1
|
Neuman G, Abulafia A, Wasser L, Zadok D. Distribution of angle alpha and angle kappa offsets among adult candidates for cataract surgery. Graefes Arch Clin Exp Ophthalmol 2024:10.1007/s00417-024-06596-6. [PMID: 39103696 DOI: 10.1007/s00417-024-06596-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 05/14/2024] [Accepted: 07/22/2024] [Indexed: 08/07/2024] Open
Abstract
PURPOSE The current study aimed to describe the distribution of angle alpha and angle kappa offsets as well as their associated ocular biometric parameters in a large population of candidates for cataract surgery. METHODS This cross-sectional retrospective study included 8,119 eyes of 4,781 candidates for cataract surgery (mean age 70.7 ± 12.9 years). There were 49.9% right eyes, and 53.0% patients were females. The angles offset and ocular biometric parameters were measured by the IOLMaster 700 (Carl Zeiss Meditec, AG, Germany). RESULTS Patient's age and gender, and most of their ocular biometric measurements were similar for the right and left eyes except for pupil diameter (4.01 ± 1.18 vs. 3.92 ± 1.14 mm, respectively, P < 0.001). The angle alpha offset magnitude was similar for the right and left eyes (0.50 ± 0.20 and 0.51 ± 0.21 mm, P = 0.08), whereas the angle kappa offset magnitude was greater in the right eyes (0.37 ± 0.21 vs. 0.33 ± 0.20 mm, P < 0.001). The angle kappa offset magnitudes were greater in the right eyes compared to the left eyes for both males (0.36 ± 0.21 vs. 0.33 ± 0.21 mm, respectively, P < 0.001) and females (0.37 ± 0.20 vs. 0.34 ± 0.20 mm, respectively, P < 0.001). The offset magnitudes of both angles varied significantly according to gender, eye laterality, angle location, and biometric parameters (e.g., axial length). The offset magnitudes of both angles were positively correlated in both right and left eyes. CONCLUSIONS The offset magnitudes of both the angle alpha and angle kappa present significant variations according to gender, eye laterality, angle location, and biometric parameters, such as AL. These values are also population-specific.
Collapse
Affiliation(s)
- Gil Neuman
- Department of Ophthalmology, The Eisenberg R&D Authority, Shaare Zedek Medical Center, The Hebrew University of Jerusalem, Jerusalem, Israel.
| | - Adi Abulafia
- Department of Ophthalmology, The Eisenberg R&D Authority, Shaare Zedek Medical Center, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Lauren Wasser
- Department of Ophthalmology, The Eisenberg R&D Authority, Shaare Zedek Medical Center, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - David Zadok
- Department of Ophthalmology, The Eisenberg R&D Authority, Shaare Zedek Medical Center, The Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
2
|
Song T, Duan X. Ocular dominance in cataract surgery: research status and progress. Graefes Arch Clin Exp Ophthalmol 2024; 262:33-41. [PMID: 37644327 DOI: 10.1007/s00417-023-06216-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 08/17/2023] [Accepted: 08/21/2023] [Indexed: 08/31/2023] Open
Abstract
Ocular dominance (OD), a commonly used concept in clinical practice, plays an important role in optometry and refractive surgery. With the development of refractive cataract surgery, the refractive function of the intraocular lens determines the achievement of the postoperative full range of vision based on the retinal defocus blur suppression and binocular monovision principle. Therefore, OD plays an important role in cataract surgery. OD is related to the visual formation of the cerebral cortex, and its plasticity suggests that visual experience can influence the visual system. Cataract surgery changes the visual experience and transforms the dominant eye, which confirms the plasticity of the visual system. Based on the concept and mechanism of OD, this review summarizes the application of OD in cataract surgery.
Collapse
Affiliation(s)
- Tingting Song
- Jinan University, Guangzhou, China
- Changsha Aier Eye Hospital, Aier Eye Hospital Group, Tianxin District, 188 Furong South Road, Changsha, 410009, China
| | - Xuanchu Duan
- Jinan University, Guangzhou, China.
