Norbert Anders

Endothelial cell loss after phacoemulsification: relation to preoperative and intraoperative parameters

PURPOSE To evaluate the effect of the location of the corneoscleral tunnel incision as well as preoperative and intraoperative parameters on total and localized endothelial cell loss. SETTING Department of Ophthalmology, Humboldt-University of Berlin, Berlin, Germany. METHODS Fifty consecutive patients scheduled for routine cataract surgery were selected prospectively for this clinical trial. Preoperatively, the axial length, anterior chamber depth, lens thickness, and astigmatism were measured. Phacoemulsification time and relative energy as well as total surgical time were recorded. With a specular microscope, endothelial cell counts were determined centrally, superiorly, and temporally preoperatively and 6 weeks and 6 and 12 months postoperatively. RESULTS After 12 months, the mean overall central endothelial cell loss in all eyes was 8.5%. The mean endothelial cell loss was 11.9% in the lateral quadrant and 11.4% in the superior quadrant. There were no significant differences between superior and temporal surgical approaches in intraoperative parameters of phacoemulsification time, relative intensity of phacoemulsification, and surgical time. There were no significant differences in central endothelial cell loss or in the area localized in the quadrant of the positions of the corneal surgical site. The only risk factors found significant for higher endothelial cell loss were shorter axial length and longer phacoemulsification time. CONCLUSIONS The location of corneoscleral incisions for phacoemulsification can be chosen according to the preoperative astigmatism without inducing additional adverse effects on the corneal endothelium. Shorter eyes have a significantly higher risk for greater endothelial cell loss.

A Prospective Evaluation of a Diffractive versus a Refractive Designed Multifocal Intraocular Lens

OBJECTIVE To evaluate prospectively a diffractive (811E, Pharmacia; power add +4.0 D) versus a refractive (PA154N, Allergan; power add +3.5 D) designed multifocal lens. PARTICIPANTS Eighty patients planned for cataract surgery without additional ocular pathologies were randomized into the diffractive or refractive group, respectively. INTERVENTION A standardized no-stitch phacoemulsification with implantation of one of the two multifocal lenses was performed in each patient. MAIN OUTCOME MEASURES Distance and near-visual acuity, contrast sensitivity, low contrast visual acuity, glare visual acuity, and depth of focus were measured after surgery. RESULTS All treated patients had best-corrected visual acuities of 20/30 or better. Near-uncorrected vision was significantly better (P < 0.0001) with the diffractive lens (mean, J1) than with the refractive lens (mean, J4). Low contrast visual acuity (61 +/- 12% versus 59 +/- 9%), glare visual acuity (39 +/- 19% versus 38 +/- 14%), and contrast sensitivity (1.48 +/- 0.08 versus 1.50 +/- 0.12) were not significantly different between the groups. CONCLUSIONS Both lens designs showed satisfactory functional results with advantages for the diffractive lens design.

Causes of severe decentration and subluxation of intraocular lenses

Abstract• Background: Severe decentration and subluxation of intraocular lenses (IOLs) may lead to double vision, glare and deterioration of vision to the point of functional aphakia. The purpose of the present study was to analyse causes for severe IOL dislocation. • Material and methods: Between January 1989 and January 1996, 37 patients required IOL exchange because of decentrated or subluxated posterior chamber lenses. Twenty-five of the exchanged lenses were implanted in our hospital, 12 lenses elsewhere. After explantation the lenses were examined by light and electron microscopy. • Results: In 10 eyes, asymmetric implantation of the posterior chamber lens was responsible for decentration. Three of the lenser concerned were multifocal IOLs. Asymmetric implantation led to a significantly higher rate of explantations in eyes with multifocal lenses (P<0.005). In five eyes decentration developed due to asymmetric capsular shrinkage, in four eyes due to posterior synechiae. A lens subluxation developed in three eyes as a result of rupture of the posterior capsule and in nine eyes because of zonular defects. In three cases decentrations were induced by an extensive secondary cataract. Macroscopically visible changed geometry of the haptics was found in nine lenses; eight of these had polypropylene haptics. Seven lenses showed severely altered haptics on electron-microscopic examination. In four eyes subluxated lenses had to be explanted together with the capsular bag because of severe defects of the zonula, which caused decentration in nine eyes. • Conclusions: Asymmetric implantation of posterior chamber lenses should be strictly avoided. Multifocal lenses require special attention concerning symmetric capsulorhexis and positioning of their haptics.

