Fortino Velasco

Artisan toric phakic intraocular lens for the correction of high astigmatism

PURPOSE To evaluate efficacy, predictability, and safety of Artisan toric phakic intraocular lens (Ophtec, Groningen, The Netherlands) implantation for the correction of astigmatism higher than 2 diopters. DESIGN Interventional case series. METHODS This prospective study included 27 eyes of 16 patients with a mean preoperative spherical equivalent of -11.78 +/- 6.24 diopters and a mean preoperative astigmatism of -3.43 +/- 0.81. The Artisan phakic intraocular lens was inserted in the anterior chamber through a posterior corneal incision; the technique is similar to the implantation of the classical Artisan lens, but in these cases it is particularly important to secure the lens accurately in the correct axis. The main parameters evaluated in this study were uncorrected visual acuity, best-corrected visual acuity, refraction, and endothelial cell count. RESULTS Twelve months after the implantation of the Artisan toric phakic intraocular lens, 62.90% of the eyes were within +/-0.50 diopters. of emmetropia and 96.20% within +/-1.0 diopters. Seventy percent of the eyes gained 1 or more Snellen lines from their preoperative best-corrected visual acuity, and 11.11% lost 1 Snellen line. Mean endothelial cell count increased 2.9%. Mean of the parallel and orthogonal components of cylinder correction were 1.97 diopters and 0.10 diopters, respectively, of the intended cylinder change. The mean of axis alignment error was 10.53 degrees. No serious complications were observed. CONCLUSION Artisan toric phakic intraocular lens implantation appears to be a safe and predictable method for the correction of high levels of astigmatism.

Secondary Artisan-Verysise aphakic lens implantation

PURPOSE: To evaluate efficacy, predictability and safety of Artisan–Verysise intraocular lens (IOL) secondary implantation for aphakia correction. SETTING: Instituto de Microcirugía Ocular, and Autonoma University of Barcelona, Barcelona, Spain. METHODS: Uncorrected visual acuity, best spectacle‐corrected visual acuity (BSCVA), manifest refraction, endothelial cell count, and clinical complications were evaluated. Sixteen consecutive eyes of 14 patients with aphakia were submitted to surgery. Postoperative examinations were done at 6 weeks, 6 months, 1 year, and every year for at least 3 years. An iris‐supported Artisan–Verysise IOL was implanted for aphakia correction. RESULTS: Thirty‐six months after Artisan–Verysise lens implantation, BSCVA was 20/40 or better in 6 eyes (37.5%). Preoperatively, 5 eyes had the same BSCVA (31.25%). Mean postoperative spherical equivalent (SE) was 0.46 diopter (D). Mean endothelial cell loss was 10.9% 36 months postoperatively. The cell loss occurred predominantly during the first year (7.78%). Cystoid macular edema was observed in 2 cases, 1 of them associated with chronic unresponsive low intraocular pressure. No other serious complications were observed. CONCLUSION: Artisan–Verysise IOL implantation seems a safe, predictable, and effective option for aphakic eyes without capsule support.

Phacoemulsification of the crystalline lens and implantation of an intraocular lens for the correction of moderate and high myopia: four- year follow-up

Purpose: To assess the safety of lens extraction and intraocular lens (IOL) implantation in patients with high myopia treated for initial lens opacity and/or refractive indications. Setting: Instituto de Microcirugía Ocular de Barcelona, Barcelona, Spain. Methods: This retrospective nonrandomized case series study comprised 44 eyes of 30 consecutive myopic patients who had surgery because of initial lens opacity and/or refractive indications during a 2‐year period. In each case, phacoemulsification was performed using an ultrasonic technique and an IOL was implanted in the capsular bag. The patients were seen preoperatively to evaluate retinal pathology. They also had a complete ophthalmologic evaluation that included detailed indirect ophthalmoscopy. All patients were followed at regular intervals. The main outcome measures were preoperative and postoperative spherical equivalent (SE), the incidence of posterior capsule opacification (PCO) and the need for capsulotomy, and the incidence of retinal complications. Results: In all eyes, the surgery was uneventful. The mean patient age at surgery was 42.83 years; the mean preoperative SE was −15.77 diopters (D) and the mean postoperative SE, −1.05 D. No eye required preoperative peripheral retinal photocoagulation. Twenty‐five eyes (56.8%) had PCO and had a neodymium:YAG laser capsulotomy. One eye had a retinal tear 14 months after surgery and was treated with focal photocoagulation. The mean endothelial cell loss was 2.1% during the first postoperative year. Two eyes had an immediate postoperative intraocular pressure (IOP) rise, 1 with an inflammatory membrane and the other with corneal edema; both resolved with topical treatment. One eye with elevated IOP and a bad response to medical treatment had argon laser trabeculoplasty. No eye had a retinal detachment during the follow‐up. Conclusion: With a thorough preoperative ophthalmologic evaluation and uneventful surgery, patients who have phacoemulsification and IOL implantation for the correction of myopia have a satisfactory chance of obtaining good visual results with few complications.

