Article

Myopia: attempts to arrest progression

Tan Tock Seng Hospital, Tumasik, 00, Singapore
British Journal of Ophthalmology (Impact Factor: 2.81). 12/2002; 86(11):1306-11. DOI: 10.1136/bjo.86.11.1306
Source: PubMed

ABSTRACT Previous studies have evaluated the efficacy of several interventions to decrease the progression of myopia. These include devices that alter the perception of the visual environment and pharmacological treatments. There is no conclusive evidence thus far that alteration of the pattern of spectacle wear, bifocals, ocular hypotensives, or contact lenses retards the progression of myopia. Several randomised clinical trials have demonstrated that the rate of progression of myopia is lower in children given atropine eye drops than those given placebo. However, atropine is associated with short term side effects such as photophobia and possible long term adverse events including light induced retinal damage and cataract formation. Other more selective antimuscarinic agents such as pirenzipine are presently being evaluated. Further well conducted randomised clinical trials with large sample sizes and adequate follow up designed to evaluate treatments to retard the progression of myopia should be conducted, since the identification of an effective intervention may have a greater public health impact on the burden and morbidity from myopia than the few treatments currently available.

0 Followers
 · 
218 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Atropine, a muscarinic antagonist, is known to inhibit myopia progression in several animal models and humans. However, the mode of action is not established yet. In this study, we compared quantitative iTRAQ proteomic analysis in the retinas collected from control and lens-induced myopic (LIM) mouse eyes treated with atropine. Myopic group received a (-15D) spectacle lens over the right eye on post-natal day 10 with or without atropine eye drops starting on post-natal day 24. Axial length was measured by Optical Low Coherence Interferometry (OLCI), AC-Master and refraction was measured by automated infrared photorefractor at post-natal 24, 38, and 52 days. Retinal tissue samples were pooled from six eyes for each group. The experiments were repeated twice and technical replicates were also performed for Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. MetaCore was used to perform protein profiling for pathway analysis. We identified a total of 3882 unique proteins with less than 1% FDR by analyzing the samples in replicates for two independent experiments. This is the largest number of mouse retina proteome reported to date. Thirty proteins were found to be up-regulated (ratio for myopia/control > global mean ratio + 1 standard deviation) and 28 proteins were down-regulated (ratio for myopia/control < global mean ratio - 1 standard deviation) in myopic eyes as compared to control retinas. Pathway analysis using MetaCore revealed regulation of γ-aminobutyric acid (GABA) levels in the myopic eyes. Detailed analysis of the quantitative proteomics data showed that the levels of GABA transporter (GAT)- GAT1 were elevated in myopic retina and significantly reduced after atropine treatment. These results were further validated with immunohistochemistry and western blot analysis. In conclusion, this study provides a comprehensive quantitative proteomic analysis of atropine-treated mouse retina and suggests involvement of GABAergic signaling in the anti-myopic effects of atropine in mouse eyes. The GABAergic transmission in the neural retina plays a pivotal role in the maintenance of axial eye growth in mammals.
    Journal of Proteome Research 09/2014; 13(11). DOI:10.1021/pr500558y · 5.00 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To retrospectively compare axial elongation in children with different degrees of myopia wearing spectacles and undergoing ortho-k treatment. The medical records of 128 patients who were fitted with spectacles or orthokeratology (ortho-k) lenses in our clinic between 2008 and 2009 were reviewed. Ortho-k group comprised 65 subjects and 63 subjects wearing spectacles were included in the control group. Subjects were also divided into low-myopia, moderate-myopia and high-myopia groups, based on the basic spherical equivalent refractive error. Axial length periodically measured over 2-year of lens wear and changes in axial length were compared between treatment groups and between subgroups with different degrees of myopia. The control group exhibited more changes in axial length than the ortho-k group at both 12 months (0.39 +/- 0.21 mm vs 0.16 +/- 0.17 mm, p <0.001) and 24 months (0.70 +/- 0.35 mm vs 0.34 +/- 0.29 mm, p <0.001). Axial length elongation was estimated to be slower by about 51% in the ortho-k group. Similar results were found for the subgroups (49%, 59% and 46% reductions, respectively). In the group with low and moderate myopia, the annual increases in axial length were significantly different between the ortho-k and control groups during both the first ( Low myopia: 0.19 +/- 0.17 mm vs 0.40 +/- 0.18 mm, p = 0.001; Moderate myopia: 0.14 +/- 0.18 mm vs 0.45 +/- 0.22 mm, p <0.001) and second ( Low myopia: 0.18 +/- 0.14 mm vs 0.32 +/- 0.19 mm, p = 0.012; Moderate myopia: 0.18 +/- 0.16 mm vs 0.34 +/- 0.30 mm, p = 0.030) years. In the high myopia groups, significant differences were only found between the ortho-k and control groups during the first year (0.16 +/- 0.18 mm vs 0.34 +/- 0.22 mm, p = 0.004). The 2-year axial elongation was significantly associated with initial age (p <0.001) and treatment (p <0.001), but not with gender, initial refractive error, initial axial length, initial corneal curvature. This 2-year study indicates that ortho-k contact lens wear is effective for reducing myopia progression in children with low, moderate and high myopia.
    BMC Ophthalmology 11/2014; 14(1):141. DOI:10.1186/1471-2415-14-141 · 1.08 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To investigate variables associated with myopic progression despite treatment in the Atropine in the Treatment of Myopia (ATOM-1) Study. Retrospective cohort study. 200 of 400 children were randomized to receive atropine 1% in one eye only in this institutional study. Children were followed up with cycloplegic autorefraction every 4 months over 2 years. Children whose myopia progressed by more than 0.5 Diopter (D) in atropine treated eye at 1 year were classified as being 'progressors'. There were 22 (12.1%) progressors amongst the 182 children still in the study at 1 year. Univariate analysis suggested these children tended to be younger (8.5±1.4years versus 9.3±1.5years, p=0.023), with higher myopic spherical equivalent (SE) at baseline (-3.6±1.3D versus -2.8±1.4D, p=0.015) and to have 2 myopic parents (77.3% versus 48.1%, p=0.012). In non-progressors, the myopia progression at 1 year was less in the atropine-treated compared to untreated fellow eyes (+0.16±0.37 D verus -0.73±0.48, p<0.001) but in progressors, progression was more similar between eyes (-0.92±0.31 versus -1.06±0.44, p=0.363). Regression analysis showed that the risk of being a progressor was 40% lower with each year of increased age, 43% lower for every 1.0 D less myopia at baseline, and 59% lower for every 1.0 D less myopic change in the untreated eyes over the first year. Doctors and parents need to be aware that there is a small group of children (younger, with higher myopia and greater tendency of myopic progression) who may still progress while on atropine treatment. Copyright © 2015 Elsevier Inc. All rights reserved.
    American Journal of Ophthalmology 01/2015; DOI:10.1016/j.ajo.2015.01.029 · 4.02 Impact Factor

Full-text (2 Sources)

Download
108 Downloads
Available from
May 31, 2014