Scandinavian Journal of Optometry and Visual Science
Scandinavian Journal of Optometry and Visual Science is an open-access peer-reviewed journal for promoting research amongst optometrists and other researchers in optometry and visual science.
Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
Visual improvement by selective filters in age-related macular degeneration involves effects other than light filtering
The use of wavelength-selective filters for patients with age-related macular degeneration (AMD) is common. An awareness of the expected effect of filters on central vision function, especially the magnitude of learning effects, is essential when deciding whether to prescribe. The aims of the present study were to examine the effect of selective and neutral-density filters on central visual function in patients with exudative AMD and to assess potential learning effects. The study was a randomised cross-over study of the effect of selective and neutral-density filters on visual acuity (Early Treatment Diabetic Retinopathy Study [ETDRS] charts), contrast sensitivity (Pelli-Robson test), and colour vision (Hardy-Rand-Rittler test) in 31 patients with pseudophakia, aged 69 to 92 years, who had exudative AMD and central visual loss. Selective filters significantly improved visual acuity (ETDRS), contrast sensitivity (Pelli-Robson), and red/green colour vision (Hardy-Rand-Rittler) in both eyes; however, they reduced blue/yellow colour vision. Neutral-density filters improved visual acuity for the better but not the worse eye and contrast sensitivity for the worse but not the better eye; they had no effect on colour vision. The improvement in contrast vision and red/green colour vision persisted immediately after the filters had been removed. The study confirmed a positive effect of selective filters on visual acuity, contrast sensitivity, and red/green colour vision but a negative effect on blue/yellow colour vision, in patients with exudative AMD. The effect of neutral-density filters in these patients, however, was more ambiguous. There was evidence that the effect of the filters may have persisted immediately after their removal, suggesting the involvement of factors other than just the filtering of light.
Copyright (c) 2026 Ivan Nisted, Mette Nedergaard, Toke Bek https://creativecommons.org/licenses/by-nc-nd/4.0
The effects on visual functions and vision-related quality-of-life after fitting of scleral lenses in keratoconus
The purpose of this study was to explore the effects of fitting scleral lenses on visual acuity (VA), contrast sensitivity (CS) and vision-related quality-of-life (VR-QoL) in persons with keratoconus. An intervention study was undertaken, with a clinical experimental, uncontrolled, single-arm intervention design. The intervention was fitting of scleral lenses to optically correct keratoconus. The outcome measures were monocular and binocular VA at distance and near, CS, and patient-reported VR-QoL using the novel Keratoconus Outcomes Research Questionnaire (KORQ) and National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). Twenty-nine participants (54 eyes) were fitted with scleral lenses. Statistically significant improvements were evident between habitual correction and scleral lens correction for all measures including monocular and binocular VA at distance and near (p < 0.001), CS (p < 0.001), KORQ activity limitations subscale (p < 0.001), KORQ symptoms subscale (p < 0.001) and NEI VFQ-25 composite score (p < 0.001). Additionally, asymmetry in VA between eyes improved significantly with scleral lenses (p < 0.001). Spearman correlations showed moderate correlations between improvements in KORQ activity limitations score, VA and CS, improvements in KORQ symptoms score and distance VA, and improvements in the NEI-VFQ-25 near subscale score and near VA. Fitting scleral lenses significantly improved VR-QoL and visual function in individuals with keratoconus. Although the correlation between improvements in VR-QoL and VA and CS was modest, the findings suggest that individuals with keratoconus should be offered the opportunity to explore scleral lenses as a treatment option to optimise both visual function and VR-QoL. However, as the study used an uncontrolled single-arm intervention design, the results should be interpreted with caution. Future studies including a comparison group are needed to confirm these findings. Keywords: scleral lenses, keratoconus, visual acuity, contrast sensitivity, vision-related quality-of-life
Patient-reported outcome measures (PROMS)
Scleral lenses, keratoconus, visual acuity, contrast sensitivity, vision-related quality-of-life
Copyright (c) 2026 Svein Magne Roten, Eilin Lundanes, Vibeke Sundling https://creativecommons.org/licenses/by-nc-nd/4.0
From practice to progress: vision research in Scandinavia
Copyright (c) 2025 Karthikeyan Baskaran; Antonio Filipe Macedo, Rigmor Baraas https://creativecommons.org/licenses/by-nc-nd/4.0
