1
|
Kessel L, Kjølholm CDB, Jordana JT. Does Foveal Hypoplasia Affect Emmetropization in Patients with Albinism? CHILDREN (BASEL, SWITZERLAND) 2023; 10:1910. [PMID: 38136112 PMCID: PMC10741917 DOI: 10.3390/children10121910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 12/07/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023]
Abstract
(1) Background: The aim of the study was to describe refractive development from early childhood to adulthood in Danish patients with albinism and to evaluate the effect of foveal developmental stage on refractive development; (2) Methods: Patients with a clinical diagnosis of ocular or oculocutaneous albinism were invited for a refractive evaluation and comprehensive phenotyping including macular optical coherence tomography (OCT) scans. Foveal hypoplasia was graded based on OCT from 0 (normal) to 4 (absence of any signs of foveal specialization). Medical files were reviewed for historical refractive values in individual patients; (3) Results: Hyperopia (spherical equivalent refraction (SEQ) of ≥+1 Diopter (D)) was common in both children (81.3%) and adults (67.1%). The lower prevalence of hyperopia in adults was predominantly explained by increasing astigmatism with age. Emmetropization (>2D change from before 3 years to adolescence) was seen in 22.2%. There was no influence on foveal hypoplasia grade on the degree of refractive errors throughout life; (4) Conclusions: We found that emmetropization was uncommon in Danish patients with albinism and that the degree of foveal developmental stage did not influence emmetropization or the distribution of refractive errors. High degrees of hyperopia and astigmatism were common. These results indicate that fear of impeding emmetropization should not refrain the clinician from providing adequate correction for refractive errors in young children with albinism.
Collapse
Affiliation(s)
- Line Kessel
- Department of Ophthalmology, Copenhagen University Hospital—Rigshospitalet, 2100 Copenhagen, Denmark; (C.D.B.K.); (J.T.J.)
- Department of Clinical Medicine, University of Copenhagen, 2200 Copenhagen, Denmark
| | | | - Joaquim Torner Jordana
- Department of Ophthalmology, Copenhagen University Hospital—Rigshospitalet, 2100 Copenhagen, Denmark; (C.D.B.K.); (J.T.J.)
| |
Collapse
|
2
|
Salchow DJ. [Nystagmus in Children - a Survey]. Klin Monbl Augenheilkd 2023; 240:617-635. [PMID: 36827996 DOI: 10.1055/a-2022-1111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
Nystagmus describes an involuntary, periodic movement of one or both eyes. About 1/600 children and adolescents have nystagmus, most of them idiopathic infantile nystagmus (IIN), also called "congenital nystagmus", which can be caused by mutations in the FRMD7 gene. Other frequent forms of nystagmus are latent nystagmus, which is usually associated with infantile strabismus, and nystagmus associated with albinism. Sometimes difficult to distinguish in young infants is a sensory nystagmus, where a defect in the visual system reduces vision and causes nystagmus. Causes include retinal dystrophies, congenital stationary night blindness and structural ocular defects including optic nerve hypoplasia or dense bilateral congenital cataracts. Unilateral nystagmus can be the sign of an anterior visual pathway lesion. Seesaw nystagmus may be associated with suprasellar and mesodiencephalic lesions and - rarely - with retinal dystrophies.The ophthalmology plays a key role in identifying the form of nystagmus. Children with new onset nystagmus, with spasmus nutans, with vertical or unilateral nystagmus and those with seesaw nystagmus require neurologic evaluation including imaging of the brain.The treatment of nystagmus depends on the underlying cause. Even minor refractive errors should be corrected, contact lenses offer advantages over glasses.Gabapentin and memantine, possibly also carbonic anhydrase inhibitors, are effective in treating IIN, nystagmus in albinism and sensory nystagmus. Nevertheless, pharmacologic treatment of nystagmus is rarely used in children; the reasons are the limited effects on vision, the need for lifelong therapy, and potential side effects. Eye muscle surgery (Anderson procedure, Kestenbaum procedure) can correct a nystagmus-related anomalous head posture. The concept of "artifical divergence" of Cüppers may help to decrease nystagmus intensity in patients whose nystagmus dampens with convergence. The four-muscle-tenotomy, which involves disinsertion and reinsertion of the horizontal muscles at the original insertion of both eyes, has a proven but limited positive effect on visual acuity.
Collapse
|
3
|
Salchow DJ. Nystagmus bei Kindern – eine Übersicht. AUGENHEILKUNDE UP2DATE 2023. [DOI: 10.1055/a-1774-3608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
ZusammenfassungNystagmus ist definiert als unwillkürliche, periodische Bewegung, bei der eines oder beide Augen vom Fixationspunkt wegdriften (sog. Drift). Auf die Drift, die langsame Phase, folgt entweder eine schnelle, refixierende Bewegung (sog. Refixationssakkade oder schnelle Phase) oder eine langsamere Bewegung zur Wiederaufnahme der Fixation. In dieser Übersichtsarbeit sollen die wichtigsten Formen von Nystagmus bei Kindern erörtert werden, für eine Übersicht bei Erwachsenen sei auf 1 verwiesen.
