Spectacle Prescription Research Articles

Clinical Characteristics of Prescribing Orthokeratology Lenses in Adult

Orthokeratology lenses are specially designed rigid gas-permeable lenses that are similar to corneal refractive surgery, in that they flatten the central cornea, reducing corneal curvature and correcting myopic refractive errors. While there have been numerous studies on the prescription of orthokeratology lenses for children, there have been relatively few studies regarding prescribing orthokeratology lenses for adults. Properly prescribed orthokeratology lenses can help to slow down the progression of myopia in young adults and have the advantage of alleviating visual fatigue symptoms compared to soft contact lenses. This paper aims to summarize the various clinical characteristics of prescribing orthokeratology lenses in adults.

Prevalence of visual impairment among primary and secondary school children in Delta State, Nigeria

Purpose: Visual impairment (VI) being a state of physiological or pathological disorders of vision posesa burden on human activities globally. The purpose of this study was to determine the prevalence and risk factors of VI among school children in Delta State.
 Methods: A descriptive cross-sectional study of 201 respondents aged 6 to 19 years were randomly selected from primary and secondary schools in the three senatorial districts of Delta State. Participants were evaluated using a structured questionnaire, distance Snellen chart, ophthalmoscope, and torchlight. Vision status was defined using World Health Organization categories of visual impairment based on presenting visual acuity (PVA). Data were presented in frequency tables, charts and analysed with Chi-Square statistics. All p-values reported were two-tailed and statistical significance was defined as P < 0.05.
 Results: The mean age of participants was 12.30± 3.14 years, while 118 (58.7%) were females. The overall prevalence of VI (PVA of <6/18 in the better eye) was 58 (28.9%). The prevalence of mild, moderate, and severe VI was 40 (19.9%), 13 (6.5%), and 5 (2.5%) respectively. Refractive error 47 (23.4%) was the leading cause of VI. The prevalence of VI was higher in females, children 13-19 years, and respondents whose parents’ income per month was >100,000. These observed differences were not statistically significant (p>0.05)
 Conclusion: Untreated refractive error was the leading cause of VI among school children in Delta State. This is an avoidable cause of VI that can be treated with spectacle prescription to ease the burden of visual loss.

Caretakers’ stated willingness to pay for children’s spectacles in cross river state, Nigeria and its implication for a cross-subsidisation scheme: a cross-sectional study

BackgroundUnderstanding caretakers’ willingness to pay (WTP) for their children’s spectacles is essential to improving the sustainability of refractive error services and spectacle provision. Therefore, we investigated the willingness of caretakers to pay for their children’s spectacles in a multi-centre study to develop a spectacle cross-subsidisation scheme in the Cross River State (CRS), Nigeria.MethodsWe administered the questionnaire to all caretakers whose children were referred from school vision screenings to four eye centres for full refraction assessment and dispensing of corrective spectacles from 9 August to 31 October 2019. We collected information on socio-demography, children’s refractive error types, and spectacle prescription and then asked the caretakers about their WTP for the spectacles using a structured questionnaire and bidding format (in the local currency, Naira, ₦).ResultsA total of 137 respondents (response rate = 100%) from four centres were interviewed: with greater proportion of women (n = 92, 67.1%), aged between 41 and 50 years (n = 59, 43.1%), government employees (n = 64, 46.7%) and had acquired college or university education (n = 77, 56.2%). Of the 137 spectacles dispensed to their children, 74 (54.0%) had myopia or myopic astigmatism (equal to or greater than 0.50D). The mean stated WTP for the sample population was ₦3,560 (US$ 8.9) (SD ± ₦1,913.4). Men (p = 0.039), those with higher education (p < 0.001), higher monthly incomes (p = 0.042), and government employees (p = 0.001) were more willing to pay ₦3,600 (US$9.0) or more.ConclusionCombining our previous findings from marketing analysis, these findings provided a basis to plan for a children’s spectacles cross-subsidisation scheme in CRS. Further research will be needed to determine the acceptability of the scheme and the actual WTP.

Functional visual tests to evaluate the effect of small astigmatism correction with toric contact lenses.

