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Background: To investigate the prevalence and correction of anisometropia among primary school children in northwestern China. Methods: A cross‐sectional school‐based study was conducted in Shaanxi Province. Visual acuity (VA) and autorefraction without cycloplegia were assessed in all participants, and some received axial length (AL) measurements. Anisometropia was categorised based on spherical equivalent (SE), cylindrical (CYL), and AL. The prevalence of anisometropia and refractive correction across different ages and sexes, and correlations between ocular parameters, were analysed. Results: The study included 29 153 children aged 6–12 (mean age 9.52 ± 1.73 years) for VA and autorefraction measurements, and 1176 children for AL measurements. The prevalence of myopia (SE ≤ −0.50 D), hyperopia (SE ≥ +0.50 D), and anisometropia (interocular SE difference ≥1.00 D) was 65.26%, 15.09%, and 16.50%, respectively. Anisometropia severity, based on SE (χ2 = 443.758, p < 0.001), CYL (χ2 = 41.669, p < 0.001), and AL (χ2 = 95.505, p < 0.001), increased with age, with no significant differences between sexes. Interocular SE difference correlated with interocular spherical power (r = 0.806, p < 0.001), CYL (r = 0.21, p < 0.001), and AL (r = 0.365, p < 0.001). Additionally, interocular CYL difference was positively correlated with interocular AL difference (r = 0.16, p < 0.001). Despite the high prevalence of anisometropia, less than 30% of affected children received refractive correction. Conclusions: Anisometropia of SE, CYL, and AL increased progressively with age. Despite the elevated prevalence of anisometropia, the utilisation of refractive correction remained strikingly low. [ABSTRACT FROM AUTHOR]

(1) Background: Defining the optimum center for laser refractive corrections is difficult, with many of the available approaches having pros and cons. Decentered ablations result in undesirable side effects like halos, glare, monocular diplopia, and a reduction in visual acuity; (2) Methods: The ideal centration in refractive corrections should fulfil three requirements: covering a scotopic pupil; respecting the visual axis; and minimizing tissue removal. The implications of different centration strategies are discussed and shown graphically; (3) Results: Oversized asymmetric offset ablation faces fewer difficulties in registering static cyclotorsion, features less tissue wastage compared to a symmetric offset, and includes a certain amount of coma (and trefoil) in the profile, benefiting eyes with a pupil offset, which typically present with relevant amounts of coma and trefoil corneal aberrations due to decentered optics; (4) Conclusions: There is a need for a flexible choice of centration in refractive procedures to design customized and non-customized treatments optimally. An ideal optical zone covering the pupil with the widest entrance may be as important as a centration reference. [ABSTRACT FROM AUTHOR]

BackgroundAmblyopia is the most common developmental vision disorder in children. The initial treatment consists of refractive correction. When insufficient, occlusion therapy may further improve visual acuity. However, the challenges and compliance issues associated with occlusion therapy may result in treatment failure and residual amblyopia. Virtual reality (VR) games developed to improve visual function have shown positive preliminary results. The aim of this study is to determine the efficacy of these games to improve vision, attention, and motor skills in patients with residual amblyopia and identify brain-related changes. We hypothesize that a VR-based training with the suggested ingredients (3D cues and rich feedback), combined with increasing the difficulty level and the use of various games in a home-based environment is crucial for treatment efficacy of vision recovery, and may be particularly effective in children.MethodsThe AMBER study is a randomized, cross-over, controlled trial designed to assess the effect of binocular stimulation (VR-based stereoptic serious games) in individuals with residual amblyopia (n = 30, 6-35 years of age), compared to refractive correction on vision, selective attention and motor control skills. Additionally, they will be compared to a control group of age-matched healthy individuals (n = 30) to account for the unique benefit of VR-based serious games. All participants will play serious games 30 min per day, 5 days per week, for 8 weeks. The games are delivered with the Vivid Vision Home software. The amblyopic cohort will receive both treatments in a randomized order according to the type of amblyopia, while the control group will only receive the VR-based stereoscopic serious games. The primary outcome is visual acuity in the amblyopic eye. Secondary outcomes include stereoacuity, functional vision, cortical visual responses, selective attention, and motor control. The outcomes will be measured before and after each treatment with 8-week follow-up.DiscussionThe VR-based games used in this study have been conceived to deliver binocular visual stimulation tailored to the individual visual needs of the patient, which will potentially result in improved basic and functional vision skills as well as visual attention and motor control skills.Trial registrationThis protocol is registered on ClinicalTrials.gov (identifier: NCT05114252) and in the Swiss National Clinical Trials Portal (identifier: SNCTP000005024).

