Katharina Kriechbaum

Effect of a silicone intraocular lens with a sharp posterior optic edge on posterior capsule opacification

Purpose: To compare the inhibiting effect on posterior capsule opacification (PCO) of a silicone intraocular lens (IOL) with a sharp posterior optic edge (ClariFlex OptiEdge®, Advanced Medical Optics) and a silicone IOL with a round optic edge (PhacoFlex SI‐40, Advanced Medical Optics). Setting: Department of Ophthalmology, University of Vienna, Vienna, Austria. Methods: This prospective randomized patient‐ and examiner‐masked study comprised 104 eyes of 52 patients with bilateral age‐related cataract. All patients had cataract surgery in both eyes and received a sharp‐edged IOL in 1 eye and a round‐edged IOL in the other eye. Postoperative examinations were at 1 week, 1 and 6 months, and 1 year. Digital slitlamp and retroillumination images were taken of each eye. The amount of PCO was assessed subjectively at the slitlamp and objectively using Automated Quantification of After‐Cataract (AQUA) automated‐image analysis software. Results: The sharp‐edged IOL group had significantly less regeneratory and fibrotic PCO 1 month, 6 months, and 1 year after surgery. The mean AQUA PCO score (scale 0 to 10) was 0.71 in the sharp‐edged IOL group and 1.40 in the round‐edged IOL group (P<.001). The sharp‐edged IOL group had less peripheral fibrotic PCO. There was no significant difference between the 2 IOL groups in patient reports of edge glare. Conclusion: The sharp‐edged design of the ClariFlex OptiEdge silicone IOL led to significantly less PCO than the round‐edged PhacoFlex SI‐40 IOL 1 year postoperatively.

Influence of operator experience on the performance of ultrasound biometry compared to optical biometry before cataract surgery

Purpose: To compare measurements performed with the IOLMaster (Carl Zeiss, Meditec AG) with those obtained by applanation ultrasound (US) and manual keratometry and to evaluate the effect of operator experience on US biometry. Setting: Department of Ophthalmology, University of Vienna, Vienna, Austria. Methods: The axial length (696 eyes) and anterior chamber depth (ACD) (462 eyes) were measured in 377 patients with cataract using the IOLMaster and applanation US. To assess the effect of operator experience on the biometric results, the operators were divided into 2 groups: experienced and less experienced in performing US biometry. The difference in measurements between the methods and the variability of the difference were compared between the 2 groups. Results: Applanation US measured axial length and ACD shorter than the IOLMaster; the mean numerical difference was 0.13 mm and 0.19 mm, respectively (P<.01). For axial length, the absolute difference was smaller with experienced operators than with less experienced operators (0.15 mm versus 0.22 mm) (P<.01). For ACD, experienced operators obtained a smaller difference between measurement techniques (0.21 mm versus 0.29 mm; P<.05). Conclusions: Experienced US operators had less difference and lower variability in the difference between applanation US and IOLMaster readings for axial length and ACD measurements. The noncontact optical method, which is essentially operator independent, gave significantly more reliable biometry before cataract surgery, especially in the case of less experienced operators.

Effect of haptic design on change in axial lens position after cataract surgery

Purpose: To compare the postoperative changes in anterior chamber depth (ACD) between single‐piece and multipiece AcrySof® intraocular lenses (IOLs) (Alcon Laboratories, Inc.) and their effect on the postoperative refractive shift. Setting: Department of Ophthalmology, University of Vienna, Vienna, Austria. Methods: This prospective randomized bilateral study with intraindividual comparison comprised 104 eyes of 52 consecutive patients with age‐related cataract. All patients had standardized cataract surgery with a temporal self‐sealing incision, phacoemulsification, and IOL implantation in the capsular bag. The first 30 patients received a single‐piece, 5.5 mm optic IOL (AcrySof SA30) in 1 eye and a multipiece IOL (AcrySof MA30) in the other eye. Another 22 patients received the corresponding 6.0 mm optic models (AcrySof SA60 and AcrySof MA60, respectively). Anterior chamber depth measurements and evaluation of the change in ACD during the first 6 postoperative months were performed using partial coherence laser interferometry. The amount of change in capsulorhexis size during the first 6 postoperative months was assessed using standardized retroillumination photographs. Results: Single‐piece IOLs shifted significantly less postoperatively than multipiece IOLs. The multipiece IOLs shifted forward, especially from 1 day to 1 month. The change in the capsulorhexis area was similar between IOL types. Conclusions: Single‐piece AcrySof IOLs shifted minimally after the first postoperative day; therefore, the prescription for spectacles in eyes with this IOL can be obtained soon after surgery.

