Search results for "High astigmatism"

showing 4 items of 4 documents

Implantation of a custom intraocular lens with a 30-diopter torus for the correction of high astigmatism after penetrating keratoplasty.

2003

Abstract We present a 62-year-old woman who had implantation of an intraocular lens (IOL) with a torus of 30.0 diopters (D) in an eye after penetrating keratoplasty. The patient presented with cataract and a best corrected visual acuity of 20/400. Penetrating keratoplasty was performed in 1975 because of decompensated keratoconus. With a clear but inferiorly decentered corneal graft, visual acuity was limited because of keratoplasty-related high corneal astigmatism of 22.5@156 that could not be successfully treated with spectacles or contact lenses. A custom toric IOL with –30.0 D of cylindrical power was implanted in the capsular bag via a sclerocorneal tunnel incision. Additionally, a sph…

medicine.medical_specialtyKeratoconusRefractive errorVisual acuitygenetic structuresmedicine.medical_treatmentEye diseaseVisual AcuityIntraocular lensAstigmatismKeratoconusProsthesis DesignCataractHigh astigmatismLens Implantation IntraocularOphthalmologymedicineHumansDioptreLenses IntraocularPhacoemulsificationbusiness.industryAstigmatismCorneal TopographyMiddle Agedmedicine.diseaseeye diseasesSensory SystemsOphthalmologyOptometrySurgeryFemalesense organsmedicine.symptombusinessKeratoplasty PenetratingJournal of cataract and refractive surgery
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Implantation of a toric poly(methyl methacrylate) intraocular lens to correct high astigmatism

1999

Abstract A 57-year-old man experienced a decrease in visual function because of cataract formation. Corneal astigmatism was 13.4 diopters (D) because he had had a penetrating keratoplasty 27 years before. Cataract surgery was planned, and biometric data for toric intraocular lens (IOL) implantation were collected for the manufacture of a custom IOL. After phacoemulsification, a toric poly(methyl methacrylate) (PMMA) IOL of +19.0 D spherical and +12.0 D cylindrical power was implanted via a sclerocorneal tunnel incision. Three months postoperatively, corneal astigmatism was 14.3 D and best corrected visual acuity (BCVA), 20/25. Postoperative refraction (+1.5 −3.0 × 90) and BCVA remained stab…

Malemedicine.medical_specialtyRefractive errorgenetic structuresmedicine.medical_treatmentVisual AcuityIntraocular lensAstigmatismRefraction OcularCataractCorneaHigh astigmatismLens Implantation IntraocularOphthalmologyHumansPolymethyl MethacrylateMedicineDioptreLenses IntraocularPhacoemulsificationbusiness.industryAstigmatismCorneal TopographyPhacoemulsificationMiddle AgedCataract surgeryequipment and suppliesmedicine.diseaseeye diseasesSensory SystemsSurgeryToric lensOphthalmologySurgerysense organsbusinessJournal of Cataract and Refractive Surgery
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Femtosecond laser–assisted intrastromal corneal ring segment implantation for high astigmatism correction after penetrating keratoplasty

2013

PURPOSE: To assess the visual and refractive outcomes of femtosecond laser-assisted implanta- tion of Ferrara-type intrastromal corneal ring segments (ICRS) in post-penetrating keratoplasty (PKP) eyes. SETTING: Instituto OftalmolFernOviedo, Spain. DESIGN: Cohort study. METHODS: Patients with previous PKP had ICRS implantation after femtosecond laser tunnel creation. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities and residual refractive errors were recorded before and 6 months after ICRS implantation. The power vector method was used to analyze refractive errors preoperatively and postoperatively. RESULTS: This study enrolled 32 eyes of 30 patients. The mean UDVA (Snell…

AdultMalemedicine.medical_specialtygenetic structuresCorneal Stromamedicine.medical_treatmentVisual AcuitySpherical equivalentAstigmatismRefraction OcularPower vectorCorneal DiseasesCohort StudiesProsthesis ImplantationYoung AdultHigh astigmatismOphthalmologymedicineHumansPolymethyl MethacrylateProspective StudiesIntrastromal corneal ring segmentbusiness.industryAstigmatismProstheses and ImplantsMiddle Agedmedicine.diseaseLaser assistedeye diseasesSensory SystemsSurgeryOphthalmologyTreatment OutcomeFemtosecondFemaleSurgeryLaser Therapysense organsCorneal ringbusinessKeratoplasty PenetratingJournal of Cataract and Refractive Surgery
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The stenopaeic slit: an analytical expression to quantify its optical effects in front of an astigmatic eye.

2001

The stenopaeic slit is a trial case accessory used in subjective refraction, especially when high astigmatism is present. In spite of its simplicity, the effect of the slit when it is not oriented along one of the principal meridians of the examined eye is difficult to predict, even in terms of classical geometrical optics. In this paper, the optical principles of the slit are considered with full details in the theoretical framework of the dioptric power space. An analytical expression to obtain the residual refractive error when a stenopaeic slit is placed in front of an astigmatic eye at any orientation is deduced. In the light of these results, some aspects of the clinical procedure are…

Refractive errorOptics and Photonicsgenetic structuresAstigmatismRefraction OcularModels BiologicalHigh astigmatismOpticsOrientation (geometry)medicineHumansPhysicsGeometrical opticsbusiness.industryVision TestsAccommodation OcularAstigmatismmedicine.diseaseRefractionSlitSubjective refractioneye diseasesSensory SystemsOphthalmologysense organsbusinessOptometryOphthalmicphysiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists)
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