Kongsberg Vision Meeting 2025 was held for the 17th time at the University of South-Eastern Norway in Kongsberg on October 20–21. The two-day event focused on clinical optometry and vision research, attracting more than 100 practicing optometrists, 60 final-year optometry students, and several commercial exhibitors, creating a dynamic arena for sharing knowledge and networking. Keynote speakers included Jan Johannson (Karolinska Institute, Sweden), Hanne-Mari Schiøtz Thorud (University of South-Eastern Norway, Norway), Erik Roberstad (Interoptikk Holt, Norway), and Eike Wehling (University of Bergen, Norway). The program addressed vision problems following acquired brain damage, the expanding role and scope of optometrists in independent prescribing, and clinical approaches to headache management. A dedicated session showcased a decade of SNOW research on children’s vision in Norway. Practical skills and applied research were central, with workshops on neurorehabilitation, tear duct irrigation, and binocular vision in schoolchildren. Two panel discussions addressed the evolving role of Norwegian optometrists as independent prescribers, and the importance of using diagnostic drops in vision examination in children and adolescents. The Scandinavian program was curated by Vibeke Sundling, Bente Monica Aakre, Rigmor C. Baraas, and Helle K. Falkenberg. Abstracts from invited and contributed talks are presented in the order they were given. The meeting reinforced the need for clinical innovation, evidence-based practice, and interdisciplinary collaboration to strengthen primary eye care services.
Copyright (c) 2025 Copyright belongs to all named authors of the abstracts. https://creativecommons.org/licenses/by-nc-nd/4.0
The Pediatric Cataract Register (PECARE): Challenges in scientific evaluation of visual development
The purpose of this study was to analyse visual acuity tests and methods used in children who have undergone cataract surgery in Sweden as well as the success rate of visual acuity testing, in order to improve current treatment. Children registered in PECARE who underwent cataract surgery between 1st January 2007 and 31st July 2016 were included. Visual acuity test methods were analysed at the follow-up ages of 1, 2, 5 and 10 years. A total of 424 children were operated, 209 girls (49%) and 215 boys (51%). The number of operated eyes was 584, of which 320 (55%) were bilateral cataracts and 264 (45%) unilateral. A total of 660 follow-up visits took place, and successful visual acuity measurements were achieved in 416 of these cases: 106/228 (46%) at 1 year of age, 128/226 (57%) at 2 years of age, 169/193 (88%) at 5 years of age, and 13/13 (100%) at 10 years of age. Visual acuity test methods differed among the follow-up clinics, making comparisons challenging. The Kasper test was widely used before the age of 2, and has been validated, but not been published scientifically. The success rate was higher for Kasper than for other tests. A challenging diversity of methods for testing visual acuity are used in Swedish paediatric cataract care. Age-related national guidelines regarding visual acuity tests methods are needed for the development and improvement of current treatment. Scientific evaluation of visual development is an important outcome in order to reach equal care. Furthermore, the Kasper test needs to be scientifically re-validated. Keywords: paediatric cataract, congenital, visual acuity test
Copyright (c) 2025 Jenny Gyllén, Birgitte Haargaard, Alf Nyström, Arzu Karatepe Hashas, Anna Linnarsson Wiklund, Eric Trocmé, Annika Rosensvärd, Ulrika Kjellström, Jenny Wallander, Kristina Tornqvist, Gunilla Magnusson https://creativecommons.org/licenses/by-nc-nd/4.0
Screening for visual deficits at a rehabilitation unit early in the rehabilitation process after stroke
Stroke patients are not routinely screened for visual deficits despite recommendations on the importance of vision for safety and design of rehabilitation plans. The aim was to examine if it was feasible to expose rehabilitation patients to vision screening. Secondly, we aimed to examine the agreement between the vision screening and items from a neurological stroke screening tool specifically targeting vision and neglect. Over a period of 6 months, patients arriving at a rehabilitation unit after having had a stroke were consecutively included. Data on aetiology, severity, and location of the stroke, time since the original admission, scores on the National Institutes of Health Stroke Scale (NIHSS), and results from a short screening/observation battery were registered. Cohen’s kappa was calculated to examine the agreement between results from the screening/observation battery and NIHSS items. Nighty-six percent of the patients were able to undergo screening of basic visual functions. Impairment was found in 52% of the patients, and 67% of these showed impairment in more than one