Ursula Scholz

Astigmatism correction with a foldable toric intraocular lens in cataract patients.

PURPOSE To determine the efficacy and rotational stability of a toric posterior chamber silicone intraocular lens (IOL) to correct preoperative astigmatism in cataract patients. SETTING Department of Ophthalmology, University Hospital of Vienna, Vienna Austria. METHODS Between 1993 and 1998, foldable toric single-piece plate-haptic silicone IOLs were implanted in 37 eyes (30 patients). The cylindrical IOL power was 2.00 diopters (D) (n = 29), 3.50 D (n = 7), or 4.00 D (n = 1). Phacoemulsification was performed through a scleral or a corneal sutureless self-sealing incision. Outcomes of Snellen visual acuity (without, with spherical, and with best correction), refractive and keratometric astigmatism, and IOL rotation after early postoperative (mean 15.9 days +/- 10.1 [SD]) and long-term (mean 20.3 +/- 16.6 months) follow-ups were evaluated. RESULTS At last follow-up, 31 eyes (83.8%) had a spherically corrected and 34 (91.9%) a best corrected visual acuity of 0.5 (20/40) or better. Mean preoperative refractive and keratometric astigmatism was 2.68 and 2.70 D, respectively. At the last postoperative follow-up, mean refractive astigmatism was reduced to 0.84 D; keratometric astigmatism was 2.30 D. In 7 eyes (18.9%), the IOL axis was rotated a maximum of 25 degrees. In all 37 eyes, the axis of the toric IOL remained within 30 degrees of rotation. CONCLUSIONS Early postoperative and long-term follow-ups showed effective and stable correction of astigmatism after implantation of a foldable toric posterior chamber silicone IOL.

Topical versus peribulbar anesthesia in clear corneal cataract surgery

Purpose: To evaluate the efficacy of topical anesthesia as an alternative to peribulbar anesthesia in clear corneal cataract surgery. Setting: Department of Ophthalmology, University of Vienna, Austria. Methods: In this prospective, double‐blind clinical trial, 36 patients had bilateral cataract surgeries performed from 1 to 3 months apart. Half of the patients had topical anesthesia for the first surgery and peribulbar anesthesia for the second surgery. The other half had peribulbar first and then topical. All surgery was done using a temporal clear corneal approach and bimanual phacoemulsification followed by in‐the‐bag intraocular lens implantation. Subjective pain was assessed using a visual analog scale of no pain (0%) to worst pain imaginable (100%) and intraoperative motility using a rank scale of adverse motility (−5) to ideal patient cooperation (+5). Results: Subjective pain was comparable whether topical or peribulbar anesthesia was used (mean 10.75 versus 10.97%; P > .6). Patient cooperation (motility) was significantly better when topical anesthesia was used (+2.16 versus +1.11; P = .03). There were no significant differences in complications. A peribulbar block was given in addition to the topical anesthesia in two cases. Conclusions: Topical anesthesia is a safe, effective alternative to peribulbar anesthesia in clear corneal cataract surgery.

Long-term endothelial changes in phakic eyes with posterior chamber intraocular lenses

Purpose: To evaluate the long‐term endothelial cell changes in phakic eyes after implantation of a posterior chamber phakic intraocular lens to correct high ametropia. Setting: Department of Ophthalmology, University Hospital of Vienna, Vienna, Austria. Methods: Thirty‐four eyes of 21 patients having implantation of an implantable contact lens (ICL, Staar Surgical) for high myopia or hyperopia were prospectively examined. The minimum follow‐up was 2 to 4 years. Preoperative and serial postoperative specular microscopy (Noncon Robo SP 8000, Konan) was performed to evaluate the long‐term endothelial cell changes. Results: The mean preoperative endothelial cell density was 2854 cells/mm2. The mean endothelial cell loss from preoperatively was 1.8% at 3 months, 4.2% at 6 months, 5.5% at 12 months, 7.9% at 2 years (n = 34), 12.9% at 3 years (n = 13), and 12.3% at 4 years (n = 11). All other endothelial cell characteristics remained stable during the 4‐year follow‐up. Conclusions: Continuous endothelial cell loss was observed after ICL implantation during a 4‐year follow‐up. There was rapid cell loss until 1 year postoperatively, after which the rate of loss was no longer statistically significant. The percentage of hexagonal cells (polymorphism) and the coefficient of variation (polymegethism) remained stable during the 4‐year follow‐up.

