Search

Evaluate the effects of corneoconjunctival transposition (CCT), posterior lamellar keratoplasty (PLK) and modified deep lamellar endothelial keratoplasty (DLEK) on streak retinoscopy in equine cadaver eyes.Intraocular pressure (IOP) was maintained at 25 ± 3 mmHg in 35 equine cadaver eyes. Streak retinoscopy was performed prior to (NO VISCO) and following (VISCO) intracameral injection of 1.0 ml of viscoelastic. Following optical coherence tomography (OCT), an axial CCT [n = 11] or PLK [n = 12], or peripheral DLEK [n = 12] was performed. Streak retinoscopy and OCT were repeated postoperatively.Postsurgical net meridional and spherical refraction for CCT [Horizontal (H): 3.4 (95% CI 2.4-4.4) diopters (D), p .001, Vertical (V): 3.5 (95% CI 2.7-4.4) D, p .001, Spherical: 3.5 (95% CI 2.6-4.3) D, p .001] and PLK [H: 3.2 (95% CI 2.2-4.1) D, p .001, V: 2.8 (95% CI 2.0-3.6) D, p .001, Spherical: 3.0 (95% CI 2.2-3.8) D, p .001] were significantly increased from presurgical (VISCO) values. No difference between presurgical (VISCO) and postsurgical values were identified for the DLEK. Postoperative OCT revealed space between anterior and posterior corneal grafts and corneal undulation associated with suture placement.Meridional and spherical refraction had a hyperopic shift following CCT and PLK, with a significantly higher value in the vertical meridian for the CCT. Pre- and postoperative refraction was not significantly different for the DLEK. This supports that the DLEK has a lesser effect on immediate postoperative refraction compared with CCT or PLK.

Purpose-\ud \ud Retinoscopy is a skill that requires the integration of procedural skill and declarative knowledge. Whilst the actual technique is simple, retinoscopy is a complex skill to acquire and is one that students often find challenging. This study compared the strategies that novices, third-year students and experts use when performing retinoscopy, with the aim of identifying the key stages of learning that may enlighten teaching practice.\ud \ud Method-\ud \ud This study employed a protocol-based approach in which the verbal protocols and cognitive strategies of novices, students and experts were recorded and then subjected to ‘problem space’ analysis.\ud \ud Results-\ud \ud Clear differences existed when the retinoscopy of novices, students and experts was directly compared using a standardised simulated task. Experts were more accurate in performance and used defined strategies to reach the goal. The presence of these strategies significantly predicted the accuracy of the retinoscopy result.\ud \ud Conclusion-\ud \ud This study highlights the importance of meta-cognitive strategies and the need for an adequate theoretical foundation in skill acquisition. The underpinning knowledge provides a pedagogic tool that specifies activities which are beneficial to learning a clinical skill.

In order to meet the demands of myopia prevention, as well as the increasing needs of measurement for refractive and cataract operations in China, a new axial length (AL) measurement system combining an improved Twyman-Green interferometer with digital signal processing has been established. The ALs of 33 eyes of different optical refractive subjects (-8.50 ~ 0.50 D) were measured with the New AL and intraocular lens (IOL) master. The repeatability of measurements with the New AL was assessed using coefficient of variation (CoV) and intra-group correlation coefficient (ICC). Comparison, correlation, linear regression and agreement of AL between devices were analyzed. There was good repeatability (CoV = 0.0617%, ICC = 0.9999) with the New AL and great agreement has been obtained with both devices. These show that the New AL is capable of providing precise AL values over the normal AL range compared to the IOL master, and indicate that the New AL developed can be used for routine clinical AL measurements.

PURPOSE This study was designed with the aim of providing practitioners with an evidence base to inform their clinical decision making as to when cycloplegic retinoscopy is necessary and when it might be appropriate to forgo. The study aimed to determine the age at which there ceases to be a clinically significant difference between cycloplegic and non-cycloplegic retinoscopy and whether age, refractive error, habitual spectacle wear and accommodation influence the relationship. METHODS A single examiner carried out cycloplegic and non-cycloplegic retinoscopy on 128 children stratified into four age groups (6-7, 8-9, 10-12 and 12-13 years). Cycloplegia was achieved using 1% cyclopentolate and retinoscopy carried out after 30 min. The examiner was masked to the lenses used and to habitual spectacle wear. Accommodation was assessed using dynamic retinoscopy prior to cycloplegia. RESULTS Cycloplegic and non-cycloplegic sphere differed significantly (z = -9.18, p

Author(s): Moore, Bret A; Maggs, David J; Kim, Soohyun; Motta, Monica J; Bandivadekar, Ruta; Tell, Lisa A; Murphy, Christopher J | Abstract: OBJECTIVE:To estimate the prevalence of ocular disease and obtain normative ocular data for free-living hummingbirds. ANIMALS STUDIED:Two hundred and sixty-three free-living, adult Hummingbirds from coastal and inland central California were studied, including Anna's (Calypte anna, n = 186) and Black-chinned (Archilochus alexandri; n = 77) hummingbirds. PROCEDURES:Slit lamp biomicroscopy and indirect ophthalmoscopy were performed on all individuals. Rebound tonometry, measurement of horizontal palpebral fissure length, and streak retinoscopy were performed on select individuals. Five conscious Anna's Hummingbirds underwent ocular imaging including fundus photography, digital slit lamp photography, and anterior segment and retinal optical coherence tomography. RESULTS:The prevalence of ocular disease in this population was 2.28%. Ocular imaging revealed a thin cornea, shallow anterior chamber, large lens, and a single central, deep convexiclivate fovea. Mean ± SD intraocular pressure was 11.21 ± 2.23 mm Hg. Mean ± SD eyelid length was 2.59 ± 0.19 mm. All eyes were emmetropic or mildly hyperopic with a mean (range) ± SD refractive error of +0.32 (-0.25 to +1) ± 0.33 diopters. CONCLUSIONS:Consistent with previous reports, these data suggest that hummingbirds have visual characteristics found in predatory and prey species, as well as a low prevalence of spontaneous ocular disease. This work provides a set of reference values and clinical findings that can be used in the future research on hummingbird vision and ocular disease. It also provides representative diagnostic images of normal birds and demonstrates that advanced ocular imaging can be performed on manually restrained hummingbirds without pharmacologic dilation.

