Comparison Between Different Investigations Used in Intraocular Lens Calculation in High Myopic Cataractous Patients
Study Details
Study Description
Brief Summary
the purpose of the study is to compare the accuracy of optical and ultrasonic biometry in intraocular lens (IOL) calculation in high myopic cataractous patients
Condition or Disease | Intervention/Treatment | Phase |
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N/A |
Detailed Description
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Prospective interventional (QUASI experimental) comparative study
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This study will be conducted on high myopic cataractous patients scheduled for phacoemulsification and IOL implantation in department of ophthalmology, Sohag university
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patients will be divided into 2 groups one will be subjected to intraocular lens (IOL) calculation by optical biometry the second one will be subjected to intraocular lens (IOL) calculation by ultrasonic biometry
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postoperative auto refraction after I month
Study Design
Arms and Interventions
Arm | Intervention/Treatment |
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Experimental: optical biometry
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Device: optical biometry
optical biometry is a fast, noncontact method it uses the method of partial coherence interferometry (PCI) to measure the axial length (AXL), based on reflection of the interference signal of the retinal pigment epithelium.
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Experimental: ultrasonic biometry
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Device: ultrasonic biometry
ultrasonic biometry is contact method depends on ultrasonic transducer producing thin sound beam travelling through different media of the eye when it faces interface of substance dissimilar from that it is travelling through part is reflecting and the other travel through the different substance
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Outcome Measures
Primary Outcome Measures
- desired post operative refraction [postoperative refraction 1 month]
detection of postoperative refraction by the use of autorefractor (one of the objective methods of assessment of refraction) after use of IOL power calculated by different investigations (optical vs ultrasonic)
Eligibility Criteria
Criteria
Inclusion Criteria:
- patients with simple cataract not associated with other pathologies suitable for phacoemulsification and 1ry IOL implantation With axial length (AXL) equal to or greater than 26.5mm
Exclusion Criteria:
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History of trauma
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Associated pathologies such as optic neuropathy, age related macular degeneration, macular edema, retinal detachment, , ocular inflammation, retinitis pigmentosa, proliferative diabetic retinopathy
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corneal opacities or irregularities, scars, dystrophy or ectasia
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Patients who underwent previous corneal surgery (including refractive surgery)
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Patients having intraoperative complications as inability to achieve secure 'in the bag' placement of the IOL (i.e. due to posterior capsule rupture, vitreous loss, weak zonules, or zonular rupture)
Contacts and Locations
Locations
No locations specified.Sponsors and Collaborators
- Sohag University
Investigators
None specified.Study Documents (Full-Text)
None provided.More Information
Publications
- Olsen T. Improved accuracy of intraocular lens power calculation with the Zeiss IOLMaster. Acta Ophthalmol Scand. 2007 Feb;85(1):84-7.
- Tappeiner C, Rohrer K, Frueh BE, Waelti R, Goldblum D. Clinical comparison of biometry using the non-contact optical low coherence reflectometer (Lenstar LS 900) and contact ultrasound biometer (Tomey AL-3000) in cataract eyes. Br J Ophthalmol. 2010 May;94(5):666-7. doi: 10.1136/bjo.2009.167700.
- Wang L, Shirayama M, Ma XJ, Kohnen T, Koch DD. Optimizing intraocular lens power calculations in eyes with axial lengths above 25.0 mm. J Cataract Refract Surg. 2011 Nov;37(11):2018-27. doi: 10.1016/j.jcrs.2011.05.042.
- Soh-Med-21-06-01