Assessing the Likely Effect of Posterior Corneal Curvature on Toric IOL Calculation for IOLs of 2.50 D or Greater Cylinder Power
Until recently, IOL power was routinely calculated using methods that only incorporated anterior keratometric curvature data. Posterior corneal astigmatism and its effect on total corneal astigmatism has long been described.1,2 The assumption that anterior keratometric curvature data were adequate to describe total corneal refractive power has been shown to be a source of system error in astigmatism correction with toric IOLs. This error can be improved by incorporating information about the posterior corneal astigmatism into IOL calculations.3 –5 Variations in correlation between anterior and (Source: Journal of Refractive Surgery)
Source: Journal of Refractive Surgery - November 8, 2017 Category: Opthalmology Authors: Benjamin R. LaHood, MBChB, PGDipOphth, FRANZCO Source Type: research
In Vivo Measurement of Longitudinal Chromatic Aberration in Patients Implanted With Trifocal Diffractive Intraocular Lenses
Multifocal corrections are increasingly used solutions for presbyopia, working by the principle of simultaneous vision (ie, projecting simultaneously focused and defocused images on the retina). These corrections, in the form of intraocular lenses (IOLs) or contact lenses, provide multifocality at the expense of reducing optical quality at all distances. Current multifocal IOLs in the market work on diffractive or refractive principles, including refractive bifocal concentric and angular, diffractive bifocal and trifocal, extended depth of focus, or hybrid designs.1 On-bench evaluations of (Source: Journal of Refractive Surgery)
Source: Journal of Refractive Surgery - November 8, 2017 Category: Opthalmology Authors: Maria Vinas, PhD Source Type: research
Monovision LASIK Versus Presbyopia-Correcting IOLs: Comparison of Clinical and Patient-Reported Outcomes
The two most commonly used surgical presbyopia correction techniques are monovision induced by excimer laser1 –10 and crystalline lens removal with either monovision using monofocal intraocular lenses (IOLs) or bilateral implantation of multifocal IOLs.11–13 With monovision, the dominant eye is corrected for distance vision and the other eye is intentionally myopic to aid near vision. The success of thi s technique depends on the patient's ability to tolerate anisometropia and to suppress the unwanted blurred image (interocular blur suppression).1,3,14 Multifocal lenses simultaneously correct (Source: Journal of Refractive Surgery)
Source: Journal of Refractive Surgery - November 8, 2017 Category: Opthalmology Authors: Steven C. Schallhorn, MD Source Type: research
Risk Factors for Opaque Bubble Layer in Small Incision Lenticule Extraction (SMILE)
As one of the major intraoperative complications of femtosecond laser –assisted lamellar refractive surgeries, opaque bubble layer (OBL) has aroused widespread concern.1–3 The OBL can be explained as temporary “debris” as a result of the intracorneal femtosecond laser photodisruption, which progressively generates gas bubbles that cannot escape in a timely man ner.4 These gas bubbles generally do not last for a long time after the femtosecond laser photodisruption; however, they sometimes diffuse into the corneal stroma, subconjunctival space, and anterior chamber.3 Also, a dense OBL may (Source: Journal of Refractive Surgery)
Source: Journal of Refractive Surgery - November 8, 2017 Category: Opthalmology Authors: Liuyang Li, MD Source Type: research
Repeatability of a Commercially Available Adaptive Optics Visual Simulator and Aberrometer in Normal and Keratoconic Eyes
Aberrations are unique features of a patient's eye that arise from refractive interfaces (eg, cornea and lens).1 Aberrations can affect the quality of vision1 and are known to increase in keratoconus and other ectatic disorders.2 –4 Adaptive optics technology could play an important role in determining the best combination of aberrations to maximize the quality of vision. When corrected with adaptive optics, visual quality and contrast sensitivity can be improved beyond the limits of spectacles and contact lenses in normal eyes.5 A new prototype device that combined the Hartmann–Shack (Source: Journal of Refractive Surgery)