Collapse
|
4
|
Oladiwura D, shweikh Y, Roberts C, Theodorou M. Nystagmus in Down Syndrome – a Retrospective Notes Review. BRITISH AND IRISH ORTHOPTIC JOURNAL 2022; 18:48-56. [PMID: 35837367 PMCID: PMC9231581 DOI: 10.22599/bioj.256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 04/27/2022] [Indexed: 11/30/2022] Open
Abstract
Introduction: Nystagmus has been reported in up to 30% of people with Down Syndrome (DS), and yet is still not well understood. Our study aims to characterise the clinical features of patients with DS and nystagmus. Methods: A retrospective medical-records review was conducted of all patients with a diagnosis of DS and nystagmus seen at Moorfields Eye Hospital over a ten-year period. Results: Fifty-one subjects were identified, with complete data in 48. The mean age at presentation was 5.1 years (range 0–26 years). The mean binocular LogMAR visual acuity was 0.55(95%CI 0.53–0.57), mean refractive error was –1.8 Dioptre Sphere, DS (95% CI – 5.251.63) with –1.2 Dioptre Cylinder, DC (95% CI – 1.6–0.7). Ocular misalignment was found in 50% of patients. A diagnosis of Fusion Maldevelopment Nystagmus Syndrome (FMNS) was made in 6.3%, Infantile Nystagmus Syndrome (INS) in 8.4% and ABducting nystagmus/Inter-Nuclear Ophthalmoplegia (INO) in 2.1%. The descriptive term ‘Manifest Horizontal Nystagmus’(MNH) was used in the majority, highlighting the difficulties in clinically differentiating the subtypes of nystagmus in DS. Eleven patients had associated cataract. Additional diagnoses unrelated to DS were made in 10.4%. Conclusions: The most frequent type of nystagmus in our cohort was ‘presumed’ INS. This study highlights the importance of differentiating between FMNS and INS (with a latent component), so that further investigations can be performed as appropriate. Almost 25% had associated cataract, and a further 10% other diagnoses un-associated to DS. Despite INS being known to be associated with DS, further investigations may be required in a small subset with true INS after careful clinical assessment and use of eye movement recordings (where available).
Collapse
|
5
|
Refractive development in individuals with ocular and oculocutaneous albinism. Int Ophthalmol 2022; 42:2007-2015. [PMID: 35587842 DOI: 10.1007/s10792-021-02165-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 12/18/2021] [Indexed: 10/18/2022]
Abstract
PURPOSE Albinism is known to disrupt emmetropisation in animal models. However, it is not clear if the same effect is seen in humans. This study aimed to investigate the refractive profile in individuals diagnosed with ocular albinism (OA) and oculocutaneous albinism (OCA) based on a large dataset. METHODS Required data from 618 individuals (61% males and 39% females) diagnosed with albinism were exported from the eyeSmart electronic medical records of L V Prasad Eye Institute. Overall, there were 112 (18%) individuals diagnosed with OA and 506 (82%) with OCA. Based on the spherical equivalent refraction (SER), individuals were classified as emmetropes, myopes, and hyperopes. RESULTS The overall spherical equivalent refraction of the individuals ranged from -25.00D to + 12.00D with a median + 0.25D (-2.00 to + 2.25 D). The proportion of individuals with albinism (combined OA, OCA) having hyperopia and myopia (overall: N = 282;45.6% vs. N = 245;39.6%) were similar (p = 0.18), and the least were with emmetropia (overall: N = 91;14.7%). Across all the age groups (0-10, 11-20, 21-30, > 30 years), the frequency of hyperopes and myopes was significantly higher (p < 0.05) compared to emmetropes. Both high degrees of hyperopia and myopia were found in individuals diagnosed with OA and OCA. Irrespective of the albinism type, with-the-rule (70%) astigmatism was the most prevalent compared to other types of astigmatism. The frequency of with-the-rule astigmatism was significantly high in the presence of nystagmus compared to individuals with no nystagmus in both OA (75% vs 25%, p = 0.01) and OCA (77% vs 23%, p = 0.014) groups. CONCLUSION The presence of both high hyperopia and high myopia and very few numbers with emmetropia across all age groups indicates disrupted normal refractive development in individuals with albinism. With-the-rule astigmatism and nystagmus may result in meridional degradation of the retinal image leading to impairment of normal emmetropisation process in individuals with albinism.
Collapse
|
6
|
Zahidi AAA, McIlreavy L, Erichsen JT, Woodhouse JM. Visual and Refractive Status of Children With Down's Syndrome and Nystagmus. Invest Ophthalmol Vis Sci 2022; 63:28. [PMID: 35195683 PMCID: PMC8883157 DOI: 10.1167/iovs.63.2.28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Purpose Children with Down's syndrome (DS) are known to have poorer visual acuity than neurotypical children. One report has shown that children with DS and nystagmus also have poor acuity when compared to typical children with nystagmus. What has not been established is the extent of any acuity deficit due to nystagmus and whether nystagmus affects refractive error within a population with DS. Methods Clinical records from the Cardiff University Down's Syndrome Vision Research Unit were examined retrospectively. Binocular visual acuity and refraction data were available for 50 children who had DS and nystagmus and 176 children who had DS but no nystagmus. Data were compared between the two groups and with published data for neurotypical children with nystagmus. Results The study confirms the deficit in acuity in DS, compared to neurotypical children, of approximately 0.2 logMAR and shows a deficit attributable to nystagmus of a further 0.2 logMAR beyond the first year of life. Children with both DS and nystagmus clearly have a significant additional impairment. Children with DS have a wide range of refractive errors, but nystagmus increases the likelihood of myopia. Prevalence and axis direction of astigmatism, on the other hand, appear unaffected by nystagmus. Conclusions Nystagmus confers an additional visual impairment on children with DS and must be recognized as such by families and educators. Children with both DS and nystagmus clearly need targeted support.