Objectives To calculate the size and dioptric power of a posterior chamber intraocular lens (IOL) to achieve emmetropia in adult rabbits and to compare the dioptric power calculation results using a proprietary predictive formula to a retinoscopy-based method. Animals studied Three wild rabbit cadavers, seven pet rabbits with cataracts and ten healthy pet rabbits. Materials and Methods Implant size was calculated using a capsular tension ring (CTR) (Acrivet®, Berlin, Germany). Published and cadaveric biometric data were used in the predictive formula. An IOL power-escalation study compared the predicted values to the refraction results of one pet rabbit (P1) fitted with a + 41D canine IOL (Acrivet®) and six pet rabbits (P2-P7) fitted with prototype IOLs (Acrivet®). Retinoscopy of 10 healthy pet rabbits served as controls. Results A 13.5 mm CTR fitted in all rabbits and permitted the use of a 13 mm IOL. The predicted IOL power ranged between +24D and +25D. The +41D IOL resulted in a refraction error of +8D. Progressive recalculation through a calibration formula led to the insertion of three +49D IOLs in two pet rabbits and a refraction of +6D to +8D, followed by seven +58D IOLs in four pet rabbits and a refraction median of 0D (range: −1.5D to +1D). Conclusions A 13 mm prototype IOL of +58D achieves emmetropia and is of adequate size for rabbits. The combined use of a CTR and retinoscopy is a useful method to calculate the size and refractive power of a new, species-specific, veterinary IOL.

Purpose To study, for the first time, the effect of wearing ready-made glasses and glasses with power determined by self-refraction on children's quality of life. Methods This is a randomized, double-masked non-inferiority trial. Children in grades 7 and 8 (age 12–15 years) in nine Chinese secondary schools, with presenting visual acuity (VA) ≤6/12 improved with refraction to ≥6/7.5 bilaterally, refractive error ≤−1.0 D and

Introduction: Chronic obstructive pulmonary disease (COPD) has multisystemic implications and comorbidities. Hypoxia and systemic inflammation are thought to involve oculary structures. In this study, our aim is to evaluate retinal nerve fiber and choroidal thickness and retinal vessel diameter using the spectral-domain optical coherence tomography (SD-OCT) in COPD subjects. Methods: Forty-three subjects diagnosed with COPD according to the Global Initiative for Chronic Obstructive Lung Disease criteria at the Pulmonology Department of Pamukkale University were enrolled in the study. All subjects underwent respiratory function testing and a carbon monoxide diffusion test. To determine hypoxic state, arterial blood gas analysis was performed. The control group consisted of 31 subjects with comparable age and gender distribution. All participants underwent a standard ophthalmic examination including visual acuity assessment, biomicroscopy, air-puff tonometry, indirect retinoscopy, and SD-OCT measurements. Results: The mean subfoveal choroidal thickness (SFCT), foveal thickness, and retinal arteriolar caliber were found to be similar in both groups, while the mean retinal venular caliber value was markedly higher in the COPD group. The mean peripapillary retinal nerve fiber layer (RNFL) thickness was 100.2±11.8 µm in the COPD group and 105.6 ± 8.1 µm in the control group (P =.03). The inferior quadrant RNFL was significantly thinner in the COPD group. Conclusions: The results of this study showed increasing diameter of the retinal veins, thinning of the RNFL, and SFCT may be associated to chronic inflammation and hypoxia in subjects with COPD. Future guidelines may include ocular findings to the present systemic manifestations of COPD. © 2016 John Wiley & Sons Ltd

Purpose Dynamic retinoscopy (DR) is a procedure for assessing the accommodative response using a standard clinical instrument. The present study compared measurements of the amplitude of accommodation (AA) obtained using this technique with two subjective methods (modified push-down and minus lens). Additionally, the expected ranges for AA when measured by DR were determined. Method AA was measured in 1298 subjects between 5 and 60 years of age using the three techniques described above. Subjects were grouped into 5-year bins, and a descriptive univariate analysis of the data performed. Goodness-of fit plots were constructed to examine the overall model fit. Centile curves were calculated from the final model. Results Mean values of AA obtained using DR were significantly lower than for the two subjective techniques. For the DR findings, no significant change was observed between 5 and 19 years of age (mean AA = 8.3 D) and between 45 and 60 years of age (mean AA = 0.6 D). AA values as a function of age were best fit by the polynomial regression equation: logAA = 1.93 + 0.49(age) − 0.19(age)2. Conclusion Measurements of AA determined using DR are significantly lower than the normative subjective findings published previously. This difference is at least partly due to the depth-of-field of the eye. These norms markedly overestimate accommodative responsivity. DR provides a simple technique for quantifying accommodation in the clinical setting.

Purpose To report prevalence, ocular characteristics and coexisting neurological, behavioural, somatic and neuroradiological abnormalities in children and adolescents with morning glory disc anomaly (MGDA). Methods In a cross-sectional population-based study, 12 patients with MGDA, aged 2–20 years, were identified. All 12 agreed to ophthalmological assessments including visual functions, refraction, fundus photography, optical coherence tomography (OCT) and ocular motor score (OMS). Neurological examinations and behavioural/developmental screening were carried out. Data from previous or new neuroradiological investigations were collected. Results The prevalence of MGDA was 2.6/100 000. MGDA was unilateral in 11/12 patients with a best-corrected visual acuity (BCVA) in the MGDA eye ranging from hand motion to 0.65 (median 0.06). Severe microphthalmus prevented unilaterality to be determined in one adolescent. All patients had a binocular BCVA of ≥0.5. OMS showed abnormalities in pupil response, vestibulo-ocular reflex, stereo visual acuity, strabismus and convergence. OCT revealed peripapillary or macular oedema in 5/8 patients and foveal aplasia in 3/8 patients. Three patients had extensive capillary hemangiomas, of which one had PHACES syndrome and one had additional cerebrovascular anomalies and corpus callosum agenesis. Neuroradiology showed craniovascular anomalies in two patients. Neurology was mostly normal. Behavioural/developmental screening showed attention deficit hyperactivity disorder in one patient. Conclusions The prevalence data, previously not reported, of morning glory disc anomaly was 2.6/100 000. Coexisting retinal peripapillary or macular oedema was common, as were cerebral abnormalities and/or cutaneous vascular malformations. The associated findings may not be discovered through routine ophthalmological examination why OCT and neuroimaging are called for.