- Changsha Aier Eye Hospital, Aier Eye Hospital Group, Tianxin District, 188 Furong South Road, Changsha, 410009, China.
| |
Collapse
|
3
|
Martino F, Castro‐Torres JJ, Casares‐López M, Ortiz‐Peregrina S, Ortiz C, Jiménez JR. Effect of interocular differences on binocular visual performance after inducing forward scattering. Ophthalmic Physiol Opt 2022; 42:730-743. [PMID: 35499140 PMCID: PMC9321610 DOI: 10.1111/opo.12992] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 04/01/2022] [Accepted: 04/04/2022] [Indexed: 12/19/2022]
Abstract
Purpose To assess binocular visual performance by means of binocular summation on visual function after inducing monocular forward scattering, and to study the influence of interocular differences on ocular parameters. Methods Seven young healthy subjects were recruited. Four Bangerter foils and five fog filters were used to induce monocular forward scattering. To analyse the impact of the scatter, visual acuity, contrast sensitivity, visual discrimination capacity and distance stereoacuity were measured binocularly with the filter placed over the dominant eye. Additionally, interocular differences were calculated for four ocular parameters: the Objective Scatter Index (OSI), Strehl ratio (SR), modulation transfer function cut‐off (MTF cut off) and straylight (log[s]). Binocular summation was determined for these visual functions. Results A statistically significant deterioration in visual acuity, contrast sensitivity and stereoacuity was seen for all of the filter conditions with respect to the natural state (baseline), with the largest change being recorded for the Bangerter foils. Similarly, the interocular difference for the three retinal image quality parameters (OSI, SR and MTF cut‐off) and log(s) increased significantly for the Bangerter foil condition, but not for the fog filters (except log(s)). Binocular summation declined gradually with the Bangerter foils, but not for the fog filters. Statistically significant correlations were found, that is, the greater the interocular differences, the lower the binocular summation of the visual functions and the greater the distance stereoacuity. Conclusion Increased forward scattering in the dominant eye resulted in interocular differences, which reduced the overall binocular visual performance, including the binocular summation of several visual functions and distance stereoacuity. The results suggest that marked interocular differences in ocular parameters should be avoided in cases of ocular pathology, amblyopia and emmetropisation procedures (such as refractive surgery) or a monovision correction for presbyopia.
Collapse
Affiliation(s)
- Francesco Martino
- Laboratory of Vision Sciences and Applications (LabVisGra), Department of Optics University of Granada Granada Spain
| | - José J. Castro‐Torres
- Laboratory of Vision Sciences and Applications (LabVisGra), Department of Optics University of Granada Granada Spain
| | - Miriam Casares‐López
- Laboratory of Vision Sciences and Applications (LabVisGra), Department of Optics University of Granada Granada Spain
| | - Sonia Ortiz‐Peregrina
- Laboratory of Vision Sciences and Applications (LabVisGra), Department of Optics University of Granada Granada Spain
| | - Carolina Ortiz
- Laboratory of Vision Sciences and Applications (LabVisGra), Department of Optics University of Granada Granada Spain
| | - José R. Jiménez
- Laboratory of Vision Sciences and Applications (LabVisGra), Department of Optics University of Granada Granada Spain
| |
Collapse
|
4
|
Song JE, Khoramnia R, Son HS, Knorz MC, Choi CY. Comparison Between Bilateral Implantation of a Trifocal IOL and Mix-and-Match Implantation of a Bifocal IOL and an Extended Depth of Focus IOL. J Refract Surg 2021; 36:528-535. [PMID: 32785726 DOI: 10.3928/1081597x-20200616-01] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 06/12/2020] [Indexed: 01/26/2023]
Abstract
PURPOSE To compare the clinical outcomes of mix-and-match implantation of a diffractive extended depth of focus intraocular lens (IOL) (TECNIS Symfony ZXR00; Johnson & Johnson Vision) and a diffractive bifocal IOL (TECNIS ZLB00 +3.25 diopters [D]; Johnson & Johnson Vision) and bilateral implantation of a diffractive trifocal IOL (AcrySof IQ PanOptix; Alcon Laboratories, Inc). METHODS This prospective comparative study compares the clinical outcomes of patients with age-related cataract undergoing cataract surgery using the IOLs described. Patients were divided into the mix-and-match group and the trifocal group. Assessment included monocular and binocular uncorrected distance visual acuity (UDVA), intermediate visual acuity (UIVA at 60 cm), and near visual acuity (UNVA at 40 cm), uncorrected defocus curves, contrast sensitivity, and reading speed. Quality of vision was measured with the Visual Function Questionnaire (VFQ-25). RESULTS A total of 50 patients (25 in each group) were enrolled. At 6 months postoperatively, outcomes of binocular UDVA, UIVA, and UNVA were similar in both groups. The binocular defocus curve only differed at vergences of -0.50 to -1.00 D (better for the mix-and-match group; P = .032 and .004, respectively) and at -4.00 D (better for the trifocal group; P = .001). Significantly higher reading speeds in the mix-and-match group were measured at 0.7 and 0.5 logMAR (P = .038 and .034, respectively). There were no significant differences between groups for contrast sensitivity and the results of the questionnaire. CONCLUSIONS The mix-and-match implantation seemed to be a good option for patients with high demands for distance and intermediate visual acuity, whereas the trifocal IOL appeared to be more suitable for patients with enhanced near vision demands. [J Refract Surg. 2020;36(8):528-535.].