Abstract Introduction The phase 3, randomized, vehicle-controlled, 14-day VIRGO study evaluated the efficacy and safety of twice-daily dosing of pilocarpine hydrochloride ophthalmic solution 1.25% (Pilo) in presbyopia. On VIRGO exit, a companion study was conducted to assess the patient experience with presbyopia and satisfaction with Pilo. Methods Recruited individuals completed the Presbyopia Patient Satisfaction Questionnaire (PPSQ) plus a three-part exit survey, or a live interview. The PPSQ evaluated respondents’ experience with Pilo. Survey parts 1 and 2 evaluated experience managing presbyopia before and during VIRGO, respectively; part 3 assessed future possibilities of using Pilo in real-world situations. The interview further informed the interviewees’ experience with presbyopia and Pilo. The primary endpoint was responders (%) in each rating category of the PPSQ items 1–7; the secondary endpoints were summary of categorical (survey) and qualitative (interviews) responses. Results The PPSQ and survey included 62 participants who received Pilo (N = 28) or vehicle (N = 34) in VIRGO; the interview included ten participants (Pilo, N = 4; vehicle, N = 6). Per the PPSQ, 64.3% of Pilo users reported vision improvement, including 17.9% with complete improvement; ≥ 46.4% were satisfied/very satisfied with their ability to perform daily activities, see up close unaided, and read in dim light. Among vehicle users, these percentages were 35.3%, 0%, and ≤ 23.5%, respectively. In both subgroups, ≥ 67.9% were interested in using Pilo or Pilo and eyeglasses/contact lenses in the future. Per the interview, vehicle users (n = 6/6) found the eyedrop easy to use but none experienced meaningful near-vision improvements, stopped using other correction method(s) part of the day, were satisfied with the eyedrop, preferred it over their previous correction method(s), or would continue using it if prescribed. Conversely, 75% (n = 3/4) of Pilo users responded positively to each of these six criteria. Conclusions Findings validate the VIRGO results and improve our understanding of the patient experience, demonstrating improved vision and satisfaction with Pilo (vs. vehicle) when performing daily activities.

Introduction: The phase 3, randomized, vehicle-controlled, 14-day VIRGO study evaluated the efficacy and safety of twice-daily dosing of pilocarpine hydrochloride ophthalmic solution 1.25% (Pilo) in presbyopia. On VIRGO exit, a companion study was conducted to assess the patient experience with presbyopia and satisfaction with Pilo. Methods: Recruited individuals completed the Presbyopia Patient Satisfaction Questionnaire (PPSQ) plus a three-part exit survey, or a live interview. The PPSQ evaluated respondents' experience with Pilo. Survey parts 1 and 2 evaluated experience managing presbyopia before and during VIRGO, respectively; part 3 assessed future possibilities of using Pilo in real-world situations. The interview further informed the interviewees' experience with presbyopia and Pilo. The primary endpoint was responders (%) in each rating category of the PPSQ items 1–7; the secondary endpoints were summary of categorical (survey) and qualitative (interviews) responses. Results: The PPSQ and survey included 62 participants who received Pilo (N = 28) or vehicle (N = 34) in VIRGO; the interview included ten participants (Pilo, N = 4; vehicle, N = 6). Per the PPSQ, 64.3% of Pilo users reported vision improvement, including 17.9% with complete improvement; ≥ 46.4% were satisfied/very satisfied with their ability to perform daily activities, see up close unaided, and read in dim light. Among vehicle users, these percentages were 35.3%, 0%, and ≤ 23.5%, respectively. In both subgroups, ≥ 67.9% were interested in using Pilo or Pilo and eyeglasses/contact lenses in the future. Per the interview, vehicle users (n = 6/6) found the eyedrop easy to use but none experienced meaningful near-vision improvements, stopped using other correction method(s) part of the day, were satisfied with the eyedrop, preferred it over their previous correction method(s), or would continue using it if prescribed. Conversely, 75% (n = 3/4) of Pilo users responded positively to each of these six criteria. Conclusions: Findings validate the VIRGO results and improve our understanding of the patient experience, demonstrating improved vision and satisfaction with Pilo (vs. vehicle) when performing daily activities. [ABSTRACT FROM AUTHOR]

Purpose: Keeping the head in a neutral position is requisite for glasses/lenses/head-up designs, the suitability of oculo-plastic surgery and for the grading the eye shift. Anatomically incompatible glasses are one of the common problems affecting accommodation, reducing comfort and disturbing by causing symptoms such as dizziness and nausea. The oculo-palpebral measurements act as a key determinant in symmetrical facial attractiveness. This study aims to investigate the most effective oculo-palpebral landmarks, head-neutral as the ideal position, taking into account of individual anatomical differences of these patients. Methods: 100 females and 100 males aged between 18 and 20 years were photographed. Digital photogrammetric measurements were made with the ImageJ program. Interpupillary and interhelical distances, besides bilateral palpebral fissure length and height, and iris diameter were calculated on front-facing photographs. Results: Mean interpupillary distance was measured wider in males than in females. The mean length of palpebral fissure was 31 mm; palpebral fissure height was 10 mm. These figures were valid in both eyes and gender. The interhelical distance was calculated as the mean and was measured longer in men. Since the measurement values were the same in both sexes and on both sides, they were determined as important landmarks for controlling the head-neutral position, evaluating whether there was a deviation in the eye, and measuring the numerical value when detected. Conclusion: It is essential to check the side-symmetry of the patient's palpebral fissure height, palpebral fissure length, diameter of iris and corneal depth during oculo-plastic invention and artificial design. [ABSTRACT FROM AUTHOR]

