact lenses in which bilateral phakic toric lens implants were effective in improving vision and controlling motor symptoms. Phakic toric ICL implantation is a reversible technique for the correction of visually significant ametropia in selected patients and has improved this patient’s quality of life.