The prescription of daily contact lenses does not often include a full astigmatic correction. We question here whether this full astigmatic correction (for low to moderate astigmatism) provides a substantial improvement in the overall visual performance compared to a more conservative approach based only on the prescription of spherical contact lenses. The visual performance of 56 contact lens neophytes divided in two contact lens fitting groups (toric versus spherical lens fit) was assessed using standard visual acuity and contrast sensitivity tests. A new set of functional tests simulating everyday tasks was also used. Results showed that subjects with toric lenses had significantly better visual acuity and contrast sensitivity than those with spherical lenses. Functional tests did not render significant differences between groups, which was explained by several factors like i) the visual demand of the functional tests, ii) the dynamic blur due to misalignments and iii) small misfits between the available and measured axis of the astigmatic contact lens.

A Comparative Study to Assess the Accommodation and Vergence Relationship of Myopia in Indian Adolescent.

Accommodation and Vergence disorder are diverse visual anomalies which can interfere with a child's school performance and impair one's ability to function efficiently. Its association with refractive error and its intervention were studied less in Indian myopia children; hence, there is a need for research in such setting. One hundred and fifty Indian adolescents aged 10 to 17 years were divided into three refractive error groups (high, moderate, and low myopia). Baseline vision examination and a comprehensive binocular vision assessment were performed on all eligible adolescents. Vision therapy was provided to participants whose parents gave consent on behalf of the children. Chi-square analysis was utilized to look at the association between the groups of refractive errors. To compare the mean constants of the experimental and control groups, a two-way RM ANOVA was performed. The most common dysfunction found in low myopia (75.3%), and moderate myopia (54%) was convergence insufficiency. High myopes (62.8%) were found to have combined convergence and accommodative insufficiency followed by accommodative dysfunction (14%) and basic exophoria (6%). In moderate myopia, a significant relationship was found between this dysfunction and refractive error. The experimental group in the overall sample showed statistically significant improvement after vision therapy (P<0.001), in comparison to the control group. Refractive error is linked to accommodative and convergence insufficiency. Thus, vergence and accommodative impairment must be tested for all myopic children, and vision therapy should be advised along with spectacle prescription for efficient binocular vision.

ChromaCorrect: prescription correction in virtual reality headsets through perceptual guidance.

A large portion of today's world population suffers from vision impairments and wears prescription eyeglasses. However, prescription glasses cause additional bulk and discomfort when used with virtual reality (VR) headsets, negatively impacting the viewer's visual experience. In this work, we remedy the usage of prescription eyeglasses with screens by shifting the optical complexity into the software. Our proposal is a prescription-aware rendering approach for providing sharper and more immersive imagery for screens, including VR headsets. To this end, we develop a differentiable display and visual perception model encapsulating the human visual system's display-specific parameters, color, visual acuity, and user-specific refractive errors. Using this differentiable visual perception model, we optimize the rendered imagery in the display using gradient-descent solvers. This way, we provide prescription glasses-free sharper images for a person with vision impairments. We evaluate our approach and show significant quality and contrast improvements for users with vision impairments.

Prevalence of refractive error in Portugal estimated from ophthalmic lens manufacturing data: Ten-years analysis.

To investigate the prevalence, distribution and trends of refractive error from ophthalmic lens manufacturing data over a ten-year period. Fully anonymized data from ophthalmic lenses, for the years between 2010 and 2020, provided by the leading ophthalmic lens manufacturer operating in Portugal were analysed (no human participants were involved in the research). Prescriptions delivered were divided in single vision prescriptions and progressive/multifocal prescriptions and categorized into 14 spherical equivalent ranges. Given the lack of absolute values, indirect estimates and a qualitative analysis of the current situation and trends on refractive error epidemiology was carried out. Dataset from manufacturer comprises percentage values of ophthalmic lenses dispensed in Portugal. The distribution of ophthalmic prescriptions for single vision prescriptions presents most of the observations in the range [-1.49, -0.50] diopters, in every year from 2010 to 2020. For the progressive prescription's lenses, most of the observations is in an interval of two ranges, [0.50, 1.49] and [1.50, 2.99] diopters. From 2010 to 2020 the proportion of single vision ophthalmic lens prescriptions for myopia increased from 38.13% to 46.21%; the proportion for high myopia increased from 2.76% to 4.45%; and the proportion for hyperopia decreased from 40.85% to 31.36%. Ophthalmic lens manufacturing data can be a valuable source for long-term analysis of refractive error prescription and trends over time. It was possible to observe a trend of increasing prevalence of myopia and high myopia from 40.89% in 2010 to 50.66% in 2020. That increase trend has important implications for public health and in the planning of services.

