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A Review of Intraocular Pressure (IOP) and Axial Myopia. J Ophthalmol 2022; 2022:5626479. [PMID: 35855886 PMCID: PMC9288324 DOI: 10.1155/2022/5626479] [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: 12/30/2021] [Revised: 06/16/2022] [Accepted: 06/17/2022] [Indexed: 11/18/2022] Open
Abstract
The pathogenesis of myopia is driven by genetic and environmental risk factors. Accommodation not only alters the curvature and shape of the lens but also involves contraction of the ciliary and extraocular muscles, which influences intraocular pressure (IOP). Scleral matrix remodeling has been shown to contribute to the biomechanical susceptibility of the sclera to accommodation-induced IOP fluctuations, resulting in reduced scleral thickness, axial length (AL) elongation, and axial myopia. The rise in IOP can increase the burden of scleral stretching and cause axial lengthening. Although the accommodation and IOP hypotheses were proposed long ago, they have not been validated. This review provides a brief and updated overview on studies investigating the potential role of accommodation and IOP in myopia progression.
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Zhu Q, Goto S, Singh S, Torres JA, Wildsoet CF. Daily or Less Frequent Topical 1% Atropine Slows Defocus-Induced Myopia Progression in Contact Lens-Wearing Guinea Pigs. Transl Vis Sci Technol 2022; 11:26. [PMID: 35323888 PMCID: PMC8963669 DOI: 10.1167/tvst.11.3.26] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Purpose This study compared the efficacy of topical 1% atropine applied daily versus every 3 days for controlling myopia progression in guinea pigs. Methods To induce myopia, pigmented guinea pigs (New Zealand strain, n = 38) wore monocular −10 D rigid gas-permeable (RGP) contact lenses, which were replaced after 3 weeks with −15 diopter (D) contact lenses. Animals were treated with 1% atropine either daily (Atr-QD; n = 12), or every 3 days (Atr-Q3D; n = 11), or with artificial tears (control group; n = 15). Spherical equivalent refractive error (SER) and axial length (AL) data, as well as retinal and choroidal thickness data were collected weekly. Results Whereas mean (±SEM) interocular differences (treated - fellow) in both SER and AL at week 0 (baseline) were similar for all groups, significant differences between the atropine-treated and control groups were evident by week 6 (SER and AL, P < 0.001). The treated eyes of the control group showed relatively more axial elongation and myopia progression than both the Atr-QD and Atr-Q3D groups. Choroidal blood vessel area also decreased over time in the treated eyes of the control group, coupled with choroidal thinning overall, with these changes being attenuated by atropine. Retinal thickness showed a developmental decrease over the treatment period but was unaffected by atropine. Conclusions For this defocus-induced guinea pig model of myopia, application of 1% topical atropine slows myopia progression, even when applied every 3 days. Translational Relevance The results from this study suggest that the frequency of dosing for topical atropine may be reduced from the widely used daily dosing regimen without loss of myopia control efficacy.
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Affiliation(s)
- Qiurong Zhu
- Herbert Wertheim School Optometry and Vision Science, University of California, Berkeley, California, USA.,Department of Optometry and Visual Science, West China Hospital of Sichuan University, Sichuan, China
| | - So Goto
- Herbert Wertheim School Optometry and Vision Science, University of California, Berkeley, California, USA.,Department of Ophthalmology, Osaka University Graduate School of Medicine, Osaka, Japan.,Laboratory for Retinal Regeneration, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Sarah Singh
- Herbert Wertheim School Optometry and Vision Science, University of California, Berkeley, California, USA
| | - Josue A Torres
- Herbert Wertheim School Optometry and Vision Science, University of California, Berkeley, California, USA
| | - Christine F Wildsoet
- Herbert Wertheim School Optometry and Vision Science, University of California, Berkeley, California, USA
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Abstract
Purpose The guinea pig is widely used in studies of refractive error development and myopia which often involve experimental optical manipulations. The study described here investigated the optical quality of the guinea pig eye, for which there are limited data, despite its fundamental importance to understanding visually guided eye growth. Methods The ocular aberrations of eight adolescent New Zealand pigmented guinea pigs (6–11 weeks old) were measured after cycloplegia using a custom-built Shack–Hartmann aberrometer and fit with a Zernike polynomial function to the 10th order (65 terms). The optical quality of their eyes was assessed in terms of individual Zernike coefficients, and data were further analyzed to derive root-mean-square (RMS) wavefront errors, modulation transfer functions (MTFs), point spread functions (PSFs), Strehl ratios, and depth of focus. A 4-mm pupil was used in all computations. The derived data are compared with equivalent data from normal young adult human eyes. Results The guinea pigs exhibited low hyperopia and a small amount of positive spherical aberration, with other aberration terms decreasing with increasing order. Their average depth of focus, estimated from through-focus modulation, was 3.75 diopters. The RMS wavefront error of the guinea pig eye was found to be larger than that of the human eye for the same pupil size, reflecting a higher degree of aberrations, although the PSF (area) on the retina was smaller and sharper due to its shorter focal length. The radial average best-focus MTF derived for the guinea pig eye showed good performance at very low spatial frequencies, with a steeper decline with increasing frequency than for the human eye, dropping below 0.3 at 9 cpd. When converted to linear units (cycles/mm), the guinea pig eye had a higher spatial frequency cutoff and a slight contrast advantage for low spatial frequencies compared to the human eye. Conclusions The optical quality of the guinea pig eye is far superior to their reported behavioral visual acuity. This implies a neuroanatomical limit to their vision, which contrasts with the close match of optical and neural limits to spatial resolution in human eyes. The significance for eye growth regulation of the relative optical advantages exhibited by guinea pig eyes, when optical quality is expressed in linear rather than angular retinal units, warrants further consideration.