Purpose A recent threefold increase in laser treatment for advanced retinopathy of prematurity (ROP) triggered a nationwide preschool ophthalmic and developmental status among extremely preterm survivors. Here, we discuss refraction and visual acuity. Methods Survivors (n = 178) from a national birth cohort (February 2004 to March 2006) of gestational age

To determine different ophthalmological parameters in 10-year-old, healthy, full-term children in Stockholm County, Sweden.Two hundred and seventeen children were included in the study. Best-corrected distance and near visual acuities (VA) were measured using logMAR charts. Cycloplegic retinoscopy was performed, and spherical equivalent and astigmatism were determined. Examination of ocular movement and cover test for distance and near were performed. Stereopsis was assessed with the TNO test, and contrast sensitivity with the Vistech test. The Royal Air Force rule was used for assessing accommodation, and near point of convergence was measured with the Lang fixation stick. Ophthalmoscopy was performed through dilated pupils.Eighty-two per cent of the children had a distance VA of -0.1 logMAR (1.3 Snellen acuity) or better. None of the children were visually impaired [VA0.6 logMAR (0.3 Snellen acuity)]. Ninety-three per cent had a near VA of -0.1 logMAR (1.25 Snellen acuity) or better. Mean spherical equivalent was 0.6 D. Eight (3.6%) children had hypermetropia (≥+2 D), and 17 (7.8%) were myopic (≤-0.5 D). Nine (4.1%) children had an astigmatism≥1 D, and two (0.9%) had anisometropia of ≥1 D. Manifest strabismus was found in seven (3.2%) children, five of whom had exotropia. Heterophoria for distance and/or near was found in 80.2% of the children. In children without manifest strabismus, stereopsis60 seconds of arc was found in five (2.4%). Three (1.4%) of 215 children had contrast sensitivity below normal limits. Binocular median near point of accommodation was 14 D, and median near point of convergence 6 cm.Knowledge of various visual functions in normally developing children is crucial to be able to draw conclusions from ophthalmological examinations in children with eye diseases. This population-based study describes different ophthalmological parameters in full-term ten-year-old children. The material can be used as a control when examining children of similar ages with various ophthalmological conditions, such as groups of children with specific neurological or retinal diseases, and syndromes.

This mini-review provides an overview of magnetic resonance imaging (MRI) applications to study rodent, cat, non-human primate, and human retinas. These techniques include T(1) - and T(2) -weighted anatomical, diffusion, blood flow, blood volume, blood-oxygenation level dependent, manganese-enhanced, physiological, and functional MRI. Applications to study the retinas in diabetic retinopathy, glaucoma, and retinal degeneration are also reviewed. MRI offers some unique advantages compared with existing imaging techniques and has the potential to further our understanding of physiology and function in healthy and diseased retinas.

Objectives To determine the effects of tropicamide 1% on the refractive state of the adult equine globe and identify the most appropriate time period (in relation to mydriasis) to perform streak retinoscopy. Animals studied Eight university-owned mares of various ages and breeds. Procedures Topical tropicamide 1% was applied to one randomly selected eye from each of the horses to induce mydriasis and cycloplegia. The contralateral eyes served as controls. Streak retinoscopy and pupillometry were performed prior to, and every 5 min after tropicamide 1% installation for 90 min. Results All values are expressed as mean ± SD. Both horizontal (2.8 ± 0.74 mm) and vertical (7.3 ± 1.29 mm) mean pupil diameters increased significantly (P

Objective To compare the Welch Allyn SureSight wavefront autorefractor with retinoscopy in normal dogs. Animals studied Fifty privately owned dogs (100 eyes) of 20 breeds, free of ocular disease. Mean ± SD age: 5.7 ± 3.25 years (range: 6 months–13 years). Procedures The refractive error was determined in each eye by two experienced retinoscopists using streak retinoscopy as well as by an autorefractor operated by two different examiners. Measurements were performed before and approximately 30–45 min after cycloplegia was induced by cyclopentolate 0.5% and tropicamide 0.5% ophthalmic solutions. Results Mean ± SD noncyclopleged retinoscopy net sphere was )0.55 ± 1.14 (range: )3.75 to 3.5) diopters (D). Mean cyclopleged retinoscopy net sphere was )0.52 ± 1.18 (range: )4.25 to 2) D. Mean ± SD noncyclopleged autorefractor spherical equivalent (SE) was )0.42 ± 1.13 D (range: )3.36 to 2.73) D. Mean cyclopleged autorefractor SE was 0.10 ± 1.47 (range: )5.62 to 3.19) D. Noncyclopleged autorefraction results were not significantly different from streak retinoscopy (whether noncyclopleged or cyclopleged, P = 0.80 and P = 0.26, respectively). Cyclopleged autorefraction results were significantly different from noncyclopleged or cyclopleged streak retinoscopy (P < 0.0001 in both states). There was no significant difference between noncyclopleged and cyclopleged streak retinoscopy (P = 0.97). Conclusions Noncyclopleged autorefraction shows good agreement with streak retinoscopy in dogs and may be a useful clinical technique. Cycloplegia does not significantly affect streak retinoscopy results in dogs.