(1) Background: Defining the optimum center for laser refractive corrections is difficult, with many of the available approaches having pros and cons. Decentered ablations result in undesirable side effects like halos, glare, monocular diplopia, and a reduction in visual acuity; (2) Methods: The ideal centration in refractive corrections should fulfil three requirements: covering a scotopic pupil; respecting the visual axis; and minimizing tissue removal. The implications of different centration strategies are discussed and shown graphically; (3) Results: Oversized asymmetric offset ablation faces fewer difficulties in registering static cyclotorsion, features less tissue wastage compared to a symmetric offset, and includes a certain amount of coma (and trefoil) in the profile, benefiting eyes with a pupil offset, which typically present with relevant amounts of coma and trefoil corneal aberrations due to decentered optics; (4) Conclusions: There is a need for a flexible choice of centration in refractive procedures to design customized and non-customized treatments optimally. An ideal optical zone covering the pupil with the widest entrance may be as important as a centration reference.

Purpose: The aim of this study was to examine the quality of assessment and the utilisation of optical low vision aids (OLVAs) among people with visual impairment (VI) in Taiwan. Methods: The study included 577 participants between 4 and 100 years of age (314 males and 263 females). All participants had been certified by the Ministry of the Interior of Taiwan, indicating that they had undergone a thorough and comprehensive low vision assessment, including evaluation of visual acuity (VA), contrast sensitivity, colour vision, visual fields and glare disability. Furthermore, all participants who consented to refraction had received prescriptions for OLVAs. Result: All participants were prescribed one or more OLVAs such as eyeglasses, tinted lenses, magnifiers, closed‐circuit television magnifiers, telescopes, or screen magnifiers. Among the 577 individuals, 515 received correction for refractive errors, providing the best‐corrected VA (BCVA). The improvement in VA was significant at both distance and near, improving from 1.29 ± 0.55 to 1.01 ± 0.52 logMAR (p < 0.001) and from 1.29 ± 0.56 to 1.01 ± 0.52 logMAR (p < 0.001), respectively. Eyeglasses were the primary OLVAs chosen by 333 participants (64.7%), while 53.3%–80.3% of participants combined eyeglasses with other OLVAs to enhance their visual performance. Conclusions: The most commonly used and effective OLVA was eyeglasses. Skilfully utilising appropriate refractive and VA measurements is crucial for determining the most suitable and beneficial OLVA for individuals with VI. [ABSTRACT FROM AUTHOR]

Abstract Background Amblyopia is the most common developmental vision disorder in children. The initial treatment consists of refractive correction. When insufficient, occlusion therapy may further improve visual acuity. However, the challenges and compliance issues associated with occlusion therapy may result in treatment failure and residual amblyopia. Virtual reality (VR) games developed to improve visual function have shown positive preliminary results. The aim of this study is to determine the efficacy of these games to improve vision, attention, and motor skills in patients with residual amblyopia and identify brain-related changes. We hypothesize that a VR-based training with the suggested ingredients (3D cues and rich feedback), combined with increasing the difficulty level and the use of various games in a home-based environment is crucial for treatment efficacy of vision recovery, and may be particularly effective in children. Methods The AMBER study is a randomized, cross-over, controlled trial designed to assess the effect of binocular stimulation (VR-based stereoptic serious games) in individuals with residual amblyopia (n = 30, 6–35 years of age), compared to refractive correction on vision, selective attention and motor control skills. Additionally, they will be compared to a control group of age-matched healthy individuals (n = 30) to account for the unique benefit of VR-based serious games. All participants will play serious games 30 min per day, 5 days per week, for 8 weeks. The games are delivered with the Vivid Vision Home software. The amblyopic cohort will receive both treatments in a randomized order according to the type of amblyopia, while the control group will only receive the VR-based stereoscopic serious games. The primary outcome is visual acuity in the amblyopic eye. Secondary outcomes include stereoacuity, functional vision, cortical visual responses, selective attention, and motor control. The outcomes will be measured before and after each treatment with 8-week follow-up. Discussion The VR-based games used in this study have been conceived to deliver binocular visual stimulation tailored to the individual visual needs of the patient, which will potentially result in improved basic and functional vision skills as well as visual attention and motor control skills. Trial registration This protocol is registered on ClinicalTrials.gov (identifier: NCT05114252) and in the Swiss National Clinical Trials Portal (identifier: SNCTP000005024).

AIM:To determine the prevalence of screening myopia and refractive correction among primary and middle school students aged from 6-18 years in Xuzhou city, Jiangsu Province.METHODS: A cross-sectional cluster sampling study was designed. The total number of screened students was 63 488 in 70 schools from Xuzhou city in this study from September 2020 to December 2020. After excluding the unqualified data, 58 149 students aged 6-18 years were included to analyse. The prevalence of screening myopia, refractive correction and full correction with the aspect of different ages, genders, regions and degrees of myopia were described.RESULTS: The overall rate of screening myopia and refractive correction were 49.26% and 31.11%, respectively and both showed an increasing trend with age(P