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Affiliation(s)
- Sarah Elizabeth Singh
- School of Optometry and Vision Science Graduate Program, University of California, Berkeley, Berkeley, California, United States
| | - Christine Frances Wildsoet
- School of Optometry and Vision Science Graduate Program, University of California, Berkeley, Berkeley, California, United States
| | - Austin John Roorda
- School of Optometry and Vision Science Graduate Program, University of California, Berkeley, Berkeley, California, United States
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Tong L, Cui D, Zeng J. Effects of topical pilocarpine on ocular growth and refractive development in rabbits. Eur J Ophthalmol 2020; 31:2107-2115. [PMID: 32524847 DOI: 10.1177/1120672120934962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE This study aimed to investigate whether topical pilocarpine affects ocular growth and refractive development as well as the underlying biochemical processes in early eye development in rabbits. METHODS Twenty three-week-old New Zealand white rabbits were treated with 0.5% pilocarpine in the right eye for 6 weeks. The left eyes served as contralateral controls. The effects of pilocarpine on refractive error, corneal curvature and ocular biometrics were assessed using streak retinoscopy, keratometry, and A-scan ultrasonography, respectively. Eyeballs were enucleated for histological analysis. The ciliary body and sclera were homogenized to determine the mRNA and protein expression levels of five subtypes of muscarinic receptors. RESULTS Compared to control eyes, pilocarpine-treated eyes exhibited approximately -1.63 ± 0.54 D myopia accompanied by a 0.11 ± 0.04 mm increase in axial length (AL) (p < 0.001, respectively). The anterior chamber depth (ACD) was reduced, whereas the lens thickness (LT) and vitreous chamber depth (VCD) increased (p < 0.001, respectively). Corneal curvature decreased over time but was not significantly different between treated and control eyes. The mRNA and protein expression levels of five subtypes of muscarinic receptors were upregulated in the ciliary body and downregulated in the sclera. CONCLUSIONS Based on these results, pilocarpine can induce myopic shift, increase LT, elongate VCD and AL, and reduce muscarinic receptor expression in the sclera early in development. These changes raise the possibility that pilocarpine may promote axial elongation in ocular development and facilitate the emmetropization of hyperopic eyes.
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Affiliation(s)
- Liyang Tong
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Dongmei Cui
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Junwen Zeng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong, China
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Disrupted potassium ion homeostasis in ciliary muscle in negative lens-induced myopia in Guinea pigs. Arch Biochem Biophys 2020; 688:108403. [PMID: 32418893 DOI: 10.1016/j.abb.2020.108403] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 04/09/2020] [Accepted: 05/01/2020] [Indexed: 11/21/2022]
Abstract
Myopia is a main cause of preventable or treatable visual impairment, it has become a major public health issue due to its increasingly high prevalence worldwide. Currently, it is confirmed that the development of myopia is associated with the disorders of accommodation. As a dominant factor for accommodation, ciliary muscle contraction/relaxation can regulate the physiological state of the lens and play a crucial role in the development of myopia. To investigate the relationship between myopia and ciliary muscle, the guinea pigs were randomly divided into a normal control (NC) group and a negative lens-induced myopia (LIM) group, and the animals in each group were further randomly assigned into 2-week (n = 18) and 4-week (n = 21) subgroups in accordance with the duration of myopic induction of 2 and 4 weeks, respectively. In the present study, right eyes of the animals in LIM group were covered with -6.0 D lenses to induce myopia. Next, we performed the haematoxylin and eosin (H&E) staining to observe the pathological change of ciliary muscle, determined the contents of adenosine triphosphate (ATP) and lactate acid (LA), and measured the Na+/K+-ATPase expression and activity in ciliary muscles in both NC and LIM groups. Moreover, we also analyzed the potassium ion (K+) flux in ciliary muscles from 4-week NC and LIM guinea pigs. As a result, we found that the arrangements of ciliary muscles in LIM guinea pigs were broken, dissolved or disorganized; the content of ATP decreased, whereas the content of LA increased in ciliary muscles from LIM guinea pigs. Monitoring of K+ flux in ciliary muscles from LIM guinea pigs demonstrated myopia-triggered K+ influx. Moreover, we also noted a decreased expression of Na+/K+-ATPase (Atp1a1) at both mRNA and protein levels and reduced activity in ciliary muscles from LIM guinea pigs. Overall, our results will facilitate the understanding of the mechanism associated with inhibitory Na+/K+-ATPase in lens-induced myopia and which consequently lead to the disorder of microenvironment within ciliary muscles from LIM guinea pigs, paving the way for a promising adjuvant approach in treating myopia in clinical practice.