Eye Care in Young Children: A Parents' Perspective of Access and Barriers.

To evaluate parental perspectives of accessing eye care for children aged under seven years. The survey was conducted during September 2020 to March 2021 using online applications and distributed to parents whose children were between the ages of three and seven years. The survey included parents' background, their knowledge of the provision of eye-care services, and the possible barriers that existed to access eye-care services. The relationship between parents' knowledge, barrier scores, level of parental education, and demographic or socioeconomic status was assessed using nonparametric tests. In total, 1037 questionnaires were completed. The respondents were from 50 cities across Saudi regions. The participants' age was 39 7.5 years, and 54% of them had at least one child under the age of seven (n = 564). Further, 47% had not taken their children for vision screening at reception/year one (n = 467). In addition, 65% of them were not aware of the mandatory screening program at reception/year 1; whereas, only 20% (n = 207) knew how to access eye-care services; and only 39% of the children had undergone any kind of eye or vision test. The pathways to eye care and the cost of eye services/glasses were the main limitations. The parents' responses were significantly influenced by their demographic and socioeconomic characteristics (Kruskal Wallis, P 0.05). There was a need for enhancing parent information on how to access eye care for young children and the currently available vision screening programs. Finally, a national protocol to cover the cost of the eye exam as well as spectacle prescription shall be proposed as a mean of incentive.

Pediatric cycloplegic refraction

Background: Cycloplegic refraction is an essential part of the pediatric ophthalmic assessment and is the cornerstone of strabismus evaluation. This narrative review aimed to ascertain the current scope of practice for cycloplegic refraction in the pediatric population.&#x0D; Methods: An extensive literature review was conducted using ScienceDirect, PubMed/MEDLINE, Scopus, and Google Scholar databases using the following search terms: cyclopentolate, tropicamide, pediatric cycloplegia, atropine, homatropine, manual retinoscope, handheld autorefractometer, spherical errors, and no spherical errors of refraction in articles published from January 2000 to December 2022. Relevant retrieved references and practical points concerning pediatric cycloplegic refraction were summarized.&#x0D; Results: Atropine has the most potent cycloplegic effect and is best used in cases of severe accommodative esotropia. Because of the unfavorable side effects and risks associated with atropine, cyclopentolate has been found to provide quite effective cycloplegia, even for moderate to severe hyperopia, and has become the standard agent for traditional pediatric cycloplegic exams. Tropicamide has also been shown to provide adequate cycloplegia while being less toxic and causing fewer side effects. Tropicamide has the fewest side effects and toxicity of all agents, while atropine has the most. Cyclopentolate is an exceptionally safe cycloplegic agent. To detect spherical and non-spherical refractive errors, refraction can be performed using a handheld autorefractometer or a manual retinoscope, as well as under general anesthesia in some cases. The optimal time to wear eyeglasses to maintain binocular vision and avoid amblyopia is also considered.&#x0D; Conclusions: Accommodative power in children is at its maximum, and this interferes with reliable - assessment of refraction. Therefore, the use of cycloplegic refraction is mandatory during childhood to obtain actual refraction, which is considered the cornerstone for eyeglass prescription. Knowledge of the various cycloplegic agents used in childhood refraction is important for ophthalmologists and optometrists to obtain safe and effective cycloplegia. High refractive errors, as well as the presence of anisometropia or squint, necessitate the use of eyeglasses as early as childhood to maintain binocularity and depth perception.

Ordering Eyeglasses Using 3D Head Scan Technology versus Established Online and Storefront Clinic Methods.

