PURPOSE To present the prospective application of the Orbscan II central 2-mm total-mean corneal power obtained by quantitative area topography in intraocular lens (IOL) calculation after refractive surgery. METHODS Calculated and achieved refraction and the difference between them were studied in 77 eyes of 61 patients with previous radial keratotomy (RK), RK and additional surgeries, myopic...

PURPOSE The purpose of this study was to evaluate the visual and refractive outcomes and rotational stability of the new aspheric Precizon(®) toric intraocular lens (IOL) for the correction of corneal astigmatism in cataract surgery. SETTING Department of Ophthalmology, Hospital Geral de Santo António - Centro Hospitalar do Porto, EPE and Hospital de Pedro Hispano, Matosinhos, Portugal. DES...

PURPOSE To compare the accuracy of intraocular lens (IOL) power calculation using conventional regression formulae or the American Society of Cataract and Refractive Surgery (ASCRS) IOL power calculator for previous corneal refractive surgery. METHODS We retrospectively reviewed 96 eyes from 68 patients that had undergone cataract surgery after keratorefractive surgeries. We calculated the fo...

Background: The non-contact optical methods are preferable in Intra-ocular Lens (IOL) power calculation as they have higher resolution, better patient tolerance and greater acceptability. Aim: to compare between LENSTAR LS900 IOL Master V4 calculation. Material Methods: This prospective comparative study included 60 eyes of 40 cataract patients. Patients with immature any age both genders were ...

PURPOSE To examine the efficacy, predictability, stability, and safety of posterior chamber phakic intraocular lens (IOL) implantation in eyes with high hyperopia. METHODS We analyzed the results of 24 eyes that received a posterior chamber hydrogel-collagen plate phakic IOL (Staar Collamer Implantable Contact Lens, ICL) for the correction of hyperopia with the goal of emmetropia. Mean follow...

In the implantation of intraocular lenses (IOL) stringent requirements are made on achieving the refractive target. This necessitates the exact determination of the basic data needed for IOL power calculation – both the axial length and, in particular, the corneal power – and additionally the cylinder power and its axis in the case of a toric lens. This gives rise to the question, especially fo...

PURPOSE To compare methods of calculating intraocular lens (IOL) power for cataract surgery in eyes that have undergone myopic laser-assisted in-situ keratomileusis (LASIK). METHODS Eleven eyes of eight patients who had previously undergone myopic LASIK (amount of LASIK correction, -5.50 +/- 2.61 D (SD); range, -8.78 to -2.38 D) and subsequently phacoemulsification with implantation of the SA...

Dear Sir, This letter is to alert about the danger of carrying out biometric calculations for the intraocular lens without being aware that the patient may be using a contact lens. This warning is valid even when the highest precision research technology is being utilised. At present, errors in the calculation of the intraocular lens (IOL) are the most frequent cause of lens exchanges as well a...