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Pucker AD, Jackson AR, McHugh KM, Mutti DO. Morphological ciliary muscle changes associated with form deprivation-induced myopia. Exp Eye Res 2020; 193:107963. [PMID: 32045599 DOI: 10.1016/j.exer.2020.107963] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 02/02/2020] [Accepted: 02/05/2020] [Indexed: 12/19/2022]
Abstract
Myopic children have larger ciliary muscles than non-myopic children, suggesting that the ciliary muscle may have an impact on or be affected by refractive error development. The guinea pig represents an attractive model organism for myopia development research. The purpose of the study was to investigate whether form deprivation-induced myopia in one or more strains of guinea pig causes thickening of the ciliary muscle as seen in human myopia. Thirty-nine guinea pigs were bred from in-house progenitors obtained from Cincinnati Children's Hospital (Cincinnati) and the United States Army (Strain 13). At 2-4 days of age the right eyes of animals were exposed to form deprivation for 7 days while the fellow eyes served as controls. Refractive error was determined with retinoscopy while vitreous chamber depth (VCD) and axial length (AL) were determined with A-scan ultrasound. Ciliary muscle characteristics (ciliary muscle length, cross-sectional area, volume, cell number, cell size, and smooth muscle actin concentration) were determined histologically with antibody labeling and analyzed according to whether the animal developed axial myopia (anisometropia > -2.00 D with VCD and/or AL differences > 0.1 mm) or was unresponsive. This analysis method yielded four groups with Group 1 having no induced myopia but with axial elongation (n = 11), Group 2 having myopia without vitreous or axial elongation (n = 8), Group 3 having myopia with either vitreous or axial elongation (n = 11), and Group 4 having myopia with both vitreous and axial elongation (n = 8). There were no post-treatment inter-ocular differences between strains or for the overall group of animals for any ciliary muscle variable; however, a higher response group number in multivariate ordinal regression was related to having a treated compared to fellow eye that had a lower smooth muscle actin concentration (p = 0.006), with a shorter ciliary muscle length (p = 0.042), and a less oblate eye shape (p = 0.010). Guinea pig ciliary muscle length and smooth muscle actin concentration were significantly less in the treated eyes of axially myopic animals suggesting that 7 days of form deprivation induced ciliary muscle cellular atrophy or inhibited ciliary muscle growth. Form deprivation myopia in the guinea pig does not result in the increase in ciliary muscle thickness associated with human juvenile and adult myopia.
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Affiliation(s)
- Andrew D Pucker
- University of Alabama at Birmingham, School of Optometry, 1716 University Blvd, Birmingham, AL, USA.
| | - Ashley R Jackson
- Nationwide Children's Hospital, Center for Clinical and Translational Research, 700 Childrens Drive, Columbus, OH, USA.
| | - Kirk M McHugh
- Nationwide Children's Hospital, Center for Clinical and Translational Research, 700 Childrens Drive, Columbus, OH, USA.
| | - Donald O Mutti
- The Ohio State University, College of Optometry, 338 W 10th Ave, Columbus, OH, USA.
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Dong L, Shi XH, Kang YK, Wei WB, Wang YX, Xu XL, Gao F, Jonas JB. Bruch's Membrane Thickness and Retinal Pigment Epithelium Cell Density in Experimental Axial Elongation. Sci Rep 2019; 9:6621. [PMID: 31036950 PMCID: PMC6488581 DOI: 10.1038/s41598-019-43212-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 04/17/2019] [Indexed: 11/09/2022] Open
Abstract
To assess anatomical changes in eyes with progressive myopia, we morphometrically examined the eyes of guinea pigs with lens-induced axial elongation. Starting at an age of 3-4 weeks, guinea pigs in the experimental group (n = 20 animals) developed unilateral lens-induced axial elongation by wearing goggles for 5 weeks compared to a control group of 20 animals without intervention (axial length:8.91 ± 0.08 mm versus 8.74 ± 0.07 mm; P < 0.001). Five weeks after baseline, the animals were sacrificed, and the eyes enucleated. As measured histomorphometrically, Bruch's membrane thickness was not significantly correlated with axial length in either group at the ora serrata (P = 0.41), equator (P = 0.41), midpoint between equator and posterior pole (MBEPP) (P = 0.13) or posterior pole (P = 0.89). Retinal pigment epithelium (RPE) cell density decreased with longer axial length at the MBEPP (P = 0.04; regression coefficient beta = -0.33) and posterior pole (P = 0.01; beta = -0.40). Additionally, the thickness of the retina and sclera decreased with longer axial length at the MBEPP (P = 0.01; beta = -0.42 and P < 0.001; beta = -0.64, respectively) and posterior pole (P < 0.001; beta = -0.51 and P < 0.001; beta = -0.45, respectively). Choroidal thickness decreased at the posterior pole (P < 0.001; beta = -0.51). Experimental axial elongation was associated with a thinning of the retina, choroid and sclera and a decrease in RPE cell density, most markedly at the posterior pole. Bruch's membrane thickness was not related to axial elongation.