Purpose: To investigate whether the movement of a rigid sphero‐cylindrical contact lens has a greater impact on the visual image quality in highly aberrated eyes than in normal eyes. Methods: For 20 normal and 20 keratoconic SyntEyes, a previously determined best sphero‐cylindrical rigid lens was permitted to shift by up to ±1 mm from the line of sight and rotate up to ±15°. Each of the 52,111 lens locations sampled was ray‐traced to determine the influence on the wavefront aberration. In turn, the logarithm of visual Strehl ratio (log10[VSX]) was calculated for each aberration structure and was used to estimate the associated changes in logMAR visual acuity. Finally, contour surfaces of two‐letter change in visual acuity were plotted in three‐dimensional misalignment space, consisting of decentrations in the x and y directions and rotation, and volumes within these surfaces were calculated. Results: The variations in image quality within the misalignment space were unique to each eye. A two‐letter loss was generally reached with smaller misalignments in keratoconic eyes (10.5 ± 4.7° of rotation or 0.27 ± 0.13 mm of shift) than in normal eyes (13.4 ± 1.8° and 0.39 ± 0.15 mm, respectively) due to larger cylindrical errors. For keratoconic eyes, on average, 14.4 ± 14.9% of misalignment space saw VSX values above the lower normal VSX threshold, well below the values of normal eyes of 48.5 ± 18.5%. In some eyes, a specific combination of lens shift and lens rotation away from the line of sight leads to a simulated improvement in visual image quality. Conclusion: Variations in visual image quality due to the misalignment of rigid sphero‐cylindrical contact lens corrections are larger for keratoconic eyes than for normal eyes. In some cases, a specific misalignment may improve visual image quality, which could be considered in the design of the next generation of rigid contact lenses. [ABSTRACT FROM AUTHOR]

Amblyopia is the most common cause for preventable monocular visual loss in children. Visual system at birth is at a stage of dramatic developmental neural plasticity. Abnormal visual impulses from eyes (e.g., visual deprivation and refractive error) can affect normal anatomical and functional organization of the system. Abnormal cortical changes thus produced can be reversed if proper treatment is instituted during this time. This so-called critical period was thought to extend from birth to 7–8 years. However, now, it is understood that cortical plasticity though reduced may extend up to 6th decade of life and this accounts for increased interest in the management of adult amblyopia. Early detection and instituting treatment on detection are important for achieving better outcomes. Classical amblyopia treatment modalities include optical correction of significant refractive errors, occlusion therapy and penalization. Pharmacologic therapy, binocular therapy, and liquid crystal display eyeglasses are the newer treatment options. This review gives a simplified update of amblyopia including simplified pathophysiological concept in different types of amblyopia which will be useful to the clinician. Recent treatment options available for treatment including that in adult amblyopia are also discussed. Literature search using Google scholar, PubMed with a combination of words appropriate to this article was done and relevant articles were reviewed.

Purpose: To expand the SyntEyes keratoconus (KTC) model to assess the Visual Image Quality (VIQ) of sphero‐cylindrical spectacle and rigid contact lens corrections as keratoconus progresses. Methods: The previously published SyntEyes KTC eye model to determine best sphero‐cylindrical spectacle and rigid contact lens correction in keratoconic eyes was expanded to include the natural progression of keratoconus, thus allowing the assessment of corrected VIQ with disease progression. Results: As keratoconus progresses, the pattern of visual Strehl ratio (VSX) in correction space for spectacles alters from a typical hourglass into a shell pattern. The former would guide the subjective refraction towards the optimal correction while the latter is relatively insensitive to large dioptric steps. In 15 out of the 20 SyntEyes, the shell pattern eventually produces two foci on different sides of the correction space separated by a clinically significant dioptric difference with a similar, albeit lower VIQ. Wearing the best possible spectacle corrections provided an average gain of up to 3.5 lines of logMAR visual acuity compared to the uncorrected cases, which increased to 5.5 lines for the best rigid contact lens correction. Continuing to wear a spectacle correction as the disease progresses often leads to a VIQ that is almost as bad as the uncorrected case. Continuing to wear a rigid contact lens correction as the disease progresses maintains a relatively high level of VIQ, albeit in the low range for typically well‐corrected normal eyes. Conclusions: The results reflect the clinical experience that subjective refraction is difficult in highly‐aberrated keratoconic eyes, the benefit of spectacle correction is short lived and that rigid contact lenses provide better and more stable VIQ with disease progression. Other aspects, such as the presence and behaviour of the second focus in some cases, remain to be confirmed clinically. [ABSTRACT FROM AUTHOR]