Collapse
|
5
|
Kang KH, Song MY, Kim KY, Hwang KY, Kwon YA, Koh K. Visual Performance and Optical Quality after Implantation of a New Generation Monofocal Intraocular Lens. KOREAN JOURNAL OF OPHTHALMOLOGY 2021; 35:112-119. [PMID: 33845556 PMCID: PMC8046615 DOI: 10.3341/kjo.2020.1115] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 02/21/2021] [Indexed: 11/26/2022] Open
Abstract
Purpose To evaluate the performance of two intraocular lenses (IOLs). The new monofocal IOL using a higher-order aspheric optic (Tecnis Eyhance ICB00) was compared to a standard monofocal IOL (Tecnis monofocal ZCB00) of the identical platform and material. Methods The medical records of the patients who had undergone cataract surgery with implantation of either the ZCB00 or the ICB00 in the dominant eye from March 2020 to August 2020 and with available data from the 3-month visit were reviewed. Subjects with ocular comorbidities or corneal astigmatism greater than 1.00 diopters were excluded. The uncorrected near, intermediate, distance visual acuity and corrected distance visual acuity were the main outcome measures. Optical quality parameters measured using an optical quality analysis system, clinical records including age, sex, laterality, ocular dominance, and information related to refractory errors was also collected. Parameters related to the refractory errors were all uniformly based on the Barrett Universal II formula. Results Of the 197 recruited patients, 111 and 86 were implanted with the ICB00 and ZCB00, respectively. No statistically significant differences in baseline parameters were observed between the two groups. While no statistically significant differences in distance visual acuity or optical quality were found between the two groups, compared to the ZCB00 group, the ICB00 group showed significantly higher intermediate visual acuity (p < 0.001) and near visual acuity (p < 0.05) 3 months postoperatively. Conclusions ICB00 provided superior intermediate vision and comparable distance performance and photic phenomena compared to a standard monofocal IOL.
Collapse
Affiliation(s)
- Kyoung Hae Kang
- Department of Ophthalmology, Kim's Eye Hospital, Konyang University College of Medicine, Seoul, Korea
| | - Mi Yeon Song
- Department of Ophthalmology, Kim's Eye Hospital, Konyang University College of Medicine, Seoul, Korea
| | - Kook Young Kim
- Department of Ophthalmology, Kim's Eye Hospital, Konyang University College of Medicine, Seoul, Korea
| | - Kyu-Yeon Hwang
- Department of Ophthalmology, Kim's Eye Hospital, Konyang University College of Medicine, Seoul, Korea
| | - Young-A Kwon
- Department of Ophthalmology, Kim's Eye Hospital, Konyang University College of Medicine, Seoul, Korea
| | - Kyungmin Koh
- Department of Ophthalmology, Kim's Eye Hospital, Konyang University College of Medicine, Seoul, Korea
| |
Collapse
|
6
|
Stahnke T, Mukwanseke E, Kilangalanga NJ, Hopkins A, Stachs O, Guthoff RF. Cataract surgery in Kinshasa-Is there a place for "Monovision"? Int J Clin Pract 2020; 74:e13588. [PMID: 32562301 DOI: 10.1111/ijcp.13588] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 06/12/2020] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVES Monovision is a method of correcting presbyopia where one eye is focused for far and the other for near vision. It is a simple, cost-effective approach to overcome the loss of accommodation with age and to become spectacles independent. METHODOLOGY About 50 patients, where bilateral cataract extraction was indicated, were included in this study performed at the St. Joseph's Eye Hospital in Kinshasa (DR Congo). Small incision cataract surgery technique (SICS) was applied with the implantation of 6 mm PMMA lenses in the capsular bag. IOL refractive power choice was made to achieve a post-operative refraction of -0.5 dpt for the eye selected for far vision. The second eye received an implant heading for a post-operative myopia of -1.5 dpt suitable for intermediated and near vision. According to the literature, monovision criteria have been regarded as fulfilled when (a) far vision was 0.5 (logMAR) or better and (b) near vision was P3 (0.40, Decimal 32 cm) or better. Spectacle dependence after bilateral cataract surgery heading for monovision was analysed using a dedicated questionnaire. RESULTS Out of all 50 patients 22 (44%) fulfilled the above defined criteria of monovision in terms of post-operative refraction and visual acuity. About 19 out of these 22 (86.3%) patients were happy without glasses. Two of them used bifocal spectacles, whereas the remaining patient refused spectacles. About 28 patients did not fulfill monovision criteria. Out of these 28 patients, however, 9 (32.1%) of them are happy without glasses. CONCLUSION In view of the described local circumstances aiming for monovision after bilateral cataract surgery is a suitable approach to optimise cataract surgical outcomes with no extra costs for surgery but considerable improvement of patient's visual performance in daily life.
