Tony Walkow

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.

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.

Comparison of visual acuities at different distances and defocus curves

Purpose: To evaluate how visual acuities at different distances correlate with results from defocus curves. Setting: Department of Ophthalmology and Institute of Medical Physics, University of Vienna, Medical School, Vienna, and Department of Ophthalmology, Krankenhaus St. Pölten, St. Pölten, Austria. Methods: This study comprised 15 eyes of 14 patients with a mean age of 67.9 years ± 9.7 (SD) with a monofocal silicone intraocular lens (911A, Pharmacia). The best corrected distance visual acuity was determined at viewing distances of 6 m, 2 m, 1 m, 67 cm, 50 cm, 40 cm, and 33 cm using logMAR charts. Defocus curves were then evaluated from −3.0 to −0.5 diopter (D) at 0.5 D increments from the best distance correction at a viewing distance of 6 m. Results: The mean distance visual acuity was logMAR 0.08 ± 0.07. The visual acuity graph from the testing at different distances was above the defocus graph at all testing points. Comparison of the visual acuity results from the 2 tests revealed statistically significant differences in the range from 2 m (–0.5 D) to 33 cm (–3.0 D). Conclusion: Results of defocus curves disregard the diminutions of minus glasses, the normally restricted viewing distance to 6 m for distance acuity determination, and in particular the physiological miosis caused by the near‐point reaction.

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.

Immunohistological findings in a patient with unusual late onset manifestation of ligneous conjunctivitis

Editor,—Ligneous conjunctivitis is a rare chronic membranous conjunctivitis with typical woody induration of the conjunctival tissue.1 2 It occurs most often bilaterally in female children and is of unknown aetiology.1-3 The disease process may involve other mucous membranes, such as the cervix and the trachea, occasionally leading to death by tracheal obstruction.4 Few patients with adult onset ligneous conjunctivitis have been seen.3 5 They generally experience a milder course and systemic involvement is less common. Autoimmune dysfunction, infection with an unidentified virus, and an inherited predisposition possibly combined with trauma have all been proposed as possible causes for the disease.3 5 6 Recent studies have found an inherited defect in the plasminogen system of affected children.7 Treatment of …

A prospective study investigating the long-term stability of changes in astigmatism following arcuate lamellar keratotomy (ALK): 3-year results

SummaryIntroduction: The correction of low to moderate astigmatism is possible today by means of photoablation (PRK), while the treatment of moderate and higher astigmatism still involves refractive keratotomy. Experience has shown that cataract surgery, using modern tunnel techniques with self-healing incisions, results in earlier stability in both the refractive outcome and wound healing. In this study, we attempted to combine the advantages of lamellar keratotomy with those of a pair-wise T-incision as arcuate lamellar keratotomy (ALK). Patients and methods: The clinical outcome of 41 patients who underwent ALK was investigate in a prospective study over a period of 3 years. The pre- and postoperative investigations undertaken included the measurement of astigmatism using a Zeiss keratometer, uncorrected visual acuity, and corrected glare vision using a Humphrey autorefractor. All patients had astigmatism between 2.0 and 7.0 D. Together with a uniform arcuate incision, we used 7 mm (n = 26) and 8 mm (n = 15) mm zones for correction. Results: The average preoperative astigmatism was 4.01 ± 1.90 (median, 3.50) D. After a 3-year follow-up the average postoperative astigmatism was 1.59 ± 1.29 (median, 1.38) D. The astigmatic change induced (Jaffé) after 3 years was about 3.23 ± 2.23 (median, 3.16) D. The average uncorrected visual acuity (log MAR) before ALK was 0.20 ± 0.12 (median, 0.22) and after follow-up, 0.41 ± 0.14 (median, 0.39). Corrected glare vision before surgery was 0.23 ± 0.19 (median, 0.10) and afterwards, 0.25 ± 0.22 (median, 0.14). Conclusions: Arcuate lamellar keratomy (ALK) stood the test as a routine clinical procedure for correction of moderate astigmatism with stable postoperative functional outcomes. We did not find impairment of glare vision following this procedure.ZusammenfassungHintergrund: Während geringe bis mäßige Astigmatismuskorrekturen heute bereits photoablativ mit gutem Erfolg durchgeführt werden können, erfordert die Korrektur mittlerer und höherer Astigmatismen nach wie vor den Einsatz refraktiver Keratotomien. Bei Verwendung heute üblicher Tunneltechniken mit selbstschließenden Inzisionen kann durch die lamellierende Präparation sowohl eine frühere postoperative Stabilisierung der Refraktion, als auch eine hohe mechanische Stabilität erreicht werden. Wir versuchten, die Vorteile dieser lamellierenden Technik mit der refraktiven Wirkung einer paarigen T-Inzision in der bogenförmigen lamellierenden Keratotomie (BLK) zu kombinieren. Patienten und Methode: Wir untersuchten prospektiv die klinischen Langzeitergebnisse (prä- und postoperativ: mit Zeiss-Ophthalmometer gemessener Astigmatismus, sc-Visus sowie cc-Blendungsvisus ‚Humphrey’-Autorefraktor) nach BLK von 41 Patienten bei durchschnittlich 3-jähriger Nachbeobachtungszeit. Alle Patienten wiesen vor BLK einen Astigmatismus von mind. 2,0 bis max. 7,0 dpt auf. Wir verwendeten bei der Korrektur 7- (n = 26) und 8- (n = 15) mm-Zonen, sowie eine einheitliche Bogenlänge von 3 mm. Alle Inzisionen wurden paarweise durchgeführt. Ergebnisse: Der durchschnittliche, präoperative mit dem Zeiss-Ophthalmometer gemessene Astigmatismus betrug 4,01 ± 1,90 (Median 3,50) dpt. Nach einer Nachbeobachtungszeit von durchschnittlich 3 Jahren betrug der postoperative Astigmatismus im Mittel 1,59 ± 1,29 (Median 1,38) dpt. Die induzierte vektoranalytische Astigmatismusänderung betrug nach 3 Jahren 3,23 ± 2,23 (Median 3,16) dpt. Der ohne Korrektur erzielte Visus (log MAR) betrug präoperativ 0,20 ± 0,12 (Median 0,22) und nach durchschnittlich 3 Jahren 0,41 ± 0,14 (Median 0,39) dpt. Der Blendvisus betrug präoperativ mit Korrektur 0,23 ± 0,19 (Median 0,10) dpt und postoperativ 0,25 ± 0,22 (Median 0,14) dpt. Schlußfolgerungen: Die bogenförmige lamellierende Keratotomie (BLK) hat sich bei mäßiggradigen Astigmatismen auch in den Langzeitergebnissen als refraktives Verfahren mit stabilen postoperativen Refraktionsergebnissen bewährt. Eine Reduktion des Blendvisus konnte nicht festgestellt werden.