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Affiliation(s)
- Li Dong
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xu Han Shi
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yi Kun Kang
- Department of Oncology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China
| | - Wen Bin Wei
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
| | - Ya Xing Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Lab, Beijing, China
| | - Xiao Lin Xu
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing Tongren Hospital, Capital Medical University, Beijing, China.,Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Lab, Beijing, China
| | - Fei Gao
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Lab, Beijing, China
| | - Jost B Jonas
- Department of Ophthalmology, Medical Faculty Mannheim of the Ruprecht-Karls-University Heidelberg, Mannheim, Germany
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Troilo D, Smith EL, Nickla DL, Ashby R, Tkatchenko AV, Ostrin LA, Gawne TJ, Pardue MT, Summers JA, Kee CS, Schroedl F, Wahl S, Jones L. IMI - Report on Experimental Models of Emmetropization and Myopia. Invest Ophthalmol Vis Sci 2019; 60:M31-M88. [PMID: 30817827 PMCID: PMC6738517 DOI: 10.1167/iovs.18-25967] [Citation(s) in RCA: 215] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Accepted: 10/20/2018] [Indexed: 11/24/2022] Open
Abstract
The results of many studies in a variety of species have significantly advanced our understanding of the role of visual experience and the mechanisms of postnatal eye growth, and the development of myopia. This paper surveys and reviews the major contributions that experimental studies using animal models have made to our thinking about emmetropization and development of myopia. These studies established important concepts informing our knowledge of the visual regulation of eye growth and refractive development and have transformed treatment strategies for myopia. Several major findings have come from studies of experimental animal models. These include the eye's ability to detect the sign of retinal defocus and undergo compensatory growth, the local retinal control of eye growth, regulatory changes in choroidal thickness, and the identification of components in the biochemistry of eye growth leading to the characterization of signal cascades regulating eye growth and refractive state. Several of these findings provided the proofs of concepts that form the scientific basis of new and effective clinical treatments for controlling myopia progression in humans. Experimental animal models continue to provide new insights into the cellular and molecular mechanisms of eye growth control, including the identification of potential new targets for drug development and future treatments needed to stem the increasing prevalence of myopia and the vision-threatening conditions associated with this disease.
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Affiliation(s)
- David Troilo
- SUNY College of Optometry, State University of New York, New York, New York, United States
| | - Earl L. Smith
- College of Optometry, University of Houston, Houston, Texas, United States
| | - Debora L. Nickla
- Biomedical Sciences and Disease, New England College of Optometry, Boston, Massachusetts, United States
| | - Regan Ashby
- Health Research Institute, University of Canberra, Canberra, Australia
| | - Andrei V. Tkatchenko
- Department of Ophthalmology, Department of Pathology and Cell Biology, Columbia University, New York, New York, United States
| | - Lisa A. Ostrin
- College of Optometry, University of Houston, Houston, Texas, United States
| | - Timothy J. Gawne
- School of Optometry, University of Alabama Birmingham, Birmingham, Alabama, United States
| | - Machelle T. Pardue
- Biomedical Engineering, Georgia Tech College of Engineering, Atlanta, Georgia, United States31
| | - Jody A. Summers
- College of Medicine, University of Oklahoma, Oklahoma City, Oklahoma, United States
| | - Chea-su Kee
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, SAR, China
| | - Falk Schroedl
- Departments of Ophthalmology and Anatomy, Paracelsus Medical University, Salzburg, Austria
| | - Siegfried Wahl
- Institute for Ophthalmic Research, University of Tuebingen, Zeiss Vision Science Laboratory, Tuebingen, Germany
| | - Lyndon Jones
- CORE, School of Optometry and Vision Science, University of Waterloo, Ontario, Canada
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Abstract
SIGNIFICANCE This article shows a successful concept for simulating central scotoma, which is associated with age-related macular degeneration (AMD), in healthy subjects by an induced dark spot at the retina using occlusive contact lenses. The new concept includes a control mechanism to adjust the scotoma size through controlling pupil size without medication. Therefore, a miniaturized full-field adaptation device was used. PURPOSE The aim of this study was to design a novel concept to simulate AMD scotoma in healthy subjects using occlusive contact lenses. METHODS To define an optimal set of lens parameters, we constructed an optical model and considered both the anatomical pupil diameter and the opaque central zone diameter of the contact lens. To adjust the scotoma size, we built a miniaturized full-field adaptation device. We demonstrate the validity of this novel concept by functional measurements of visual fields using automated threshold perimetry. Finally, we conducted a perception study including two tasks, consisting of pictograms and letters. The stimuli were presented at different eccentricities and magnifications. RESULTS The visual fields of all 10 volunteers exhibited absolute scotomas. The loss of contrast sensitivity ranged within 27 and 36 dB (P < .05), and the scotoma localizations were nearly centered to the macula (mean variation, 2.0 ± 4.8° horizontally; 3.5 ± 4.7° vertically). The eccentric perception of letters showed the largest numbers of correctly identified stimuli. The perception of pictograms showed significantly reduced numbers (P < .0001) and revealed a dependency on magnification. The results suggest that best perception is possible for magnified stimuli near the scotoma. Conclusions We demonstrated that the creation of an absolute simulated AMD scotoma is possible using occlusive contact lenses combined with a miniaturized full-field adaptation device.
