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Der Ophthalmologe 05/2012; 104(10):896-898. · 0.62 Impact Factor
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ABSTRACT: The aim of the study was an assessment of refraction error after implantation of two types of hydrophobic acrylic intraocular lenses and derivation of customized IOL constants for the SRK II, SRK/T, Hoffer Q, Holladay 1 and Haigis formula.
The purpose of the present study was to analyze the refractive outcome of two hydrophobic acrylic intraocular lenses and to present a computerized calculation scheme for customization of lens-specific parameters provided by the lens manufacturers based on the refractive results of a surgeon or study center.
In this prospective monocentric study 100 consecutive cataract eyes were treated at the Eye Hospital of the Barmherzige Brüder (Compassionate Brothers) in Linz/Austria with a hydrophobic acrylic aspherical intraocular lens (Polytech Y10AS, n = 50) or a hydrophobic acrylic spherical intraocular lens (Hoya PC-60R, n = 50). The biometrical data were assessed preoperatively together with the refractive outcome 8-10 weeks after treatment in order to analyze the deviation of postoperative refraction (spherical equivalent) from target refraction (ΔREF) and to customize the lens constants for the SRK II, SRK/T, Hoffer Q, Holladay 1 and Haigis formula.
Based on this data set it could be demonstrated that using the lens constant provided by the manufacturer (ΔREF) the Polytech lens showed a systematic trend to myopia in contrast to the Hoya lens which ranged around zero. This trend could be compensated by selecting appropriate lens specific constants. For the Polytech/Hoya lens median lens constants of: A = 118.0/118.6 (SRK II), A = 117.9/118.6 (SRK/T), pACD = 4.8/5.1 (Hoffer Q), SF = 1.1/1.5 (Holladay I) and d = 4.2/4.6 (Haigis) were extracted and using linear regression a lens constant triplet for the Haigis formula of a(0) = 4.39, a(1) = 0.29, a(2) = 0.11/a0 = 4.73, a(1) = 0.30, a(2) = -0.01 could be derived.
Ophthalmic surgeons or surgical centers are encouraged to check (refractive) outcomes after cataract surgery permanently in terms of quality control. If a systematic trend in ΔREF could be extracted from the data set a customization of the lens-specific constants is recommended to eliminate systematic errors. Such customization is only valid for a dedicated environment (e.g. for one surgical center with standardized surgical techniques and measurement equipment) and cannot be generalized.
Der Ophthalmologe 05/2012; 109(5):468-73. · 0.62 Impact Factor
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Der Ophthalmologe 04/2012; 104(12):1068-1071. · 0.62 Impact Factor
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ABSTRACT: HintergrundBulbusverletzungen führen häufig zu einer dauerhaften Beeinträchtigung des Sehvermögens. Insbesondere bei Bulbusrupturen ist
die Chance, einen Visus >0,1 zu erreichen 50-mal geringer als nach Bulbuskontusion. Neben Netzhaut- und Aderhauttrauma kommt
dem Iris-Linsendiaphragma (ca. 10% Irisdefekte und 1% Aniridie nach stumpfer Verletzung) bei der visuellen Rehabilitation
eine häufig unterschätzte Rolle zu. Vor diesem Hintergrund wurden die operativen Ergebnisse nach Implantation von Aniridie-Intraokularlinsen
untersucht.
Patienten und Methoden11Patienten (41,9±19,6Jahre) mit Z.n. Bulbustrauma (3-mal Bulbusruptur, 8-mal penetrierende Bulbusverletzung mit Iris-Linsenbeteiligung)
wurden mit einem Aniridie-Implantat versorgt.
ErgebnisseDie Implantation der Aniridie-IOL erfolgte im Mittel 1,0±0,6Jahre (Spanne 0,4–2,3Jahre) nach der primären Wundversorgung.
Bei 10 Augen wurde eine Aniridie-IOL Modell HMK ANI 2 (Ophtec/Polytech), bei 1 Auge eine Aniridie-IOL Modell 67 (Morcher)
implantiert. Die postoperative Patientenzufriedenheit war hoch (korrigierter Visus im Mittel 0,48; 0,05–1,0). 63% der operierten
Augen erreichten einen Visus ≥0,4. Alle Patienten erfuhren eine Reduktion der präoperativ bestandenen Blendungsempfindlichkeit.
Die Inzidenz von Sekundärglaukomen wurde durch die Sekundärimplantation nicht erhöht. Ein Patient erlitt 3Monate nach Implantation
eine Netzhautablösung, die durch ppV und Gastamponade behoben werden konnte.