Collapse
Affiliation(s)
- Thomas Stahnke
- Department of Ophthalmology, Rostock University Medical Center, Rostock, Germany
| | | | | | - Adrian Hopkins
- Programme National de Santé Oculaire et Vision (PNSOV), Kinshasa, DRC
| | - Oliver Stachs
- Department of Ophthalmology, Rostock University Medical Center, Rostock, Germany
| | - Rudolf F Guthoff
- Department of Ophthalmology, Rostock University Medical Center, Rostock, Germany
| |
Collapse
|
7
|
The Modulation of Laser Refractive Surgery on Sensory Eye Dominance of Anisometropia. J Ophthalmol 2020; 2020:3873740. [PMID: 32351721 PMCID: PMC7152944 DOI: 10.1155/2020/3873740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 02/20/2020] [Indexed: 01/08/2023] Open
Abstract
Purpose To evaluate the effect of laser refractive surgery on sensory eye dominance of anisometropia. Methods A total of 156 subjects with nonanisometropic myopia and 70 subjects with anisometropic myopia were enrolled in the first part of the study. The dichoptic motion coherence threshold technique was applied to collect the normal dataset and distribution of sensory eye dominance. The second part of the study included 40 subjects with nonanisometropic myopia and 40 subjects with anisometropic myopia who received the femtosecond laser-assisted in situ keratomileusis (Fs-LASIK). A comprehensive ophthalmologic evaluation was performed with particular attention to sensory eye dominance preoperatively and one-week and one-month postoperatively. The ocular dominance index (ODI) was applied to evaluate the subject's overall degree of sensory ocular dominance. Visual acuity, sighting eye dominance, and stereo acuity were also accessed. Results In experiment one, the mean ODI in the nonanisometropic group and the anisometropic group was 1.48 ± 0.63 and 1.95 ± 1.07, respectively. The ODI values of the anisometropic group were significantly higher than those of the nonanisometropic group (Mann–Whitney U test, P < 0.001). The demographics information and the distribution of ODI values in both groups are summarized in tables and figures. In experiment two, all LASIK procedures were uneventful and no postoperative complications were observed during the postoperative follow-up. Preoperatively, the ODI values of the anisometropic LASIK group were significantly higher than those of the nonanisometropic LASIK group, which was consistent with the results of part 1. However, one week after operation, the mean ODI values of the anisometropic LASIK group had significantly decreased from 1.89 ± 1.09 to 1.39 ± 0.44. And, the mean ODI values slightly increased to 1.65 ± 0.61 one-month postoperatively. In the nonanisometropic LASIK group, there were no statistically significant differences of ODI changes among preoperative, post-one-week and post-one-month visits. The demographics information and the changes of ODI of both LASIK groups are summarized in tables and figures. Conclusion Stronger sensory eye dominance is seen in the subjects with anisometropic myopia compared to subjects with nonanisometropic myopia. The strong sensory dominance of anisometropia becomes more balanced at one week of postoperation but returns to the preoperative level after one month. Laser refractive surgery had a short-term modulation of sensory eye dominance.