Postoperative astigmatism and relative strength of tunnel incisions: a prospective clinical trial.

Purpose: To investigate the influence of incision depth and site on wound strength and postoperative astigmatism. Setting: Virchow Memorial Hospital Eye Clinic, Berlin, Germany. Methods: In this prospective, randomized study, 180 patients with a 7.0 mm tunnel incision were examined. They were divided into the following subgroups: primary incision depth of 300 and 500 [&mgr;m; limbal incision and scleral incision; temporal scleral incision and scleral incision at the 12 o’clock position; temporal limbal incision and limbal incision at the 12 o’clock position. Postoperative astigmatism was measured by keratometry and videokeratoscopy 1 day, 1 and 4 weeks, and 8 months postoperatively. Wound strength was measured with an ophthalmodynamometer on the first postoperative day and after 1 week at the site with the least mechanical stability adjacent and posterior to the primary incision. Results: The temporal incision, which was performed 1.0 mm behind the surgical limbus, led to induced astigmatism of 0.65 diopters (D) ± 0.23 (SD) after 8 months. When the incision was at the 12 o’clock position, the induced astigmatism was 0.97 ± 0.41 D. Induced astigmatism was highest following a limbal incision in the 12 o’clock position (1.33 ± 0.63 D). This effect was less pronounced with a temporal incision. Incision depth did not significantly influence induced astigmatism. An incision depth of 500 [Lm led to induced astigmatism of 0.94 ± 0.50 D; a depth of 300 R,m led to induced astigmatism of 0.78 ± 0.64 D. After 1 week, wound strength was highest with temporal scleral incisions (38.6 ± 2.1 kPa by ophthalmodynamometer) and lowest with limbal incisions in the 12 o’clock position (30.8 ± 7.7 kPa). Conclusions: Incision site significantly influenced mechanical wound strength and induced astigmatism; incision depth influenced neither. In general, incisions in the 12 o’clock position induced more astigmatism than temporal incisions.

Long-term endothelial cell loss after phacoemulsification: peribulbar anesthesia versus intracameral lidocaine 1%: prospective randomized clinical trial.

Purpose: To evaluate endothelial cell loss after phacoemulsification with posterior chamber intraocular lens implantation using peribulbar anesthesia or topical anesthesia combined with intracameral unpreserved lidocaine 1%. Setting: Department of Ophthalmology, Charité, Humboldt‐University of Berlin, Berlin, Germany. Methods: Before and 20 months ± 5.1 (SD) after surgery, specular microscopy was used to evaluate the number and morphology of endothelial cells in 78 eyes having peribulbar anesthesia or topical anesthesia combined with an intracameral injection of 0.15 cc unpreserved lidocaine 1%. Results: The mean endothelial cell loss was 11.11% in the peribulbar group and 12.55% in the topical/lidocaine group. There was no statistically significant difference in the amount of endothelial cell loss or cell morphology between the 2 groups. Conclusion: The long‐term postoperative endothelial cell course showed that topical anesthesia combined with an intracameral injection of 0.15 cc unpreserved lidocaine 1% is a safe alternative to peribulbar anesthesia.

Clinical and electrophysiologic results after intracameral lidocaine 1% anesthesia: A prospective randomized study

OBJECTIVE To evaluate the efficacy and safety of intracameral lidocaine in cataract surgery compared to peribulbar anesthesia. DESIGN A prospective, randomized, controlled study. PARTICIPANTS A total of 200 consecutive cataract patients (200 eyes) participated. INTERVENTION Eyes were randomly assigned to two groups: one group received 0.15 ml intracameral 1% unpreserved lidocaine combined with topical anesthesia (oxybuprocaine); the other group received 6 ml prilocaine peribulbar before phacoemulsification with sclerocorneal tunnel incision. MAIN OUTCOME MEASURES Duration of surgery was measured; implicit time and amplitudes of the b-waves of the photopic electroretinogram (ERG) potentials (single-flash ERG and the 30-Hz flicker ERG) were recorded; frequencies of intraoperative problems, complications, intraoperative, and postoperative pain were evaluated. RESULTS After lidocaine anesthesia combined with topical anesthesia, similar complications were found, longer operation time (P < 0.001), and significantly better visual acuity immediately after surgery (P < 0.001). The ERG amplitudes were not significantly reduced after 0.15-ml intracameral lidocaine half an hour after surgery (P > 0.05). CONCLUSION Intracameral lidocaine 1% combined with topical anesthesia can be recommended as an alternative procedure to peribulbar anesthesia in cataract surgery with corneoscleral tunnel incision.