SchlussfolgerungBei Trauma-Augen mit partieller oder vollständiger Aniridie und gleichzeitig bestehender Aphakie erscheint die Implantation
von Aniridie-IOLs als eine therapeutische Option mit z.T. guter visueller Rehabilitation. Bei der postoperativen Verlaufskontrolle
ist auf ausreichende Tensionseinstellung und Ablatioprodromi zu achten.
BackgroundGlobe injuries frequently are the cause of permanent loss of visual function. Especially ruptures of the globe have a 50 times
lower chance of achieving a final visual acuity better than 20/200 as compared to contusions of the globe. Besides injury
to the retina and choroids, injury of the iris-lens diaphragm plays an important role for visual rehabilitation (10% iris
defects and 1% aniridia after blunt trauma). Against this background the surgical results after implantation of aniridia intraocular
lenses were investigated.
Patients and methodsEleven patients (41.9±19.6years of age) after globe injury (three ruptures of the globe, eight penetrating injuries with
trauma of the iris) were implanted with an aniridia IOL.
ResultsThe implantation of an aniridia IOL was performed on average 1.0±0.6years (range: 0.4–2.3years) after the primary injury.
In ten eyes an aniridia IOL model HMK ANI 2 (Ophtec/Polytech) was implanted and in one eye an aniridia IOL model 67 (Morcher).
Most patients were very satisfied with the results achieved (average corrected visual acuity 0.48; 0.05–1.0). Of the operated
eyes, 63% reached a visual acuity ≥0.4. All patients noticed a significant reduction in glare disability as compared to the
preoperative condition. The incidence of secondary glaucoma remained unchanged after the secondary implantation. One patient
demonstrated retinal detachment 3months after receiving the secondary implant, which was successfully treated with vitrectomy
and gas tamponade.
ConclusionsThe implantation of aniridia IOLs seems to be a beneficial therapeutic option in post-traumatic eyes with partial or complete
aniridia and aphakia with good visual recovery. During the postoperative follow-up special attention must be paid to sufficient
regulation of intraocular pressure and to the retinal situation.
Der Ophthalmologe 04/2012; 105(8):744-752. · 0.62 Impact Factor
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ABSTRACT: Die Bulbusruptur ist eine der schwersten offenen Augenverletzungen, beeinträchtigt das Sehvermögen dauerhaft oder führt zur
Erblindung. Risikofaktoren für eine Bulbusruptur sind vorherige Augenoperationen (27-fach erhöhtes Risiko), Myopie, fortgeschrittenes
Alter, weibliches Geschlecht und Stürze. Die Abgrenzung der gedeckten Bulbusruptur von der Kontusion kann bei ausgeprägtem
Hyposphagma mit Chemosis der Bindehaut erschwert sein. Im Zweifelsfall muss nach einer schweren stumpfen Augenverletzung eine
Bulbusruptur ausgeschlossen werden. Die 360°-Peritomie dient zur Limbus- und Skleraexploration und sichert die Diagnose. Die
Wunde muss zeitnah wasserdicht verschlossen werden, um eine expulsive Blutung, persistierende Bulbushypotonie oder Epitheleinwachsung
zu verhindern. Ein verzögerter Wundverschluss potenziert das Risiko einer posttraumatischen Endophthalmitis. Mit einer Frühvitrektomie
bei hohem Risiko einer Netzhautbeteiligung mit Glaskörperblutung kann der traktiven Netzhautablösung vorgebeugt werden. Die
Silikonölinstillation bei offenem Bulbustrauma stabilisiert die zentrale Netzhaut, die prophylaktische Cerclage ist noch umstritten.
Globe rupture is one of the most severe open globe injuries, permanently impairing visual acuity or leading to blindness.
The risk of globe rupture is increased after previous intraocular surgery (27-fold), in myopia, older age, females, and after
sudden falls. The differentiation between an occult globe rupture and severe ocular contusion may be complicated by pronounced
subconjunctival hemorrhage with conjunctival swelling. In case of doubt, a rupture of the eyeball should be ruled out after
a severe blunt ocular trauma. Limbal and scleral exploration after 360° peritomy leads to the correct diagnosis. Immediate
and watertight wound closure is essential to avoid expulsive choroidal hemorrhage, persisting ocular hypotony or epithelial
ingrowth. Delayed wound closure raises the risk of posttraumatic endophthalmitis. Early vitrectomy may prevent tractional
retinal detachment in case of retinal injury with vitreal bleeding. Silicone oil instillation stabilizes the central retina
after open globe injury; scleral buckling is controversial.