This study investigates how a new smartphone scanning technology compares with established online and storefront vendors in providing remote measurement and adjustment of prescription eyeglasses. This study aimed to evaluate a new technology for ordering prescription eyeglasses online. Thirty participants with 2.00 to 2.75 D of presbyopia (aged 49 to 74 years) were asked to order eyeglasses with progressive addition lenses from four vendors: one online vendor using a new head scan technology (Topology, San Francisco, CA), two established Web site-based vendors (vendors A and B), and one storefront vendor: Université de Montréal's Vision Clinic (UMVC). The resulting measurements were compared with those of opticians. Participant-reported preferences on visual and physical comfort of eyeglasses were collected after 15-minute trials of eyeglasses from each vendor. Pupillary half-distance measured with Topology matched optician measurements, but online vendors A and B diverged (mean difference, - 0.80 mm [ Z = -2.79; P = .005]). Topology and vendor B segment addition heights were similar to optician measurements, but vendor A diverged (mean, -1.40 mm [ Z = -2.58; P = .01]). The personalization parameter values obtained with Topology were different from optician measurements for pantoscopic angle (-5.30° [ Z = -4.12; P < .001]) and face wrap angle (+1.25° [ Z = -2.94; P = .003]). The UMVC eyeglasses scored best for adjustment (8.71/10 [ Z = -5.53; P < .001]), with Topology coming second (7.23/10). Topology scores were equivalent to UMVC scores for all eight items of patient-reported preferences (nonparametric Friedman analysis of variance, P < .05). Basic lens centration measurements obtained with Topology compare well with those of opticians, but some aspects of the methodology for measuring personalization parameters could be improved. In comparison with two established online vendors, resulting measurements with Topology are more consistent. Initial wearer satisfaction with Topology eyeglasses was also better.

Did Christiaan Huygens need glasses? A study of Huygens' telescope equations and tables

In the later stages of his life, Christiaan Huygens semi-empirically derived a set of relations between the objective focus and diameter, the eyepiece focus, and the magnification that resulted from combining the two lenses. These relations were used by him and his brother to build what he believed were optimized telescopes. When comparing these equations to the ones derived from modern optical principles, Huygens' telescopes were in fact far from optimal. While there are several potential reasons for this discrepancy, one possible reason, explored in this work, is that Huygens might have suffered from a mild case of myopia (or near-sightedness) and that he compensated this condition by building telescopes that overmagnified by a factor of 3.5. Based on this hypothesis, Huygens' visual acuity is estimated to be around 20/70, which on average corresponds to an optical prescription of −1.5 diopters.

Intrasession repeatability and agreement of a new method to measure the foveal fixation axis.

Ophthalmic lens adaptation, particularly with progressive addition lenses, requires accurate measurements of the patient nasopupillary distance (NPD) and interpupillary distance (IPD), which are usually collected using the pupil centre as a reference. However, differences between the pupil centre and visual or foveal axis could induce some subsidiary effects of correcting lenses. This study aimed to assess the intrasession repeatability of a new prototype (Ergofocus®; Lentitech, Barakaldo, Spain) that can measure the foveal fixation axis (FFA) distance and assess the agreement with the NPD measurements collected using a traditional method (frame ruler). The FFA at far and near distances was measured three consecutive times in 39 healthy volunteers to determine the intrasession repeatability according to the British Standards Institute and International Organization for Standardization. Additionally, the FFA and NPD (standard frame ruler) were measured in 71 healthy volunteers and compared using Bland-Altman analysis. Two blinded experienced practitioners conducted each FFA and NPD measurement. The FFA measurements showed acceptable repeatability at far distances (right eye (RE): Sw = 1.16 ± 0.76 mm and coefficient of variation (CV) = 3.92 ± 2.51%; left eye (LE) Sw = 1.11 ± 0.79 mm and CV = 3.76 ± 2.51%) and at near distances (RE: Sw = 0.97 ± 0.85 mm and CV = 3.52 ± 3.02%; LE: Sw = 1.17 ± 0.96 mm and CV = 4.54 ± 3.72%). Additionally, agreement with the NPD showed large differences at far distances (RE: -2.15 ± 2.34, LoA = -6.73 to 2.43 mm (P < 0.001); LE: -0.61 ± 2.62, LoA = -5.75 to 4.53 mm (P = 0.052)) and near distances (RE: -3.08 ± 2.80, LoA -8.57 to 2.42 mm (P < 0.001); LE: -2.97 ± 3.97, LoA: -10.75 to 4.80 mm (P < 0.001)). FFA measurements showed clinically acceptable repeatability at both far and near distances. Agreement with the NPD measured using a standard frame ruler showed significant differences, suggesting that both measurements are not interchangeable in clinical practice to prescribe and center ophthalmic lenses. Further research is necessary to assess the impact of FFA measurement in ophthalmic lens prescriptions.