Purpose To compare non-cycloplegic refractive results obtained with the Plusoptix A12 (Plusoptix, Germany) and the 2WIN (Adaptica, Italia), to Retinomax K-Plus 3 (Righton, Virginia) in a pediatric cohort. Methods 106 eyes of 53 childrens were included prospectively between March 2015 and June 2015. On each eye, no-cycloplegic refraction was performed with the Plusoptix A12 and the 2WIN, and cycloplegic refraction was performed with the Retinomax K-Plus 3, which was used as gold-standard reference method. All data from each device, concerning sphere and cylinder power and axis, were compared to cycloplegic refractive measurements. The measures were considered reliable when the difference on sphere or cylinder power was between −0.5 D and +0.5 D, and when the difference on axis was less than 10°. Results The mean age was 7.3 years (range, 1–17 years). Regarding sphere, measures were reliable in 37.7% for the right eye and 35.8% for the left eye with the Plusoptix A12 and in 35.8% with the 2WIN, regardless the eye. The sphere was underestimated respectively in 59.3 and 57.5%. Regarding the cylinder power, measures were adequate in 66% for the right eye and 69.8% for the left eye with the Plusoptix A12 and in 79.2% for the right eye and 64.2% for the left eye with the 2WIN. Concerning the cylinder axis, values were reliable in 32% for the right eye and 47% for the left eye with Plusoptix A12 and 42% for the right eye and 62% for the left eye with the 2WIN . Conclusions The Plusoptix A12 and the 2WIN seem reliable for the evaluation of the cylinder power but not for the axis. These devices trend to underestimate the sphere. These devices can be used for screening of children refractive errors, but can not restitute cyloplegic retinoscopy measurements for prescription of optical corrections.

A 2-month-old, 110-kg Saddlebred filly presented for evaluation of bilateral cataracts. A hypermature cataract in the left eye (OS) and an incipient nuclear cataract in the right eye (OD) were diagnosed. Electroretinography and ocular ultrasound revealed no contraindications for surgical removal of the cataractous lens OS. Phacoemulsification and implantation of a +14 diopter (D) intraocular lens (IOL) OS were performed at 4 months of age without complication, with the exception of a partial iridectomy performed on a small iris section that prolapsed through the corneal incision. Complete ophthalmic examinations, including ocular ultrasound and streak retinoscopy, were performed 1, 2, 6 weeks, 4 months, 1, and 2 years postoperatively. Diffuse corneal edema and a superficial corneal ulcer developed OS during the early postoperative period and resolved without complication. Dyscoria was identified owing to anterior synechia of the dorsomedial iris at the incision site. Two years after surgery, menace response, palpebral reflex, dazzle reflex, and pupillary light reflexes were present in both eyes (OU). The IOL remained centrally positioned within the capsule, with mild anterior tilting of the superior portion of the IOL and mild fibrosis of the lens capsule. The postoperative net refractive error was +0.31 D OS. Based on this report, a +14 D IOL may be the appropriate choice following lens extraction in a foal to achieve refraction near emmetropia at maturity. To our knowledge, this is the first report of phacoemulsification and IOL implantation in a foal with long-term follow-up.

Objective To assess the refractive state of the equine eye utilizing retinoscopy. To compare the refractive state of Spanish Thoroughbred horses with the refractive state of Crossbred horses. Procedures The refractive state of 135 horses (264 eyes) was assessed utilizing streak retinoscopy. Two perpendicular meridians were examined in order to assess astigmatism at a working distance of approximately 67 cm. A group of 81 Spanish Thoroughbred horses was compared with a group of 54 Crossbred horses. Cyclopentolate ophthalmic solution was instilled in the eyes of a group of 18 horses to determine if accommodation has any influence on the assessment of the refractive state. Results Mean ± SE refractive state of all horses examined was −0.17 ± 0.04 D. The mean refractive state of the Spanish Thoroughbred was −0.28 ± 0.06 D while that of the Crossbred was −0.01 ± 0.05 D. The refractive state of the Spanish Thoroughbred was found to be statistically different to that of the Crossbred. The most prevalent refractive state was emmetropia in all cases, followed by hyperopia for the Crossbred, and myopia for the Spanish Thoroughbred. Astigmatism ≥0.50 D present in both eyes from the same individual was found in 21.7% of all horses examined. Anisometropia ≥1.00 D was diagnosed in 4 out of 129 horses with both visual eyes. Cycloplegia did not statistically affect the refractive state of the evaluated eyes. Conclusions The equine eye has a refractive state close to emmetropia. Myopia is higher among Spanish Thoroughbred horses than among Crossbred horses.

Purpose: Chicks developing experimentally-induced myopia show profound thinning of the choroid. We observed a wide range of choroidal thicknesses in a sample of normal chicks prior to their use in a pedigree-based study of form-deprivation myopia. Hence, we tested whether pre-treatment choroidal thickness predicted susceptibility to myopia. Methods: Retinal, choroidal and scleral thickness were measured using A-scan ultrasonography in normal White Leghorn chicks (n = 891) aged 4 days old, and again (n = 498) after 4 days of monocular form-deprivation at age 8 days of age. Refractive error was assessed by retinoscopy. Relationships between pre-treatment choroidal thickness and other variables were investigated using general linear models and variance components analysis. Results: Untreated 4 day-old male chicks had choroids approximately 10% thinner than females (p < 0.001), but sex explained

Purpose: To determine the sensitivity and specificity of noncycloplegic autorefraction for determining refractive status compared to cycloplegic autorefraction. Methods: The target population was noninstitutionalized citizens of all ages, residing in Tehran in 2002, selected through stratified cluster sampling. From 6497 eligible residents, 70.3% participated in the study, from August to November 2002. Here, we report data on 3501 people over the age of 5 years who had autorefraction with and without cycloplegia (two drops of cyclopentolate 1.0% 5 min apart, with autorefraction 25 min after the second drop). Results: Overall, the sensitivity of noncycloplegic autorefraction for myopia was 99%, but the specificity was only 80.4%. In contrast, the sensitivity for hyperopia was only 47.9%, but the specificity was 99.4%. At all ages, noncycloplegic autorefraction overestimated myopia and underestimated hyperopia. Overestimation of myopia was highest in the 21–30 and 31–40 year groups. Underestimation of hyperopia was high up to the age of 50 (20–40%), but decreased with age, to about 8% after the age of 50, down to almost 0% after 70. The difference in mean spherical equivalent with and without cycloplegia fell from 0.71 dioptres (D) in the 5–10 age group to 0.14D in those over 70. Conclusion: Use of noncycloplegic autorefraction in epidemiological studies leads to considerable errors relative to cycloplegic measurements, except in those over 50–60. The difference between cycloplegic and noncycloplegic measurements varies with age and cycloplegic refractive category, and there is considerable individual variation, ruling out adjusting noncycloplegic measurements to obtain accurate cycloplegic refractions.