Influence of optic edge design and anterior capsule polishing on posterior capsule fibrosis.

Purpose: To evaluate the role of posterior optic edge design and the effect of anterior capsule polishing on peripheral fibrotic posterior capsule opacification (PCO). Setting: Department of Ophthalmology, University of Vienna, Vienna, Austria. Methods: This randomized prospective study comprised 144 eyes of 72 patients with bilateral age‐related cataract. Each patient had standardized cataract surgery in both eyes by the same surgeon. Group 1 (46 patients) received a round‐edged hydrophobic acrylic IOL (AMO Sensar® AR40) in 1 eye and a sharp‐edged hydrophobic acrylic IOL (AMO Sensar® OptiEdge AR40e) in the other eye. Group 2 (26 patients) received a silicone IOL (Pharmacia CeeOn® 911A) with a truncated optic in both eyes. In this group, the anterior capsule was extensively polished in 1 eye and was left unpolished in the other eye. Digital slitlamp photographs were taken 1 year postoperatively using a standardized photographic technique for fibrotic PCO. The intensity of PCO was subjectively graded (score 0 to 4) by 2 masked examiners. Results: Subjective PCO scores correlated well between the 2 examiners (r = 0.88). In Group 1, the mean PCO score was 0.26 for the OptiEdge AR40e IOL and 0.90 for the AR40 IOL (P<.01). In Group 2, the mean PCO score was 0.24 in eyes with a polished capsule and 0.17 in eyes in which the capsule was not polished (P = .31). Conclusions: The sharp‐edged OptiEdge AR40e IOL led to significantly less peripheral fibrotic PCO 1 year postoperatively than the round‐edged AR40 IOL. In eyes with the sharp‐edged silicone 911A IOL, anterior capsule polishing caused no significant difference in fibrotic PCO.

Postoperative change in effective lens position of a 3-piece acrylic intraocular lens

Purpose: To study the change in postoperative position of an angulated, 3‐piece, foldable acrylic intraocular lenses (IOLs) and evaluate the effect of a sharp posterior optic edge compared with that of a round optic edge on the change in postoperative anterior chamber depth (ACD). Setting: Department of Ophthalmology, University of Vienna, Vienna, Austria. Methods: This randomized intraindividual‐comparison study comprised 104 eyes of 52 patients with age‐related cataract. Patient received a sharp‐edged Sensar® OptiEdge AR40e IOL (Allergan Surgical) in 1 eye and a round‐edged Sensar AR40 IOL in the other eye. Postoperative follow‐up included ACD measurement by partial coherence interferometry and evaluation of the capsulorhexis area by standardized retroillumination photography at 1 day, 1 week, and 1 and 6 months. Results: A decrease in ACD during the first postoperative week was followed by a small increase in ACD during the first 6 months. There was no significant difference between the sharp‐edged group and the round‐edged group. Conclusions: The angulated 3‐piece acrylic IOLs showed significant forward movement over the first postoperative 6 months. Although the change in refraction was small, there was variability among patients. The sharp posterior optic edge design did not affect the IOLs movement in the capsular bag.

Determining postoperative anterior chamber depth.