Intracorneal Ring Segments After Laser in situ Keratomileusis

PURPOSE To evaluate the safety and efficacy of intracorneal ring segments (ICRS) for correction of residual refractive error in patients previously operated with laser in situ keratomileusis (LASIK). METHODS Thirteen postoperative LASIK eyes (eight patients) with residual myopic refractive error underwent implantation with INTACS (Keravision) intracorneal ring segments. Correction of the residual error was the first goal, but also improved best spectacle-corrected visual acuity was obtained by correcting residual irregular astigmatism. RESULTS Mean spherical equivalent refraction improved from -3.25 to +0.75 D and mean uncorrected visual acuity improved from 0.2 to 0.6 after ICRS insertion. Best spectacle-corrected visual acuity remained stable or improved; no eyes lost lines of corrected visual acuity. In one of the 13 eyes, the intracorneal ring segments were removed because of progressive stromal melting. CONCLUSIONS The use of corneal ring segments in selected eyes with residual myopic refractive errors after LASIK was safe and effective.

Confocal microscopy of corneas with an intracorneal lens for hyperopia

PURPOSE We evaluated short-term results and confocal microscopic corneal changes following intracorneal lens implantation. METHODS In six eyes of three patients with hyperopia between +3.00 and +6.00 diopters (D), an intrastromal hydrogel lens (Permavision, Anamed, Anaheim, Calif) was implanted. Mean baseline hyperopia was +3.90 D. Manifest refraction, uncorrected visual acuity, and spectacle-corrected visual acuity were evaluated. We also performed confocal real-time microscopy with a water immersion objective. Corneal optical sections were recorded and reviewed frame by frame. Examinations were done at months 3, 6, and 12 after intracorneal lens implantation. RESULTS After surgery, the spherical equivalent refraction was within +/- 0.50 D in 83% (five of six eyes) at 3 months and 100% (six eyes) at 6 and 12 months. Uncorrected visual acuity (UCVA) at 3 months was within 20/40 or better in 67% (four eyes) and in 100% (six eyes) at 6 and 12 months; no eyes had 20/20 or better UCVA at 3 and 6 months. One eye (17%) had 20/20 or better UCVA at 12 months. On confocal microscopy, one eye had an amorphous deposit adjacent to the lens and presumed fibroblastic activity in the same stromal area at 6 months, which was non-progressive up to 12 months. CONCLUSION Intracorneal lenses may be a treatment option for correction of spherical hyperopia. Predictability must be improved but results in these six eyes were stable up to 1 year. Confocal miscroscopy confirmed biocompatibility and showed no abnormal changes, except two spots of hypercellularity in one eye.

Phakic intraocular lens implantation.

Currently, there are four general approaches to correct a refractive defect: refractive corneal surgery, crystalline lens surgery, and implantation of an intraocular lens (IOL) in the anterior or posterior chamber. In any case, the main goal of refractive surgery is the smallest residual refractive error preserving vision quality with the same visual capacity. Corneal refractive surgery might be divided into three types. One would be incisional and thermal corneal surgery, the second is ablational corneal surgery, and the third is addional corneal surgery (intracorneal lens, intraestromal ring segments, etc.). Most of them, except for some lenses, will try to modify the anterior curvature of the cornea in order to obtain its effect. Radial keratotomy has been the keystone of corneal refractive surgery to correct myopia but, as Waring pointed out in 1986 regarding instability of the corneal dome, the number of incisions considered permissible had declined from 16 to 8, with the limitation to treat myopia of not more than–6.00 to –8.00, and eyes with myopia less than approximately 5.00 D achieve better results than do eyes with myopia greater than 5.00 D. Meanwhile, other keratorefractive procedures have been described: epikeratoplasty, in situ keratomileusis, excimer laser photorefractive keratectomy, and more recently excimer laser in situ keratomileusis (LASIK). Although this is still a topic for debate, the best results have been obtained with LASIK; however, in general, such complications as unpredictability, regression, and mainly poor quality of vision under dim illumination conditions have diminished its use in high myopia correction. The second approach in correcting high ammetropia is the substitution of the natural lens with an IOL of proper dioptric power. This procedure has been called clear o semiclear lens extraction by some and refractive lensectomy by others. Predictability and stability of the results, comparable to those observed after IOL implantation at the time of cataract surgery, are the main advantages of this technique. It also offers the added

Topographically guided ablations for the correction of irregular astigmatism after corneal surgery

Jose I. Barraquer theorized that because the cornea accounts for two-thirds of the refractive power of the eye, a change in its curvature could have a great effect on the refractive error. Subsequently, researchers have developed several refractive procedures in the cornea for this purpose. The corrections of the spherical refractive errors, such as myopia and hyperopia, have progressed much more efficiently than has the correction of astigmatism. Patients with astigmatism cannot accommodate or “correct” for it as do patients with hyperopia and, besides sparing defocus, they may complain of ghost images or even diplopia. This is why astigmatism must be properly diagnosed and also corrected. Corneal astigmatism may be regular or irregular. In the astigmatic eye, the refractive power is not the same in all meridians: When it is regular, the maximal and minimal powers of the eye are 90 degrees apart, or orthogonal, and when corneal, topography is uniformly nonspherical, usually designated as a toric surface. Conversely, irregular astigmatism occurs when the power changes irregularly along the meridians, and when it is corneal as usual, it is clearly seen with the topographical map. Irregular astigmatism can occur as a result of trauma, keratoconus, corneal disease, corneal infection and others. Sometimes it is the result of surgical procedures, such as pterigyum removal, penetrating keratoplasty (PK), and cataract extraction. In fact, there are numerous descriptions of irregular astigmatism as a complication of several refractive procedures, such as photoablative techniques with the excimer laser. Although there are several ethiologies, some of the most common have been central islands, a small optical zone, and decentrations.