(1932). Corresponding and Oblique Movements in Retinoscopy. Clinical and Experimental Optometry: Vol. 14, No. 12, pp. 10-11.

The principles of the construction of the instrument are described and the practical application outlined. The essential place of Retinoscopy in Refraction is indicated and the use of cycloplegics is lucidly discussed without bias.

Aims: It is common for refraction to be measured using different testing methods in children, with much debate still ongoing on the preferred method. Therefore, we compared cycloplegic refraction measurements using three objective methods in a large cohort of children. Methods: We present the findings from a total of 51 children who were recruited and examined as part of the Strabismus, Amblyopia and Refractive error in Singapore preschool children (STARS) study. Each child underwent a comprehensive eye examination, which included cycloplegic refraction using a hand-held autorefractor (Retinomax), a table mounted autorefractor (Canon FK-1) and streak retinoscopy. Spherical equivalent (SE) was calculated as (sphere + half of minus cylinder) and astigmatism was determined using the negative cylindrical component. Results: The current study sample consisted of 29 boys and 22 girls aged between 24 and 72 months (mean age 52.3 months). The mean spherical equivalent (SE) using the table-mounted autorefractor (1.03 ± 1.64 D) was not significantly different from the streak retinoscopy (1.09 ± 1.58 D, p = 0.66). However, the mean SE using the hand-held Retinomax (0.80 ± 1.43 D) was significantly different (more ‘minus’p = 0.0004) to streak retinoscopy. The astigmatism measured using the hand held (−0.89 ± 0.51 D) and table-mounted autorefractor (−0.83 ± 0.61 D) were significantly greater than that obtained with streak retinoscopy (−0.58 ± 0.56, p = 0.0003). Conclusions: The table-mounted autorefractor provided a reading more similar to that of streak retinoscopy than to that of the hand-held autorefractor. However, there were only small differences in mean SE (

Purpose: To investigate whether optical coherence tomography (OCT) is helpful in the diagnosis of foveal hypoplasia in children. Methods: Children with albinism and aniridia were examined with Stratus OCT 3 software 4.0.1 (Carl Zeiss Meditec, Dublin, California, USA). A qualitative examination of the macular area was performed with a 128 A-scans ⁄ secondsingle-scan. Macular thickness was measured quantitatively with an automatic fast macular map protocol. The average thickness ⁄ volume of the macula was presented as numerical values and as a false colour code in nine modified early treatment of diabetic retinopathy study (ETDRS) areas (A1–A9). A previously collected control group of children was used for comparison. Results: Macular thickness in 13 children with albinism and three children with aniridia was measured with OCT. Comparison with healthy children in the same population was performed. Patients with albinism and aniridia had significantly thicker central macula (A1) and foveola than children in the control group. Conclusion: OCT was found to be useful in the diagnosis of foveal hypoplasia in children.

A prospective study was performed on 46 eyes to compare results of different methods of objective refraction, namely automated refraction with the Nidek AR-1000 autorefractometer and retinoscopy in cycloplegia. We found that automated refraction in cyclopentolate cycloplegia gave results that differed little from results of retinoscopy in atropine cycloplegia both with respect to sphere and cylinder. Axis determination was even better with automated refraction. Dry automated refraction gave inaccurate results for the spheric component presumably because of suboptimal control of accommodation in this group of young patients. We recommend automated refraction in cyclopentolate cycloplegia as an easy, rapid, accurate and convenient method for obtaining an objective refraction where accommodative disorders are suspected.

Accommodation was measured in a double-blind study on 10 healthy volunteers (22-29 years) before and after the instillation of 0.1%, 1.0% and 10% phenylephrine eye drops. Accommodation decreased exponentially with increasing concentration, reaching an average of 3 dioptres after one drop of 10% phenylephrine. The effect of adding phenylephrine to an atropinized eye was studied in 20 children (3-6 years). The children were randomized to placebo or phenylephrine treatment. The cycloplegic effect of atropine was unchanged in 8 out of 9 placebo-treated children, whereas 5 out of 11 phenylephrine-treated children showed a slight, but not significant, increase in hypermetropia.

Static refraction in children after the topical instillation of atropine twice a day during 3.5 days was compared with the refraction after a single instillation of one drop of 0.85% cyclopentolate + 1.5% phenylephrine in a randomized cross-over study. Antropine eye drops were applied by the parents at home, while the combination drop was applied by personnel at the eye clinic. Refraction was determined by retinoscopy in 40 children (3–6 years) in a single blind manner. No statistically significant difference in cycloplegic effect was found between the 2 methods. The results imply that in clinical practice a single instillation of a combination of 0.85% cyclopentolate and 1.5% phenylephrine can be substituted for coventional »full« atropinisation during 3.5 days.