A prospective comparison of two multifocal lens models

SummaryBackground: The functional results of two different types of multifocal intraocular lenses (based on the diffractive and refractive principle, respectively) were investigated prospectively. Materials and methods: Altogether 50 patients who had a multifocal lens implanted were examined 4–6 weeks postoperatively. Visual acuity for distance and near vision, contrast sensivity, low contrast visual acuity and glare visual acuity were investigated. Results: Distance visual acuity, contrast sensitivity, low contrast visual acuity and glare visual acuity did not show significantly different results. Near visual acuity was statistically significantly better with the diffractive type of multifocal lens (because of a stronger adjustment for near vision). When the focus depth was tested by defocus curves, both lenses had better results within different areas of defocus. Conclusions: All patients in both groups showed satisfactory results. When choosing a multifocal intraocular lens, the individual needs of each patient should be taken into consideration.Fragestellung: Zwei unterschiedliche Multifokallinsenmodelle verschiedener Wirkmechanismen (diffraktives und refraktives Prinzip) wurden prospektiv hinsichtlich ihrer funktionellen Ergebnisse verglichen. Material und Methode: Bei insgesamt 50 Patienten wurden 4–6 Wochen postoperativ Fernvisus, Nahvisus, Kontrastempfindlichkeit, Kontrastsehschärfe und Blendungssehschärfe bestimmt. Ergebnisse: Beide Linsenmodelle zeigten keine signifikanten Unterschiede hinsichtlich Fernvisus, Kontrastempfindlichkeit, Kontrastsehschärfe und Blendungssehschärfe. Ein signifikant besserer Nahvisus wurde mit der diffraktiven Linse (bei stärkerem Nahzusatz des Linsenmodells) erreicht. Bei der Defokussierung zur Bestimmung der Tiefensehschärfe zeigten sich in jeweils unterschiedlichen Bereichen bessere Ergebnisse zugunsten beider Linsenmodelle. Schlußfolgerung: Beide untersuchten Linsenmodelle zeigen gute funktionelle Ergebnisse. Bei der Wahl des Modells sollten die individuellen Patientenbedürfnisse berücksichtigt werden.

Effect of incision location on preoperative oblique astigmatism after scleral tunnel incision

Purpose: To evaluate the effect of incision location on clinically relevant preoperative oblique astigmatism. Setting: Department of Ophthalmology, Virchow Medical Center, Humboldt‐University, Berlin, Germany. Methods: This prospective study included 63 patients who had phacoemulsification and posterior chamber intraocular lens implantation using a standardized 7.0 mm self‐sealing trapezoidal scleral tunnel incision. Each patient was randomly assigned to one of three incision locations: Group A, conventional superior incision; Group B, temporal incision; Group C, oblique incision centered on the steeper meridian (modified BENT incision). Astigmatism analysis was performed by manual keratometry and corneal topography. Results: A significant mean reduction in astigmatism of 0.58 diopter (D) (P < .01) was achieved in only the modified BENT incision group. Postoperatively, significant flattening of 0.27 D (P < .01) in the steeper meridian as well as steepening of 0.29 D (P < .01) in the flatter meridian occurred. No decrease in astigmatism was noted in the superior or temporal incision groups. Five months postoperatively, vector analysis showed that surgically induced astigmatism was significantly higher in the superior incision group (1.16 D ± 0.44 [SD]) than in the temporal incision group (0.66 ± 0.32 D) or modified BENT incision group (0.82 ± 0.50 D). Corneal topographic analysis confirmed these results within ± 0.3 D. Conclusions: Only the oblique incision centered on the steeper meridian (modified BENT incision) effectively and predictably reduced preoperative oblique astigmatism. In eyes with clinically relevant oblique astigmatism, we recommend using a modified BENT incision.

