Hans Liesenhoff

Evaluation of contrast acuity and defocus curve in bifocal and monofocal intraocular lenses

ABSTRACT We compared visual quality of the following intraocular lenses in a prospective study: monofocal, True Vista bifocal, 3M diffractive bifocal, and Nordan aspheric VariFocal silicone. Four to six months postoperatively we measured distance acuity, Snellen near acuity (Lighthouse chart), reading acuity (Nieden chart), and contrast acuity at far and near focus (Regan charts: 96%, 50%, 25%,11 % contrast) with different pupil sizes. A defocus curve was obtained by spectacle defocus (+1 diopter [D] to −5 D). Eleven patients had True Vista in one eye and monofocal in the fellow. Contrast acuity at far focus decreased with decreasing contrast and increasing pupil size. This decrease was more pronounced with the True Vista than with the monofocal lenses. These differences were significant, with a 4.5 mm pupil at lower contrast (25%, P = .02; 11 %, P = .01). Depth of focus was 4.5 D (+1.0 D to −2.0 D) with True Vista lenses and 2.5 D (+1.0 D to −1.5 D) with monofocal lenses. Corrected distance acuity was 20/22 with True Vista, 20/25 with 3M, and 20/20 with VarIFocal. Distance corrected Snellen near acuity was 20/39 with True Vista, 20/34 with 3M, and 20/57 with VariFocal. Distance corrected reading acuity was 20/29 with True Vista, 20/23 with 3M, and 20/44 with VariFocal (P = .005). Contrast acuity at far focus was best with the VariFocal IOL, followed by True Vista and 3M. At near focus it was best with 3M, followed by True Vista and VariFocal. Contrast acuity at near focus was lower than at far focus. Average acuity differences were as follows: VariFocal 0.43, P = .01; True Vista 0.19, P = .05; 3M 0.04, P = .3. Depth of focus was 4.5 D (+1.0 D to −3.5 D) with True Vista and 3M and was 3 D (+1.0 D to −2.0 D) with VariFocal. Each design offers unique features. VariFocal is best at distance, but near vision is not sufficient. The 3M lens is best at near vision but distance contrast acuity is somewhat reduced. The True Vista lens provides a good compromise as distance contrast acuity is good and near vision is sufficient.

Comparison of the optical and visual quality of poly(methyl methacrylate) and silicone intraocular lenses

ABSTRACT We evaluated experimentally the optical quality of poly(methyl methacrylate) (PMMA) (Storz 681JV, AMO PC58) and silicone (AMO S119, Adatomed 90D) intraocular lenses (IOLs) and compared the results with our clinical data. We measured surface and image quality using the Zygo laser interferometer and modulation transfer function (MTF) using the Ealing EROS MTF analyzer. Contrast acuity was tested clinically with glare and without glare (Regan charts); AMO PC58, n = 18; AMO SI19, n = 7; Adatomed 90D, n = 18). Modulation transfer function and image quality were slightly better with PMMA IOLs but the reduction of MTF with silicone lenses was within the 1/a diopter defocus range. Surface quality of silicone IOLs was superior to that of PMMA IOLs. Contrast acuity measured clinically was also slightly better with PMMA IOLs at low contrast and with glare but differences were not significant. Our results suggest that optical and visual quality of silicone IOLs is slightly lower than with PMMA IOLs. Experimental and clinical results correlated closely. However, the small differences observed are unlikely to be significant clinically.

Diode laser photocoagulation for stage 3+ retinopathy of prematurity.