Source: Journal of Refractive Surgery - November 8, 2017 Category: Opthalmology Authors: Rohit Shetty, FRCS, DNB, PhD Source Type: research
Accuracy of Visual Estimation of LASIK Flap Thickness
The use of the femtosecond laser for the creation of LASIK flaps has gained popularity due to its safety and reproducibility. Several studies have compared the femtosecond laser to the microkeratome and demonstrated more accurate and reproducible flap thickness.1 –5 This has led some surgeons to abandon the practice of routinely calculating the flap thickness prior to performing ablation on the stromal bed. One of the most feared complications of refractive surgery is corneal ectasia. Numerous risk factors have been implicated in the development of post-refractive ectasia, including (Source: Journal of Refractive Surgery)
Source: Journal of Refractive Surgery - November 8, 2017 Category: Opthalmology Authors: Jason E. Brenner, MD Source Type: research
Corneal Cross-Linking (CXL): Standardizing Terminology and Protocol Nomenclature
Since the first publication reporting outcomes of corneal cross-linking (CXL) in 2003,1 the peer reviewed literature on this topic has expanded exponentially, with studies reporting outcomes, variations in protocols in terms of fluence, time, epithelial integrity, chromophores, and multiple indications for cross-linking procedures.2 A foreseeable but unfortunate consequence of this rapid expansion has been the tremendous variability in nomenclature and raw data reported. This variability limits direct comparison between various studies. When attending ophthalmic meetings or perusing the (Source: Journal of Refractive Surgery)
Source: Journal of Refractive Surgery - November 8, 2017 Category: Opthalmology Authors: J. Bradley Randleman, MD Source Type: research
Erratum for “Intracorneal Ring Segments Implantation for Corneal Ectasia”
The article “Intracorneal Ring Segments Implantation for Corneal Ectasia” by Giacomin et al., which was published in the December 2016 issue of the Journal of Refractive Surgery (volume 32, number 12, pp. 829–839), has been amended to include a factual correction. An error was identified subsequent to its original printing. On page 829, the author name “Cristine C. Serpe” should be “Crislaine C. Serpe.” This error was acknowledged on page 788, volume 33, issue 11. The online article and its erratum are considered the version of record. (Source: Journal of Refractive Surgery)
Source: Journal of Refractive Surgery - November 8, 2017 Category: Opthalmology Authors: TBD Source Type: research
Intraoperative Optical Coherence Tomography –Guided Management of Cap–Lenticule Adhesion During SMILE
Small incision lenticule extraction (SMILE) is a new keratomileusis technique for laser vision correction. In this technique, an intrastromal refractive lenticule is extracted through a small peripheral incision (2 to 4 mm), obviating the need for creation of a flap.1 The most crucial step in the SMILE procedure is dissecting the intrastromal lenticule from the anterior stromal cap. Inadvertent entry of the dissector posterior to the lenticule can result in cap –lenticule adhesion and difficult lenticule extraction.2 An inability to recognize cap–lenticule adhesion and repeated efforts to find (Source: Journal of Refractive Surgery)
Source: Journal of Refractive Surgery - November 8, 2017 Category: Opthalmology Authors: Jayanand Urkude, MD Source Type: research
Keratoconus Screening With Dynamic Biomechanical In Vivo Scheimpflug Analyses: A Proof-of-Concept Study
Identifying patients with ectatic predispositions is crucial in corneal refractive surgery.1,2 Further, a reliable and easy to handle screening device could enable screening programs for keratoconus in adolescents to facilitate early treatment of the otherwise sight-threatening disease.3,4 Despite noticeable improvements of topography and tomography analysis, keratoconus screening remains challenging in borderline cases.5 Most devices are expensive, large, and prone to interference and require a calm positioning of the patients for several seconds to enable good quality results, which can be (Source: Journal of Refractive Surgery)
Source: Journal of Refractive Surgery - November 8, 2017 Category: Opthalmology Authors: Johannes Steinberg, MD Source Type: research
Secondary Lenticule Remnant Removal After SMILE