Frühpostoperativer Endothelzellverlust nach korneoskleralem Tunnelschnitt und Phakoemulsifikation bei Pseudoexfoliationssyndrom

Introduction: Corneal endothelial involvement can be found in pseudoexfoliation syndrome (PEX). Evaluation of possible differences in endothelial cell loss following cataract extraction was compared to normal eyes.Patients and methods: In a controlled clinical study we prospectively studied 20 patients with PEX and compared them with an age-matched control group with senile cataract. All patients were treated with a standardized self-sealing 7-mm corneoscleral tunnel incision, phacoemulsification and posterior intraocular lens implantation using sodium hyaluronate. In addition to a complete ophthalmological examination, quantitative and qualitative endothelial cell analysis of the central and peripheral cornea was performed preoperatively, at the first postoperative day and after 4 weeks using non-contact specular microscopy (Konan Noncon Robo-ca SP 8000, Konan, Japan).Results: In eyes with PEX (2394±271 cells/mm2) endothelial cell counts were 10.5% (P<0.05) lower than in the control group (2674+341 cells/mm2). Intraoperatively, ultrasound time (90±51 s) and power (38±17%) did not differ between the two groups. After 4 weeks the mean endothelial cell loss in the two groups was 10.4% and 9.8%, respectively (P<0.001). The mean cell area increased by 55 and 48 µm2 (P<0.001), respectively. Polymegethism increased postoperatively in both groups and stabilized at 4 weeks at preoperative values. Pleomorphism increased significantly only in the PEX group.Conclusions: In eyes with PEX no increased cell loss was found in the early postoperative period compared to normal eyes following corneoscleral tunnel incision and phacoemulsification. Due to preoperative reduced endothelial cell densities, endothelium-protecting measures are recommended in eyes with PEX.Einleitung: Bei Pseudoexfoliationssyn-drom (PEX) kann es zu morphometrischen und qualitativen Veränderungen des Hornhautendothels kommen. In dieser Untersuchung sollte überprüft werden, ob nach Kataraktoperation das Endothelzellverhalten gegenüber normal-gesunden Augen verändert ist.Patienten und Methoden: In einer kontrollierten klinischen Studie wurden prospektiv 20 Patienten mit PEX und ein gleich großes alterskorreliertes Vergleichskollektiv mit standardisiertem, selbstschließendem, 7 mm breitem korneoskleralem Tunnelschnitt, Phakoemulsifikation und HKL-Implantation unter Hyaluronsäureschutz operiert. Neben einem vollständigem ophthalmologischen Status wurden präoperativ, am 1. postoperativen Tag sowie nach 4 Wochen quantitative und qualitative Endotheluntersuchungen der zentralen und peripheren Hornhaut mit der Non-Kontaktspekularmikroskopie (Konan Noncon Robo-ca SP 8000, Konan, Japan) durchgeführt.Ergebnisse: Präoperativ zeigte sich bei PEX (2394±271 Zellen/mm2) eine um 10,5% (p<0,05) erniedrigte Endothelzelldichte im Gegensatz zur Kontrollgruppe (2674±341 Zellen/mm2). Intraoperativ unterschieden sich Phakoemulsifikationszeit (90±51 s) und -leistung (38±17%) nicht. Die mittlere Endothelzelldichte nahm sowohl in der PEX-Gruppe als auch beim Vergleichskollektiv nach 4 Wochen um 10,4 bzw. 9,8% (p<0,001) ab. Die mittlere Zellfläche nahm gleichzeitig um 55 bzw. 48 µm2 (p<0,001) zu. Der Polymegathismus nahm postoperativ zu, um im späteren Verlauf nach 4 Wochen annähernd präoperative Werte zu erreichen. Der Pleomorphismus nahm nur in der PEX-Gruppe signifikant zu.Schlußfolgerung: Bei PEX scheint es trotz präoperativ reduzierter Zelldichte im Vergleich zu normal-gesunden Augen frühpostoperativ zu keinem erhöhten Endothelzellverlust nach korneoskleralem Tunnelschnitt und Phakoemulsifikation zu kommen. Aufgrund der präoperativ reduzierten Endothelzelldichte werden bei bekanntem PEX endothelschützende Maßnahmen empfohlen.