function. Visual impairment occurred for all levels of stroke severity. Reduced distance visual acuity was found in 15% of all patients. Accordance between the screening/observation battery and NIHSS items varied between κ = 0.36 and κ = 0.64. Screening battery vs NIHSS items showed impairment in 31% vs. 21% of patients for oculomotor deficits, 31% vs. 34% for visual field deficits and 31% vs. 29% for neglect. Results show that patients are assessable for basic visual functions early in the rehabilitation process. Items from the NIHSS cannot replace a dedicated vision screening tool because they exclude essential functions such as visual acuity, and oculomotor deficits may go undetected. Only the visual field assessment indicates substantial agreement and high sensitivity. Regarding stroke severity, agreement was substantial only in the severe group. In summary, we conclude that the NIHSS items cannot be recommended to replace systematic screening of visual function and neglect.
visual impairment, stroke, subacute, NIHSS, neurorehabilitation
Copyright (c) 2025 Eike Wehling, Eirik Vikane, Siri Hanne Betten Lysgård, Tina Taule, Silje Karin Pedersen, Anne Helen Jacobsen, Eline A. Kordt https://creativecommons.org/licenses/by-nc-nd/4.0
One Eye on the Prize: The Impact of monocular vision on aiming responses
The ability to move one's hand quickly and accurately towards a target is an essential skill that underpins many activities of daily living, such as writing or threading a needle. In-lab research has previously demonstrated that the time taken to complete an aiming task is proportional to task difficulty; however, the strength of this relationship appears to reduce as the quality of visual input becomes degraded (Wu et al, 2010). There is also evidence that when compared to full vision, monocular vision leads to a general increase in movement time during aiming tasks (Sheppard et al, 2021). Despite these valuable findings, logistical challenges (e.g. recruitment from hard-to-reach populations) make in-lab testing difficult or even impossible. These potential challenges could be overcome by introducing online tests if they are sufficiently sensitive to capture visual deficits accurately. The present study aimed to test (i) whether monocular vision was associated with increased response time and (ii) the feasibility of using simple, online tasks to probe the relationship between visual and motor function. Using a computer mouse or touchpad to move to targets as quickly as possible, 65 participants (aged 18–77) completed (i) a visual search task (moving to a 34 target embedded amongst a grid of distractors) and (ii) a basic visual-motor aiming task (moving to individual targets of varying size/distance). Participants completed both tasks online, either with full vision or monocular vision. Visual search time and aiming task response time increased significantly under monocular vision (≈1.8 s and ≈40 ms, respectively). These results suggest that a simple, online aiming task can be suitable for testing the effects of a visual deficit on motor function.
Copyright (c) 2025 William E. A. Sheppard, Richard M. Wilkie, Rigmor C. Baraas, Carlo Campagnoli, Rachel O. Coats https://creativecommons.org/licenses/by-nc-nd/4.0
Contact Lens Discomfort (CLD) Treatment with MY MASK Light Modulation® LED mask
The purpose of this study was to understand how the use of the light modulation LED mask MY MASK affects Contact Lens Discomfort (CLD). Forty-two (42) soft contact lens wearers with dry eye symptoms were recruited for a 3-week descriptive observational study. Treatment using the light modulation LED mask was applied three times, each lasting 15 minutes; on day 1, day 3 and after one week. Symptoms of CLD were quantified with the help of a specific questionnaire (CLDEQ-8) before and after treatment. Ocular surface and tear film measurements were conducted at baseline and 1 week after the last treatment. Visual acuity remained stable (0.00 LogMAR ± 0.10). The number of symptomatic contact lens wearers decreased by 43% (18 out of 42 subjects), as indicated by the CLDEQ-8 scores (t−test=5.14; p < 0.001) (R2=0.218). Non-invasive tear film breakup time (NIBUT) improved significantly. Before treatment, 70% of eyes (59 out of 84) showed a NIBUT of less than 10 s; after treatment, 26% had values below this cut-off (t-test=3.06; p=0.001) (R2=0.241). Meibography values did not change (t-test= 1.17; p= 0.121) (R2 = 0.872). TearScope showed considerable improvement in tear film lipid layer thickness and the data obtained through the Gland Evaluator also demonstrated an improvement. Treatment using light modulation LED mask could be an interesting option in improving the aspects that characterise CLD. Additional research is required to establish the reliability of the observed improvement and investigate the necessity of repeated treatments as a means of stabilising or sustaining satisfaction in contact lens wearers.
