Intraokularlinsen zur Korrektur von Refraktionsfehlern

Anterior Uveitis with Posterior Synechia and Iris Atrophy Following Implantation of a Phakic Intraocular Lens

Purpose

To describe a case with acute postoperative uveitis, posterior synechia and iris atrophy following iris-claw phakic intraocular lens (pIOL) implantation.

Methods

A case report.

Results

A 26-year-old man with high myopia had implantation of a −14.0 diopter, foldable, iris-claw Artiflex (model 401) anterior chamber pIOL (Ophtec B.V.) in both eyes. On the third postoperative day, the patient had significant postoperative inflammation in the left eye and received topical steroids and mydriatic eye drops. On the fifth postoperative day, the right eye had a round pupil and centered pIOL, but the left eye had an atrophic iris and dilated pupil with significant posterior synechias over the inferior half of the pupil. Despite intensive topical steroid application, the synechias remained one year after surgery.

Conclusion

Severe uveitis with posterior synechia can occur after iris-claw pIOL implantation. We hypothesized that excessive iris tissue enclavation in the pIOLs haptics and large iridotomies may be an associated factor.

Optimized multielement accommodative intraocular lens with a four-freeform-surface Alvarez lens and a separate aspheric lens

This paper proposes an accommodative intraocular lens (IOL), which consists of a two-element Alvarez lens and an aspheric lens for changing focal power and refractive power, respectively. The four-freeform-surface Alvarez lens is optimized for a multiple field of view; further, the aspheric lens also corrects the aberrations induced by the corneal asphericity of the human eye over the whole range of accommodation. A simulation using optical design software demonstrates its excellent performance in that the values of the modulation transfer function at 100 cycles/mm all reach ∼0.4 with a ±5° field of view for 3 and 5 mm pupils.

[Explantation of two historical posterior chamber phakic intraocular lenses 31 years after implantation]

This article reports the case of a 56-year-old male patient who had undergone implantation of posterior chamber phakic intraocular lenses in 1987 in Russia. The patient presented to this clinic 31 years after the initial surgery with anterior cortical cataracts and initial stages of corneal decompensation in both eyes. Strategic planning and execution of surgical treatment and the further clinical course are portrayed in this report.

[Scheimpflug photography for the examination of phakic intraocular lenses]

BACKGROUND

High myopia phakic intraocular lenses (IOL) have become an established means of surgical correction for high ametropia. Scheimpflug photography is one of the methods which are frequently applied for postoperative examination of the implants.

MATERIAL AND METHODS

Results from published studies employing Scheimpflug photography for examination of anterior chamber angle-fixated, iris-fixated and sulcus-fixated phakic IOLs were evaluated.

RESULTS

In several published studies Scheimpflug photography was used to examine the position of the implant and opacification of the crystalline lens. The results provided valuable evidence for the improvement of phakic IOL design.

CONCLUSION

Scheimpflug photography offers an easy to use, rapid non-contact examination of phakic IOLs.

A retrospective analysis of the first Yemeni experience on Artisan phakic intraocular lens for the treatment of moderate and high myopia

OBJECTIVES

To evaluate the outcome and safety of the iris-fixated Artisan phakic intraocular lens (PIOL) for the correction of moderate and high myopia.

MATERIALS AND METHODS

A retrospective non-controlled clinical study of the data of patients who underwent Artisan PIOLs between March 2006 and July 2008 was evaluated. Pre-operative examination included age, gender, refraction, uncorrected (UCVA) and best spectacle corrected (BSCVA) visual acuity, predictability and safety were analyzed. Post-operative time course ranged from 12 to 36 months.

RESULTS

An Artisan myopia lens was implanted in 62 eyes of 39 patients. The mean pre-operative spherical equivalent (SE) was -13.17 ± 5.62 D. The pre-operative myopia ranged from -4.5 to -24 D. Mean patient age was 25.44 ± 5.22 years. At last follow-up visit, residual SE was within ±1.00 D in 36 eyes (58.1%) and ±2.00 D in 56 eyes (90.3%). In the last visit UCVA was equal to or better than pre-operative BSCVA in 57 (91.9%) of the eyes. One eye (1.6%) lost one Snellen line, three eyes (4.8%) lost two or more Snellen lines and one eye lost vision (1.6%). Post-operative complications included anterior chamber reaction in one eye, rise in intraocular pressure in two eyes and retinal detachment in one eye.