Subjective Verification of Refraction- A Quality Section Indicator: A Cross-sectional Study

Introduction: Subjective refraction helps in establishing the suitable lens for a patient. But it also needs a patient’s cooperation for the proper estimation of the refractive error. Aim: To determine the impact of counselling of Optometrists on subjective refraction and spectacle prescription to patients attending Ophthalmology Out Patient Department (OPD) at their first visit. Materials and Methods: This was a cross-sectional study conducted for a period of two months from June 2020 to July 2020. All patients attending the OPD at Department of Ophthalmology at R L Jalappa Hospital and Research Centre, Tamaka, Karnataka, India, were included in the study. A total of 120 patients, whose vision was &lt;6/9, were included in each group. Group A, before counselling the Optometrists and Group B, after counselling the Optometrists by systemic random sampling method. The number of patients who required spectacle correction and those who were given spectacle prescriptions at their first visit were identified. The data was analysed using Statistical Package for the Social Sciences (SPSS) version 22.0. Results: In Group A, out of 120 patients only 62 patients (51.7%), had undergone subjective refraction along with spectacle prescription at their first visit. In Group B, (88.3%) 106 patients out of 120, underwent subjective refraction and spectacle correction was given on their first visit. Conclusion: This study shows a clear positive impact of counselling to Optometrists and the importance of counselling in achieving patient’s satisfaction.

Colorado Challenge: The Court Battel for the Prescribing of Soft Contact Lenses, The Use of the Tonometer and the Diagnosis of Glaucoma

There have been many challenges to the profession of optometry at both the state and federal level during its 110 years of legalized existence. These challenges have involved the passage of the original state practice acts, clarification of the original optometry laws, passage of state board rules and regulations and efforts to eliminate commercialism. This was followed by the expansion of state optometry practice acts authorizing the use of diagnostic drugs, therapeutic drugs or other clinical procedures. Additional challenges have been federal in nature and therefore broader in scope but still of great importance for the profession. Colorado is unique in that the Colorado Optometric Association (COA) defended optometry’s right to use the tonometer and fit soft contact lenses in a lawsuit that had national implications.

Toolpath generation for ultraprecision machining: Freeform surface generation and extrapolation

The rise in complexity of freeform optics drives the development of equally complex manufacturing processes needed to produce them. Complex optical designs, however, require equally complex machining toolpaths and techniques that can generate them. This paper and subsequent research develops and investigates toolpath generation techniques for explicitly defined surfaces of the form Z(X,Y). A generalized approach is developed for the toolpath generation of optical surfaces themselves as well as techniques for transitioning between surfaces in an array. All surfaces herein are continuous, well-behaved, and differentiable – constraints satisfied by most optical prescriptions today. The current paper describes the toolpath generation and extrapolation process for a tilted freeform surface defined inside a non-circular boundary. Boundaries are defined so that some non-convexity is acceptable, and it is simple to determine whether a toolpath coordinate lies inside or outside them. Using the proposed coordinate frame transformation and boundary definition, it is shown that by tilting a surface and boundary together, the tilted surface retains its original form and boundary in a rotated coordinate frame. With the proposed extrapolating surface, it is possible to modify a freeform surface outside its defined boundary so it is smooth and well-behaved inside its overall region of interest – an important consideration for both toolpath generation and opto-mechanical design. By combining freeform and extrapolating surfaces together, a smooth piecewise surface is generated whose overall continuity increases as the order of the extrapolating surface increases. As a result, it is possible to increase the overall continuity of a toolpath along its cutting direction. To verify the utility of the proposed extrapolating surface, experimental data are presented for several spiral toolpaths generated for a 6th order polynomial surface prescription defined inside a rectangular boundary. Subsequent research, using the techniques herein as a starting point, develop and investigate blending multiple freeform surfaces together.