Der Ophthalmologe 04/2012; 105(12):1163-1175. · 0.62 Impact Factor
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ABSTRACT: Die Implantation von pseudophaken und phaken torischen Kunstlinsen entwickelte sich in den vergangenen Jahren zunehmend zum
Mittel der Wahl, einen hohen Hornhautastigmatismus im Rahmen einer Kataraktextraktion bzw. eines refraktiven Eingriffs auszugleichen.
Im vorliegenden Beitrag werden das Einsatzgebiet pseudophaker und phaker torischer Kunstlinsen vorgestellt, die Ermittlung
notwendiger Messgrößen erläutert, ein matrixbasiertes Schema für die Berechnung pseudophaker und phaker torischer Kunstlinsen
aufgezeigt und anhand von Beispielen Schritt für Schritt erläutert. Zudem wird auf die intraoperative Positionierung der Linse
sowie die Auswirkungen einer Dislokation (speziell Rotation) eingegangen.
In the last decades, the implantation of pseudophakic and phakic toric lenses has become widespread for correcting corneal
astigmatism: in cataract surgery cases with implantation of a posterior chamber lens and in refractive surgery cases with
implantation of phakic lenses. The purpose of this educational and training article is to familiarize the reader with the
application of pseudophakic and phakic toric lenses, to show which parameters are necessary for calculating toric lenses,
to present a matrix-based calculation scheme for pseudophakic and phakic toric lenses, to explicitly demonstrate the step-by-step
calculations with clinical examples, and to show the impact of lens dislocation (especially rotation) on refractive outcome.
Der Ophthalmologe 04/2012; 107(2):189-201. · 0.62 Impact Factor
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ABSTRACT: HintergrundDie digitale Visualisierung des Augenvorderabschnittes zur Diagnostik und Biometrie gewinnt zunehmend an Bedeutung. Als kommerziell
erhältliche optische Kohärenztomographen (OCT) wurden das Visante-OCT (Carl-Zeiss Meditec, Jena) und das Spaltlampen-OCT (SL-OCT;
Heidelberg Engineering) evaluiert. AM SC-OCT wurden zusätzlich ein manueller und ein semiautomatischer Biometriealgorithmus
miteinander verglichen.
Patienten und MethodenFünfzig Augen wurden durch drei Ophthalmologen standardisiert untersucht. Bei allen Patienten wurde ein kompletter Augenstatus
erhoben. Es wurden je drei Vorderabschnittsaufnahmen horizontal und vertikal erstellt. Während beim Visante-OCT die Auswertung
mit einem im Gerät integrierten manuellen Auswertemodus erfolgte, wurde beim SL-OCT die am besten zentrierte Aufnahme mittels
manuell zu bedienender Software (EyelabGlobal/4Optics) und digitaler, semiautomatischer Software (HEYEX) evaluiert. Verglichen
wurden die zentrale Hornhautdicke (CCT), die Vorderkammertiefe (VKT), der Pupillendurchmesser (PD) sowie der Kammerwinkel-Kammerwinkel-Abstand
(KW-KW).
Ergebnisse
Gerätevergleich: Der horizontale Kammerwinkel-Kammerwinkel-Abstand (KW-KW) betrug beim Visante-OCT 11,65±0,47mm und beim SL-OCT mit 12,0±0,57mm
(n=33, p=0,002). Vergleichende Vertikalscans waren nur bei 10 Augen möglich. Die zentrale Hornhautdicke betrug im Horizontalscan
mit dem Visante-OCT 568±61µm, mit dem SL-OCT 581±48µm (n=35, p=0,03); im Vertikalscan mit dem Visante-OCT 565±62µm und
mit dem SL-OCT 568±51 µm (n=27, n.s.). Die Abweichungen beider Messmethoden schwanken im Horizontalscan zwischen −54,7 und
80,8µm und im Vertikalscan zwischen −84,9 und 91,1µm um die mittlere Differenz beider Messmethoden.