Copyright (c) 2024 Enrico Pavan M., Pietro Gheller, David Pinero, Luca Stanco https://creativecommons.org/licenses/by-nc-nd/4.0
Pilot study: simulating myopic chromatic aberration on a computer screen induces progressive choroidal thickening in myopes
The purpose of this study was to determine whether repeated exposure to a digitally simulated myopic chromatic aberration (“red in focus” filter) on a computer screen, can change axial length (AL) and choroidal thickness (ChT) in young human subjects. Six myopic and four emmetropic subjects worked on a computer screen with a “red in focus” filter for 2 hours per day over 12 consecutive days (days 1–12). The treatment period was followed by 2 days of recovery where subjects performed computer work for 2 hours per day without filtering (days 13 and 14). Before and after each computer work episode, axial length and subfoveal choroidal thickness were measured in both eyes. Additionally, on days 1, 12, and 14, visual acuity and contrast sensitivity were measured in three luminance-matched light conditions: red, blue, and white light. Myopic, but not emmetropic eyes showed progressive thickening of the choroid and shortening of the axial length over 12 consecutive days with the “red in focus” filter (AL:−31 ± 39 µm, p < 0.01; ChT: +18 ± 14 µm, p < 0.0001) with significant recovery when compared to the last days of the treatment period (AL: +10 ± 26 µm, p < 0.05; ChT:−16 ± 10 µm, p < 0.001). Visual acuity improved in both emmetropic and myopic eyes, under all light conditions, however, a significant difference was measured only in emmetropic eyes in red light (−0.03 ± 0.15 vs. −0.19 ± 0.14 LogMAR, p < 0.05). Contrast sensitivity did not significantly change during the entire experiment in emmetropic or myopic eyes. Working on a computer screen with the “red in focus” filter may have an inhibitory effect on myopia progression since it causes progressive thickening of the choroid and associated shortening of axial length over 12 days. However, long-term studies with larger sample sizes are necessary to verify a general effect.
Copyright (c) 2024 Barbara Swiatczak, Lea Ingrassia, Hendrik P. N. Scholl, Frank Schaeffel https://creativecommons.org/licenses/by-nc-nd/4.0
Wrap-up of 2024 with eyes focused on 2025!