Collapse
Affiliation(s)
- Asma A A Zahidi
- Optometry Programme, School of Health Professions, University of Plymouth, Plymouth, United Kingdom
| | - Lee McIlreavy
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Jonathan T Erichsen
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - J Margaret Woodhouse
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| |
Collapse
|
7
|
Papageorgiou E, Lazari K, Gottlob I. The challenges faced by clinicians diagnosing and treating infantile nystagmus Part II: treatment. EXPERT REVIEW OF OPHTHALMOLOGY 2021. [DOI: 10.1080/17469899.2021.1970533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Eleni Papageorgiou
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, University of Leicester, Leicester, UK
- Department of Ophthalmology, University Hospital of Larissa, Mezourlo Area, Larissa, Greece
| | - Katerina Lazari
- Department of Ophthalmology, University Hospital of Larissa, Mezourlo Area, Larissa, Greece
| | - Irene Gottlob
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, University of Leicester, Leicester, UK
- Department of Neurology, Cooper University Hospital, Neurological Institute, Camden, New Jersey, USA
| |
Collapse
|
8
|
Bedell HE, Song S. High- and Low-contrast Letter Acuity during Image Motion in Normal Observers and Observers with Infantile Nystagmus Syndrome. Optom Vis Sci 2021; 98:150-158. [PMID: 33534376 PMCID: PMC7897239 DOI: 10.1097/opx.0000000000001643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
SIGNIFICANCE High-contrast acuity in individuals with infantile nystagmus syndrome (INS) is poorer than expected from their ongoing retinal image motion, indicating a sensory loss. Conversely, acuity for larger low-contrast letters in these observers may be limited by image motion alone. PURPOSE The aim of this study was to assess visual acuity for letters of different contrast in normal observers and individuals with idiopathic INS under conditions of comparable retinal image motion. METHODS Visual acuity was measured using projected Landolt C charts in 3 normal observers and 11 observers with presumed idiopathic INS. Normal observers viewed each chart after reflection from a front-surface mirror that underwent continuous 4-Hz ramp motion with amplitudes ranging from 4 to 9.6° and simulated foveation durations of 20 to 80 milliseconds. Observers with INS viewed the charts directly. By reciprocally varying the luminance of the projected charts and a superimposed veiling source, Landolt C's were presented on a background luminance of 43 cd/m2 with Weber contrasts between -12 and -89%. RESULTS Whereas normal observers' high-contrast acuity during imposed image motion depends only on the duration of the simulated foveation periods, acuity for low-contrast optotypes also worsens systematically as motion intensity (frequency × amplitude) increases. For comparable parameters of retinal image motion, high-contrast acuity in all but one of the observers with INS was poorer than in normal observers. On the other hand, low-contrast acuity in the two groups of observers was similar when the retinal image motion was comparable. CONCLUSIONS Reduced high-contrast acuity in observers with INS appears to be attributable primarily to a sensory deficit. On the other hand, the reduction of low-contrast acuity in observers with INS may be accounted for on the basis of retinal image motion.
Collapse
|
9
|
Papageorgiou E, Gottlob I. The challenges faced by clinicians diagnosing and treating infantile nystagmus Part I: diagnosis. EXPERT REVIEW OF OPHTHALMOLOGY 2020. [DOI: 10.1080/17469899.2021.1860754] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Eleni Papageorgiou
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, University of Leicester, Leicester, UK
- Department of Ophthalmology, University Hospital of Larissa, Larissa, Greece
| | - Irene Gottlob
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, University of Leicester, Leicester, UK
| |
Collapse
|
10
|
Kuht HJ, Han J, Maconachie GDE, Park SE, Lee ST, McLean R, Sheth V, Hisaund M, Dawar B, Sylvius N, Mahmood U, Proudlock FA, Gottlob I, Lim HT, Thomas MG. SLC38A8 mutations result in arrested retinal development with loss of cone photoreceptor specialization. Hum Mol Genet 2020; 29:2989-3002. [PMID: 32744312 PMCID: PMC7645707 DOI: 10.1093/hmg/ddaa166] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/09/2020] [Accepted: 07/10/2020] [Indexed: 01/09/2023] Open
Abstract
Foveal hypoplasia, optic nerve decussation defects and anterior segment dysgenesis is an autosomal recessive disorder arising from SLC38A8 mutations. SLC38A8 is a putative glutamine transporter with strong expression within the photoreceptor layer in the retina. Previous studies have been limited due to lack of quantitative data on retinal development and nystagmus characteristics. In this multi-centre study, a custom-targeted next generation sequencing (NGS) gene panel was used to identify SLC38A8 mutations from a cohort of 511 nystagmus patients. We report 16 novel SLC38A8 mutations. The sixth transmembrane domain is most frequently disrupted by missense SLC38A8 mutations. Ninety percent of our cases were initially misdiagnosed as PAX6-related phenotype or ocular albinism prior to NGS. We characterized the retinal development in vivo in patients with SLC38A8 mutations using high-resolution optical coherence tomography. All patients had severe grades of arrested retinal development with lack of a foveal pit and no cone photoreceptor outer segment lengthening. Loss of foveal specialization features such as outer segment lengthening implies reduced foveal cone density, which contributes to reduced visual acuity. Unlike other disorders (such as albinism or PAX6 mutations) which exhibit a spectrum of foveal hypoplasia, SLC38A8 mutations have arrest of retinal development at an earlier stage resulting in a more under-developed retina and severe phenotype.