Analyseprogramm-Vergleich: Beim Horizontalscan korrelierte die manuelle Analyse mit der semiautomatischen bei der CCT 581±51µm vs. 572±53µm (r=0,903),
bei der VKT 2,89±0,74mm vs. 2,95±0,72mm (r=0,98), beim PD 5,22±2,12mm vs. 5,14±1,91mm (r=0,917) und beim KW-KW 11,59±1,02mm
vs. 11,79±0,60mm (r=0,47). Die manuelle und semiautomatische Auswertung von CCT und VKT unterschieden sich signifikant (p<0,026).
Beim Vertikalscan korrelierte die manuelle Analyse mit der semiautomatischen bei der CCT 578±65µm vs. 573±63µm (r=0,593),
bei der VKT 3,04±0,83mm vs. 3,03±0,75mm (r=0,92), beim PD 5,28±1,99mm vs. 5,45±2,00mm (r=0,899) und beim KW-KW mit 11,75±0,66mm
vs. 11,82±0,60mm (r=0,537).
SchlussfolgerungenIm Vergleich zum Vertikalscan erlaubt ein Horizontalscan zumeist die Untersuchung des gesamten Hornhaut-Vorderkammer-Iris-Segmentes
inklusive Kammerwinkel. Hierzu stehen OCT zur Visualisierung und Biometrie des vorderen Augenabschnitts zur Verfügung, die
mittels der Non-Contact-Methode einfach zu bedienen sind. Die untersuchten Geräte zeigen eine eingeschränkte Vergleichbarkeit.
Mit der manuell zu bedienenden EyelabGlobal-Analyse war im Vergleich zum semiautomatischen HEYEX eine Untersuchung aller Augen
möglich. Beide Softwaresysteme ermöglichen vergleichbare Vorderabschnittsmessungen. Der semiautomatische Biometriemodus kann
die Auswertungszeit auf 10% reduzieren, setzt allerdings exzellente und gut zentrierte SL-OCT-Scans voraus.
BackgroundDigital visualisation of the anterior eye segment is becoming more and more important. Two commercially available optical
coherence tomographs (OCTs) — Visante OCT (Carl-Zeiss Meditec Jena) and Slit Lamp-OCT (SL-OCT. Heidelberg Engineering) — were
evaluated. Additionally, a manual and a semiautomatic analysis mode for the anterior segment biometry were compared using
the SL-OCT.
Patients and methodsFifty eyes were examined by three ophthalmologists with complete eye status in a standardised fashion. Three anterior segment
scans (horizontal and vertical) were performed using the Visante OCT and the SL-OCT. The manual integrated analysis mode of
the Visante OCT was used. The best centred SL-OCT scan was analysed with a manual (EyelabGlobal/4Optics) and a semiautomatic
procedure (HEYEX). Central corneal thickness (CCT), anterior chamber depth (ACD), pupillary diameter (PD) and chamber angle–angle
distance (CAAD) were compared.
Results
Comparison of Visante OCT and SL-OCT: The horizontal CAAD was 11.65±0.47mm for the Visante-OCT and 12.0±0.57mm for the SL-OCT (p=0,002), vertical scans were comparable
in 10eyes only. The CCT was 568±61 µm with the Visante-OCT and 581±48 µm with the SL-OCT (n=35, p=0.03) in horizontal scans
and 565±62 µm with the Visante-OCT and 568±51 µm with the SL-OCT in vertical scans (n=27, not significant). Deviation of the
two measurement methods varied between –54.7 and 80.8 µm in horizontal scans and between –84.9 and 91.1 µm in vertical scans
from the mean difference of the two methods.
Comparison of the analysis programs: Horizontal scans: Manual analysis correlated with semiautomatic analysis in CCT as 581±51 µm vs. 572±53 µm (r=0.903), ACD
2.89±0.74mm vs. 2.08±0.72mm (r=0.98), PD 5.22±2.12mm vs. 5.14±1.91mm (r=0.917) and CAAD 11.59±1.02mm vs. 11.79±0.6mm
(r=0.47). The manual and a semiautomatic analysis modes for CCT and ACD differed significantly (p<0.026). Vertical scan: Manual
versus semiautomatic analysis modes correlated in CCT as 578±65 µm vs. 573±63 µm (r=0.593), ACD with 3.04±0.83mm vs. 3.03±0.75mm
(r=0.92), PD with 5.28±1.99mm vs. 5.45±2.00mm (r=0.899) and CAAD with 11.75±0.66mm vs. 11.82±0.6mm (r=0.537).
ConclusionsA near complete investigation of the cornea–anterior–chamber–iris segment is provided by the horizontal scan compared with
the vertical scan. The noncontact OCT method is an easily handled tool for visualisation and biometry of the anterior eye
segment. The investigated OCTs show a limited comparability.