Background: The Quality of Life Impact Refractive Correction (QIRC) questionnaire is a Rasch-validated instrument to assess the quality of life of ametropes with refractive correction. The original QIRC was validated in the United Kingdom. This study aimed to validate the Malay version of the QIRC among refractive correction wearers in Malaysia using Rasch analysis.Methods: The original 20-item QIRC was forward-backward translated into Malay in preparation for the Pilot Malay QIRC. The pilot version was pre-tested on 105 spectacle/contact lens-corrected myopes, and the results were reviewed and cross-culturally adapted to produce the Final Malay QIRC. The final version was self-administered to a new sample of 304 participants. A Rasch analysis was conducted to evaluate the items and response categories of the Pilot and the Final Malay QIRC. Test-retest reliability was also analysed on the Final Malay QIRC.Results: Based on the pre-test findings, Rasch analysis revealed a multidimensional scale (functional scale [Items 1 to 13] and emotional scale [Items 14 to 20], which were separated in subsequent analysis), unordered response categories for the functional scale (Category 3 was collapsed into Category 2), one misfit item (Item 3 was removed) and six items required modification (Items 4, 6 to 9, and 12 were reworded and cross-culturally adapted). In the Final Malay QIRC, both the functional and emotional scales had ordered response categories, good person reliability (functional, 0.80; emotional, 0.81) and separation index (functional, 2.01; emotional, 2.06), well-targeted items (targeting precision: functional, 0.28 logits; emotional, 0.08 logits), and satisfactory fit statistics (infit and outfit mean square were less than 1.50 for all items). A noticeable differential item functioning (DIF) between genders was found in Item 18 (DIF contrast, 0.40 logits; p = 0.04). Test-retest reliability analysis demonstrated a high intraclass correlation coefficient (0.94) and Cronbach's alpha (0.97) with a coefficient of repeatability of ±8.14 units.Conclusions: The Malay-translated version of the QIRC has good psychometric characteristics for assessing the quality of life of refractive correction wearers in Malaysia. This translated and cross-culturally adapted Malay QIRC is a valid and reliable instrument that can be used in routine clinical practice. [ABSTRACT FROM AUTHOR]

Context The use of small incision lenticule extraction (SMILE) for compound myopic astigmatism has been subject to experimentation in the recent years. Furthermore, examination of corneal alterations has revealed conflicting conclusions, which could be attributable to demographic variation. Aims The aim of this study was to measure visual and keratometric efficacy of SMILE and correlate spherical equivalent (SE) decrements to keratometric alterations. Settings and design This was a prospective nonrandomized study. Thirty eyes of 15 patients were included in the study. Preoperative assessment included oculus Pentacam analysis. Patients were followed-up for up to 3 months, after which tomography was repeated. Statistical analysis used Descriptive statistics, t test, and linear regression analysis were carried out. Results There was a statistically significant improvement in postoperative uncorrected distance visual acuity and SE and a statistically significant change in Q value (P

AIM: To evaluate the refractive correction for standard automated perimetry (SAP) in eyes with refractive multifocal contact lenses (CL) in healthy young participants. METHODS: Twenty-nine eyes of 29 participants were included. Accommodation was paralyzed in all participants with 1% cyclopentolate hydrochloride. SAP was performed using the Humphrey SITA-standard 24-2 and 10-2 protocol under three refractive conditions: monofocal CL corrected for near distance (baseline); multifocal CL corrected for distance (mCL-D); and mCL-D corrected for near vision using a spectacle lens (mCL-N). Primary outcome measures were the foveal threshold, mean deviation (MD), and pattern standard deviation (PSD). RESULTS: The foveal threshold of mCL-N with both the 24-2 and 10-2 protocols significantly decreased by 2.2-2.5 dB CONCLUSION: Despite the induced mydriasis and the optical design of the multifocal lens used in this study, our results indicated that, when the dome-shaped visual field test is performed with eyes with large pupils and wearing refractive multifocal CLs, distance correction without additional near correction is to be recommended.

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Purpose: To review the safety of the implantable phakic contact lens (IPCL V1, Caregroup Sight Solutions, India) for correction of myopia and myopic astigmatism. Methods: Retrospective interventional case series including 134 eyes which underwent IPCL implantation for correction of myopia and myopic astigmatism at a tertiary eye care hospital in South India. Intraoperative and postoperative complications were analyzed. The following parameters were analyzed at preoperative and 1, 6 and 12 month postoperative visits: visual acuity (in logMAR) and manifest refraction, slit lamp bio microscopy, dilated fundus examination, IOP and endothelial cell density measurement. Results: No intraoperative complications were noted. Cataract was the most common postoperative complication, wherein three eyes (2.2%) underwent observation for visually insignificant anterior subcapsular cataract and one eye (0.7%) required surgical intervention. Four eyes developed transient increased IOP due to steroid response (3 eyes) and pupillary block glaucoma (1 eye). The endothelial cell loss noted over a 1-year follow-up was 2.01%±4.12% (P=0.71). One eye developed hypopyon on the third postoperative day, which resolved subsequently with an unaided vision of 20/20. No vision threatening complications were noted. The mean follow-up in the cohort was 25.66±16.45 months. Conclusion: The IPCL is a safe and effective treatment modality for correction of myopia and myopic astigmatism. [ABSTRACT FROM AUTHOR]

Context The use of small incision lenticule extraction (SMILE) for compound myopic astigmatism has been subject to experimentation in the recent years. Furthermore, examination of corneal alterations has revealed conflicting conclusions, which could be attributable to demographic variation. Aims The aim of this study was to measure visual and keratometric efficacy of SMILE and correlate spherical equivalent (SE) decrements to keratometric alterations. Settings and design This was a prospective nonrandomized study. Thirty eyes of 15 patients were included in the study. Preoperative assessment included oculus Pentacam analysis. Patients were followed-up for up to 3 months, after which tomography was repeated. Statistical analysis used Descriptive statistics, t test, and linear regression analysis were carried out. Results There was a statistically significant improvement in postoperative uncorrected distance visual acuity and SE and a statistically significant change in Q value (P<0.001). The mean residual SE postoperatively was −0.14 D. A highly statistically significant negative correlation existed between SE difference and mean K difference with r=−0.980 and P value less than 0.001, and a highly statistically significant positive correlation existed between SE difference and Q value difference, with r=0.787 and P value less than 0.001. Conclusion SMILE is a safe and effective technique to correct cases with myopic astigmatism with an SE of up to −10 D, and a predictable positive correlation could be established between decrements in SE and decrements in anterior corneal steepening. [ABSTRACT FROM AUTHOR]