Collapse
Affiliation(s)
- Helen J Kuht
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Jinu Han
- Institute of Vision Research, Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea
| | - Gail D E Maconachie
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
- Academic Unit of Ophthalmology and Orthoptics, University of Sheffield, Sheffield S10 2RX, UK
| | - Sung Eun Park
- Institute of Vision Research, Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea
| | - Rebecca McLean
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Viral Sheth
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Michael Hisaund
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Basu Dawar
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Nicolas Sylvius
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Usman Mahmood
- Department of Ophthalmology, Hull and East Yorkshire Hospitals NHS Trust, Hull HU3 2JZ, UK
| | - Frank A Proudlock
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Irene Gottlob
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Hyun Taek Lim
- Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Mervyn G Thomas
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
| |
Collapse
|
11
|
Hennein L, de Alba Campomanes A. Longitudinal Analysis of Refractive Errors in Premature Children during the First Three Years of Life. J Binocul Vis Ocul Motil 2020; 70:170-176. [PMID: 33095122 DOI: 10.1080/2576117x.2020.1830670] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE To examine the longitudinal behavior of refractive errors in both retinopathy of prematurity (ROP) and non-ROP screened premature children during the first three years of life. METHODS This retrospective cohort included premature children (less than 37 weeks gestational age) born between 10/2011 and 8/2013 with ≥ two cycloplegic refractions. Cycloplegic refractions were converted into power vectors: M (spherical equivalent), J0 [positive for with-the-rule (WTR) and negative for against-the-rule (ATR) astigmatism], and J 45 (oblique astigmatism). Each power vector component was fitted by multilevel mixed-effects linear regression models; the mean change over time was analyzed. RESULTS Mean J0 was 0.59 (95% CI 0.53-0.66) at six months and 0.29 (95% CI 0.19-0.39) at 18 months; afterward, the change was <0.1 per year. J0 decreased -0.32 (0.64 diopters) over three years. When analyzed in one-year increments, the mean change in J0 and M was lowest at 24 months. M decreased 1.13 diopters over three years. CONCLUSION WTR astigmatism and spherical equivalent decreased over the first three years of life. WTR astigmatism accounted for the majority of amblyopogenic refractive errors. The change in J0 leveled after 18 months and the lowest rate of change was at 24 months in J0 and M, thus it may be appropriate to screen this high-risk population around 18-24 months.
Collapse
Affiliation(s)
- Lauren Hennein
- Department of Ophthalmology, University of California San Francisco , San Francisco, California
| | | |
Collapse
|
12
|
Woltsche N, Werkl P, Posch-Pertl L, Ardjomand N, Frings A. Astigmatismus. SPEKTRUM DER AUGENHEILKUNDE 2019. [DOI: 10.1007/s00717-019-00440-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Zusammenfassung
Der Astigmatismus ist der weltweit häufigste Refraktionsfehler vor Hypermetropie und Myopie. Man unterscheidet den äußeren vom inneren Astigmatismus. Der äußere Astigmatismus kann weiter in „mit der Regel“, „gegen die Regel“ und „schräg“ unterteilt werden. Die Summierung des äußeren und inneren Astigmatismus ergibt den refraktiven Zylinder. Astigmatismus wurde lange als zweidimensionales Phänomen gesehen, doch erst die dreidimensionale Betrachtung hat den Blick auf bestehende Analyseverfahren (Topo- und Tomographie) erweitert. Die Vektoranalyse nach Alpins ist hierbei eine bekannte Methode zur Therapieplanung. Zur Therapie des Astigmatismus stehen konservative Optionen wie Brille oder torische Kontaktlinse sowie unterschiedlichste chirurgische Verfahren wie photorefraktive Keratektomie, Femtosekundenlaser-assistierte Keratotomie, Laser-in-situ-Keratomileusis, „small-incision lenticule extraction“ und die Implantation torischer Intraokularlinsen zur Verfügung.
Collapse
|
13
|
Abstract
Astigmatism is the most frequent refractive error worldwide followed by hyperopia and myopia. Internal astigmatism has to be differentiated from external astigmatism. Furthermore, external astigmatism can be divided into "with the rule", "against the rule" and "oblique". The summation of internal and external astigmatism results in the refractive cylinder. Astigmatism has for a long time been regarded as a two-dimensional phenomenon; however, only a three-dimensional consideration expanded the view on existing analytical methods (topography and tomography). Alpins' vector analysis is a commonly used method for treatment planning. Multiple options exist for treatment of astigmatism with conservative approaches, such as eyeglasses or toric contact lenses as well as various surgical procedures, such as photorefractive keratectomy, femtosecond laser-assisted keratotomy, laser in-situ keratomileusis, small incision lenticule extraction and toric intraocular lens implantation.