Abstract• Background: Laser photocoagulation in retinopathy of prematurity (ROP) appears to have fewer adverse effects than cryotherapy and seems to be at least as effective. • Methods: To evaluate the efficacy and safety of diode laser photocoagulation, we included 42 eyes with stage 3+ ROP of 24 preterm infants (gestational age 24–29 weeks, mean ± SD 26.6 ± 1.3 weeks; birth weight 480–1400 g, 896 ± 196 g) in a prospective clinical study. Photocoagulation treatment was performed using a diode laser (810 nm) with a laser indirect ophthalmoscope delivery system. Follow-up ranged from 3 to 16 months (8.8 ± 4.0 months). • Results: In 39 (93%) of 42 eyes ROP regressed after a single laser treatment and the outcome was a flat, attached retina. One eye (2%) had a second laser session and another eye (2%) had additional retinal detachment surgery, resulting in the regression of ROP and a flat, attached retina. Thus, the success rate was 41 (98%) out of 42 eyes. In one (2%) of the 42 eyes treatment failed and ROP progressed to stage 5, although additional retinal detachment surgery was performed. No adverse side effects of diode laser treatment were noticed except for a small amount of retinal/preretinal bleeding in the ridge in five eyes (12%) and a small postoperative anterior chamber hemorrhage in one eye (2%) with dense tunica vasculosa lentis. Neither lenticular opacities nor cataract formation were encountered. • Conclusion: Diode laser photocoagulation for stage 3+ ROP showed only minor side effects and was at least as effective as cryotherapy treatment.

Laser in situ keratomileusis (LASIK) in myopia: 2-year results

SummaryBackground: Long-term results on LASIK are not available to date. We therefore evaluated the predictability, stability and complication rate after LASIK in moderate – to-high myopia. Patients and methods: We treated 70 eyes (41 patients) using the Automatic Corneal Shaper and the Keracor 116 excimer laser. Patients were followed for 1, 6, 12 and 24 months. Spectacle refraction, visual acuity, rate of retreatment, and patient satisfaction were evaluated. Results: At 24 months the results were as follows: Myopia −5 to −9.9 D (n =18): 94 % within 1 D; regression between 1 and 12 (12 and 24) months > 1 D in 6 % (6 %); uncorrected acuity 20/40 or better in 83 %; no loss of 2 ore more lines of visual acuity; 89 % highly satisfied. Myopia −10 to −14.9 D (n = 12): 88 % within 1 D; regression between 1 and 12 (12 and 24) months > 1 D in 20 % (0 %) ; uncorrected acuity 20/40 or better in 72 %; 4 % lost 2 or more lines of visual acuity; 96 % highly satisfied. Myopia −15 to −29 D (n = 22): 33 % within 1 D; regression between 1 and 12 (12 and 24) months > 1 D in 41 % (18 %); uncorrected acuity 20/40 or better in 7 %; no loss of 2 or more lines of visual acuity; 67 % highly satisfied. Conclusion: LASIK is an accurate, effective and stable procedure for correcting myopia of −5 to −10 D. Results are less precise in myopia up to −15 D, and some visual loss occurs in a number of patients. In myopia > −15 D, results are not satisfactory because of poor accuracy and low stability.ZusammenfassungFragestellung: Bisher liegen keine Erfahrungen über die Langzeitergebnisse nach LASIK vor. Wir untersuchten daher die Präzision, die Stabilität und die Komplikationsrate nach LASIK zur Korrektur der mittleren und hohen Myopie. Patienten und Methode: Eingeschlossen wurden 70 Augen (41 Patienten), die mit dem Automatic Corneal Shaper und dem Keracor 116 Excimer Laser operiert wurden und 1, 6, 12 und 24 Monate postoperativ nachuntersucht wurden. Wir untersuchten Refraktion, Visus, Reoperationsrate und Patientenzufriedenheit. Ergebnisse: Nach 24 Monaten fanden sich folgende Ergebnisse: Myopie −5 bis −9,9 dpt (n = 18): 94 % ± 1 dpt; Regression zwischen 1 und 12 (12 und 24) Monaten > 1 dpt in 6 % (6 %); unkorrigierter Visus 0,5 oder besser in 83 %; kein Visusabfall um 2 oder mehr Stufen; 89 % sehr zufrieden. Myopie −10 bis −14,9 dpt (n = 25): 88 % ± 1 dpt; Regression zwischen 1 und 12 (12 und 24) Monaten > 1 dpt in 20 % (0 %); unkorrigierter Visus 0,5 oder besser in 72 %; Visusabfall um 2 Stufen in 4 %; 96 % sehr zufrieden. Myopie −15 bis −29 dpt (n = 27): 33 % ± 1 dpt; Regression zwischen 1 und 12 (12 und 24) Monaten > 1 dpt in 41 % (18 %); unkorrigierter Visus 0,5 oder besser in 7 %; kein Visusabfall um 2 oder mehr Stufen, 67 % sehr zufrieden. Schlußfolgerung: Die LASIK stellt ein wirksames und stabiles Verfahren zur Korrektur der Myopie von −5 bis −10 dpt dar. Korrekturen bis −15 dpt zeigen eine geringere Genauigkeit und Langzeitstabilität sowie in einigen Fällen eine Verschlechterung der Sehschärfe. Korrekturen über −15 dpt sind aufgrund der geringen Genauigkeit und magelnden Stabilität als unbefriedigend anzusehen.