Copyright (c) 2024 António Filipe Teixeira Macedo, Karthikeyan Baskaran, Rigmor C Baraas https://creativecommons.org/licenses/by-nc-nd/4.0
Copyright (c) 2024 Alberto Recchioni https://creativecommons.org/licenses/by-nc-nd/4.0
Copyright (c) 2024 Rigmor C Baraas https://creativecommons.org/licenses/by-nc-nd/4.0
Evaluation of pediatric vision screening and digital referral routines in an interprofessional setting in Norway
Vision is crucial for childhood development, and ensuring good vision in children is one of the United Nation’s sustainability goals. Most countries have a childhood vision screening programme, and in Norway screening in children aged 4–5 years is performed in community health centres (CHC). Specialist health services such as ophthalmology and/or orthoptics are the referral bodies. However, access to these may be limited and they may be a long distance away from the child’s home, while optometrists are often more available and accessible. This study aims to investigate if vision screening reliably detects vision problems and to explore if using paediatric optometry as a referral body can relieve the specialist health services. The study also aims to report frequency of refractive errors and management of vision problems in this age group. Of 274 children who attended vision screening by school nurses at the CHC in Kongsberg, Norway, parents of 213 (77.7%) consented to a separate eye and vision examination by a paediatric optometrist. Agreements in screening results between school nurses and the paediatric optometrists were evaluated. Separately, an ophthalmologist and an orthoptist assessed records from the eye examinations through a digital communication tool (Eyecheck System AS). Agreements in diagnoses and management decisions between optometrists and the specialist health services were evaluated. Amblyopia or ocular pathology was found in 1.9% of the children, which were all identified by the vision screening. The vision screening had a sensitivity and specificity of 62.3% and 58.6%, respectively, for detecting other vision problems in need of treatment or follow-up. Hypermetropia was present in 82.7% of the children (58.0% low, 18.5% moderate, 6.5% high hypermetropia), 16.4% had emmetropia and 1.0% had myopia. Glasses were prescribed to 8.5% of the children and 16.4% were scheduled for follow-ups. There was a high level of agreement in management between optometrists and specialists (ophthalmologist 80.3%, orthoptist 81.7%). The vision screening reliably detected amblyopia and ocular pathology, and most refractive errors were detected. The high degree of agreement between the three eye care professions suggests that paediatric optometrists can be used as the referral body for this age group. Availability of a digital communication tool provides support for the paediatric optometrists in their decision making and can help relieve the specialist health services by providing children with an eye examination and vision correction earlier and more easily.
Vision screening, children, amblyopia, hypermetropia, refractive errors
Copyright (c) 2024 Gro Horgen, Marlies Hummelen, Eva Strasser, Ellen Svarverud, Lotte-Guri Bogfjellmo Sten https://creativecommons.org/licenses/by-nc-nd/4.0
In response to the editorial "What is happening in Sweden?".
Copyright (c) 2024 Sara Flodin https://creativecommons.org/licenses/by-nc-nd/4.0
Validation of the Norwegian International Reading Speed Texts (IReST) in adult readers with normal vision
There is a lack of standardised reading tests in Norwegian suitable for adults and persons with visual impairment (VI). The International Reading Speed Texts (IReST) measure reading performance of longer paragraphs. The aim of this project was to translate and validate the IReST in Norwegian. Each of the German, English and Swedish IReST were translated into Norwegian. The translations were matched for length, linguistic difficulty, and structure, and piloted in five adults. Reading speed was assessed in 25 readers (41 years, SD = 10) with normal vision and the readings were recorded. Reading speeds were analysed for variability between texts and participants. There were no statistically significant differences between the ten texts (135 words, 765 characters [SD=18], word variation index 91.8% [SD = 0.9%]). Reading speed in adult readers was 204 (SD=31) words/min. There was no difference across texts for any of the participants (p>0.05). Reading speed variance was 77.4% between subjects and 22.6% between texts. The Norwegian IReST is standardised and comparable to the international IReST tests. Reading speed falls within normative values in adult readers. The Norwegian IReST will be a valuable tool in assessing reading in clinical health care, rehabilitation and educational practice of adult and visually impaired readers and in reading research.
Copyright (c) 2024 Dan A. Nachtnebel, Helle K. Falkenberg https://creativecommons.org/licenses/by-nc-nd/4.0
This a reply to the letter to Editors from Sara Flodin.