Objective To evaluate the effect of lens design and biomaterial on formation of posterior capsular opacification (PCO) and refractive correction. Animals studied Sixty dogs undergoing bilateral phacoemulsification for mature or diabetic cataracts. Procedures One randomly selected eye received a rounded edge 41D polymethyl-methacrylate (PMMA) intraocular replacement lens (IOL) and the contralateral eye received either a squared edge 41D hydrophilic acrylic IOL (n = 35) or a squared edge 40D hydrophobic acrylic IOL (n = 25). At the (mean = 79 day) reexamination period, PCO was graded using direct slit-lamp observation and by masked observer evaluation of digital images of the IOLs. Streak retinoscopy and B-mode ultrasound were performed at this period. Results The PCO score via direct slit-lamp was significantly lower for the hydrophilic acrylic IOL when compared to the PMMA IOL. Masked observer evaluation of digital images revealed that the acrylic IOLs had lower but generally not statistically significant PCO scores than the PMMA IOLs. Streak retinoscopy showed that the PMMA IOL was significantly closer to emmetropia (+0.44 D) when compared to either the hydrophilic acrylic (+0.96 D) or the hydrophobic acrylic (+1.2 D) IOLs. B-mode ultrasonography revealed the center of the hydrophilic acrylic IOL is 0.31 mm closer to the retina and the center of the hydrophobic acrylic IOL is 0.63 mm further from the retina when compared to the center of the PMMA to retina distance. Conclusions Square edged foldable acrylic IOLs show a predisposition towards generating slightly less PCO than round edged PMMA IOLs in the early postoperative period, however, both acrylic IOLs had greater persistent hyperopia than the PMMA IOLs.

Purpose: The aim of this study was to determine the prevalence of myopia and hyperopia in a population of Polish schoolchildren. Methods: A total of 4422 students were examined (2107 boys and 2315 girls, aged 6–18 years, mean age 11.1, S.D. 3.5). The examination included retinoscopy under cycloplegia induced with 1% tropicamide. Myopia was defined as a spherical equivalent (SE) of at least −0.5 dioptres (D), and hyperopia as a SE of at least +1.0 D. Data analysis was performed using Spearman's rank correlation coefficients and chi-squared test; p-values of

Objective.—To assess whether migraine is associated with retinal microvascular caliber. Background.—Migraine is believed to be associated with vascular disease, but few studies have investigated the relationship between structural microvascular changes and migraine. Design.—Population-based cross-sectional study. Methods.—Participants in the Blue Mountains Eye Study follow-up (1997 to 1999, n = 2335, aged 54+) had retinal photographs taken. A computer-assisted method was used to measure average retinal arteriolar and venular diameters and calculate the arteriole-to-venule ratio. History of migraine was recorded by interview using International Headache Society criteria (1988). Results.—Subjects giving a history of migraine without aura (n = 128) had narrower retinal arterioles than subjects giving a history of migraine with aura (n = 182) or subjects with no migraine history (n = 1619). After multivariate adjustment, mean retinal arteriolar diameter was 4.3 μm (95% confidence interval 0.5, 8.1) narrower in subjects reporting migraine without aura as compared to subjects with no migraine. Conclusions.—Individuals with a history of migraine without aura were more likely to have slightly narrower retinal arteriolar caliber than individuals without migraine. This relationship was not present for migraine with aura. These data support the hypothesis that microvascular disease may be associated with certain types of migraine.

Purpose: To estimate the repeatability of refractive error measurement (REM) in a clinical environment in cataractous, pseudophakic and healthy eyes. Methods: The refractive error of patients referred for cataract surgery or consultation measured by ophthalmic professionals was re-examined and the measurement results were compared. A total of 99 eyes from 99 persons (41 cataractous, 36 pseudophakic and 22 healthy eyes) with visual acuity (VA) of 0.3–1.3 (logMAR 0.52 to − 0.11) were included. The differences between measurements 1 and 2 were calculated as 3-dimensional vector values and spherical equivalents (SEs) and expressed as the coefficient of repeatability (CR). The mean time interval between the first and second examinations was 45 days. Results: The CRs for all eyes for vertical (V), torsional (T) and horizontal (H) vectors were 0.74 D, 0.34 D and 0.93 D, respectively. The CR of SE for all eyes was 0.74 D. Eyes with lower VA (0.3–0.45) had larger variability in vector and SE values but the differences between VA groups were not statistically significant. The difference in the mean defocus equivalent (DE) between measurements 1 and 2 was, however, significantly greater in the group with lower VA. In all VA groups the mean difference vector was very close to the zero vector, which means that there was no systematic difference. Conclusions: Repeatability of refractive error measurements in clinical settings has a certain degree of variability. In this series, the variability in eyes with better VA was not great and was in accordance with earlier findings in healthy eyes. Eyes with lower VA had greater variability due to greater tolerance to defocus. Thus, conclusions concerning changes in the refractive state and the need to make changes in the refractive correction of eyes with poorer vision should be made with caution.

Background: To report the structural and refractive outcome after laser photocoagulation for retinopathy of prematurity (ROP). Methods: Nineteen consecutive patients who had undergone photocoagulation for ROP between 1997 and 2002 at our clinic were examined for this non-comparative, consecutive, interventional, retrospective case series. A total of 37 eyes received either transscleral or transpupillary laser treatment. Data consisted of grade of ROP pre- and postoperatively, birth weight, perioperative and postoperative complications and refraction. Based on indirect ophthalmoscopy, independent observers graded the extent of ROP and determined the postoperative refraction by retinoscopy. Results: A total of 97% of all eyes responded to laser treatment with regression of ROP. Only one eye out of 37 progressed to stage IV B despite photocoagulation and therefore an encircling procedure was performed. After further progression a vitrectomy was carried out. Perioperative complications included haemorrhages in 22% that resorbed spontaneously and cataract formation in one eye (3%). Postoperative refractive errors at mean ages of 23 ± 12 months and 45 ± 14 months were evaluated in 15/19 patients (79%). The spherical equivalents ranged between −8 D and +6 D at the first examination and between −12 D and +7 D at the second examination. In all only 14% of the refracted eyes were myopic. Conclusions: Photocoagulation for ROP in our patients resulted in regression of threshold ROP. In addition, the analyses of the refractive outcomes demonstrated a predominance of hypermetropia in our patients.