Diode Laser Photocoagulation for Threshold Retinopathy of Prematurity in Eyes With Tunica Vasculosa Lentis

PURPOSE To determine possible side effects of diode laser photocoagulation for threshold retinopathy of prematurity in eyes with tunica vasculosa lentis. METHODS In a prospective clinical study, threshold retinopathy of prematurity was treated in 14 eyes of seven consecutive preterm infants with tunica vasculosa lentis (birth weight, 480 to 980 g; mean +/- S.D., 777 +/- 175 g; gestational age, 24 to 27 weeks; mean +/- S.D., 25.7 +/- 0.9 weeks) by using the diode laser indirect ophthalmoscope. Main outcome measure was the incidence of adverse treatment effects. Follow-up included anterior segment examination with a hand-held slit lamp and ranged from seven to 17 months (12.6 +/- 3.5 months). RESULTS The tunica vasculosa lentis did not interfere with photocoagulation in any of the 14 eyes. Laser power ranged from 200 to 400 mW (260 +/- 52 mW). Duration of a single spot was 200 msec. Number of burns ranged from 1,060 to 2,132 (1,556 +/- 315). Retinopathy of prematurity regressed in all eyes, and the outcome was a flat, attached retina. A small amount of postoperative anterior chamber bleeding was noticed in one eye (7% of the eyes, 14% of the patients). There were neither lenticular opacities nor cataract formation. CONCLUSION Diode laser photocoagulation with the laser indirect ophthalmoscope can be used safely in eyes with tunica vasculosa lentis. At the laser energy levels used in our study, no transient lens opacities or cataract formation occurred. However, the results of this study are limited by a relatively small number of patients and a relatively short follow-up.

Contrast sensitivity with monofocal and bifocal intraocular lenses.

Bifocal intraocular lenses (BIOLs) reduce image contrast. We measured contrast sensitivity (CS) to evaluate the clinical significance of the loss in image contrast. Four groups were compared: 15 patients with a monofocal IOL, 13 with the True Vista BIOL, 13 with the AcuraSee BIOL, 11 with the diffractive BIOL. CS was measured using the Mentor B-VAT II-SG. Distance CS was slightly better in monofocal eyes than in all bifocal eyes, and distance CS was considerably better than near CS in eyes with the True Vista or the AcuraSee BIOL. With the diffractive BIOL, values were about the same at distance and near focus. Our results demonstrate that BIOLs reduce CS. thereby performing differently: both True Vista and AcuraSee favor distance vision, while the diffractive BIOL provides about the same contrast at distance and near focus.

Ergebnisse nach Implantation einer Worst Iris Claw Lens zur Korrektur der hohen Myopie