In this work we look at 3D acquisition of semi-submerged structures with a triangulation based underwater laser scanning system. The motivation is that we want to simultaneously capture data above and below water to create a consistent model without any gaps. The employed structured light scanner consist of a machine vision camera and a green line laser. In order to reconstruct precise surface models of the object it is necessary to model and correct for the refraction of the laser line and camera rays at the water-air boundary. We derive a geometric model for the refraction at the air-water interface and propose a method for correcting the scans. Furthermore, we show how the water surface is directly estimated from sensor data. The approach is verified using scans captured with an industrial manipulator to achieve reproducable scanner trajectories with different incident angles. We show that the proposed method is effective for refractive correction and that it can be applied directly to the raw sensor data without requiring any external markers or targets. [ABSTRACT FROM AUTHOR]

Purpose: The optimal management of infantile nystagmus syndrome (INS) is still unclear. Contact lenses (CL) may be superior to glasses in improving visual function in INS but it is not known whether their beneficial effects are due to optical correction alone, or to an additional proprioceptive effect, and whether soft CLs would be as effective as rigid CLs. There is little data on feasibility and and the present study aimed to provide this information. Methods: We completed a pilot Randomized Control Trial (RCT) at a single tertiary referral centre in London, UK. We enrolled 38 adults with idiopathic INS and randomised them to either plano CL (with corrective spectacles if required) or to corrective CL. CL wear was required for a minimum of 2 weeks. Primary outcome measures were feasibility and safety of CL wear in INS; secondary outcome measures were visual acuity and nystagmus waveform parameters. Results: 27 completed the study (27/38,71%). 4 partcipants withdrew due to difficulty with CL insertion/removal and 7 were lost to follow up. CL tolerability was high (24/27,89%) - 2 found the CLs irritant, and 1 had an exacerbation of allergic eye disease. At two weeks, mean improvement in binocular visual acuity from baseline with plano CLs was 0.07 logMAR (95% confidence interval (CI: 0.03-0.11) and 0.06 logMAR with fully corrective CLs (95% CI:0.02-0.1). Mean improvement in the eXpanded Nystagmus Acuity Function (NAFX, a nystagmus acuity function based on eye movement recording) with plano CLs was -0.04(95% CI: -0.08-0.005) and -0.05 with fully corrective CLs(95% CI: -0.09–0.003). Conclusions: CLs are well tolerated, with a low risk profile. Whilst our study was not powered to detect significant changes in BCVA and waveform parameters between treatment arms, we observed a trend towards an improvement in visual function at two weeks from baseline with CLs. [ABSTRACT FROM AUTHOR]

Blue-intra-tissue refractive index shaping (Blue-IRIS) is a new approach to laser refractive correction of optical aberrations in the eye, which alters the refractive index of the cornea rather than changing its shape. Before it can be implemented in humans, it is critical to establish whether and to what extent, Blue-IRIS damages the cornea. Here, we contrasted the impact of −1.5 D cylinder refractive corrections inscribed using either Blue-IRIS or femtosecond laser in-situ keratomileusis (femto-LASIK) on corneal cell viability. Blue-IRIS was used to write a −1.5 D cylinder gradient index (GRIN) lens over a 2.5 mm by 2.5 mm area into the mid-stromal region of the cornea in six freshly-enucleated feline eyes. The same correction (−1.5 D cylinder) was inscribed into another four cat eyes using femto-LASIK. Six hours later, all corneas were processed for histology and stained for terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling (TUNEL) and p-γ-H2AX to label damaged cells. In Blue-IRIS-treated corneas, no tissue was removed and TUNEL-stained cells were confined to the laser focal zone in the stroma. In femto-LASIK, photoablation removed 14 μm of anterior stroma, but in addition, TUNEL-positive cells clustered across the femto-flap, the epithelium at the flap edges and the stroma below the ablation zone. Keratocytes positive for p-γ-H2AX were seen adjacent to all Blue-IRIS focal zones, but were completely absent from femto-LASIK-treated corneas. Unlike femto-LASIK, Blue-IRIS attains refractive correction in the cornea without tissue removal and only causes minimal, localized keratocyte death within the laser focal zones. In addition, Blue-IRIS induced DNA modifications associated with phosphorylation of γ-H2AX in keratocytes adjacent to the laser focal zones. We posit that this p-γ-H2AX response is related to alterations in chromatin structure caused by localized changes in osmolarity, a possible mechanism for the induced refractive index changes. [ABSTRACT FROM AUTHOR]