Collapse
|
8
|
Ang RE. Visual Performance of a Small-Aperture Intraocular Lens: First Comparison of Results After Contralateral and Bilateral Implantation. J Refract Surg 2020; 36:12-19. [DOI: 10.3928/1081597x-20191114-01] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 11/14/2019] [Indexed: 11/20/2022]
|
9
|
Kwon JW, Bae JM, Kim JS, Jee D, Choi JA. Asymmetry of the macular structure is associated with ocular dominance. Can J Ophthalmol 2019; 54:237-241. [DOI: 10.1016/j.jcjo.2018.04.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Revised: 04/20/2018] [Accepted: 04/25/2018] [Indexed: 10/28/2022]
|
10
|
Lee M, Shin KC. Clinical Study of Changes in Eye Dominance after Pseudophakic Conventional Monovision. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2019. [DOI: 10.3341/jkos.2019.60.6.534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Minsub Lee
- Department of Ophthalmology, Konkuk University School of Medicine, Seoul, Korea
| | - Ki Cheul Shin
- Department of Ophthalmology, Konkuk University School of Medicine, Seoul, Korea
| |
Collapse
|
11
|
Zhou D, Ni N, Ni A, Chen Q, Hu DN, Zhou J. Association of Visual Acuity with Ocular Dominance in 2045 Myopic Patients. Curr Eye Res 2017; 42:1155-1159. [PMID: 28494159 DOI: 10.1080/02713683.2017.1297464] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
PURPOSE Previous studies of the relationship between visual acuity (VA) and ocular dominance have produced conflicting results. We hypothesized that (1) the discrepancies were related mostly to sample size and interocular visual acuity difference (IOVAD); (2) in large samples of individuals with marked IOVADs, the eye with the better uncorrected distance visual acuity (UDVA) would be dominant. These hypotheses were tested in a large group of myopic patients. METHODS This prospective study of cycloplegic refraction involved 2045 myopic refractive surgery candidates. Patients with amblyopia or strabismus were excluded. Ocular dominance was assessed using the hole-in-the-card test. RESULTS In 2045 patients, the dominant eye had significantly better UDVA (p = 0.028) and was less astigmatic (p = 0.000) than the nondominant eye. In 426 patients with marked interocular difference in the UDVA (≥0.2 logMAR), the dominant eye not only had significant UDVA (p = 0.022) but also significantly less myopic (p = 0.028) and had a shorter axial length (AL; p = 0.001). In patients with smaller differences in UDVA (0.1 logMAR, n = 411) or no difference (n = 1208), the dominant and nondominant eyes did not differ significantly with respect to UDVA, myopic power, and AL (p > 0.05). CONCLUSIONS The present study showed that the dominant eyes had significantly better UDVA than the nondominant eyes, especially in individuals with marked differences in UDVA. These results supported our hypothesis regarding the relationship between better VA and ocular dominance.
Collapse
Affiliation(s)
- Dan Zhou
- a Department of Ophthalmology , Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , P. R . China.,b Department of Ophthalmology , Shanghai Pudong New District Zhoupu Hospital, Shanghai University of Medicine & Health Sciences , Shanghai , P. R . China
| | - Ni Ni
- a Department of Ophthalmology , Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , P. R . China
| | - Aiping Ni
- b Department of Ophthalmology , Shanghai Pudong New District Zhoupu Hospital, Shanghai University of Medicine & Health Sciences , Shanghai , P. R . China
| | - Qinjin Chen
- b Department of Ophthalmology , Shanghai Pudong New District Zhoupu Hospital, Shanghai University of Medicine & Health Sciences , Shanghai , P. R . China
| | - Dan-Ning Hu
- c Departments of Ophthalmology and Pathology , New York Eye and Ear Infirmary of Mount Sinai , New York , NY , USA
| | - Jibo Zhou
- a Department of Ophthalmology , Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , P. R . China
| |
Collapse
|
12
|
Lateral thinking - Interocular symmetry and asymmetry in neurovascular patterning, in health and disease. Prog Retin Eye Res 2017; 59:131-157. [PMID: 28457789 DOI: 10.1016/j.preteyeres.2017.04.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 03/24/2017] [Accepted: 04/24/2017] [Indexed: 02/07/2023]
Abstract
No biological system or structure is likely to be perfectly symmetrical, or have identical right and left forms. This review explores the evidence for eye and visual pathway asymmetry, in health and in disease, and attempts to provide guidance for those studying the structure and function of the visual system, where recognition of symmetry or asymmetry may be essential. The principal question with regards to asymmetry is not 'are the eyes the same?', for some degree of asymmetry is pervasive, but 'when are they importantly different?'. Knowing if right and left eyes are 'importantly different' could have significant consequences for deciding whether right or left eyes are included in an analysis or for examining the association between a phenotype and ocular parameter. The presence of significant asymmetry would also have important implications for the design of normative databases of retinal and optic nerve metrics. In this review, we highlight not only the universal presence of asymmetry, but provide evidence that some elements of the visual system are inherently more asymmetric than others, pointing to the need for improved normative data to explain sources of asymmetry and their impact on determining associations with genetic, environmental or health-related factors and ultimately in clinical practice.
Collapse
|