Long-term course of induced astigmatism after clear corneal incision cataract surgery

Purpose: To determine whether a small clear corneal temporal incision produces less surgically induced astigmatism than a larger incision. Methods: One hundred three consecutive cases of postoperative astigmatism after clear corneal incision cataract surgery were studied for a minimum of 1 year. Only self‐sealing incisions from the temporal side were made as follows: 3.2 mm (Group A); 4.0 mm (Group B); 5.2 mm (Group C). We considered the amount and axes of the keratometric readings at different times as well as their course over time. Induced astigmatism was calculated using three methods. Axial changes were also analyzed. Results: Immediately after the surgery, there was a small, surgically induced, withthe‐rule astigmatic shift in all groups, which in most cases decreased to near preoperative levels with time. One year postoperatively, mean induced astigmatism was 0.09 diopter (D) in Group A, 0.26 D in Group B, and 0.54 D in Group C. Most cases had minimal axial changes. In Group A, 86% had an axial change of fewer than 30 degrees; in Group B, 76%; and in Group C, 73%. Conclusion: The smallest incision group had the least surgically induced astigmatism and axial change. All incision groups remained stable and had satisfactory clinical results.

Three-year clinical outcome after penetrating keratoplasty for keratoconus with the guided trephine system

PURPOSE To determine the long-term clinical outcome after keratoplasty with the guided trephine system in keratoconus eyes. METHODS In a prospective study, all consecutive cases of penetrating keratoplasty had trephination performed with the guided trephine system, with which both donor and recipient cornea are trephined from the epithelial side with a same-sized blade. For wound closure, a double running antitorque suture technique with 10-0 nylon was used. Uncorrected and best-corrected Snellen visual acuity, subjective refraction, and astigmatism by keratometry were evaluated after final suture removal, 2 and 3 years postoperatively. RESULTS In the 31 patients (31 eyes) enrolled, mean best-corrected visual acuity improved from 0.72 +/- 0.16 (20/30) after final suture removal to 0.88 +/- 0.15 (20/25) 3 years postoperatively (P < .001). The mean spherical equivalent increased from -0.86 +/- 2.10 diopters after final suture removal to -2.35 +/- 2.65 diopters 3 years postoperatively (P < .001). Mean keratometric astigmatism decreased from 4.68 +/- 1.76 diopters after final suture removal to 3.57 +/- 1.37 diopters 3 years postoperatively (P = .001). Furthermore, an increase in mean keratometric levels with time (P = .01) was observed and associated with myopic shift (r(s) = -.46, P = .008). CONCLUSION With the guided trephine system, we attained favorable visual results, with prolonged improvement of visual acuity during the entire follow-up period. Our data show low and decreasing degrees of corneal astigmatism over time. During the follow-up period, a myopic shift was found after final suture removal. Nevertheless, this technique of performing same-sized grafts reduces postoperative residual myopia.

Postoperative astigmatism after no-stitch, small incision cataract surgery with 3.5 mm and 4.5 mm incisions.

Abstract We studied postoperative astigmatism in 107 patients who were followed for 12 months after phacoemulsification and posterior chamber lens implantation. A scleral incision of 3.5 mm was used in Group A patients and one of 4.5 mm in Group B patients. In both groups a no‐stitch wound closure technique was used. A high correlation between preoperative and 12‐month postoperative height and time shift of keratometric values was found. In both groups the mean difference was less than 0.60 diopters (D). The mean postoperative cylinder increase was less than 0.50 D; it was less than 0.25 D after six months. The induced astigmatism was confirmed by three different methods. Immediately after surgery, a negative induced astigmatism was found in both groups. After 12 months, induced astigmatism in Group A was −0.37 D and in Group B, −0.67 D. Immediately after surgery there was an axis change; a decrease of with‐the‐rule astigmatism occurred concurrently with an increase toward oblique and against‐the‐rule astigmatism. This axis change was somewhat evident after 12 months.

Postoperativer Astigmatismusverlauf bei Kleinschnittkataraktchirurgie und No-stitch-Wundverschluß

Eine prospektive Studie untersucht eine Gruppe von 47 Patienten nach Phakoemulsifikation und Implantation einer Hinterkammerlinse bezuglich ihres postoperativen Astigmatismusverlaufes uber mindestens 6 Monate. Zum Wundverschlus wurde eine Nostitch-Technik angewendet. Die Skleralschnittlange betrug je nach Linsentyp in Gruppe A 3,5 mm und in Gruppe B 4,5 mm. Die Daten wurden an 6 Kontrollzeitpunkten erhoben und in bezug auf die Hohe und Verlauf der Keratometriewerte ausgewertet. Nach 6 Monaten zeigte sich eine hohe Korrelation zu den Ausgangswerten, die Differenz war im Mittel jeweils kleiner als 0,5 Dioptrien (D). Es wurde der absolute Astigmatismus bestimmt. Der postoperative Anstieg betrug im Mittel 0,5 D, nach 6 Monaten war der Anstieg in beiden Gruppen 0,15 D. Weiters wurde der induzierte Astigmatismus berechnet. Bereits unmittelbar postoperativ lag in beiden Gruppen ein negativ induzierter Astigmatismus, d.h. in Richtung eines Astigmatismus gegen die Regel, vor. Nach 6 Monaten betrug dieser in Gruppe A — 0,43D und in Gruppe B -0,61 D, der Gruppenvergleich erbrachte keine signifikant unterschiedlichen Ergebnisse. Die Achsenverlaufe zeigten bereits postoperativ eine Abnahme von Astigmatismen nach der Regel bei gleichzeitiger Zunahme von schiefen Achsenlagen und Astigmatismen gegen die Regel. Diese Umverteilung war in geringerem Ausmas auch nach 6 Monaten zu beobachten.

