BACKGROUND Phacoemulsification and intraocular lens (IOL) implantation during cataract surgery in horses occur with increasing frequency. To reduce the postoperative refractive error it is necessary to determine the proper IOL power. In the present study retinoscopy, keratometry and ultrasonographic biometry were performed on 98 healthy equine eyes from 49 horses. The refractive state, corneal ...

OBJECTIVE To assess intraocular lens (IOL) power calculations in patients undergoing cataract surgery after excimer laser photorefractive keratectomy (PRK) for myopia. METHODS Four eyes of two patients underwent phacoemulsification with IOL implantation after PRK for myopia. The estimated refractive error that would have been induced had the IOL predicted for emmetropia been implanted was cal...

Refractive outcomes following cataract surgery in patients that have previously undergone laser refractive surgery have traditionally been underwhelming. This is related to several key issues including the preoperative assessment (keratometry) and intraocular lens power calculations. Peer-reviewed literature is overwhelmed by the influx of methodology to manipulate the corneal or intraocular le...

AIMS To determine the accuracy of intraocular lens (IOL) power calculation in a group of pseudophakic children. METHODS A retrospective analysis of biometric and refractive data was performed on 52 eyes of 40 infants and children, who successfully underwent cataract extraction and IOL implantation. The following parameters were included: age at the time of surgery, keratometry, axial length, ...

The calculation of the intraocular lens (IOL) power required for a specific patient typically uses a “lens constant” back-calculated from the refractive outcomes of earlier surgical results.1,2 An early recommendation was for clinicians to personalize their own lens constants to address systematic errors. However, the introduction of phacoemulsification equipment, continuous curvilinear capsulo...

We studied 400 eyes which underwent cataract extraction with posterior chamber intraocular lens (IOL) implantation to compare the predictive accuracy of various IOL power calculation formulae. The new Sanders-Retzlaff-Kraff (SRK) II formula was more accurate than the original SRK and Binkhorst II formulae. Modification of the A constants used in the SRK II formula to make it 'surgeon specific' ...

A series of 50 eyes received an intraocular lens (IOL) of power calculated for emmetropia from data of axial length, corneal curvature, and postoperative anterior chamber depth by R. D. Binkhorst's formulae. The postoperative refraction results were compared with those of 100 control eyes which received +19 D standard power IOLs without calculation. The calculated group had postoperative refrac...

PURPOSE To identify and quantify sources of error in the refractive outcome of cataract surgery. SETTING AMO Groningen BV, Groningen, The Netherlands. METHODS Means and standard deviations (SDs) of parameters that influence refractive outcomes were taken or derived from the published literature to the extent available. To evaluate their influence on refraction, thick-lens ray tracing that a...

We reviewed the SRK-II method and introduce a new equation to calculate the intraocular lens (IOL) power for eyes which underwent laser phototherapeutic keratectomy (PTK). The Gullstrand series was used to determine the power and the radius of curvature of planoconvex IOLs which alter the focal point from the cornea to reach the conjugate point on the retina. The radius of anterior corneal curv...

A prospective series of 25 eyes received an intraocular lens (IOL) of power calculated for planned ametropia, by means of the formulae of R. D. Binkhorst, from data of axial length, corneal curvature, and postoperative anterior chamber depth. All the postoperative refractions were within the +/- 2 D range from the predicted refraction, confirming the clinical value of such calculation. A retros...