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Changes in Iridocorneal Angle and Anterior Chamber Structure in Eyes With Anatomically Narrow Angles: Laser Iridotomy Versus Pilocarpine. J Glaucoma 2018; 27:1073-1078. [PMID: 30256278 DOI: 10.1097/ijg.0000000000001097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To compare the effects of laser iridotomy (LI) and pilocarpine on iridocorneal angle and anterior chamber structure in anatomically narrow angles (ANAs). MATERIALS AND METHODS Temporal LI was performed 90 minutes after 2% pilocarpine administration in patients with occludable ANA. Swept-source optical coherence tomography B-scans of the anterior segment were obtained at baseline, 60 minutes after 2% pilocarpine administration, and 1 week after LI. Angle-opening distance (AOD), trabecular-iris surface area (TISA), and angle recess area (ARA) were measured at the temporal, superior, nasal, and inferior quadrants. Anterior chamber depth (ACD) and lens vault (LV) were also measured. AOD, TISA, ARA, ACD, and LV were compared among 3 time points: at baseline, 60 minutes after 2% pilocarpine administration, and 1 week after LI. RESULTS Twenty-four eyes (24 patients; mean age, 55 y) were included. In all 4 quadrants and globally, AOD, TISA, and ARA increased from baseline after pilocarpine and after LI (all P<0.010). The increase in AOD, TISA, and ARA was greater after LI than after pilocarpine globally and in the temporal and superior quadrants (all P<0.040). ACD decreased and LV increased from baseline after pilocarpine (both P<0.001). Postpilocarpine anterior chambers were shallower with higher LV than post-LI (both P<0.016). CONCLUSION LI is more effective than pilocarpine in widening the iridocorneal angle without significant shallowing the anterior chamber in eyes with ANA.
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Douglas RH. The pupillary light responses of animals; a review of their distribution, dynamics, mechanisms and functions. Prog Retin Eye Res 2018; 66:17-48. [PMID: 29723580 DOI: 10.1016/j.preteyeres.2018.04.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 04/24/2018] [Accepted: 04/25/2018] [Indexed: 11/28/2022]
Abstract
The timecourse and extent of changes in pupil area in response to light are reviewed in all classes of vertebrate and cephalopods. Although the speed and extent of these responses vary, most species, except the majority of teleost fish, show extensive changes in pupil area related to light exposure. The neuromuscular pathways underlying light-evoked pupil constriction are described and found to be relatively conserved, although the precise autonomic mechanisms differ somewhat between species. In mammals, illumination of only one eye is known to cause constriction in the unilluminated pupil. Such consensual responses occur widely in other animals too, and their function and relation to decussation of the visual pathway is considered. Intrinsic photosensitivity of the iris muscles has long been known in amphibia, but is in fact widespread in other animals. The functions of changes in pupil area are considered. In the majority of species, changes in pupil area serve to balance the conflicting demands of high spatial acuity and increased sensitivity in different light levels. In the few teleosts in which pupil movements occur they do not serve a visual function but play a role in camouflaging the eye of bottom-dwelling species. The occurrence and functions of the light-independent changes in pupil size displayed by many animals are also considered. Finally, the significance of the variations in pupil shape, ranging from circular to various orientations of slits, ovals, and other shapes, is discussed.
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Affiliation(s)
- Ronald H Douglas
- Division of Optometry & Visual Science City, University of London, Northampton Square, London, EC1V 0HB, United Kingdom.
