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Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Optical coherence tomography provides high-resolution cross-sectional images of macular pathology in vivo. Owing to its noninvasive noncontact nature and use of near-infrared illumination of the fundus, it is well tolerated by patients. The images can be obtained without dilation and are highly reproducible,quantifying retinal thickness with an axial resolution of 10 microm. These qualities make OCT a powerful diagnostic tool complementary to fluorescein angiography, photography, and biomicroscopy. Optical coherence tomography has proved to be particularly useful for the clinical evaluation of vitreoretinal interface disorders and alterations of the structural anatomy of the macula, such as from edema, choroidal neovascularization, and detachment of the neurosensory retina or RPE. The information obtained from high-resolution evaluation of retinal anatomy allows the diagnosis of conditions that are difficult to establish with biomicroscopy or angiography and improves the clinician's ability to make the optimal treatment decision. The quantitative assessment of OCT allows an objective means to monitor disease progression and therapeutic response.A logical application of this technology is the evaluation of underlying macular pathology in patients considering cataract extraction. Uncovering vitreomacular traction, epiretinal membranes, occult choroidal neovascular membranes with minimal CME, subretinal fluid accumulation, and RPE detachments greatly impacts the clinical management of cataract patients and the weighing of surgical risks and benefits. OCT is a uniquely powerful means of visualizing retinal morphology and pathology that may not be revealed using current techniques of biomicroscopy, fluorescein angiography, or B-scan ultrasonography, and serves as the newest adjunct in diagnostic technology.
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PMID:Clinical applications of optical coherence tomography for the diagnosis and management of macular diseases. 1510 11

Three phakic intraocular lens (IOL) models were implanted in 3 different patients. With the usual slitlamp examination, it was not possible to determine whether there was contact between the IOLs and the natural crystalline lens. Using the anterior chamber optical coherence tomography (AC OCT) scanner, direct contact between the natural crystalline lens and the 3 phakic IOLs was revealed. A dynamic study of the contact was performed during accommodation. These observations show that examination of the anterior segment with the AC OCT scanner provides new data about the status of the anterior segment after implantation of phakic IOLs.
J Cataract Refract Surg 2004 Sep
PMID:Contact between 3 phakic intraocular lens models and the crystalline lens: an anterior chamber optical coherence tomography study. 1534 71

Perfect tolerance is expected when one implants a phakic intraocular lens (pIOL) in the anterior segment. Not only should the material be compatible, but the pIOL must respect the anatomy of the anterior chamber. Based on 3 years of experience using an anterior segment optical coherence tomographer (Visante OCT, Carl Zeiss Meditec), I have defined numerous safety criteria for pIOLs. The internal dimensions of the anterior chamber must be considered along different meridians. I propose an objective measurement of the iris dome, the crystalline lens rise (CLR), which is the distance between the anterior pole of the crystalline lens and a line joining the 2 opposite iridocorneal angles. In a series with the Artisan IOL (Ophtec), pigment dispersion syndrome appeared in 70% of cases in which the CLR was greater than 600 microm. Angle-supported IOLs must be placed relative to the anterior chamber's largest diameter; in the same series of cases, the anterior chamber was oval with a large vertical axis in 74% of cases. The posterior face of an angle-supported IOL must have a 700 microm vault to respect the physiological modifications of the crystalline lens. It is difficult to know the posterior chamber's exact diameter as it varies with the horizontal or vertical axis. It also undergoes constant modifications due to accommodation and aging.
J Cataract Refract Surg 2006 Nov
PMID:Anterior segment OCT and phakic intraocular lenses: a perspective. 1708 65