Copyright (c) 2024 António Filipe Teixeira Macedo https://creativecommons.org/licenses/by-nc-nd/4.0
Copyright (c) 2024 Rigmor C Baraas; Karthikeyan Baskaran, António Filipe Teixeira Macedo https://creativecommons.org/licenses/by-nc-nd/4.0
NorVIS 2nd Young Researchers Conference: Abstracts 2024
The second NorVIS Young Researchers Conference was held at the University of South-Eastern Norway (USN) in Kongsberg the 28th of May 2024. This year, it was a hybrid conference with digital attendance from Sweden and Bergen to accommodate those unable to travel. The primary goal was to share knowledge, experiences and projects for researchers in the start of their careers and to stimulate to more vision and brain research. Further it is an arena for discussing clinical problems and research ideas, and to gain network with other professionals working in the field. The one-day meeting had presentations including study protocols, master’s project, PhD and post doc clinical research from a variety of professionals. The interdisciplinary professions included a neuropsychologist, specialized nurse, occupational therapists, speech therapist and optometrists. After the presentations, Jan Johansson and Helle K. Falkenberg shared their tips and experiences on writing abstracts for papers and conferences. The meeting was organised by Torgeir S. Mathisen and Helle K. Falkenberg from USN and was partly financed by the NorVIS network, www.synogslagnett.no. The abstracts from contributed authors are listed in the order of presentation.
Copyright (c) 2024 Helle K. Falkenberg, Torgeir Mathisen https://creativecommons.org/licenses/by-nc-nd/4.0
Copyright (c) 2023 Torgeir S. Mathisen, António Filipe Teixeira Macedo, Helle K. Falkenberg https://creativecommons.org/licenses/by-nc-nd/4.0
Copyright (c) 2023 Rigmor C Baraas; Karthikeyan Baskaran, Helle Kristine Falkenberg, Alberto Recchioni, António Filipe Teixeira Macedo https://creativecommons.org/licenses/by-nc-nd/4.0
Copyright (c) 2023 Rigmor C Baraas https://creativecommons.org/licenses/by-nc-nd/4.0
Comparative Evaluation of the ETDRS Visual Acuity Chart and Arclight Cloth Chart (ARCchart) for Primary Eye Care in Resource-Limited Settings
This study compared the Arclight Cloth Chart (ARCchart) to the gold standard ETDRS chart for visual acuity (VA) measurement in 63 participants. Despite its potential limitations as a tool to measure subtle changes in VA over time, the ARCchart showed a limit of agreement between -0.23logMAR and 0.26logMAR with ETDRS values. It demonstrated 93% (95% Confidence Interval 86% to 100%) sensitivity and 90% (84% to 97%) specificity when used to screen for vision worse than 0.20logMAR. This low-cost, portable cloth VA chart is a valuable alternative for measuring VA and screening for low vision in resource poor settings.
Copyright (c) 2023 Christine Jaffray, Niall Strang, Obaid Kousha, Gavin Galloway, Laura Sweeney, Andrew Blaikie https://creativecommons.org/licenses/by-nc-nd/4.0
Kongsberg Vision Meeting was arranged at Buskerud University College in Kongsberg for the third time on October 8, 2010. Rigmor C. Baraas and Gaute T. Einevoll organized the meeting. Keynote speakers were Joseph Carroll from the Medical College of Wisconsin, Milwaukee (USA) and Espen Hartveit from Department of Biomedicine, University of Bergen, Bergen (Norway).
Copyright (c) 2022 https://creativecommons.org/licenses/by-nc-nd/4.0
Colour vision: From sensation to science (in Norwegian)
Throughout history there have been different approaches to pursuing a better understanding of colour and colour vision, depending on the phenomena one wanted to explain. For instance, although seemingly irreconcilable, the opponent-colour theory of Hering (with its yellow-blue and red-green chromatic pairs) and the three-colour theory of Young-Helmholtz (with red, green, and violet as mixture primaries) did in fact illuminate different aspects of colour vision. Thomas Young and Hermann von Helmholtz set out to explain the qualities of colours, but with the help of James C. Maxwell this theory eventually became a three-receptor theory describing additive colour mixtures and colour matches. The three-receptor theory is the foundation of trichromatic colour measurements and a thriving colour technology. Ewald Hering, who also had colour perception as his main concern, appears to have recognized the distinction between receptor excitations and perception. He postulated opponent physiological processes as basis for the two pairs of chromatic colours. Today these theories are combined in an attempt to understand how colour is processed in the higher brain centres.