Collapse
Affiliation(s)
- N Woltsche
- Univ.-Augenklinik Graz, Medizinische Universität Graz, Auenbruggerplatz 4, 8036, Graz, Österreich.
| | - P Werkl
- Univ.-Augenklinik Graz, Medizinische Universität Graz, Auenbruggerplatz 4, 8036, Graz, Österreich
| | - L Posch-Pertl
- Univ.-Augenklinik Graz, Medizinische Universität Graz, Auenbruggerplatz 4, 8036, Graz, Österreich
| | - N Ardjomand
- Sehzentrum für Augenlaser & Augenchirurgie, Leechgasse 58, 8010, Graz, Österreich
| | - A Frings
- Univ.-Augenklinik Düsseldorf, Heinrich-Heine-Universität, Moorenstr. 5, 40225, Düsseldorf, Deutschland.,UCL Institute of Ophthalmology, 11-43 Bath St, EC1V 9EL, London, Großbritannien.,Moorfields Eye Hospital NHS Foundation Trust, 162 City Rd, EC1V 2PD, London, Großbritannien
| |
Collapse
|
14
|
Reading speed of patients with infantile nystagmus for text in different orientations. Vision Res 2019; 155:17-23. [DOI: 10.1016/j.visres.2018.12.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 12/02/2018] [Accepted: 12/12/2018] [Indexed: 11/20/2022]
|
15
|
Changes in refractive errors in albinism: a longitudinal study over the first decade of life. J AAPOS 2018; 22:462-466. [PMID: 30343058 DOI: 10.1016/j.jaapos.2018.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 08/15/2018] [Accepted: 08/16/2018] [Indexed: 11/24/2022]
Abstract
PURPOSE To analyze longitudinal changes in refraction in patients with albinism. METHODS The medical records of 481 patients were reviewed retrospectively to identify patients who had cycloplegic refractions at three ages: visit A, 0-18 months old; visit B, 4-6 years old; visit C, 8-10 years old. We recorded refraction, type of albinism, glasses wear, and best-corrected visual acuity at visit C. Only right eyes were analyzed. RESULTS A total of 75 patients were included. Of these, 73 wore glasses. Mean best-corrected visual acuity at visit C was 20/72 (range, 20/25-20/200). Mean spherical equivalent was 2.81 ± 2.4 D at visit A, 2.53 ± 3.4 D at visit B, and 2.15 ± 4.0 D at visit C. These values did not differ significantly from visits A to C (P = 0.0578). Mean astigmatism for the three time points was 1.60 ± 1.00 D, 2.50 ± 1.14 D, and 2.87 ± 1.45 D; these values did differ significantly from A to C (P < 0.0001). Subgroup analysis for OCA1A (16 eyes), OCA1B (20 eyes), and OCA2 (30 eyes) showed an increase in astigmatism from A to C, with a significant difference in means (P < 0.0001, P < 0.0001, and P = 0.0001, resp.). Worse best-corrected visual acuity and higher mean astigmatism at visit C were found for OCA1A (20/104 and +4.08 ± 1.34) compared to OCA1B (20/59 and +2.30 ± 1.36; P < 0.0001) and OCA2 (20/66 and +2.53 ±1.21; P < 0.0001). CONCLUSIONS Children with albinism require periodic cycloplegic refraction, because astigmatism often increases within the first 10 years of life.
Collapse
|
16
|
Zahidi AA, Woodhouse JM, Erichsen JT, Dunn MJ. Infantile nystagmus: an optometrist's perspective. CLINICAL OPTOMETRY 2017; 9:123-131. [PMID: 30214368 PMCID: PMC6118861 DOI: 10.2147/opto.s126214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Infantile nystagmus (IN), previously known as congenital nystagmus, is an involuntary to-and-fro movement of the eyes that persists throughout life. IN is one of three types of early-onset nystagmus that begin in infancy, alongside fusion maldevelopment nystagmus syndrome and spasmus nutans syndrome. Optometrists may also encounter patients with acquired nystagmus. The features of IN overlap largely with those of fusion maldevelopment nystagmus syndrome, spasmus nutans syndrome, and acquired nystagmus, yet the management for each subtype is different. Therefore, the optometrist's role is to accurately discern IN from other forms of nystagmus and to manage accordingly. As IN is a lifelong condition, its presence not only affects the visual function of the individual but also their quality of life, both socially and psychologically. In this report, we focus on the approaches that involve optometrists in the investigation and management of patients with IN. Management includes the prescription of optical treatments, low-vision rehabilitation, and other interventions such as encouraging the use of the null zone and referral to support groups. Other treatments available via ophthalmologists are also briefly discussed in the article.
