Retinal Nerve Fiber Layer Thickness and Macular Thickness in Myopia, Hyperopia and Emmetropia : An OCT Study

Study Overview
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Brief Summary
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The purpose of this study is to investigate the variability of RNFL and macular thickness between myopia , hyper metropia and emmetropia

Detailed Description
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The world health organization (WHO) has estimated that the visual impairment caused by uncorrected refractive errors to be present in 153 million people worldwide (1) the prevalence of myopia ranges from 22.7% to 38.7% in large population study According to the WHO regions the estimated prevalence (EP) of hyperopia is 30.6% with the lowest EP in south east Asia 2.2% and the highest EP in the Americas 14.3% (2-3) During optic nerve development 2.85 million nerve fibers exist but by the third trimester we lose about 35% of these fibers (4) and the perpapillary retinal nerve fiber layer (RNFL) thickness will continue to decrease with advancing age (5). The relationship of the RNFL thickness with the refractive errors has been extensively investigated in adults and in children (6) and there was significant increase in the RNFL thickness in hypermetrope than in emmetrope and myope Understanding the derminants that affect the RNFL reserve helps us in the diagnosis and monitoring of optic nerve diseases. In macular region the thickness measured through optocal coherent tomography OCT shows high variability with value ranging from 190mm (centerpoint) to 389 mm (superior inner/nasal inner macula) (7) for both retinal and macular regions while decreasing in the retinal thickness has been reported with increasing age. Different studies have shown racial differences in RNFL thickness (8) white race (9) and myopia which has high prevelance in East Asian regions (10-12) have been associated with thinner RNFL (11) on the contrary Asian or Hispanic race has been associated with a thicker RNFL

Official Title
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Retinal Nerve Fiber Layer Thickness and Macular Thinckness in Myopia, Hyperopia and Emmetropia : An OCT Study

Conditions
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OCT Study RNFL and Macular Thickness

Intervention / Treatment
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* Other: Optical cehernce tomography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All individuals having similar type of refractive status in both eyes and with no known confounding factor affecting retinal intensity or CDVA and willing to participate. Exclusion Criteria: • Eyes with amplyopia Patients having posterior segment pathology or media opacity Patients with history of glaucoma History of retinal laser therapy History of ocualr trauma Any medical disease that prevents patients from positioning on the device

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Myopes<br>myopes (≤ -1.0 D) | Other: Optical cehernce tomography<br>* OCT macula and disc<br>|
| Hyperopes<br>hyperopia (≥ +1.0D). | Other: Optical cehernce tomography<br>* OCT macula and disc<br>|
| Emmetropes<br>emmetropes (> -1.0 to < 1.0 D) | Other: Optical cehernce tomography<br>* OCT macula and disc<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Retinal nerve fiber layer thickness and macular thickness in myopia , hyperopia and emmetropia : An OCT study | investigate the variability of RNFL and macular thickness between myopia , hyper metropia and emmetropia The peripapillary RNFL thickness in central ,perimacular and paramacular regions will be measured using the OCT and compared between three groups of refractive states | Baseline | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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OCT study