CONCLUSION

When laser keratorefractive surgery is not an option, implantation of Artisan PIOL to correct moderate to high myopia results in a stable and good refractive result with few complications that must be kept in mind.

Factors influencing the reliability of autorefractometry after LASIK for myopia and myopic astigmatism

PURPOSE

To study the factors influencing the reliability (accuracy) of autorefractometry before and after laser in situ keratomileusis (LASIK) for myopia and myopic astigmatism.

DESIGN

Retrospective case series.

METHODS

A total of 250 consecutive eyes (132 patients, mean age 37 years) were included from the Department of Ophthalmology, J.W. Goethe University, Frankfurt, Germany. The mean preoperative spherical equivalent of the subjective refraction (SR) was -6.59 diopters (D) (-1.38 to -15.13). The patient data were reviewed before and 1 month after LASIK, including SR, objective automated refraction (AR), and visual acuity. Subgroup analysis was performed with regard to the preoperative myopia and the excimer laser optical zone (OZ). The Holm-Sidak and Wilcoxon matched-pairs tests were used for statistical analysis.

RESULTS

The correlation coefficient between AR und SR is r = 0.98 before LASIK versus r = 0.79 afterwards (P < .001). The mean difference between the spherical equivalents (DSE) is +0.13 ± 0.51 D preoperatively versus -0.30 ± 0.58 D after LASIK (P < .001). With a small optical zone size (5.0-5.5 mm) the postoperative difference is -0.61 D, versus -0.36 D for OZ 5.6-6.0, versus -0.16 for OZ 6.1-7.0 mm. With a rising preoperative amount of myopia, the postoperative AR results become increasingly more myopic than the SR.

CONCLUSIONS

Following LASIK, autorefractometry is less accurate than in nonoperated eyes. The reliability of the AR is influenced by the OZ and the preoperative amount of myopia, with a small OZ and high myopia resulting in a greater difference between AR and SR and with the AR determining more myopic results.

Basic knowledge of refractive surgery: correction of refractive errors using modern surgical procedures

INTRODUCTION

Refractive ophthalmic surgery allows refractive errors to be corrected permanently in a safe, effective, and reliable way with few complications.

METHODS

Selective literature review with special reference to the guidelines of the German Commission for Refractive Surgery.

RESULTS

With a total of almost 18 million treatments performed to date, laser in-situ keratomileusis (LASIK) is the most commonly used refractive surgical procedure worldwide. Alternatives to LASIK include surface ablation procedures (PRK, LASEK, Epi-LASIK) and phakic intraocular lens implantation. If ocular accommodation is lost, removal of the crystalline lens and implantation of modern multifocal intraocular lenses (refractive lens exchange) provide an alternative means of correcting myopia, hyperopia and presbyopia.

DISCUSSION

The treatment effect is maximized and complications kept to a minimum if strict inclusion criteria are applied and a high technical standard maintained during the procedure.

[Application of wavefront analysis in clinical and scientific settings. From irregular astigmatism to aberrations of a higher order--Part II: examples]

In recent years, wavefront analysis has ceased to be purely a laboratory application and emerged as a method used in ophthalmological diagnosis. This development has been promoted mainly by the widespread use of wavefront-guided LASIK (laser in situ keratomileusis). However, aberrometry is still not a common diagnostic technique, and for many ophthalmologists interpretation of the results is difficult. The second part of this serial paper reviews findings that are relevant for the ophthalmological community and highlights current scientific applications in this area.

Komplikationen nach refraktiver Chirurgie im Ausland

BACKGROUND

In this article a retrospective analysis of patients presenting at a German university following refractive surgery abroad is presented.

PATIENTS AND METHODS

A total of 20 cases of patients who had undergone treatment between 1998 and 2006 in China (1 case), Greece (1 case), Iran (1 case), Russia (2 cases), Switzerland (1 case), Slovakia (1 case), Spain (2 cases), South Africa (3 cases), Turkey (6 cases) and the USA (2 cases) were analyzed retrospectively.