Remote measurement of spherocylindrical spectacle lens prescriptions

A system has been developed to measure spherocylindrical spectacle lenses. The global pandemic limited access to regular eye exams. The system bypasses this limitation by providing at-home prescription measurements. The power and orientation of the spectacle lenses are obtained with a cell phone camera, a displayed or printed target, and a magnetic stripe card. The spatially varying magnification of the lenses is calculated by examining the image captured through the lens of the target at a fixed distance. This information is then used to calculate a clinical prescription, i.e., Sph/Cyl × Axis. The system is tested with 48 single-power spherocylindrical lenses with a range of −11.25 to +4.25 D for Sph, −5.25 to −0.25 D for Cyl, and a whole range of Axis. The results are plotted in comparison with these reference prescriptions provided by a commercially available lensmeter and show good agreement. The image processing and clinical prescription calculation are discussed here.

Refractive management of a bilateral lens subluxation case in marfan syndrome patient

AbstractPurpose: To report refractive management of bilateral lens subluxation case in Marfan Syndrome patient.Methods: Diagnosis based on a history‐taking, a physical examination, and an ancillary test. The refractive state of the patient was examined by an autorefractometer, streak retinoscopy and best‐corrected visual acuity (BCVA), before and after cycloplegic on each eye.Results: A 7‐years‐old girl diagnosed with Marfan Syndrome by the Department of Paediatric Cardiology complained for blurred vision in both eyes. Initial visual acuity of the patient was 0.027 in her right and left eyes. Anterior segment examination showed phacodenesis in both eyes. After cycloplegic refraction with enlarging pupil diameter and performed streak retinoscopy, BCVA in the right eye was 0.040 with a refractive correction of −22.00 diopters (D) and left eye was 0.021 with −20.00 D. After several follow ups, the refractive state remains highly fluctuates due to severe lens subluxation degree, which is seen through a half pupillary area. Consequently, operative approach using intracapsular lens extraction technique is considered. A month after the surgery, the distance visual acuity in right eye was 0.125 and 0.080 in left eye. With a refractive correction of +5.50 D, visual acuity became 0.500, while for the left eye became 0.125 with +5.00 D. Whereas, binocular distance visual acuity with refractive correction became 0.400. Therefore, spectacle was prescribed to achieve optimal visual acuity.Conclusions: The refractive management steps in lens subluxation associated with Marfan Syndrome case is very challenging depends on patient's condition. The intracapsular lens extraction procedure prior to spectacle prescription should be considered as a management of severe lens subluxation in patient with Marfan syndrome, in order to achieve BCVA.

Characterization of rotational symmetry and noise in multifocal contact lens power maps

AbstractPurpose: Spherical multifocal contact lenses are typically designed with a rotationally symmetrical power profile. Imperfections in the raw material, manufacturing and measurement process can break this symmetry, altering the intended lens design. The purpose of this work is to develop a method to separate the intended symmetric design profile from the asymmetries and to give the spatial distribution of the measurement noise uncertainty in diopters.Methods: NIMO TR1504 (Lambda‐X) version V.2.13.2 has been used to measure the local power map of various multifocal contact lenses. From the map, a set of radial power profiles is obtained for different angles (0°, 180°), (0°, 360°). A symmetrical lens should show a constant radial profile for different angles, while asymmetries manifest as differences in the set of radial power profiles. They are analysed using a Principal Components Method (PCA) implemented in MATLAB.Results: The method displays a map of the symmetric radial profile of the lens, another map of the deviations with spatial structure indicating the angles where the deviations are stronger (rotational asymmetries), and noise with three separated components (spatially random variations). Asymmetries of the order of 0.17D (with maximums of 0.4D), and random noise values of 0.12D were found in some lenses.Conclusions: The characterization of multifocal contact lens prescription is important in visual optics. The prescription perceived by the patient depends on the distribution of the radial power profile on the pupil. That is the reason why asymmetries and imperfections estimation is important. The method developed in this work allows to calculate a diopter equivalent number for them.