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12
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Jnawali A, Beach KM, Ostrin LA. In Vivo Imaging of the Retina, Choroid, and Optic Nerve Head in Guinea Pigs. Curr Eye Res 2018; 43:1006-1018. [PMID: 29641938 DOI: 10.1080/02713683.2018.1464195] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
PURPOSE Guinea pigs are increasingly being used as a model of myopia, and may also represent a novel model of glaucoma. Here, optical coherence tomography (OCT) imaging was performed in guinea pigs. In vivo measurements of retinal, choroidal, and optic nerve head parameters were compared with histology, and repeatability and interocular variations were assessed. METHODS OCT imaging and histology were performed on adult guinea pigs (n = 9). Using a custom program in MATLAB, total retina, ganglion cell/nerve fiber layer (GC/NFL), outer retina, and choroid thicknesses were determined. Additionally, Bruch's membrane opening (BMO) area and diameter, and minimum rim width were calculated. Intraobserver, interocular, and intersession coefficients of variation (CV) and intraclass correlation coefficients (ICC) were assessed. RESULTS Retina, GC/NFL, outer retina and choroid thicknesses from in vivo OCT imaging were 147.7 ± 5.8 μm, 59.2 ± 4.5 μm, 72.4 ± 2.4 μm, and 64.8 ± 11.6 μm, respectively. Interocular CV ranged from 1.8% to 11% (paired t-test, p = 0.16 to 0.81), and intersession CV ranged from 1.1% to 5.6% (p = 0.12 to 0.82), with the choroid showing the greatest variability. BMO area was 0.192 ± 0.023 mm2, and diameter was 493.79 ± 31.89 μm, with intersession CV of 3.3% and 1.7%, respectively. Hyper reflective retinal layers in OCT correlated with plexiform and RPE layers in histology. CONCLUSION In vivo OCT imaging and quantification of guinea pig retina and optic nerve head parameters were repeatable and similar between eyes of the same animal. In vivo visibility of retinal cell layers correlated well with histological images. ABBREVIATIONS optic nerve head (ONH), retinal ganglion cell (RGC), spectral domain optical coherence tomography (SD-OCT), enhanced depth imaging (EDI), minimum rim width (MRW), hematoxylin and eosin (H & E).
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Affiliation(s)
- Ashutosh Jnawali
- a College of Optometry , University of Houston , Houston , TX , USA
| | - Krista M Beach
- a College of Optometry , University of Houston , Houston , TX , USA
| | - Lisa A Ostrin
- a College of Optometry , University of Houston , Houston , TX , USA
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Liu Y, Wang Y, Lv H, Jiang X, Zhang M, Li X. α-adrenergic agonist brimonidine control of experimentally induced myopia in guinea pigs: A pilot study. Mol Vis 2017; 23:785-798. [PMID: 29204068 PMCID: PMC5693025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 11/13/2017] [Indexed: 11/26/2022] Open
Abstract
PURPOSE To investigate the efficacy of α-adrenergic agonist brimonidine either alone or combined with pirenzepine for inhibiting progressing myopia in guinea pig lens-myopia-induced models. METHODS Thirty-six guinea pigs were randomly divided into six groups: Group A received 2% pirenzepine, Group B received 0.2% brimonidine, Group C received 0.1% brimonidine, Group D received 2% pirenzepine + 0.2% brimonidine, Group E received 2% pirenzepine + 0.1% brimonidine, and Group F received the medium. Myopia was induced in the right eyes of all guinea pigs using polymethyl methacrylate (PMMA) lenses for 3 weeks. Eye drops were administered accordingly. Intraocular pressure was measured every day. Refractive error and axial length measurements were performed once a week. The enucleated eyeballs were removed for hematoxylin and eosin (H&E) and Van Gieson (VG) staining at the end of the study. RESULTS The lens-induced myopia model was established after 3 weeks. Treatment with 0.1% brimonidine alone and 0.2% brimonidine alone was capable of inhibiting progressing myopia, as shown by the better refractive error (p=0.024; p=0.006) and shorter axial length (p=0.005; p=0.0017). Treatment with 0.1% brimonidine and 0.2% brimonidine combined with 2% pirenzepine was also effective in suppressing progressing refractive error (p=0.016; p=0.0006) and axial length (p=0.017; p=0.0004). The thickness of the sclera was kept stable in all groups except group F; the sclera was much thinner in the lens-induced myopia eyes compared to the control eyes. CONCLUSIONS Treatment with 0.1% brimonidine alone and 0.2% brimonidine alone, as well as combined with 2% pirenzepine, was effective in inhibiting progressing myopia. The result indicates that intraocular pressure elevation is possibly a promising mechanism and potential treatment for progressing myopia.