Refractive errors are the leading cause of visual impairment and at the same time the most treatable cause of visual impairment in children and students. The aim of this study is to determine the prevalence of the unmet need for refractive correction and the spectacle coverage rate among 7-year-old Iranian children with refractive errors. The present cross-sectional study was performed in 2013 through multistage cluster sampling across eight cities in Iran. For ail students, noncycloplegic autorefraction was done by a technician. The unmet need for glasses was defined as the ratio of people who did not have glasses or their vision with their current glasses was worse than 6/12 despite achieving 6/12 or better visual acuity with proper correction. A total of 67 schools were selected by multistage cluster sampling; 4106 subjects participated in the study (response rate, 89%), and 48.2% (n= 1979) were girls. The prevalence of spectacle need was 4.11% (95% confidence interval [CI: 3.19-5.04]), the unmet need was 2.74% (95% CI [1.89-3.59]), and the spectacle coverage rate (met need/[met need + unmet need]) was 33.3%. Also, the unmet need in children whose families were in the low e r income quartile was 7.14 times the rate seen in children in the upper income quartile. The concentration index for the unmet need was -.27 (±.05). The findings of this study confirm that in light of the detrimental effects of refractive errors in schoolchildren's academic progress and their future, identification of the students who live in poorer families and have multiple risk factors for developing vision disorders should be a health priority . [ABSTRACT FROM AUTHOR]

Aims: To promote consideration of whether patients should be encouraged to continue wearing a refractive correction in cases where the vision in the amblyopic eye remains very poor. To highlight the benefits of full refractive correction in cases of a densely amblyopic eye when there is no improvement in the visual acuity. Method: A case is described where a young adult presented in clinic with a secondary strabismus with eccentric fixation, a grossly amblyopic eye due to stimulus deprivation, nystagmus and diplopia. Results: Once the full refractive correction was prescribed, the cosmesis improved and the diplopia was eliminated. However, there was no improvement in the visual acuity of the amblyopic eye. Conclusion: All patients should be refracted in house and the full prescription ordered. The patient should then be re-assessed by an orthoptist to decide on the best management options.

Purpose: The aim of this study was to assess the impact of refractive correction [spectacles vs rigid gas-permeable contact lenses (RGP CLs)] on the vision-related quality of life (VR-QoL) obtained with the standardized questionnaire, NEI-VFQ-25, in keratoconus patients compared with healthy myopic subjects.Methods: The Spanish version of NEI-VFQ-25 was administered two consecutive times to 25 keratoconus patients (RGP CL wearers) and 25 healthy myopic subjects (RGP and soft CL wearers). The first time was to assess the VR-QoL for spectacle wearing, such as those for refractive correction, and the second time was for CL wearing.Results: Keratoconus patients showed a lower VR-QoL impairment (P < 0.01) than healthy subjects in the total and all subscale score of NEI-VFQ-25 related to wearing spectacles. With CL correction, keratoconus patients showed a VR-QoL improvement with statistically significant differences (P < 0.04) in only four subscales, including distance activities, mental health, color vision and peripheral vision, compared with healthy subjects. In the keratoconus group, compared to spectacle use, CL wear improved the VR-QoL score (P = 0.01) and all subscales except for ocular pain (P < 0.01) and mental health (P = 0.25).Conclusions: The use of the NEI-VFQ-25 to explore the difference in the VR-QoL between healthy subjects and patients with keratoconus provides further evidence of improved VR-QoL with RGP CL wear compared with spectacles in keratoconus patients. RGP CL management in keratoconus patients could minimize the impact of the disease on the patient's well-being. [ABSTRACT FROM AUTHOR]

Purpose To determine whether dizziness and falls rates change due to routine cataract surgery and to determine the influence of spectacle type and refractive factors. Methods Self-reported dizziness and falls were determined in 287 patients (mean age of 76.5 ± 6.3 years, 55% females) before and after routine cataract surgery for the first (81, 28%), second (109, 38%) and both eyes (97, 34%). Dizziness was determined using the short-form of the Dizziness Handicap Inventory. Six-month falls rates were determined using self-reported retrospective data. Results The number of patients with dizziness reduced significantly after cataract surgery (52% vs 38%; χ2 = 19.14, p < 0.001), but the reduction in the number of patients who fell in the 6-months post surgery was not significant (23% vs 20%; χ2 = 0.87, p = 0.35). Dizziness improved after first eye surgery (49% vs 33%, p = 0.01) and surgery on both eyes (58% vs 35%, p < 0.001), but not after second eye surgery (52% vs 45%, p = 0.68). Multivariate logistic regression analyses found significant links between post-operative falls and change in spectacle type (increased risk if switched into multifocal spectacles). Post-operative dizziness was associated with changes in best eye visual acuity and changes in oblique astigmatic correction. Conclusions Dizziness is significantly reduced by first (or both) eye cataract surgery and this is linked with improvements in best eye visual acuity, although changes in oblique astigmatic correction increased dizziness. The lack of improvement in falls rate may be associated with switching into multifocal spectacle wear after surgery. [ABSTRACT FROM AUTHOR]