ZusammenfassungFragestellung. Ziel dieser prospektiven klinischen Studie war die Erfassung der Refraktion, des korrigierten Visus und des Vorderkammerreizzustandes nach Implantation einer Worst Iris Claw Lens zur Korrektur der hohen Myopie. Patienten und Methode. Von Dezember 1996 bis Februar 1999 wurde bei insgesamt 44 phaken Augen von 28 Patienten eine Worst Iris Claw Lens implantiert. Es folgte eine Nachbeobachtungszeit von 6 Wochen bzw. 6 Monaten. Ergebnisse. Das mittlere präoperative sphärische Äquivalent betrug −17,35±3,57 dpt. Sechs Monate postoperativ lag die Refraktion bei 79% der Augen im Intervall von ±1,0 dpt von der Zielrefraktion entfernt. Der mittlere korrigierte Visus stieg von präoperativ 0,43 auf postoperativ 0,65 an. Die postoperative Lasertyndallometrie ergab nach 6 Monaten bei 21% der Augen keinen nachweisbaren Vorderkammerreiz. Bei 76% aller Augen konnte ein milder Vorderkammerreizzustand festgestellt werden. Der mediane Flarewert lag bei 20 p/ms. Schlussfolgerung. Die Implantation einer Worst Iris Claw Lens stellt eine präzise Methode zur Korrektur der hohen Myopie dar. Die postoperativen Ergebnisse zeigten bei fast allen Augen einen guten Visus und nur einen geringen Vorderkammerreizzustand. Langzeitbeobachtungen stehen bisher jedoch noch aus.AbstractBackground. The purpose of this clinical study was to evaluate refraction, best visual acuity and anterior chamber flare after implantation of a Worst Iris Claw Lens to correct high myopia. Patients and methods. From September 1996 to February 1999 the implantation of a Worst Iris Claw lens was performed on 44 highly myopic phakic eyes of 28 patients. Data after 6 weeks and 6 months follow-up were assessed. Results. The mean preoperative spherical equivalent was −17.35±3.57 dpt and 6 months after implantation 79% of the eyes were within ±1.0 dpt of target refraction. The mean best corrected visual acuity increased from 0.43 preoperatively to 0.65 postoperatively and 6 months after the treatment there was no flare (<10 photons/ms) in 21% and a mild anterior chamber flare (10–80 photons/ms) in 76% of the treated eyes. The median laser flare was 20 p/ms. Conclusions. In conclusion, implantation of a Worst Iris Claw lens has proved to be a precise method to correct high myopia. No or mild anterior chamber flare and a good visual acuity were measured in most eyes 6 weeks and 6 months after surgery. Longer follow-up periods are needed to assess the long-term safety and efficiency.

Expression of Fibroblast Growth Factors 1 and 2 in a Human Retinal Pigment Epithelium Cell Line (K1034)

The primary source of fibroblast growth factors (FGFs) is the retinal pigment epithelium (RPE). Investigations on FGF secretion in RPE primary cultures are hampered by the rapid run-down of cell vitality after a few passages. Therefore, long-term experiments require an alternative to primary cultures. We detected FGF-1 and FGF-2 in the established human K1034 cell line by immunohistochemistry. In addition, mRNA for both FGFs was found by RT-PCR. By immunohistochemistry, the signal was more pronounced with FGF-2 than with FGF-1. K1034 is capable of expressing both FGF-1 and FGF-2. With respect to these features, this cell line can be used as an alternative to primary cultured human RPE cells.