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Chang LYL, Turuwhenua J, Qu TY, Black JM, Acosta ML. Infrared Video Pupillography Coupled with Smart Phone LED for Measurement of Pupillary Light Reflex. Front Integr Neurosci 2017; 11:6. [PMID: 28326023 PMCID: PMC5339232 DOI: 10.3389/fnint.2017.00006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 02/21/2017] [Indexed: 01/05/2023] Open
Abstract
Clinical assessment of pupil appearance and pupillary light reflex (PLR) may inform us the integrity of the autonomic nervous system (ANS). Current clinical pupil assessment is limited to qualitative examination, and relies on clinical judgment. Infrared (IR) video pupillography combined with image processing software offer the possibility of recording quantitative parameters. In this study we describe an IR video pupillography set-up intended for human and animal testing. As part of the validation, resting pupil diameter was measured in human subjects using the NeurOptics™ (Irvine, CA, USA) pupillometer, to compare against that measured by our IR video pupillography set–up, and PLR was assessed in guinea pigs. The set-up consisted of a smart phone with a light emitting diode (LED) strobe light (0.2 s light ON, 5 s light OFF cycles) as the stimulus and an IR camera to record pupil kinetics. The consensual response was recorded, and the video recording was processed using a custom MATLAB program. The parameters assessed were resting pupil diameter (D1), constriction velocity (CV), percentage constriction ratio, re-dilation velocity (DV) and percentage re-dilation ratio. We report that the IR video pupillography set-up provided comparable results as the NeurOptics™ pupillometer in human subjects, and was able to detect larger resting pupil size in juvenile male guinea pigs compared to juvenile female guinea pigs. At juvenile age, male guinea pigs also had stronger pupil kinetics for both pupil constriction and dilation. Furthermore, our IR video pupillography set-up was able to detect an age-specific increase in pupil diameter (female guinea pigs only) and reduction in CV (male and female guinea pigs) as animals developed from juvenile (3 months) to adult age (7 months). This technique demonstrated accurate and quantitative assessment of pupil parameters, and may provide the foundation for further development of an integrated system useful for clinical applications.
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Affiliation(s)
- Lily Yu-Li Chang
- School of Optometry and Vision Science, Faculty of Medical and Health Sciences, The University of AucklandAuckland, New Zealand; Auckland Bioengineering Institute, The University of AucklandAuckland, New Zealand; Centre for Brain Research, The University of AucklandAuckland, New Zealand; New Zealand National Eye Centre, The University of AucklandAuckland, New Zealand
| | - Jason Turuwhenua
- School of Optometry and Vision Science, Faculty of Medical and Health Sciences, The University of AucklandAuckland, New Zealand; Auckland Bioengineering Institute, The University of AucklandAuckland, New Zealand; New Zealand National Eye Centre, The University of AucklandAuckland, New Zealand
| | - Tian Yuan Qu
- School of Optometry and Vision Science, Faculty of Medical and Health Sciences, The University of Auckland Auckland, New Zealand
| | - Joanna M Black
- School of Optometry and Vision Science, Faculty of Medical and Health Sciences, The University of AucklandAuckland, New Zealand; Centre for Brain Research, The University of AucklandAuckland, New Zealand; New Zealand National Eye Centre, The University of AucklandAuckland, New Zealand
| | - Monica L Acosta
- School of Optometry and Vision Science, Faculty of Medical and Health Sciences, The University of AucklandAuckland, New Zealand; Centre for Brain Research, The University of AucklandAuckland, New Zealand; New Zealand National Eye Centre, The University of AucklandAuckland, New Zealand
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15
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Schaeffel F, Feldkaemper M. Animal models in myopia research. Clin Exp Optom 2016; 98:507-17. [PMID: 26769177 DOI: 10.1111/cxo.12312] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 03/20/2015] [Accepted: 04/26/2015] [Indexed: 12/18/2022] Open
Abstract
Our current understanding of the development of refractive errors, in particular myopia, would be substantially limited had Wiesel and Raviola not discovered by accident that monkeys develop axial myopia as a result of deprivation of form vision. Similarly, if Josh Wallman and colleagues had not found that simple plastic goggles attached to the chicken eye generate large amounts of myopia, the chicken model would perhaps not have become such an important animal model. Contrary to previous assumptions about the mechanisms of myopia, these animal models suggested that eye growth is visually controlled locally by the retina, that an afferent connection to the brain is not essential and that emmetropisation uses more sophisticated cues than just the magnitude of retinal blur. While animal models have shown that the retina can determine the sign of defocus, the underlying mechanism is still not entirely clear. Animal models have also provided knowledge about the biochemical nature of the signal cascade converting the output of retinal image processing to changes in choroidal thickness and scleral growth; however, a critical question was, and still is, can the results from animal models be applied to myopia in children? While the basic findings from chickens appear applicable to monkeys, some fundamental questions remain. If eye growth is guided by visual feedback, why is myopic development not self-limiting? Why does undercorrection not arrest myopic progression even though positive lenses induce myopic defocus, which leads to the development of hyperopia in emmetropic animals? Why do some spectacle or contact lens designs reduce myopic progression and others not? It appears that some major differences exist between animals reared with imposed defocus and children treated with various optical corrections, although without the basic knowledge obtained from animal models, we would be lost in an abundance of untestable hypotheses concerning human myopia.