Amblyopia is one of the most significant paediatric disorders in ophthalmic and orthotic practice and it is the most common cause of monocular visual loss. It is usually unilateral. It can be bilateral, usually where there is high bilateral refractive error or other binocular pathology. The aim of the study is to determine the effectiveness of spectacles alone in the treatment of anisometropia in paediatric population. This was a hospital based prospective study conducted at Regional Hospital of Fier in Albania between 2012 and 2014. A total of 40 patients (80 eyes) with mean age 11.2 ± 2.72 years were included in the study. There were 30 males (75%) and 10 females (300%). (Table 1) Among these, 28 (70%) had unilateral amblyopia and 12 (30%) had bilateral amblyopia. Many children will have a residual visual deficit despite compliance with treatment. Failure of visual acuity to improve within six months of the commencement of amblyopia treatment should prompt re-refraction and re-examination of the fundus, looking in particular for optic nerve hypoplasia and subtle macular pathology. Progression of visual deficit during treatment, in the absence of obvious ocular pathology, raises the possibility of progressive cerebral pathology. [ABSTRACT FROM AUTHOR]

Congenital cataract is an important cause of lifelong visual impairment in children. Its treatment is different from that of senile cataract since visual functions of the affected children are still under development. However, consensus has not be made in surgical management of congenital cataract, especially in the surgical approach,intraocular lens selection and postoperative refractive correction. This study reviews researches on the surgical therapy and its postoperative visual function recovery conducted in recent years.

AIM: To investigate the visual acuity of people over 50 years in ophthalmic clinic and visual impairment before and after refractive correction.METHODS: Totally 149 cases(298 eyes)of refractive error were examined and corrected using autorefractor and retinal optometry. The information of age, sex, economy, income and living standard were collected by questionnaire.RESULTS: Out of 149 cases(298 eyes), 281 eyes(98.6%)had refractive error. 119 eyes(42.3%)had myopia, 94 eyes(33.5%)had hyperopia and 68 eyes(24.2%)had mixed astigmatism. The mean visual acuity was 0.42±0.21 and 0.63±0.32 respectively before and after correction. Corrected visual impairment was in 186 eyes(65.3%). Old age, low education, low income and rural area were risk factors for visual impairment. CONCLUSION: Uncorrected refractive error is an important cause of visual impairment in elderly people. It can be promoted by refractive correction, which may benefit for their living quality.

The objective is to characterize the impact of different ablation parameters on the thermal load during corneal refractive surgery by means of excimer laser ablation on porcine eyes. One hundred eleven ablations were performed in 105 porcine eyes. Each ablation was recorded using infrared thermography and analyzed mainly based on the two tested local frequencies (40 Hz, clinical local frequency; 1000 Hz, no local frequency). The change in peak corneal temperature was analyzed with respect to varying ablation parameters [local frequency, system repetition rate, pulse energy, optical zone (OZ) size, and refractive correction]. Transepithelial ablations were also compared to intrastromal ablations. The average of the baseline temperature across all eyes was 20.5°C ± 1.1 (17.7°C to 22.2°C). Average of the change in peak corneal temperature for all clinical local frequency ablations was 5.8 °C ± 0.8 (p = 3.3E - 53 to baseline), whereas the average was 9.0°C ± 1.5 for all no local frequency ablations (p = 1.8E - 35 to baseline, 1.6E - 16 to clinical local frequency ablations). A logarithmic relationship was observed between the changes in peak corneal temperature with increasing local frequency. For clinical local frequency, change in peak corneal temperature was comparatively flat (r²=0.68 with a range of 1.5°C) with increasing system repetition rate and increased linearly with increasing OZ size (r² = 0.95 with a range of 2.4°C). Local frequency controls help maintain safe corneal temperature increase during excimer laser ablations. Transepithelial ablations induce higher thermal load compared to intrastromal ablations, indicating a need for stronger thermal controls in transepithelial refractive procedures. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study is to report the safety and efficacy of a new application of collagen cross-linking using a novel device to achieve predictable refractive myopic changes in virgin corneas. Methods: Four cases were treated with a novel device employing very high-fluence collagen cross-linking applied in a myopic pattern. Prior to treatment, riboflavin solution was applied to the intact epithelium. The collagen cross-linking device was then engaged for a total of 12 J/cm², to be applied transepithelially in a predetermined pattern. Cornea clarity, corneal keratometry, and corneal topography were evaluated by both Placido disc and Scheimpflug imaging, along with cornea anterior segment optical coherence tomography and endothelial cell counts. Results: An average of 2.3 diopters was achieved in the first week in all four cases treated with the very high-fluence myopic collagen cross-linking intervention. There was a slight regression to 1.44 diopters at 1 month, which remained stable at 6-month follow-up. The mean keratometry change was from 44.90 diopters to 43.46 diopters. There was no significant change in endothelial cell counts or corneal clarity. There was some mild change in epithelial thickness distribution, with the treated area showing a slight but homogeneous reduction in mean thickness from 52 μm to 44 μm. Conclusion: This report describes the novel application of very high-fluence collagen cross-linking with a predictable well defined myopic refractive (flattening) corneal effect. This technique has the advantages of essentially no postoperative morbidity, immediate visual rehabilitation, and the potential for tapering until the desired result is achieved. [ABSTRACT FROM AUTHOR]

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The article presents a study on the effect of refractive correction to ocular dominance. The study utilized binocular rivalry based method and retinometers to examine ocular dominance. The results of the study suggest that refractive correction has an effect to ocular dominance that can possibly develop a new occlusion type for amblyopia.