Anterior segment imaging is a rapidly advancing field of ophthalmology. New imaging modalities, such as rotating Scheimpflug imaging (Pentacam-Scheimpflug) and anterior segment optical coherence tomography (Visante OCT and Slit-Lamp OCT), have recently become commercially available. These new modalities supplement the more established imaging devices of Orbscan scanning slit topography and ultrasound biomicroscopy (UBM). All devices promise quantitative information and qualitative imaging of the cornea and anterior chamber. They provide a quantitative angle estimation by calculating the angle between the iris surface and the posterior corneal surface. Direct angle visualisation is possible with the OCT devices and UBM; they provide images of the scleral spur, ciliary body, ciliary sulcus and even canal of Schlemm in some eyes. Pentacam-Scheimpflug can measure net corneal power, a feature particularly useful for cataract patients having undergone previous corneal surgery. Anterior segment OCT can measure corneal flap depth following LASIK and anterior chamber width prior to phakic intraocular lens implantation. The arrival of the new imaging devices may herald the dawn of a new era for ophthalmic diagnosis, particularly in view of the ease and non-contact nature of examination.
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PMID:Recent advances in ophthalmic anterior segment imaging: a new era for ophthalmic diagnosis? 1737 41

We present a patient with residual Descemet's membrane diagnosed by anterior segment optical coherence tomography (AS-OCT) after Descemet's stripping endothelial keratoplasty (DSEK). Postoperatively, persistent partial corneal edema and interface fluid without dislocation of the donor button were observed. No improvement of interface fluid was found during the follow-up period. A primary donor graft failure was diagnosed within 4 months, and the patient was regrafted with penetrating keratoplasty. Pathology examination of the specimen revealed the presence of residual Descemet's membrane in the recipient corneal button, confirmed using AS-OCT imaging. This case report demonstrates that inadequate Descemet's stripping in the recipient button could be a potential cause of DSEK failure; AS-OCT is a useful and noninvasive instrument for diagnosing and monitoring this post-DSEK complication.
J Cataract Refract Surg 2007 Jul
PMID:Diagnosis of residual Descemet's membrane after Descemet's stripping endothelial keratoplasty with anterior segment optical coherence tomography. 1758 94

We report a case of corneal infection caused by Streptococcus pneumoniae after hyperopic photorefractive keratectomy (PRK) that produced severe corneal melting, ulceration, and multiple perforations. Treatment included antibiogram-based antibiotic topical therapy and multilayer amniotic membrane transplantation (AMT) performed to seal the perforations and restore the globe integrity. Clinical and anterior segment optical coherence tomography (Visante OCT, Carl Zeiss Meditec) examinations documented progressive integration of the amniotic membrane tissues within the cornea, stromal and epithelial healing, and recovery of a stable and regular anterior chamber. The cornea healed with an avascular leucoma; the best corrected visual acuity was reduced to 20/200. Severe pneumococcal ulcerative perforation is a potential complication of PRK. Penetrating keratoplasty, at high risk for failure in the acute settings of an infected and inflamed eye, can be delayed until the cornea is healed. Amniotic membrane transplantation may be an alternative surgical option to achieve this goal.
J Cataract Refract Surg 2007 Sep
PMID:Multilayer amniotic membrane transplantation for bacterial keratitis with corneal perforation after hyperopic photorefractive keratectomy: case report and literature review. 1772 83

Frequency domain optical coherence tomography (FD-OCT), based on an all-reflective high-speed InGaAs spectrometer, operating in the 1050 nm wavelength region for retinal diagnostics, enables high-speed, volumetric imaging of retinal pathologies with greater penetration into choroidal tissue is compared to conventional 800 nm three-dimensional (3-D) ophthalmic FD-OCT systems. Furthermore, the lower scattering at this wavelength significantly improves imaging performance in cataract patients, thereby widening the clinical applicability of ophthalmic OCT. The clinical performance of two spectrometer-based ophthalmic 3-D OCT systems compared in respect to their clinical performance, one operating at 800 nm with 150 nm bandwidth (approximately 3 microm effective axial resolution) and the other at 1050 nm with 70 nm bandwidth (approximately 7 microm effective axial resolution). Results achieved with 3-D OCT at 1050 nm reveal, for the first time, decisive improvements in image quality for patients with retinal pathologies and clinically significant cataract.
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PMID:Three-dimensional optical coherence tomography at 1050 nm versus 800 nm in retinal pathologies: enhanced performance and choroidal penetration in cataract patients. 1786