A complete analysis was possible in all eyes with the EyelabGlobal system in contrast to the HEYEX analysis software. Both
analysis programs provided comparable measurements of the anterior eye segment. The semiautomatic biometrical mode may reduce
the analysis time in qualitative excellent and well-centred scans to 10%.
Der Ophthalmologe 04/2012; 106(8):723-728. · 0.62 Impact Factor
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ABSTRACT: For the contactless diagnosis of the human cornea and anterior chamber in clinical routine, two systems have been established besides the slit lamp: the Scheimpflug camera and optical coherence tomography (OCT). A short introduction into these imaging methods is provided along with a comparison with respect to imaging quality and the visibility of relevant ocular structures. We present different examples from special clinical diagnostics such as keratoconus, condition after keratoplasty or tumours in ocular tissue.
Klinische Monatsblätter für Augenheilkunde 12/2011; 228(12):1052-9. · 0.51 Impact Factor
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ABSTRACT: A high corneal astigmatism is a major limitation for the attainable visual acuity with spectacle or contact lens correction. In addition, people with higher ametropia may feel discomfort while wearing contact lenses or spectacles which leads to the desire for a permanent correction. Phakic intraocular lenses provide correction possibilities of higher spherocylindrical ametropies beyond those of corneal refractive surgery.
For the calculation of toric phakic lenses the matrix formalism for calculation of toric pseudophakic implants is applied. The methods are presented and explained using clinically relevant data examples. A Java-based program JPhakicIOL was used for calculation of the examples and is provided online for teaching and experimental purposes.
Phakic IOLs can be calculated using a matrix scheme similar to the one used for toric pseudophakic implants. With the Java programme JPhakicIOL we provide a software tool to assist ophthalmologists in understanding and performing the phakic IOL calculation.
Klinische Monatsblätter für Augenheilkunde 08/2011; 228(8):690-7. · 0.51 Impact Factor
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ABSTRACT: A high corneal astigmatism limits the attainable visual acuity and the ability of correction with spectacles or contact lenses. The astigmatism can also be an impairment for visual rehabilitation, especially after penetrating keratoplasty. A pseudohakic toric intraocular lens (T-IOL) can correct high corneal astigmatism during cataract surgery. For the calculation of the correct power for the T-IOL several additional factors need to be considered, which are less relevant for spherical IOL calculation.
With the matrix-based vergence transformation an elegant paraxial calculation scheme is available for calculating the optical system "pseudophakic eye" as a closed system. The basic elements of this method are explained in detail along with some clinical examples. The Java-based software JToricIOL is provided online to support comprehension of the examples and to enable readers to make their own calculations for teaching and experimental purposes. The examples mentioned in this article have been calculated with JToricIOL.
Toric intraocular lenses are an essential tool for correcting high corneal astigmatism if cataract surgery is needed. For preoperative calculation of the lens power and axis, the matrix method provides a qualified tool for precise calculations. The software JToricIOL enables surgeons and students to reproduce the examples in this paper and to experiment with their own calculations.
Klinische Monatsblätter für Augenheilkunde 04/2011; 228(8):681-9. · 0.51 Impact Factor
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ABSTRACT: In concomitant cataract surgery and penetrating keratoplasty (PKP), the sequential procedure is supposed to have a higher accuracy in calculation of the intraocular lens (IOL) power compared to the triple procedure. The purpose of this study was to evaluate the refractive results of cataract surgery in patients after PKP.
Our retrospective study included 72 operations on 65 patients. In 35 eyes (group 1, G 1), all corneal sutures had been removed before cataract surgery (median time interval after PKP 3.1 years), while in 37 eyes (group 2, G 2) corneal sutures were in place but removed intra- or postoperatively (median time interval after PKP 1.5 years). Mean age of the patients (65 / 67 years), mean target refraction (-1.8 diopters, D), and mean follow-up interval (2.9 / 3.4 years) were comparable in G1 / G2. Pre- and postoperatively refraction, keratometry, and best corrected visual acuity were recorded. Main outcome measures included the deviation of the spherical equivalent of the real refraction from the target refraction after cataract surgery.