Collapse
Affiliation(s)
- Asma Aa Zahidi
- Research Unit for Nystagmus, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK,
| | - J Margaret Woodhouse
- Research Unit for Nystagmus, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK,
| | - Jonathan T Erichsen
- Research Unit for Nystagmus, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK,
| | - Matt J Dunn
- Research Unit for Nystagmus, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK,
| |
Collapse
|
17
|
Welton T, Ather S, Proudlock FA, Gottlob I, Dineen RA. Altered whole-brain connectivity in albinism. Hum Brain Mapp 2016; 38:740-752. [PMID: 27684406 DOI: 10.1002/hbm.23414] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 09/13/2016] [Accepted: 09/19/2016] [Indexed: 12/15/2022] Open
Abstract
Albinism is a group of congenital disorders of the melanin synthesis pathway. Multiple ocular, white matter and cortical abnormalities occur in albinism, including a greater decussation of nerve fibres at the optic chiasm, foveal hypoplasia and nystagmus. Despite this, visual perception is largely preserved. It was proposed that this may be attributable to reorganisation among cerebral networks, including an increased interhemispheric connectivity of the primary visual areas. A graph-theoretic model was applied to explore brain connectivity networks derived from resting-state functional and diffusion-tensor magnetic resonance imaging data in 23 people with albinism and 20 controls. They tested for group differences in connectivity between primary visual areas and in summary network organisation descriptors. Main findings were supplemented with analyses of control regions, brain volumes and white matter microstructure. Significant functional interhemispheric hyperconnectivity of the primary visual areas in the albinism group were found (P = 0.012). Tests of interhemispheric connectivity based on the diffusion-tensor data showed no significant group difference (P = 0.713). Second, it was found that a range of functional whole-brain network metrics were abnormal in people with albinism, including the clustering coefficient (P = 0.005), although this may have been driven partly by overall differences in connectivity, rather than reorganisation. Based on the results, it was suggested that changes occur in albinism at the whole-brain level, and not just within the visual processing pathways. It was proposed that their findings may reflect compensatory adaptations to increased chiasmic decussation, foveal hypoplasia and nystagmus. Hum Brain Mapp 38:740-752, 2017. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Thomas Welton
- Radiological Sciences, Division of Clinical Neuroscience, University of Nottingham, Room W/B 1441, Queen's Medical Centre, Derby Road, Nottingham, NG7 2UH, United Kingdom
| | - Sarim Ather
- Radiological Sciences, Division of Clinical Neuroscience, University of Nottingham, Room W/B 1441, Queen's Medical Centre, Derby Road, Nottingham, NG7 2UH, United Kingdom.,Leicester Royal Infirmary, Ulverscroft Eye Unit, Ophthalmology, University of Leicester, Knighton Street Offices, Leicester, LE2 7LX, United Kingdom
| | - Frank A Proudlock
- Leicester Royal Infirmary, Ulverscroft Eye Unit, Ophthalmology, University of Leicester, Knighton Street Offices, Leicester, LE2 7LX, United Kingdom
| | - Irene Gottlob
- Leicester Royal Infirmary, Ulverscroft Eye Unit, Ophthalmology, University of Leicester, Knighton Street Offices, Leicester, LE2 7LX, United Kingdom
| | - Robert A Dineen
- Radiological Sciences, Division of Clinical Neuroscience, University of Nottingham, Room W/B 1441, Queen's Medical Centre, Derby Road, Nottingham, NG7 2UH, United Kingdom
| |
Collapse
|
18
|
Mohammad S, Gottlob I, Sheth V, Pilat A, Lee H, Pollheimer E, Proudlock FA. Characterization of Abnormal Optic Nerve Head Morphology in Albinism Using Optical Coherence Tomography. Invest Ophthalmol Vis Sci 2015. [PMID: 26200501 DOI: 10.1167/iovs.15-16856] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To characterize abnormalities in three-dimensional optic nerve head (ONH) morphology in people with albinism (PWA) using spectral-domain optical coherence tomography (SD-OCT) and to determine whether ONH abnormalities relate to other retinal and clinical abnormalities. METHODS Spectral-domain OCT was used to obtain three-dimensional images from 56 PWA and 60 age- and sex-matched control subjects. B-scans were corrected for nystagmus-associated motion artefacts. Disc, cup, and rim ONH dimensions and peripapillary retinal nerve fiber layer (ppRNFL) thickness were calculated using Copernicus and ImageJ software. RESULTS Median disc areas were similar in PWA (median = 1.65 mm2) and controls (1.71 mm2, P = 0.128), although discs were significantly elongated horizontally in PWA (P < 0.001). In contrast, median optic cup area in PWA (0.088 mm2) was 23.7% of that in controls (0.373 mm2, P < 0.001), with 39.4% of eyes in PWA not demonstrating a measurable optic cup. This led to significantly smaller cup to disc ratios in PWA (P < 0.001). Median rim volume in PWA (0.273 mm3) was 136.6% of that in controls (0.200 mm3). The ppRNFL was significantly thinner in PWA compared with controls (P < 0.001), especially in the temporal quadrant. In PWA, ppRNFL thickness was correlated to ganglion cell thickness at the central fovea (P = 0.007). Several ONH abnormalities, such as cup to disc ratio, were related to higher refractive errors in PWA. CONCLUSIONS In PWA, ocular maldevelopment is not just limited to the retina but also involves the ONH. Reduced ppRNFL thickness is consistent with previous reports of reduced ganglion cell numbers in PWA. The thicker rim volumes may be a result of incomplete maturation of the ONH.
Collapse
|
19
|
Penix K, Swanson MW, DeCarlo DK. Nystagmus in pediatric patients: interventions and patient-focused perspectives. Clin Ophthalmol 2015; 9:1527-36. [PMID: 26345377 PMCID: PMC4551307 DOI: 10.2147/opth.s62786] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Nystagmus refers to involuntary, typically conjugate, often rhythmic oscillations of the eyes. The most common cause of nystagmus in children is infantile nystagmus syndrome (INS). INS presents within the first few months of life and is sometimes accompanied by an ocular condition associated with sensory impairment. Because this condition affects a person throughout life, it is important to understand the options available to manage it. This review focuses on the underlying nystagmus etiology, psychosocial and functional effects of nystagmus, as well as current principles of management, including optical, pharmacological, surgical, and rehabilitative options. Currently, the neural mechanisms underlying INS are not fully understood. Treatment options are designed to increase foveation duration or correct anomalous head postures; however, evidence is limited to mainly pre- and post-study designs with few objective comparisons of treatment strategies. Management of INS should be individualized. The decision on which treatment is best suited for a particular patient lies with the patient and his/her physician.