Use of the ISNT rule for optic disc evaluation in 40 to 79 year old patients seen in optometric practice
The purpose this study was to investigate the association between intraocular pressure (IOP) and the outcome of ISNT rule assessment of the optic disc in healthy patients seen in mainstream optometric practice. Consecutive patients over the age of 40 years and with no known general- or ocular pathology were enrolled from 4 optometric practices in Norway and Sweden during a period of 9 months. The sample was stratified by age group (40-49, 50-59, 60-69 and 70-79 years) and ISNT rule outcome (obeyed or broken). Subjects underwent a full optometric examination including stereoscopic assessment of the optic disc with the use of the ISNT rule, followed by measurements of intraocular pressure (IOP), central corneal thickness (CCT) and vertical size of the optic disc. Odds ratio (OR) was used to assess the association between IOP and the outcome measure. Stratified and multivariable analyses were employed to investigate the effect of age, gender, CCT, refractive error and disc size on the association. IOP was dichotomized at a cut-off corresponding to the 75th percentile (18 mmHg), whereas numeric covariables were categorized at cut-offs corresponding to the 33rd (ONH 1.6 mm, CCT 545 μm) and 66th percentile (ONH 1.8 mm, CCT 571 μm), respectively. A total of 177 patients (F: 57%, age range 40-79 years) were included. IOP was significantly higher in patients with broken ISNT rule (16.6 vs. 15.5 mmHg, p = 0.046), corresponding to a crude OR of 2.0 (CI 0.95-4.24). In stratified and multivariable analyses the association between IOP and outcome of the ISNT rule was strengthened in males (OR 4.8) and in subjects with small discs (OR 2.2), however only the effect modification by gender reached significance. Further research is necessary to understand the possible implications of these findings on the assessment of optic discs with the use of the ISNT rule.
Prevalence and incidence of keratoconus in Sweden. A nationwide register study between 2010 and 2020.
The purpose of this study was to estimate the prevalence and incidence of keratoconus in Sweden. The study had a cross-sectional descriptive design, using data from the Swedish Patient Register. Data about keratoconus registered from 1st January, 2010, to 31st December, 2020, were analysed. Prevalence was estimated from the total number of patients registered. Incidence was estimated from the number of first-time registrations per year for the age group 0 to 40 years and stratified by decades of age. From 2010 to 2020, 16,055 patients were registered with keratoconus in the Swedish Patient Register, giving a total estimated keratoconus prevalence of 169.5 per 100,000 (95% CI: 144.9–194.1), 74.2% were male. The estimated annual incidence of keratoconus was 11.8 per 100,000 (95% CI: 5.1–18.5). The average annual incidence was highest in the decade 21 to 30 years, 26.1 per 100,000 (95% CI: 16.1–36.1). For the age group 0 to 40 years, the estimated incidence of keratoconus was 22.5 per 100,000 (95% CI: 13.7–32.3). Keratoconus should not be regarded as an uncommon condition. The prevalence of keratoconus may be even higher because of under-registration among older citizens. The estimated prevalence and incidence of keratoconus in Sweden is comparable to estimated prevalence in Norway.
Copyright (c) 2023 Jonathan Binder, Vibeke Sundling https://creativecommons.org/licenses/by-nc-nd/4.0
Refractive trends in 15-year-old adolescents at optometric practices in southern Sweden between 2007 and 2020
The purpose of this study was to analyse the distribution of refractive errors in 15-year-old adolescents at optometric practices in southern Sweden between 2007 and 2020. Refractive data were collected retrospectively from clinical records in five optometric practices in southern Sweden. The inclusion criteria were individuals visiting the practice at an age of 15 years between 2007 and 2020. The refractive errors were classified by the spherical equivalent (SE) (sphere + 1⁄2 cylinder) as follows: myopia (SE ≤ -0.5 D), hyperopia (SE ≥ 0.5 D), emmetropia (-0.5 > SE < 0.5 D). The astigmatism axis (-1.5 DC) was analysed as with-the-rule, against-the-rule and oblique according to traditional methods. To examine trends, the average refraction and distribution of refractive errors were compared between two selected time periods, 2007–2013 and 2014–2020. During the time frame 500 adolescents aged 15 years were examined in the selected optometric practices. Myopia was found in 34%, emmetropia in 35% and hyperopia in 31%. Among 37 individuals with astigmatism, the most common axis was with- the-rule (41%), followed by oblique (32%) and against-the-rule (27%). No significant differences could be found in the distribution of different refractive errors between the periods 2007–2013 and 2014–2020. Nor could any significant difference in average refraction be found. In contrast to the expected global rise in myopia as predicted by WHO and the high prevalence of myopia reported in some parts of the world, we could not find convincing changes in distribution between myopia and hyperopia in this cohort of Swedish adolescents.