Laser in situ keratomileusis (LASIK) in high myopia

Background: Laser in situ keratomileusis (LASIK) preserves the corneal epithelium and Bowmans layer, which theoretically minimizes corneal scarring. We, therefore, evaluated the accuracy, stability and safety of LASIK in moderate to high myopia. Patients and methods: Eighty-five eyes (50 patients) treated using the Automatic Corneal Shaper and the Keracor 116 excimer laser were followed up for 1, 6, and 12 months. Spectacle refraction, visual acuity and rate of retreatments were evaluated. Results: At 12 months, results were as follows: Myopia −5 to −9.9 D (n = 20); 85 % within 1 D; regression between one and 12 months K 1 D in 90 %; uncorrected acuity 20/40 or better in 75 %; no loss of two or more lines of visual acuity. Myopia −10 to −14.9 D (n = 33): 73 % within 1 D; regression between 1 and 12 months K 1 D in 91 %; uncorrected acuity 20/40 or better in 79 %; 6.1 % lost two lines of visual acuity. Myopia −15 to −29 D (n = 32): 31 % within 1 D; regression between one and 12 months K 1 D in 63 %; 6.3 % lost two or more lines of visual acuity. Reoperations were performed in two eyes (2.4 %) due to epithelial ingrowth or folds of the flap, and in four eyes (4.7 %) because of undercorrections or “central islands”. Conclusions: LASIK is an accurate and stable procedure for correcting myopia of −5 to −15 D. In higher myopia, however, results are not satisfactory.Fragestellung: Die Laser-in-situ-Keratomileusis (LASIK) erhält das Hornhautepithel und die Bowman-Grenzschicht, was theoretisch die Narbenbildung verringert. Wir untersuchten daher die Wirksamkeit, Stabilität und Sicherheit der LASIK zur Korrektur der mittleren und hohen Myopie. Patienten und Methode: 85 Augen (50 Patienten), die mit dem Automatic Corneal Shaper und dem Keracor 116 Excimer Laser operiert wurden und 1, 6 und 12 Monate postoperativ nachuntersucht wurden. Bestimmt wurden Refraktion, Visus und Reoperationsrate Ergebnisse: Nach 12 Monaten fanden sich folgende Ergebnisse: Myopie −5 bis −9,9 dpt (n = 20): 85 % ± 1 dpt; Regression zwischen 1 und 12 Monaten K 1 dpt in 90 %; unkorrigierter Visus 0,5 oder besser in 75 %; kein Visusabfall um 2 oder mehr Stufen. Myopie −10 bis −14,9 dpt (n = 33): 73 % ± 1 dpt; Regression zwischen 1 und 12 Monaten K 1 dpt in 91 %; unkorrigierter Visus 0,5 oder besser in 79 %; Visusabfall um 2 Stufen in 6,1 %. Myopie −15 bis −29 dpt (n = 32): 31 % ± 1 dpt; Regression zwischen 1 und 12 Monaten K 1 dpt in 63 %; Visusabfall um 2 oder mehr Stufen in 6,3 %. Reoperationen aufgrund von Epitheleinwachsung bzw. Falten der Hornhautlamelle wurden bei 2 Augen (2,4 %) und aufgrund von Unterkorrekturen bzw. “central islands” bei 4 Augen (4,7 %) durchgeführt. Schlußfolgerung: Die LASIK stellt ein wirksames und stabiles Verfahren zur Korrektur der Myopie von −5 bis −15 dpt dar. Korrekturen über −15 dpt zeigen andererseits unbefriedigende Ergebnisse.

Software for retinopathy of prematurity screening

SummaryBackground: The goal of retinopathy of prematurity (ROP) screening is complete detection of all preterm infants with threshold ROP. Aim: We wanted to develop software to facilitate registration of ROP findings, checking due dates of re-examination, and evaluation of screening data. By means of complete and faultless registration and evaluation of the data of preterm infants, the effectiveness and safety of the screening should increase. Methods: We developed software that runs under Microsoft Windows 3.1 or Windows 95 and is programmed in Microsoft Access Basic and Microsoft Visual Basic. The software allows all screening data to be registered and evaluated. Intuitive handling, third level of normalization in database architecture, and automatic plausibility checks guarantee the utmost integrity of data and efficacy of database. Results and conclusion: To date, the software has been used routinely in 2000 examinations in 1000 preterm infants. Our software facilitates clinical management and evaluation of ROP screening, which therefore becomes more safe.ZusammenfassungHintergrund: Das Screening auf Retinopathia praematurorum (RPM) hat das Ziel, ausnahmslos alle Frühgeborenen mit einem therapiebedürftigen Stadium der Erkrankung zu erfassen. Ziel der vorliegenden Arbeit ist, eine Software zu entwickeln, die die Eingabe von Untersuchungsergebnissen, Terminierung von Kontrolluntersuchungen sowie klinische und wissenschaftliche Auswertung der beim RPM-Screening gewonnenen Daten erleichtert und die Sicherheit des Screenings durch lückenlose und fehlerfreie Erfassung der Frühgeborenen erhöht. Material und Methode: Mittels der Programmiersprachen Microsoft Access Basic und Microsoft Visual Basic wurde eine Datenbank-Software für Personalcomputer unter Microsoft Windows 3.1 oder höher zur Erfassung und Auswertung aller beim Screening gewonnenen Daten entwickelt. Einfache Bedienung, dritte Normalform der Datenbankkonstruktion und automatisierte Plausibilitätskontrollen gewährleisten größtmögliche Datenintegrität und Datenbankeffizienz. Ergebnisse und Schlußfolgerung: Die vorliegende Software hat sich bisher bei 2000 Untersuchungen bei 1000 Frühgeborenen zur vollen Zufriedenheit bewährt. Klinische und wissenschaftliche Auswertung der Daten werden erleichtert und die Sicherheit des Screenings erhöht.