RESULTS

The following complications were observed: epithelial ingrowth into the interface with or without melting of the flap (6 cases), corneal ectasia (2 cases), dislocation of a phakic posterior chamber intraocular lens and prolapse into the anterior chamber with endothelial cell loss (1 case), secondary increase of intraocular pressure following implantation of a phakic intraocular lens (1 case), flap-related complications following laser-in-situ keratomileusis (LASIK) (2 cases), keratitis (1 case), dislocation of the complete flap (1 case), diffuse lamellar keratitis (DLK) grade IV (1 case), hyperopia as a consequence of radial keratotomy (1 case), and under correction/over correction and poor optical quality following laser epithelial keratomileusis (LASEK) and LASIK for high myopia (5 cases) with possible early corneal ectasia.

CONCLUSIONS

There are four important problems arising from refractive surgery abroad, often referred to as "LASIK tourism": wrong indications, insufficient management of complications, lack of postoperative care and the health economic aspect.

Torische Intraokularlinsen und Astigmatismuskorrektur

Toric intraocular lenses (tIOLs) have the potential to correct corneal astigmatism. The purpose of this review paper is: 1. to describe the biometric, keratometric and topographic conditions for implantion of tIOLs, 2. to highlight the advantages and disadvantages of tIOLs, 3. to define indications for and contraindications to tIOL implantation, 4. to provide clinical recommendations for the implantation of toric lenses, and 5. to report the specifications of all tIOLs that are currently available commercially.

Implants phakes de chambre antérieure versus chambre postérieure

At a time when some of the limitations of photoablation have been defined, such as worry concerning secondary ectasia, a renewed interest in phakic implantation has arisen. This is driven by the goal of avoiding correcting high ametropia with LASIK and is based on the development of soft foldable biomaterials. When all phakic IOLs are in front of the natural lens, two varieties of lenses can be distinguished, depending on whether it is located in the anterior or posterior chamber. The various models available in 2006 and those under current evaluation are reviewed. We do not report details of clinical studies that vary in cohort size and follow-up. The advantages and limitations are discussed for each type of phakic IOL. Adequate although not exclusive indications are deduced. There is no phakic lens that has proved to be superior to the others in terms of safety. All have the ability to provide a visual benefit with a gain in best corrected visual acuity. The difference is based on anatomical effects, requiring long-term follow-up in the evaluation of angles, lens, iris, and endothelium.

Internal anterior chamber diameter using optical coherence tomography compared with white-to-white distances using automated measurements

PURPOSE

To compare internal horizontal anterior chamber (AC) diameter determined by optical coherence tomography (OCT) and horizontal corneal diameter (white-to-white [WTW]) using automated measurements.

SETTING

Department of Ophthalmology, Johann Wolfgang Goethe-University, Frankfurt am Main, Germany.

METHODS

Internal AC diameter and WTW distance was measured in 52 eyes of 26 patients using the Visante OCT (Carl Zeiss Meditec), IOLMaster (Carl Zeiss Meditec), and Orbscan IIz topography system (Bausch & Lomb). Statistical evaluation was performed using the Bland-Altman method and regression analysis for comparison of measurement techniques. The Kruskal-Wallis test was used to measure the repeatability of each device.

RESULTS

The mean internal AC diameter was 12.45 mm +/- 0.53 (SD) with OCT; the mean WTW distance was 12.17 +/- 0.45 mm with the IOLMaster and 11.84 +/- 0.41 mm with the Orbscan IIz. A positive regression was determined for AC diameter and both WTW measurements. Measurement values varied little between both WTW measurement systems (R(2) = 0.9384).

CONCLUSIONS

Anterior chamber measurement using optical coherence tomography (Visante OCT) was easy to handle and showed good repeatability. The internal horizontal diameter of the AC was larger than the horizontal corneal diameter determined by automated WTW measurements (IOLMaster, Orbscan IIz). Optical coherence tomography with the Visante OCT allows direct measurement of the AC width.