Copyright (c) 2023 Tomas Bro, Rune Brautaset https://creativecommons.org/licenses/by-nc-nd/4.0
The need for cycloplegic refraction in adolescents and young adults
Cycloplegic refraction is considered the gold standard method when examining children and for ensuring accurate refractive error assessment within epidemiological studies. Recent reports underline that cycloplegia is equally important for ensuring accurate refractive error assessment in Chinese adolescents and young adults (Sun et al., 2018). The aim of this study was to assess whether cycloplegia is of equal importance for refractive error assessment in Norwegian adolescents and young adults. Non-cycloplegic and cycloplegic autorefraction (Huvitz HRK-8000A), and cycloplegic ocular biometry (IOLMaster 700), were undertaken in 215 Norwegian adolescents (101 males) aged 16–17 years. Topical cyclopentolate hydrochloride 1% was used for cycloplegia. Two years later, autorefraction and ocular biometry were repeated in 93 of the participants (34 males), both non-cycloplegic and cycloplegic. Non-cycloplegic spherical equivalent refractive errors (SER = sphere + 1⁄2 cylinder) were more myopic (less hyperopic) than cycloplegic SER in 93.6% of the participants (overall mean ±SD difference in SER: -0.59 ±0.50 D, 95% limit of agreement: -1.58 – 0.39 D). Refractive error classification by non-cycloplegic SER underestimated the hyperopia frequency (10.4% vs. 41.4%; SER ≥ +0.75 D) and overestimated the myopia frequency (12.1% vs. 10.7%; SER ≤ -0.75 D), as compared with refractive error classification by cycloplegic SER. Mean crystalline lens thickness decreased and mean anterior chamber depth increased with cycloplegia, with the largest changes in the hyperopes compared with the emmetropes and myopes (p ≤ 0.04). The individual differences between non-cycloplegic and cycloplegic SER varied by more than ±0.25 D between first and second visit for 31% of the participants. Accurate baseline measurements — as well as follow-up measurements — are imperative for deciding when and what to prescribe for myopic and hyperopic children, adolescents, and young adults. The results here confirm that cycloplegia is necessary to ensure accurate measurement of refractive errors in Norwegian adolescents and young adults.
Copyright (c) 2023 Lene A. Hagen, Stuart J. Gilson, Rigmor C. Baraas https://creativecommons.org/licenses/by-nc-nd/4.0
Framework analysis for Vision Scientists: a clear step-by-step guide
Vision sciences has traditionally been a quantitative discipline. However, to fully capture all aspects of clinical vision care, researchers increasingly need to be conversant in both quantitative and qualitative methodologies. This has resulted in qualitative methodologies becoming more common in vision sciences research literature. From the authors’ perspective, vision researchers often struggle to identify suitable qualitative methodologies when coming from a tradition of a realist ontology, or the view that independent truth exists. This study explores the ontological and epistemological considerations when approaching qualitative research in vision sciences and proposes framework analysis as a qualitative methodology that is accessible for vision scientists. Framework analysis is a flexible and highly utilitarian qualitative analysis method which complements quantitative methodologies. This paper also presents a step-by-step guide for conducting framework analysis in a logical, transparent, and repeatable way that will provide a clear audit trail of how results are obtained from subjective data. This is done using a worked example from a recent eye care study.
Copyright (c) 2023 Joel Somerville https://creativecommons.org/licenses/by-nc-nd/4.0
Copyright (c) 2023 António Filipe Teixeira Macedo; Oskar Johansson, Rigmor C. Baraas https://creativecommons.org/licenses/by-nc-nd/4.0