Ein Jahr Erfahrung mit der „Memory-Lens™“, einer thermoplastischen Linse für Kleinschnittimplantation

Die „Memory-Lens™“, die von der Firma ORC hergestellt wird, ist eine Hinter kammerlinse fur Kleinschnitt-Kataraktchirurgie. Der optische Teil der Linse besteht aus thermoplastischem Material (MMA, Hema, EDGMA, UV-Absorber). Die Linse wird in der sog. „Thermal Exchange Unit“ erhitzt. Dadurch wird das Material weich und verformbar. Mit einem „Roller“ wird die erhitzte Linse gerollt und im „Roller“ eingespannt wieder abgekuhlt. Unmittelbar vor der Implantation wird die Linse aus dem „Roller“ genommen und — da sie sich sofort zu entfalten beginnt — moglichst schnell implantiert. Zwischen November 1990 und Oktober 1991 wurden an unserer Klinik 35 Linsen implantiert (Modell U 780 A und U 940 A). In 9 Fallen muste die Wunde genaht werden, sonst konnte die Wunde immer mit no-stitch-Technik dicht geschlossen gehalten werden. Schnittlange 3,5 mm bzw. 4,5 mm. Die einzigen Probleme traten bei der Faltung auf. Kleinste Optikbruche im Bereich des Bugelansatzes fuhrten zu Bugellockerungen im „Roller“. Auch Doppelfaltungen wurden beobachtet. Die Vertraglichkeit des Materials ist bisher hervorragend. Es trat keinerlei Zellbesiedlung des Implantates auf. Im Spatverlauf wurde auf 2 Implantaten eine feine Membran zirkular zentral von der Kapsulorhexis beobachtet. Spezifische Komplikationen traten bislang keine auf.

Die postoperative Vorderkammertiefe bei kapselsackimplantierten Silikon-Disk-Linsen

ZusammenfassungObwohl die postoperative Vorderkammertiefe vor der Implantation einer IOL nicht bestimmt werden kann, stellt sie bei theoretischen Biometrieformeln eine wichtige Eingangsgröße zur Berechnung der Dioptrienstärke einer Kunstlinse dar.Für die Silikonlinse Typ 90 D der Firma Adatomed, die man gefaltet durch eine kleine Wundöffnung in den Kapselsack implantieren kann, liegen bisher keine Daten über die postoperative Vorderkammertiefe vor. Deshalb wurde bei einer Gruppe von 42 Patienten die Vorderkammertiefe postoperativ mindestens 3 Monate nach der Linsenimplantation mittels Echographie gemessen und statistisch geprüft, ob eine Korrelation zur axialen Bulbuslänge besteht. Es konnte keine Korrelation gefunden werden.Daher rechtfertigen unsere Untersuchungen nur die Verwendung einer Standard-Vorderkammertiefe. Der Mittelwert der postoperativen Vorderkammertiefe war in unserer Untersuchung 4,47 mm (+ / −0,24). Dieser Wert kann bei theoretischen Formeln als Standardvorderkammertiefe verwendet werden.SummaryEven though one cannot determine the postoperative anterior chamber depth before implantation of an IOL, the chamber depth, when utilizing theoretic formulas for biometry, is an important factor for the calculation of the refractive power of an IOL. There is no definate data on the postoperative chamber depth of the silicone disc lens type 90 D (Adatomed), which can be folded and inserted into the capsular bag through a small incision.In a case study of 42 patients, who received the IOL implantation at least three months previously, the chamber depth was sonographically measured and statistically tested to determine weather there is a correlation between the chamber depth and the axial bulbus length.No correlation could be found.Therefore our research justifies only the use of a standard anterior chamber depth; the average value of the postoperative chamber depth was 4.47mm (SD + /−0.24).When utilizing theoretic formulas, the previous value can be used as the standard anterior chamber depth.

Corneal flap incision technique for sutureless cataract surgery

Abstract A self‐sealing incision technique for cataract surgery has been developed. It is appropriate for implantation of rigid‐optic intraocutar lenses (IOLs) up to 7.0 mm. The incision is designed to meet the principle criteria of sutureless cataract surgery, such as optimal instrument handling, easy IOL implantation, and minimal postoperative patient care.