Collapse
Affiliation(s)
- Kimberly Penix
- School of Optometry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Mark W Swanson
- School of Optometry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Dawn K DeCarlo
- School of Optometry, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| |
Collapse
|
20
|
McCafferty BK, Wilk MA, McAllister JT, Stepien KE, Dubis AM, Brilliant MH, Anderson JL, Carroll J, Summers CG. Clinical Insights Into Foveal Morphology in Albinism. J Pediatr Ophthalmol Strabismus 2015; 52:167-72. [PMID: 26053207 PMCID: PMC4948980 DOI: 10.3928/01913913-20150427-06] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Accepted: 01/13/2015] [Indexed: 11/20/2022]
Abstract
PURPOSE A hallmark of albinism is foveal hypoplasia. However, literature suggests variable foveal development. This study evaluates the association between ocular phenotype and foveal morphology to demonstrate the broad structural and functional spectrum. METHODS Best-corrected visual acuity (BCVA), nystagmus, angle kappa, stereoacuity, iris transillumination, macular melanin presence, foveal avascular zone, and annular reflex were recorded in 14 patients with albinism. Spectral-domain optical coherence tomography provided macular images. RESULTS The clinical phenotype was broad, with BCVA varying from 20/20 to 20/100. Better BCVA was associated with a preserved foveal avascular zone, annular macular reflex, stereoacuity, and macular melanin. Imaging demonstrated a continuum of foveal development correlating with BCVA. Individuals with a rudimentary pit had normal inner and outer segment lengthening and better BCVA. CONCLUSIONS The spectrum of ocular structure and visual function in albinism is broad, suggesting a possible diagnosis of albinism in a patient with an even more normal clinical presentation.
Collapse
MESH Headings
- Adolescent
- Adult
- Aged, 80 and over
- Albinism, Ocular/diagnosis
- Albinism, Ocular/genetics
- Albinism, Ocular/physiopathology
- Albinism, Oculocutaneous/diagnosis
- Albinism, Oculocutaneous/genetics
- Albinism, Oculocutaneous/physiopathology
- Child
- DNA Mutational Analysis
- Depth Perception/physiology
- Evoked Potentials, Visual
- Eye Abnormalities/diagnosis
- Eye Abnormalities/genetics
- Eye Abnormalities/physiopathology
- Eye Proteins/genetics
- Female
- Fovea Centralis/abnormalities
- Fovea Centralis/pathology
- Humans
- Male
- Membrane Proteins/genetics
- Nystagmus, Pathologic/diagnosis
- Phenotype
- Polymerase Chain Reaction
- Prospective Studies
- Tomography, Optical Coherence
- Visual Acuity/physiology
- Young Adult
Collapse
|
21
|
Fledelius HC, Goldschmidt E, Haargaard B, Jensen H. Human parallels to experimental myopia? A literature review on visual deprivation. Acta Ophthalmol 2014; 92:724-9. [PMID: 24767542 DOI: 10.1111/aos.12412] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 03/07/2014] [Indexed: 11/27/2022]
Abstract
Raviola and Wiesel's monkey eyelid suture studies of the 1970s laid the cornerstone for the experimental myopia science undertaken since then. The aim has been to clarify the basic humoral and neuronal mechanisms behind induced myopization, its eye tissue transmitters in particular. Besides acquiring new and basic knowledge, the practical object of the research is to reduce the burden of human myopia around the world. Acquisition and cost of optical correction is one issue, but associated morbidity counts more, with its global load of myopia-associated visual loss and blindness. The object of the present PubMed literature-based review is to evaluate apparent similarities between experience from disturbed imaging in experimental laboratory science and varieties within the spectrum of childhood human myopia. So far, the main impression is that macroscopical optical deprivation appears absent in the prevalent types of human myopia, nor is myopia a regular sequel where early eye pathology has led to poor imaging and optical deprivation. Optical aberrations of a higher order are a relatively new issue in myopia research, and microstructural deprivation is only marginally dealt within the survey. Links between experimental and human myopia appear mainly occasional, and with only few examples in humans where factual parallels appear credible. Clinical and epidemiological data on refraction remain important, in particular with a view to life style and environmental factors. Such knowledge may further serve as inspiration to the laboratory research, which aims at solving the basic enigmas on a tissue level.