In G1 / G2 median visual acuity increased from preoperatively 0.2 / 0.15 to 0.6 / 0.5 after a follow-up period of 3 years on average. Mean deviation from target refraction was -0.3 ± 2.2 (-4.95 to + 3.15) D in G 1 and -0.4 ± 3.0 (-7.3 to + 7.25) D in G 2. After cataract surgery, the steepening of the cornea on average was significantly less in G 1 (0.5 ± 1.6 D) than it was in G 2 (3.3 ± 2.1 D; p = 0.003).
Although the mean deviation from target refraction is minimal after cataract surgery following PKP, our results indicate a high level of variability. If corneal sutures have been completely removed before biometry, the accuracy of the IOL power calculation seems to be better.
Klinische Monatsblätter für Augenheilkunde 11/2010; 228(8):698-703. · 0.51 Impact Factor
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Klinische Monatsblätter für Augenheilkunde 09/2010; 227(9):739-40. · 0.51 Impact Factor
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ABSTRACT: The purpose of this study was to investigate whether digital planimetry is appropriate for quantification of neuroretinal rim loss in patients with glaucoma, with and without progression.
The optic discs of 44 patients, whose illness had been well documented with photographs over a period of at least eight years were divided in a progression group and an unchanged group with regard to glaucoma. After this evaluation we measured each disc by digital planimetry and correlated the results. The researcher conducting the measurements was unaware of the patients' date of examination and the diagnosis.
While the neuroretinal rim decreased by only 0.06 A+/- 0.15 mm(2) on average in the group of patients without glaucoma, the average decrease was 0.30 A+/- 0.27 mm(2) in the group with progression. This corresponds to a yearly decrease on average of merely 0.0043 A+/- 0.011 mm(2) (0.25%/a) in the group without progression and one of 0.0228 A+/- 0.025 mm(2) (1.9%/a) in the group with progression. Mean neuroretinal rim loss was 0.25% per year in the group without progression of glaucoma, and 1.9% per year in the group with progression. This annual difference is significant. (p = 0.003). The average observation time in the morphologically better group was on average significantly shorter (12.3 years compared to 14.5 years).
Digital planimetry was able to determine if a morphological progression was found in a clinical examination or if a glaucoma showed no signs of worsening. So we can use this method of digital planimetry of optic discs to examine and re-examine older and more recent photographs to always get the best results of a possible progression of glaucoma.
Klinische Monatsblätter für Augenheilkunde 03/2010; 227(3):215-20. · 0.51 Impact Factor
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ABSTRACT: In the last decades, the implantation of pseudophakic and phakic toric lenses has become widespread for correcting corneal astigmatism: in cataract surgery cases with implantation of a posterior chamber lens and in refractive surgery cases with implantation of phakic lenses. The purpose of this educational and training article is to familiarize the reader with the application of pseudophakic and phakic toric lenses, to show which parameters are necessary for calculating toric lenses, to present a matrix-based calculation scheme for pseudophakic and phakic toric lenses, to explicitly demonstrate the step-by-step calculations with clinical examples, and to show the impact of lens dislocation (especially rotation) on refractive outcome.
Der Ophthalmologe 02/2010; 107(2):189-201. · 0.62 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: An 83-year old female was given an intravitreal injection of 0.4 ml of triamcinolone acetonide (TA) by her local ophthalmologist for age-related maculopathy with a large choroidal neovascularisation in the left eye. During the injection, globe explosion occurred with nasal limbal rupture and extrusion of intraocular contents. Emergency primary wound repair was performed at the Eye Surgery Centre Erlangen-Mitte. During surgery, a 9 mm limbal rupture with prolapse of half of the iris and subconjunctival extrusion of the complete natural lens was discovered. After lens removal, anterior vitrectomy and iris repositioning, the wound was closed and the eye left aphakic. The further postoperative course was unremarkable and the patient retained her preoperative visual acuity of counting fingers. In this case, several factors may have contributed to the dramatic events: relative nanophthalmus (preoperative refraction + 5.0dpt), scleral weakness secondary to chemotherapy for leukemia, older age, and a relatively large volume of injected TA. The intravitreal injection of drugs may cause serious complications. Paracentesis or limited pars plana vitrectomy should be considered prior to intravitreal injection in high-risk cases to prevent such disastrous complications.
Klinische Monatsblätter für Augenheilkunde 01/2009; 225(12):1087-90. · 0.51 Impact Factor
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ABSTRACT: Post-traumatic endophthalmitis is one of the most severe complications occurring in 2-17% after open globe injuries. Early intravenous antibiotics may minimise the risk of post-traumatic endophthalmitis. The design of a new study to evaluate the role of an additional intravitreal antibiotic injection in the prevention of post-traumatic endophthalmitis is presented in this paper.