Aim: To determine the effect of acute and chronic hyperglycaemia on the refraction and development of the rabbit eye. Methods: Ocular dimensions of five alloxan-induced hyperglycaemic and six control rabbits were measured over 9 weeks using A scan biometry. Refraction was measured using retinoscopy. The animals were 10 weeks of age at the start of the experiment. Results: The acute onset of hyperglycaemia was associated with a fast and stable 2 D hyperopic shift in refraction. Lens thickness increased during the first 2 weeks of hyperglycaemia, returned to near normal thickness after 3–5 weeks of hyperglycaemia and then decreased in thickness in the last 4 weeks of the study. The hyperopic refraction remained unchanged during changes in lens thickness. Nine weeks of hyperglycaemia was associated with a 25% reduction in the growth of both the globe and the lens and a 17% decrease in body mass compared with the controls. Conclusion: The hyperopic refraction change of acute hyperglycaemia is likely to be because of a change in the refractive index of the cortical fibres of the lens and is the probable source of the fluctuating refraction seen in diabetic patients. Chronic hyperglycaemia reduced the axial development of the eye and is the probable source of the chronic hyperopic refraction seen in children with Type I diabetes.

Aims To determine the sensitivity and specificity for sight-threatening eye disease (STED) of the diabetic retinopathy screening scheme for Stockport during the period 1 April 2000 to 31 March 2001. Methods A random sample of screen-negative patients was recalled for further assessment by consultant ophthalmologists. Screen-positive patients, who were referred, were tracked through the hospital system to determine the outcome. Results In a 12-month period, 3510 individuals with diabetes were screened, which is 1.2% of the district population. Sensitivity for STED was 75.8%[95% confidence interval (CI) 49.3, 99.99] and specificity for STED was 99.0% (95% CI 98.6, 99.3). Conclusions The current screening arrangements in Stockport are satisfactory in terms of sensitivity and specificity. Population coverage was 1.2% over 12 months and 1.5% over 15 months and needs to be improved. An integrated computerized register requires further development.

This study aimed to determine the accuracy (and usability) of the Retinomax, a hand-held autorefractor, compared to measurements taken from hand-held retinoscopy (HHR) in a sample of normal 1-year-old children. The study was a method comparison set at four Community Child Health Clinics. Infants (n = 2079) of approximately 1 year of age were identified from birth/immunization records and their caregivers were contacted by mail. A total of 327 infants ranging in age from 46 weeks to 81 weeks (mean 61 weeks) participated in the study. The children underwent a full ophthalmic examination. Under cycloplegia, refraction was measured in each eye by streak retinoscopy (HHR) and then re-measured using the Retinomax autorefractor. Sphere, cylinder, axis of cylinder and spherical equivalent measurements were recorded for HHR and Retinomax instruments, and compared. Across the range of refractive errors measured, there was generally close agreement between the two examination methods, although the Retinomax consistently read around 0.3 D less hyperopic than HHR. Significantly more girls (72 infants, 47.7%), struggled during examination with the Retinomax than boys (52 infants, 29.5%) (P < 0.001). Agreement deteriorated between the two instruments if the patient struggled during the examination (P < 0.001). In general, the Retinomax would appear to be a useful screening instrument in early childhood. However, patient cooperation affects the accuracy of results and is an important consideration in determining whether this screening instrument should be adopted for measuring refractive errors in early infancy.

Dynamic retinoscopy (DR) is an objective technique that has been used successfully to examine accommodative function of non-communicative patients. However, there are few studies examining its repeatability and validity. This paper addresses the repeatability and validity of a form of DR (a modified Nott technique), by comparing results to the Shin-Nippon SRW-5000 Autorefractor whose validity and repeatability have previously been demonstrated. Accommodative responses of 41 subjects (aged 6-43 years) were assessed using DR and the Shin-Nippon SRW-5000 Autorefractor. Three different target demands were used (10, 6 and 4 D). DR was shown to be repeatable for all target demands (paired t-test, p > 0.05). The results demonstrated good agreement between the autorefractor and DR. The results of the present study suggest that DR is a repeatable and valid objective technique for assessing accommodative function.

The evolution of the accommodative function and development of ocular movement are evaluated in a non-clinical paediatric population (1056 subjects) aged 6-12 years, providing means for each age in the optometric tests that evaluate the accommodative amplitude, accommodative facility, accommodative response (lag), and saccadic movements. A comparison of these values between ages (anova) established three distinct trends in the behaviour of these parameters. The accommodative amplitude, measured by modified dynamic retinoscopy, and the evaluation of the saccadic movements by the development of ocular movements [developmental eye movement (DEM)] test showed continuous change with age. The values for monocular and binocular accommodative facility, measured by +/-2.00 D flippers, indicated the need to divide the population into two age groups (6-7 and 8-12 years). Finally, the means of accommodative response, measured by monocular estimation model (MEM) retinoscopy, and the direct observation of saccadic movement revealed no significant differences between ages, establishing a single mean reference value for the age group studied.

The accommodative response in 34 patients with accommodative and binocular disorders was assessed with two different techniques of dynamic retinoscopy used in clinical practice: monocular estimate method (MEM) and Nott retinoscopy. The data obtained by both techniques were compared, evaluating the correlation and agreement between them. Results showed that there were statistically significant differences between the techniques with MEM values being more plus than Nott ones. There was a high correlation between the two techniques (0.90) and the regression analysis indicated that a linear relationship existed between MEM and Nott dynamic retinoscopy, so that accommodative lag value for Nott dynamic retinoscopy would be calculated by dividing the MEM result by 2. However, although both retinoscopies were related, there was a lack of agreement between them (+/-0.53 D) indicating that the two methods are not interchangeable for clinical purposes.

Purpose To determine the distribution of keratometric indices, corneal thickness, anterior chamber depth, pupil diameter and corneal diameter by Orbscan in a young Iranian population. Methods In this cross-sectional study, samples were selected through multistage cluster sampling from among the students of Mashhad University of Medical Sciences, Iran. After performing refraction and retinoscopy, Orbscan was used for imaging. Results Of 1330 selected students, 1121 participated in the study. After applying the exclusion criteria, final analysis was performed on 1051 subjects. The mean age of the subjects was 26.1±3.2 years (19-34 years old). The mean and 95% confidence interval (CI) of maximum keratometry, minimum keratometry, pupil diameter corneal diameter, anterior chamber depth, and central corneal thickness were 44.5(44.4-44.6), 43.1(43.0-43.2), 4.3(4.3-4.4), 11.7(11.7-11.7), 3.7(3.6-3.7) and 550.5 (548.4-552.6), respectively. After adjusting with age and spherical equivalent (SE), the maximum and minimum keratometry, thinnest corneal thickness were higher in females while the corneal diameter and anterior chamber depth were more in males. Corneal diameter and anterior chamber depth showed significant changes with age. The SE was only correlated significantly with maximum keratometry and anterior chamber depth. Conclusion The results of this study showed the normal ranges and averages of some Orbscan indices in a young Iranian population. The insignificant changes of the corneal diameter and anterior chamber depth with age and the differences between males and females in the evaluated indices should be considered in refractive surgery.