Small incision lenticule extraction (SMILE) was first described by Sekundo et al.1 more than 5 years ago, and numerous studies have demonstrated its safety, efficacy, and stability in correcting myopia and myopic astigmatism.2 –7 However, both intraoperative and postoperative complications have been reported.8,9 In cases of difficult lenticule dissection, there could be incomplete lenticule removal, leaving a lenticule remnant in the eye. This could result in irregular astigmatism and reduced visual acuity.10,11 We have encountered several cases of incomplete lenticule removal that were (Source: Journal of Refractive Surgery)
Source: Journal of Refractive Surgery - November 8, 2017 Category: Opthalmology Authors: Alex L.K. Ng, FRCSEd (Ophth) Source Type: research
Assessing the Likely Effect of Posterior Corneal Curvature on Toric IOL Calculation for IOLs of 2.50 D or Greater Cylinder Power
Until recently, IOL power was routinely calculated using methods that only incorporated anterior keratometric curvature data. Posterior corneal astigmatism and its effect on total corneal astigmatism has long been described.1,2 The assumption that anterior keratometric curvature data were adequate to describe total corneal refractive power has been shown to be a source of system error in astigmatism correction with toric IOLs. This error can be improved by incorporating information about the posterior corneal astigmatism into IOL calculations.3 –5 Variations in correlation between anterior and (Source: Journal of Refractive Surgery)
Source: Journal of Refractive Surgery - November 8, 2017 Category: Opthalmology Authors: Benjamin R. LaHood, MBChB, PGDipOphth, FRANZCO Source Type: research
In Vivo Measurement of Longitudinal Chromatic Aberration in Patients Implanted With Trifocal Diffractive Intraocular Lenses
Multifocal corrections are increasingly used solutions for presbyopia, working by the principle of simultaneous vision (ie, projecting simultaneously focused and defocused images on the retina). These corrections, in the form of intraocular lenses (IOLs) or contact lenses, provide multifocality at the expense of reducing optical quality at all distances. Current multifocal IOLs in the market work on diffractive or refractive principles, including refractive bifocal concentric and angular, diffractive bifocal and trifocal, extended depth of focus, or hybrid designs.1 On-bench evaluations of (Source: Journal of Refractive Surgery)
Source: Journal of Refractive Surgery - November 8, 2017 Category: Opthalmology Authors: Maria Vinas, PhD Source Type: research
Monovision LASIK Versus Presbyopia-Correcting IOLs: Comparison of Clinical and Patient-Reported Outcomes
The two most commonly used surgical presbyopia correction techniques are monovision induced by excimer laser1 –10 and crystalline lens removal with either monovision using monofocal intraocular lenses (IOLs) or bilateral implantation of multifocal IOLs.11–13 With monovision, the dominant eye is corrected for distance vision and the other eye is intentionally myopic to aid near vision. The success of thi s technique depends on the patient's ability to tolerate anisometropia and to suppress the unwanted blurred image (interocular blur suppression).1,3,14 Multifocal lenses simultaneously correct (Source: Journal of Refractive Surgery)
Source: Journal of Refractive Surgery - November 8, 2017 Category: Opthalmology Authors: Steven C. Schallhorn, MD Source Type: research
Risk Factors for Opaque Bubble Layer in Small Incision Lenticule Extraction (SMILE)
As one of the major intraoperative complications of femtosecond laser –assisted lamellar refractive surgeries, opaque bubble layer (OBL) has aroused widespread concern.1–3 The OBL can be explained as temporary “debris” as a result of the intracorneal femtosecond laser photodisruption, which progressively generates gas bubbles that cannot escape in a timely man ner.4 These gas bubbles generally do not last for a long time after the femtosecond laser photodisruption; however, they sometimes diffuse into the corneal stroma, subconjunctival space, and anterior chamber.3 Also, a dense OBL may (Source: Journal of Refractive Surgery)
Source: Journal of Refractive Surgery - November 8, 2017 Category: Opthalmology Authors: Liuyang Li, MD Source Type: research