Prospective controlled evaluation on radiotherapy of subfoveolar neovascularization

SummaryDespite the successful therapy of subretinal neovascular membranes by laserphotocoagulation there are many problems to be overcome. In the case of subfoveolar neovascularization, photocoagulation leads to a sudden decrease in visual acuity.Recently radiotherapy is considered as an alternative. Complications and effectivity were evaluated in this prospective and randomized trial. The initial results are presented. Patients and methods: There are 76 patients (51 women, 25 men, average age 77.7 ± 8.6 years) included in the prospective randomized study. All of them show subfoveolar neovascular membranes in FLA and a decrease in visual acuity between 0.05 and 0.5. They were randomly assigned to either the radiotherapy or the control group. Radiotherapy was done within 6 days by 6 × 2 Gy (6 MV photons). The follow-up was at 4 weeks, after 3 months, after 6 months and then every 6 months after the end of radiotherapy. On average the follow-up is at 15.1 months. Results: Concerning age and visual acuity before therapy, the control group and the radiotherapy group were not significantly different. At 4 weeks after radiotherapy, visual acuity was 0.13 ± 0.46 (LogMAR). After 12 months, visual acuity at a distance was 0.11 ± 0.30 in the therapy group and 0.09 ± 0.13 (P = 0.838) in the control group. Patients with a preoperative visual acuity better than 0.2 improved more after radiotherapy. Metamorphopsy improved in 75 % of the therapy group. The following complications could be observed: In the control group 3 patients suffered subretinal bleeding, in the radiotherapy group 3 patients, respectively. Conclusions: At present, the follow-up is too short to recommend radiotherapy as a standard procedure in the case of subfoveolar neovascularization. The results in patients with a better preoperative visual acuity encourage us to continue this study.ZusammenfassungHintergrund: Die Therapie der durch subretinale neovaskuläre Membranen bedingten altersabhängigen Makuladegeneration stellt trotz der Möglichkeiten der Laserkoagulation noch immer ein großes Problem dar. Besonders bei subfoveolär gelegenen Neovaskularisationen kann eine Lasertherapie nur unter Inkaufnahme eines erheblichen sofortigen Visusverlustes durchgeführt werden. Als Alternative wird nun seit einiger Zeit wieder die Strahlentherapie genannt. Die Wirksamkeit und die Komplikationen sollten in der vorliegenden randomisierten Studie untersucht werden. Patienten und Methoden: In die prospektive und randomisierte Studie sind bislang 76 Patienten (51 Frauen, 25 Männer, Durchschnittsalter 77,7 ± 8,6 J.) mit fluoreszenzangiographisch nachweisbaren subretinalen choroidalen Neovaskularisationen und einem Visus zwischen 0,05 und 0,5 aufgenommen worden. Sie wurden randomisiert zu gleichen Teilen einer Strahlentherapiegruppe und einer Kontrollgruppe zugeteilt. Die Bestrahlungen erfolgten innerhalb von 6 Tagen mit 6 × 2 Gy (6 MV Photonen eines Linearbeschleunigers) unter weitestgehender Schonung der Linse. Die Nachuntersuchungen wurden 4 Wochen nach Abschluß der Strahlenbehandlung, nach 3 Monaten, nach 6 Monaten und dann im halbjährigen Abstand vorgenommen. Die durchschnittliche Nachkontrollzeit betrug 15,1 Monate. Ergebnisse: Kontrollgruppe und Strahlentherapiegruppe waren bezüglich des Ausgangsvisus in Ferne und Nähe und des Lebensalters nicht signifikant unterschiedlich. 4 Wochen nach Bestrahlung lag in der Strahlentherapiegruppe ein Visus von 0,13 ± 0,46 (LogMAR) vor. Nach 12 Monaten betrug in der Verumgruppe der Fernvisus 0,11 ± 0,30 und in der Kontrollgruppe 0,09 ± 0,13 (p = 0,838). Bei einem höheren Ausgangsvisus als 0,2 konnten im Trend bessere Resultate nach Bestrahlung erzielt werden. Hervorzuheben ist die Besserung von Metamorphopsien in der Behandlungsgruppe bei 75 % der Patienten. An Komplikationen fanden sich in der Verumgruppe und in der Kontrollgruppe 3 Patienten mit subretinalen Blutungen. Schlußfolgerung: Bei einer derzeitigen Nachkontrollzeit von 15 Monaten lassen sich noch keine eindeutigen Vorteile der Strahlentherapie- gegenüber der Kontrollgruppe erkennen, wenngleich Metamorphopsien nach Bestrahlung signifikant seltener auftraten. Ein höherer Ausgangsvisus als 0,2 läßt tendenziell bessere Resultate nach Bestrahlung erwarten, was jedoch mit höheren Fallzahlen noch untermauert werden müßte.