Collapse
Affiliation(s)
- Hans C. Fledelius
- Capital Region; Copenhagen University Eye Department; Rigshospitalet; Glostrup Denmark
| | | | | | - Hanne Jensen
- National Eye Clinic Kennedy Institute; Glostrup Denmark
| |
Collapse
|
22
|
Abstract
PURPOSE OF REVIEW Mechanisms underlying infantile nystagmus are unclear. The aim of this review is to outline recent developments in understanding the aetiology of infantile nystagmus. RECENT FINDINGS There have been advances in understanding mechanisms underlying idiopathic infantile nystagmus, which has progressed through determining the role of the FRMD7 gene in controlling neurite outgrowth, and albinism, in which recent models have investigated the possibility of retinal miswiring leading to nystagmus. We also briefly review aetiology of infantile nystagmus in afferent visual deficits caused by ocular disease, and PAX6 mutations. Improved phenotypical characterization of all these infantile nystagmus subtypes has been achieved recently through high-resolution retinal imaging using optical coherence tomography. Several new hypotheses proposing common mechanisms that could underlie various infantile nystagmus subtypes are also highlighted. SUMMARY Although there is still no consensus of opinion regarding the mechanisms causing infantile nystagmus, identification of new genes and determining their cellular function, phenotypical characterization of genetic subtypes, and improvements in animal models have significantly advanced our understanding of infantile nystagmus. These recent developments pave the way to achieving a much clearer picture of infantile nystagmus aetiology in the future.
Collapse
|
23
|
Healey N, McClelland JF, Saunders KJ, Jackson AJ. Longitudinal study of spherical refractive error in infantile nystagmus syndrome. Ophthalmic Physiol Opt 2014; 34:369-75. [PMID: 24446667 DOI: 10.1111/opo.12117] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 12/11/2013] [Indexed: 11/27/2022]
Abstract
PURPOSE To explore the onset and progression of spherical refractive error in a population with infantile nystagmus syndrome. METHODS Retrospective refractive error data were obtained from 147 medical records of children with infantile nystagmus syndrome (albinism n = 98; idiopathic infantile nystagmus n = 49), attending a low vision clinic in Northern Ireland, over a 24 year period (1986-2010). Data were categorised by age to allow for comparisons with published studies. A prospective group of participants with Infantile nystagmus syndrome (INS) [n = 22 (albinism n = 18, idiopathic infantile nystagmus n = 4)] (aged 0-4) were also recruited. Cycloplegic streak retinoscopy was performed biannually, over a 3 year period. Spherical equivalent refractive error and most ametropic meridian were analysed. RESULTS The mean spherical equivalent refractive errors for albinism and idiopathic infantile nystagmus groups (across all age categories) were hypermetropic, with highest levels demonstrated by the participants with albinism aged 1 ≤ 4 years (Mann-Whitney U test, p = 0.013). Mean most ametropic meridian was highest in the albinism group aged 1 ≤ 12 years (Mann-Whitney U test, p < 0.05). Individual data demonstrated relatively static spherical equivalent refractive errors over time. Prospective participants were hypermetropic at all visits and those with albinism had, on average, higher refractive errors than those with idiopathic infantile nystagmus (IIN). No significant correlations were noted between visual acuity and spherical equivalent refractive errors or most ametropic meridian. CONCLUSIONS Hypermetropia is the most prevalent spherical refractive error in the INS population, irrespective of level of visual acuity. Individuals with infantile nystagmus syndrome fail to demonstrate typical patterns of emmetropisation, particularly in the presence of albinism.
Collapse
Affiliation(s)
- Natasha Healey
- University of Ulster, Coleraine, UK; The Royal Group of Hospitals, Belfast, UK; Altnagelvin Area Hospital, Altnagelvin, UK
| | | | | | | |
Collapse
|
24
|
Infantile nystagmus and visual deprivation: foveal instability and refractive development in a low vision register series. Eur J Ophthalmol 2013; 24:599-607. [PMID: 24366772 DOI: 10.5301/ejo.5000409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2013] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate whether effects of early foveal motor instability due to infantile nystagmus might compare to those of experimental visual deprivation on refraction in a childhood series. METHODS This was a retrospective analysis of data from the Danish Register for Blind and Weaksighted Children with infantile nystagmus recorded as prime diagnosis. We perused 90 records of children now aged 10-17 years, some of whom eventually exceeded the register borderline of 0.3 as best-corrected visual acuity. Spherical equivalent refraction was the primary outcome parameter, but visual acuity, astigmatism, and age were further considered. The series comprised 48 children with nystagmus as single diagnosis, whereas 42 had clinical colabels (Down syndrome [13], dysmaturity [9], and mental retardation, encephalopathy [20]). RESULTS Median binocular visual acuity was 0.3 in the full series, and median refraction was emmetropia in all subgroups. Compared with Danish control data, myopia was over-represented, and generally of juvenile onset. The Down syndrome subgroup was separated from the remainder by an even higher myopia prevalence. Astigmatism above 1 D cylinder value was recorded in 52% of all cases. CONCLUSIONS The prevalence of myopia and astigmatism was higher among children with nystagmus than in controls. Myopia was mainly juvenile, and not related to the period of infancy when the motor foveal smear is considered most disturbing and possibly influencing visual development.
Collapse
|
25
|
Kee CS. Astigmatism and its role in emmetropization. Exp Eye Res 2013; 114:89-95. [DOI: 10.1016/j.exer.2013.04.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Revised: 04/23/2013] [Accepted: 04/24/2013] [Indexed: 10/26/2022]
|
26
|
Fresina M, Benedetti C, Marinelli F, Versura P, Campos EC. Astigmatism in patients with idiopathic congenital nystagmus. Graefes Arch Clin Exp Ophthalmol 2013; 251:1635-9. [DOI: 10.1007/s00417-013-2290-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 01/21/2013] [Accepted: 02/12/2013] [Indexed: 11/28/2022] Open
|