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Affiliation(s)
- Frank Schaeffel
- Section of Neurobiology of the Eye, Ophthalmic Research Institute, Tuebingen, Germany.
| | - Marita Feldkaemper
- Section of Neurobiology of the Eye, Ophthalmic Research Institute, Tuebingen, Germany
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Pucker AD, Jackson AR, Morris HJ, Fischer AJ, McHugh KM, Mutti DO. Ciliary Muscle Cell Changes During Guinea Pig Development. Invest Ophthalmol Vis Sci 2016; 56:7691-6. [PMID: 26641547 DOI: 10.1167/iovs.15-17927] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Guinea pig ciliary muscle (CM) increases robustly in volume, length, and thickness with age. We wanted to characterize CM cells during development to determine the contributions of hypertrophy (cell size increase) and hyperplasia (cell number increase) during development. METHODS Six pigmented guinea pig eyes were collected at each of five ages: 1, 10, 20, 30, and 90 days. Refractive errors and axial lengths were determined. Eyes were temporally marked, enucleated, hemisected, and fixed. Nasal and temporal eye segments were embedded and 30-μm serial sections were collected; the two most central slides from each hemisection were analyzed with an epifluorescence microscope and Stereo Investigator software to determine normal morphologic parameters. RESULTS Refractive errors became less hyperopic (P = 0.0001) while axial lengths and CM lengths, cross-sectional areas, volumes, and cell sizes all increased linearly with log age (all P < 0.00001). Ciliary muscle cell numbers increased only during the first 20 days of life (P = 0.02). Nasal and temporal CM lengths (P = 0.07), cross-sectional areas (P = 0.18), and cell numbers (P = 0.70) were not different, but CM cell sizes were initially larger temporally and became larger nasally after age 30 days. CONCLUSIONS The mechanism of guinea pig CM cell growth during the first 90 days of life was characterized by early hyperplasia combined with hypertrophic cell growth throughout development that results in larger CM lengths, cross-sectional areas, and volumes. Nasal-temporal CM development was generally symmetric, but there was more CM hypertrophy nasally at older ages.
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Affiliation(s)
- Andrew D Pucker
- College of Optometry The Ohio State University, Columbus, Ohio, United States
| | - Ashley R Jackson
- Center for Molecular and Human Genetics, Nationwide Children's Hospital, Columbus, Ohio, United States
| | - Hugh J Morris
- College of Optometry The Ohio State University, Columbus, Ohio, United States
| | - Andrew J Fischer
- Department of Neuroscience, The Ohio State University, Columbus, Ohio, United States
| | - Kirk M McHugh
- Center for Molecular and Human Genetics, Nationwide Children's Hospital, Columbus, Ohio, United States
| | - Donald O Mutti
- College of Optometry The Ohio State University, Columbus, Ohio, United States
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18
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Fang F, Huang F, Xie R, Li C, Liu Y, Zhu Y, Qu J, Zhou X. Effects of muscarinic receptor modulators on ocular biometry of guinea pigs. Ophthalmic Physiol Opt 2014; 35:60-9. [PMID: 25376436 DOI: 10.1111/opo.12166] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 10/04/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Fang Fang
- School of Optometry and Ophthalmology and Eye Hospital; Wenzhou Medical College; Zhejiang China
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science; Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry; Ministry of Health P.R. China; Zhejiang China
| | - Furong Huang
- School of Optometry and Ophthalmology and Eye Hospital; Wenzhou Medical College; Zhejiang China
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science; Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry; Ministry of Health P.R. China; Zhejiang China
| | - Ruozhong Xie
- School of Optometry and Ophthalmology and Eye Hospital; Wenzhou Medical College; Zhejiang China
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science; Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry; Ministry of Health P.R. China; Zhejiang China
| | - Cheng Li
- School of Optometry and Ophthalmology and Eye Hospital; Wenzhou Medical College; Zhejiang China
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science; Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry; Ministry of Health P.R. China; Zhejiang China
| | - Yin Liu
- School of Optometry and Ophthalmology and Eye Hospital; Wenzhou Medical College; Zhejiang China
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science; Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry; Ministry of Health P.R. China; Zhejiang China
| | - Ying Zhu
- School of Optometry and Ophthalmology and Eye Hospital; Wenzhou Medical College; Zhejiang China
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science; Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry; Ministry of Health P.R. China; Zhejiang China
| | - Jia Qu
- School of Optometry and Ophthalmology and Eye Hospital; Wenzhou Medical College; Zhejiang China
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science; Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry; Ministry of Health P.R. China; Zhejiang China
| | - Xiangtian Zhou
- School of Optometry and Ophthalmology and Eye Hospital; Wenzhou Medical College; Zhejiang China
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science; Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry; Ministry of Health P.R. China; Zhejiang China
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