A prospective, multicentre, randomised controlled study was designed. Patients with penetrating or perforating eye injuries will be included up to the year 2010. The wound closure and IOFB (intraocular foreign body) removal must be performed within 24 hours after the trauma. After grouping into low risk (e. g., metallic IOFB) or high risk patients (e. g., agricultural trauma, organic IOFB) each patient will be randomised for 1) intravenous moxifloxacin only or 2) intravenous moxifloxacin plus intravitreal 1 mg Vancomycin plus 2.25 mg [DOSAGE ERROR CORRECTED] Ceftazidim.
17 European Departments of Ophthalmology have agreed to participate. The rate of post-traumatic endophthalmitis in each group will be statistically compared. The follow-up period of this study will last 6 months.
Other Departments of Ophthalmology are invited to join the TEPT.
Klinische Monatsblätter für Augenheilkunde 12/2008; 225(11):941-6. · 0.51 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: Globe rupture is one of the most severe open globe injuries, permanently impairing visual acuity or leading to blindness. The risk of globe rupture is increased after previous intraocular surgery (27-fold), in myopia, older age, females, and after sudden falls. The differentiation between an occult globe rupture and severe ocular contusion may be complicated by pronounced subconjunctival hemorrhage with conjunctival swelling. In case of doubt, a rupture of the eyeball should be ruled out after a severe blunt ocular trauma. Limbal and scleral exploration after 360 degrees peritomy leads to the correct diagnosis. Immediate and watertight wound closure is essential to avoid expulsive choroidal hemorrhage, persisting ocular hypotony or epithelial ingrowth. Delayed wound closure raises the risk of posttraumatic endophthalmitis. Early vitrectomy may prevent tractional retinal detachment in case of retinal injury with vitreal bleeding. Silicone oil instillation stabilizes the central retina after open globe injury; scleral buckling is controversial.
Der Ophthalmologe 12/2008; 105(12):1163-74; quiz 1175. · 0.62 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: Digital visualisation of the anterior eye segment is becoming more and more important. Two commercially available optical coherence tomographs (OCTs) - Visante OCT (Carl-Zeiss Meditec Jena) and Slit Lamp-OCT (SL-OCT. Heidelberg Engineering) - were evaluated. Additionally, a manual and a semiautomatic analysis mode for the anterior segment biometry were compared using the SL-OCT.
Fifty eyes were examined by three ophthalmologists with complete eye status in a standardised fashion. Three anterior segment scans (horizontal and vertical) were performed using the Visante OCT and the SL-OCT. The manual integrated analysis mode of the Visante OCT was used. The best centred SL-OCT scan was analysed with a manual (EyelabGlobal/4Optics) and a semiautomatic procedure (HEYEX). Central corneal thickness (CCT), anterior chamber depth (ACD), pupillary diameter (PD) and chamber angle-angle distance (CAAD) were compared.
Comparison of Visante OCT and SL-OCT: The horizontal CAAD was 11.65+/-0.47 mm for the Visante-OCT and 12.0+/-0.57 mm for the SL-OCT (p=0,002), vertical scans were comparable in 10 eyes only. The CCT was 568+/-61 microm with the Visante-OCT and 581+/-48 microm with the SL-OCT (n=35, p=0.03) in horizontal scans and 565+/-62 microm with the Visante-OCT and 568+/-51 microm with the SL-OCT in vertical scans (n=27, not significant). Deviation of the two measurement methods varied between -54.7 and 80.8 microm in horizontal scans and between -84.9 and 91.1 microm in vertical scans from the mean difference of the two methods. Comparison of the analysis programs: Horizontal scans: Manual analysis correlated with semiautomatic analysis in CCT as 581+/-51 microm vs. 572+/-53 microm (r=0.903), ACD 2.89+/-0.74 mm vs. 2.08+/-0.72 mm (r=0.98), PD 5.22+/-2.12 mm vs. 5.14+/-1.91 mm (r=0.917) and CAAD 11.59+/-1.02 mm vs. 11.79+/-0.6 mm (r=0.47). The manual and a semiautomatic analysis modes for CCT and ACD differed significantly (p<0.026). Vertical scan: Manual versus semiautomatic analysis modes correlated in CCT as 578+/-65 microm vs. 573+/-63 microm (r=0.593), ACD with 3.04+/-0.83 mm vs. 3.03+/-0.75 mm (r=0.92), PD with 5.28+/-1.99 mm vs. 5.45+/-2.00 mm (r=0.899) and CAAD with 11.75+/-0.66 mm vs. 11.82+/-0.6 mm (r=0.537).