We assess the accuracy of the Visante anterior segment optical coherence tomographer (AS-OCT) and present improved formulas for measurement of surface curvature and axial separation. Measurements are made in physical model eyes. Accuracy is compared for measurements of corneal thickness (d(1)) and anterior chamber depth (d(2)) using-built-in AS-OCT software versus the improved scheme. The improved scheme enables measurements of lens thickness (d(3)) and surface curvature, in the form of conic sections specified by vertex radii and conic constants. These parameters are converted to surface coordinates for error analysis. The built-in AS-OCT software typically overestimates [mean+/-standard deviation(SD)]d(1) by +62+/-4 mum and d(2) by + 4 +/- 88 microm. The improved scheme reduces d(1) (-0.4 +/- 4 microm) and d(2) (0 +/- 49 microm) errors while also reducing d(3) errors from +218 +/- 90 (uncorrected) to +14 +/- 123 microm (corrected). Surface x coordinate errors gradually increase toward the periphery. Considering the central 6-mm zone of each surface, the x coordinate errors for anterior and posterior corneal surfaces reached +3 +/- 10 and 0 +/- 23 microm, respectively, with the improved scheme. Those of the anterior and posterior lens surfaces reached +2 +/- 22 and +11 +/- 71 microm, respectively. Our improved scheme reduced AS-OCT errors and could, therefore, enhance pre- and postoperative assessments of keratorefractive or cataract surgery, including measurement of accommodating intraocular lenses.
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PMID:Accuracy of cornea and lens biometry using anterior segment optical coherence tomography. 1816 39

Epimacular membrane (ERM) formation is an age-dependent more or less vision-threatening finding. Increased life expectancy and patient demand for better vision have led to increasing numbers of patients seeking therapy, making selection for surgery mandatory. The impressive improvements in macular hole surgery have influenced the epiretinal membrane and have renewed its therapeutic approach. Disturbing metamorphopsia, visual deterioration under 5/10, especially near-vision alteration and binocular disturbance, are major symptoms to motivate surgery. As epiretinal membrane removal can be considered a relatively safe and effective procedure today, with ILM peeling and simultaneous cataract surgery, visual acuity alone is no longer the single criterion. The patient's demands regarding vision in daily life should be taken into account. Patients with moderate visual loss, recent onset of symptoms, or progression are the best candidates for ERM surgery. Functional outcome in patients with poor initial visual acuity or long-standing disease is unsatisfactory. The OCT macular profile helps detect the best candidates with thickening between 300 and 450 microns. The presence of a pseudo hole, traction, or an intraretinal cyst does not impair functional results. Complete traction relief during pucker surgery is believed to be a precondition for good functional results. Intended ILM peeling is a tool to achieve this goal.
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PMID:[Which epiretinal membranes should be operated?]. 1840 22

We describe the case of a middle-aged woman who presented to us after injury from a clenched fist 3 days previously. The diagnosis was occult scleral perforation, severe conjunctival chemosis, and traumatic aphakia. However, the lens could not be localized during posterior segment examination. An anterior segment optical coherence tomography (AS-OCT) examination showed scleral discontinuity and a heterogeneous reflection in the subconjunctival area, suggesting a possible phacocele. Surgical exploration confirmed these findings. Aphakia was managed using the "glued intraocular lens" technique in the same sitting. This case highlights the use of AS-OCT in noncontact exploration of the traumatized anterior segment and in diagnosis of a possible phacocele along with an occult scleral perforation with uveal prolapse. To our knowledge, this is the first report of successful implantation of a glued IOL as a primary procedure combined with scleral perforation repair.
J Cataract Refract Surg 2009 Apr
PMID:Anterior segment optical coherence tomography-aided diagnosis and primary posterior chamber intraocular lens implantation with fibrin glue in traumatic phacocele with scleral perforation. 1930 6


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