Keratoconus is a mysterious disease of cornea with diverse genetic complexity. Past 160 years of molecular genetics revolution has witnessed the identification of candidate genes with multiple loci through genome-wide association studies (GWAS). This article provides key insight into the genetics of keratoconus along with diagnosis, treatment and management. Key Concepts: Keratoconus is a noninflammatory corneal progressive ectasia that is bilateral and asymmetric, characterised by steepening and deformation of the cornea, thinning of the apical cornea and corneal scarring. Patients with moderate keratoconus are observed with Fleischer ring around the cone base due to an accumulation of iron deposits. Also Vogt striae, which are fine vertical lines due to compression of Descemet membrane, can be seen. In keratoconus, the cornea's normal defence system is lost and leads to accumulation of free radicals in the tissue, which can cause structural damage. Monozygotic twins have higher concordance of keratoconus than dizygotic twins, which is shown by their phenotypic similarity. This type of evaluation can be made in situations where a clinical sign does not show a genetic pattern. As far as the age groups that get afflicted with the disease are concerned, the keratoconus-affected individuals between 30–40 years of age are higher than the other groups. Approximately 17 genomic loci have been described from 12 studies based on linkage analysis. This propounds at large the genetic disparities in keratoconus. Further, these studies make possible to consider the mutational effects in different genes that are responsible for the disease. Visual System Homeobox 1 (VSX1) is the most widely reported gene for keratoconus. This gene codes for a transcription factor that helps in ocular development and development of cornea. Mutations in the locus of this gene are reported to be pathogenic and are positive in keratoconus patients. Early signs for diagnosing include irregularity of reflex observed by retinoscopy, distortion of the corneal reflection observed by keratometry and conical contour revealed by the fit of a corneal lens. Nowadays, surgical procedures to selectively replace either the anterior or the posterior layer are used. Keratoplasty is employed to remove the damaged cornea. The distorted cornea is replaced entirely or partially by graft. Entire removal of the keratoconic cornea is called penetrating keratoplasty, whereas if a part of the cornea is removed, it is called lamellar keratoplasty. Keywords: keratoconus; cornea; mutations; GWAS; VSX1

Purpose In this study, we aimed to compare the cycloplegic effect of cyclopentolate HCI 1% and atropine sulphate 1% in patients with refractive accommodative esotropia by means of retinoscopy, autorefractometer and the measurement of lens thickness by biometry. Methods Thirty-two patients with refractive accommodative esotropia aged from 5 to 10 (mean 6.8+/-1.4), had a deviation under 10 prism diopters, and underwent retinoscopic, autorefractometric and biometric study in dry and wet conditions. Results The retinoscopic, autorefractometric and biometric findings of the right eye were 5.10+/-1.21 diopter (D), 5.03+/-1.20 D, 3.43+/-0.16 mm with cyclopentolate, and 5.2+/-1.2 D, 5.2+/-1.2 D, 3.4+/-0.1 mm with atropine. In the left eye, the measurements were 5.2+/-1.4 D, 5.1+/-1.4 D, 3.5+/-0.2 mm with cyclopentolate, and 5.3+/-1.2 D, 5.20+/-1.3 D, 3.4+/-0.2 mm with atropine, respectively. When these obtained data were compared by the Student's t test no statistical significance was found (p > 0.05). Conclusions We suggest that the cyclopentolate cycloplegia applied to the patients with refractive accommodative esotropia is sufficient to produce good cycloplegia, with an effect similar to atropine.

Purpose Between 1992 to 1994 in the Sultanate of Oman, 6292 randomly selected school children from Grade 1 (6-year-olds) and Grade 6 (12-year-olds) were examined for visual acuity. The purpose of this paper is to present results that relate to the prevalence of myopia in this population. Methods All children with uncorrected visual acuity below 0.5 in one or both eyes received a thorough eye examination including cycloplegic retinoscopy. Results In the 6-year-olds there was an overall myopia (> or =-1.0 D) of 0.56% and in the 12-year-olds there was 5.16%. In rural, remote areas there was statistically significantly less myopia in the older group when compared with the rest of the country. In the town of Nizwa in the region of Dakhlia, the value for high myopia (> or =-7.0 diopters) in 12-year-old girls was 2.82% compared to an average prevalence 0.13%. Conclusion In the Sultanate of Oman the prevalence of myopia showed consistency with findings in Europe and North America. There was significantly less myopia in remote areas. An increased prevalence of high myopia was seen in one of Oman's major cities.

The aim of this study was to analyse the refractive state of four different groups of children: those with spastic cerebral palsy (CP), aged between 7 and 81 months (N=50); psychomotor retardation, aged between 19 and 70 months (N=16); other neuromotor dysfunctions, aged between 12 and 75 months (N=37); and without psychomotor retardation, aged between 9 and 73 months (N=181). Refractive errors were determined using cycloplegic retinoscopy and non-cycloplegic retinoscopy (Mohindra's technique). We found higher percentages of hyperopia, tendency toward hyperopia, and other refractive anomalies in all the pathological groups of children than in the non-pathological control groups. Children from both the non-CP pathological control group and the group with psychomotor retardation had similar or even higher levels of hyperopia than children from the group with spastic CP. Our results in different age groups indicate a less effective normal emmetropization course in all the pathological groups of children studied. The correction of refractive errors is needed in these children before the end of the neural plasticity period.