A near complete investigation of the cornea-anterior-chamber-iris segment is provided by the horizontal scan compared with the vertical scan. The noncontact OCT method is an easily handled tool for visualisation and biometry of the anterior eye segment. The investigated OCTs show a limited comparability. A complete analysis was possible in all eyes with the EyelabGlobal system in contrast to the HEYEX analysis software. Both analysis programs provided comparable measurements of the anterior eye segment. The semiautomatic biometrical mode may reduce the analysis time in qualitative excellent and well-centred scans to 10%.
Der Ophthalmologe 10/2008; 106(8):723-8. · 0.62 Impact Factor
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ABSTRACT: In the last decades, toric posterior chamber lenses (TPCLs) for cataract surgery and phakic toric lenses (PTLs) for refractive surgery have become more and more popular for correcting high or excessive corneal astigmatism. The purpose of this article is to present a vergence-based calculation scheme for TPCLs and PTLs.
In Gaussian optics (in the paraxial space), spherocylindrical optical surfaces can be described in a mathematically equivalent formulation as vergences. There are dual notations: The standard notation is used for transforming vergences through a homogeneous optical medium, and the component notation is applied to add up the power of a refractive surface to the vergence. Both notations can be used interchangeably. For calculating TPCLs, the vergences in front of and behind the predicted pseudophakic lens position are determined and subtracted. For calculating PTLs, the anterior vergence at the predicted lens position is estimated for the preoperative and postoperative states, and the difference between the two yields the desired lens power. WORKING EXAMPLES: In the 1(st) example, the power of a thin TPCL is determined step by step by applying the presented calculation scheme, which was designed to be transferred directly to a simple computer program (e.g., Microsoft Excel). In the 2(nd) example, the postoperative refraction is estimated for a simulation in which a TPCL similar to that in example 1 is implanted in a slightly misaligned orientation. In a 3(rd) example, the power of a PTL is determined step by step using the above-mentioned calculation scheme.
The presented calculation scheme allows determination of"thin" TPCLs or PTLs to achieve spherocylindrical target refraction with a cylinder axis at random or to predict the postoperative refraction for any toric lens implanted in any axis. The concept can be easily generalized to"thick" toric intraocular lenses if the geometric data and refraction index of the material are known.
Der Ophthalmologe 08/2008; 105(7):685-92. · 0.62 Impact Factor
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ABSTRACT: In the last decades the implantation of pseudophakic and phakic toric lenses has become wide-spread for the correction of corneal astigmatism in cases of classical cataract surgery with implantation of a posterior chamber lens or in cases of refractive surgery with implantation of a piggyback lens. The purpose of this review article is to present an en bloc mathematical strategy for calculating pseudophakic and phakic toric lenses and for deriving the spectacle refraction after implantation of an arbitrary lens.
We restrict ourselves to a centred coaxial optical system containing spherocylindrical surfaces and interspaces with a homogeneous optical medium. All calculations are done in the paraxial space according to linear Gaussian optics. We define an optical model for the pseudophakic and phakic eye and characterise all known refractive surfaces and interspaces between the surfaces with 4 x 4 refraction and translation matrices, respectively. The entire optical system is described with a 4 x 4 system matrix, which relates the impinging beam (slope angle and height, both in x and y directions) with the exiting beam (slope angle and height, both in x and y directions) and extract the required parameters from the matrix representation.
In example 1, we describe step-by-step how to derive a pseudophakic toric lens implant from the biometric parameters and in example 2 we estimate the residual refraction at spectacle plane after implantation of a pseudophakic lens. In example 3, we describe step-by-step how to derive a phakic toric lens implant from the initial refraction and biometric measurements and in example 4 we estimate the residual refraction at spectacle plane after implantation of a phakic lens.
The calculation scheme presents a strategy for calculating toric lenses and residual refractions based on a thin lens model of the spectacle correction, the cornea and the lens implant. This model can be generalised easily to a thick lens model, if the appropriate geometric parameters of both lens surfaces are known. The phakic lens calculation can directly be transferred to the case of pseudophakic piggyback lenses.
Klinische Monatsblätter für Augenheilkunde 07/2008; 225(6):541-7. · 0.51 Impact Factor