Current Trends in Scleral Lens Prescription, Management, and Evaluation.

To report current trends in scleral contact lens prescription and management, including lens designs prescribed, care products recommended, and procedures performed during routine scleral lens (SL) evaluation. An online survey was designed by the Scleral Lenses in Current Ophthalmic Practice Evaluation study team and administered to eye care practitioners attending a specialty contact lens meeting. The survey was available from November 8, 2019, through March 31, 2020. Participants' demographic data were collected, along with information on lens diameters, landing zone (LZ) designs, recommended care products, and components of routine SL evaluation. In total, 715 participants responded to at least one of the survey items of interest. Most lenses prescribed (63%) were 16 mm or more in diameter. Lenses with toric LZs were the most frequently prescribed (48%), followed by spherical (40%), quadrant-specific (8%), and impression-based or image-based designs (3%). Most participants (61%) recommended hydrogen peroxide products for lens care. Nonpreserved saline in a single-use vial was most frequently recommended to fill the bowl of the lens before application. Intraocular pressure was measured during SL evaluation by 45% of participants; 38% of participants routinely measured corneal thickness. Practitioners increasingly are prescribing SLs with advanced LZ designs. Most practitioners recommend hydrogen peroxide-based disinfection systems and single-use vials of nonpreserved saline for lens care and application. Because differences in components of routine SL evaluations were reported, clinicians may benefit from reaching a consensus on essential components of SL evaluation.

Relationship Between Screen Time and Dry Eye Symptoms During the COVID-19 Pandemic in the Pediatric Population of the Western Region of Saudi Arabia.

Objective To measure the prevalence of dry eye disease (DED) and study the relationship between screen time and dry eye symptoms in the pediatric population during the coronavirus disease 2019 (COVID-19) pandemic using the Ocular Surface Disease Index (OSDI) questionnaire. Methods In this descriptive, observational, cross-sectional study, our survey included the pediatric population, ages 1 to 18 years, of both genders,who attended outpatient clinics of two main hospitals in Jeddah, Saudi Arabia. Collected data included age, gender, dry eye symptoms, and common DED risk factors, followed by the Ocular Surface Disease Index (OSDI) questionnaire, which consists of 12 items graded on a five-point scale (0 = never to 4 = all the time). Results A total of 329 pediatric participants were included, with more than half of the participants (56.1%) males and 58.5%aged 12-18 years. The most frequently reported symptoms (reported as often or always) were decreased vision (23.0%) and itchy eyes (22.1%). Environmental factors have an effect on developing DED symptoms, as some participants (21.8%)have reported being uncomfortable in windy weather and 15.8% have reported this in places with air conditioners. Based on the OSDI diagnostic criteria, 250(76.1%) participants had DED. Furthermore, in terms of severity, 44 (13.3%)participants had mild DED, 62 (18.8%) participants had moderate DED, and 145 (43.9%) participants had severe DED. We found that prolonged exposure to mobile screens for two to three hoursor four hours or more was associated with a higher DED incidence compared to those exposed for shorter periods. Older age categories were more likely to experience DED (80.8% and 78.2% in age categories 12-18 and 7-12, respectively, versus 57.6% in the youngest age category(p = 0.001)). Additionally, DED was independently associated with participants with a previous history of eyeglasses prescription and those experiencing dry eyes while using electronic devices. Conclusion Since many children use electronic devices for education and entertainment, we found that symptoms of DED due to prolonged screen time have increased among the pediatric population during the COVID-19 pandemic. Therefore, awareness efforts should be directed to reduce the rate of controllable risk factors like personal computer use. In addition, educational campaigns are warranted to provide all possible preventive measures against DED, especially to children with uncontrollable risk factors for developing DED.