Purpose: To compare measured and calculated postoperative anterior chamber depths (ACDs). Setting: Department of Ophthalmology and Institute of Medical Physics, University of Vienna, Vienna, Austria, and Department of Ophthalmology, University of Mainz, Mainz, Germany. Methods: The postoperative ACD was measured in 189 pseudophakic eyes using a laboratory prototype of partial coherence interferometry (PCI). In 6 intraocular lens (IOL) groups, the mean ACD was calculated by ray tracing based on the best‐known A‐constants of the SRK formulas. In addition, for each IOL type, each measured ACD was compared with a value calculated using the individual spherical equivalent of the postoperative refraction. Results: The measured and the calculated ACD values were close and did not show systematic differences. The ACD values obtained in the study, however, differed significantly from the values published by the IOL manufacturers. A comparison of the PCI‐assessed ACDs and the calculated values using the postoperative refraction showed more scattered results for the refraction‐based data, which was probably the result of higher measurement errors with the autorefractometer than with PCI. Conclusions: High‐precision interferometry measurements and ray‐tracing calculations confirmed each other. The resulting mean ACD values should be used instead of the manufacturers values. The refractive outcome of cataract surgery can be improved by combining preoperative high‐precision PCI biometry and numerical ray tracing for IOL power calculations.

Systemisches und intravitreales Bevacizumab (Avastin®) bei neovaskulärer altersbezogener Makuladegeneration

SummaryA number of experimental and clinical studies have show the important role of the vascular endothelial growth factor (VEGF) in most neovascular and exudative ocular diseases. The therapeutic concept of an anti-VEGF therapy has been most promising in a number of prospective controlled clinical trials. In the treatment of neovascular age-related macular degeneration (AMD) intravitreal anti-VEGF therapy has shown not only to stabilize vision in most patients, but also to improve vision in a significant number of patients. Bevacizumab (Avastin®) is a monoclonal antibody designed to bind all isoforms of VEGF. It has been primarily developed for the systemic treatment of colon cancer in oncology. But several prospective and retrospective case series evaluating the use of systemic and intravitreal bevacizumab in neovascular AMD and other neovascular and exudative ocular diseases have shown most promising results. Despite the fact that results of large, prospective, long-term studies are currently unavailable, a number of studies have shown anatomic, functional and safety results up to 6 months similar to other anti-VEGF drugs. An approval of bevacizumab in ophthalmology by regulatory agencies cannot be expected in the near future. Similar to a number of drugs in clinical use, bevacizumab will remain available in ophthalmology only as off label treatment or in clinical trials. To clarify the role of bevacizumab for the treatment of a number of neovascular and exudative eye diseases, prospective long-term studies are necessary.ZusammenfassungDie wichtige Rolle des vaskulären endothelialen Wachstumsfaktors (VEGF) bei vielen neovaskulären und exsudativen Erkrankungen des Auges hat sich in den letzten Jahren in zahlreichen experimentellen und klinischen Studien herausgestellt. Das therapeutische Konzept der Anti-VEGF-Therapie zeigte sich in zahlreichen prospektiven, kontrollierten Studien mit unterschiedlichen Anti-VEGF-Präparaten als viel versprechend. Besonders bei der neovaskulären altersbezogenen Makuladegeneration (AMD) scheint es möglich geworden zu sein, nicht nur den Visusverlust zu verlangsamen, sondern in einem nicht unerheblichen Anteil der Patienten eine Visusverbesserung zu erreichen. Bevacizumab (Avastin®) ist ein monoklonaler Antikörper, der alle Isoformen des VEGF bindet. Er wurde primär für die systemische Therapie in der Onkologie entwickelt. Prospektive und retrospektive Fallserien zur systemischen und intravitrealen Anwendung von Bevacizumab bei der neovaskulären AMD aber auch bei anderen neovaskulären und exsudativen Erkrankungen des Auges haben sehr viel versprechende Ergebnisse bei insgesamt gutem Sicherheitsprofil gezeigt. Es ist jedoch nicht davon auszugehen, dass Bevacizumab in nächster Zukunft eine Zulassung für die Anwendung in der Augenheilkunde erhalten wird. Wie bei vielen anderen Präparaten in der Augenheilkunde wird die Behandlung mit Bevacizumab weiterhin nur off label oder in klinischen Studien möglich sein. Um die Rolle von Bevacizumab bei der Behandlung verschiedener Augenerkrankungen abschließend bewerten zu können, bleiben jedoch prospektive Langzeitstudien abzuwarten.