Ralph Becker

Examination of young children with Lea symbols

Aims: In order to establish normal values and interocular differences of visual acuity, Lea symbols were applied to neurologically and ophthalmologically normal children. Methods: 385 children (21–93 months old) were examined, within a routine check up in an urban paediatric practice where Lea symbol acuity (LS) was measured. Of these children, 90 were re-examined in hospital comparing Lea symbol acuity (LS) and Landolt C acuity (LC). Strabismus, ametropia, and any organic eye disease were excluded. Results: In the paediatric practice, LS could be measured on both eyes in 54% of the children. In the age group above 36 and 48 months the success rate was 76% and 95%, respectively. Acuity in the paediatric practice ranged from 0.1 to 2.0 (median 1.25) in the whole group. Interocular acuity difference was one line or less in 80%. In the hospital, LS and LC could be measured on both eyes of 77% and 48% of the 90 children, respectively. Cooperation increased with age. LS in the hospital ranged from 0.32 to 2.0 (median 1.0) and LC from 0.16 to 1.25 (median 0.8). Interocular difference of LS acuity was one line or less in 90%. Conclusion: Lea symbols were found to be useful for visual acuity assessment in early childhood. Significant variability of visual acuity in this age group is caused by cooperation. When monocular measurements are possible on both eyes, however, the intraindividual interocular difference of visual acuity usually does not exceed one line.

Lea symbols: visual acuity assessment and detection of amblyopia

Abstract · Objective: Lea symbols can be used for measuring visual acuity in childhood. Therefore, these symbols might be useful for early detection of amblyopia. We evaluated whether the visual acuity determined with Lea symbols (LS) corresponds to the visual acuity determined with the Landolt-C (LC). · Patients and methods: In 55 strabismic amblyopic volunteers aged 5–59 years, the monocular visual acuity of both eyes was determined using LC and LS. For comparison, the right eye of 20 healthy volunteers was examined. Single optotypes (LC, LS) were used in 55 amblyopes and crowded optotypes (LC17.2, LC2.6, CLS) in 40 amblyopes. The luminance of the test charts was 180–200 cd/m2, with a contrast >85%. The refraction of the subjects was corrected beforehand. · Results: In the 40 amblyopic eyes tested under each condition, LS exceeded CLS and LC by about 1 line (dB), LC17.2 by 2 lines and LC2.6 by 3 lines (mean values ± SD: LS 0.62±1.8 dB, CLS 0.46±1.7 dB, LC 0.5±2.0 dB, LC17.2 0.41±2.3 dB, LC2.6 0.29±2.3 dB). The non-amblyopic fellow eyes and healthy eyes showed smaller differences (fellow eyes LS 1.32±1.1 dB, CLS 1.17±1.1 dB, LC 1.15±0.9 dB, LC17.2 1.05±0.9 dB, LC2.6 0.93±1.1 dB; healthy eyes LS 1.74±0.9 dB, CLS 1.58±0.8 dB, LC 1.48±0.6 dB, LC17.2 1.41±0.7 dB, LC2.6 1.32±1.1 dB). In the amblyopic eyes, the reduction of LC was more distinct than the reduction of LS. Fifty-two amblyopes had an amblyopia >1 dB of LC, LC17.2 and LC2.6, while 50 had an interocular acuity difference >1 dB CLS. · Conclusions: Using Lea symbols, a recognition acuity can be determined and amblyopia can reliably be detected. Due to their design, the Lea symbols are particularly suitable and recommendable for application in young children. However a slight systematic difference between LS and LC has to be considered.

Use of preoperative assessment of positionally induced cyclotorsion: a video-oculographic study

Purpose: Positionally induced cyclotorsion could be an important factor concerning correction of astigmatism in refractive surgery. The method of binocular three dimensional infrared video-oculography (3D-VOG) was used to determine a possible influence of body position on cyclotorsion. Methods: 38 eyes (19 healthy subjects, median value of age 25.5) with normal binocular vision were examined using 3D-VOG. This method records ocular motions and positions of both eyes simultaneously in the x, y, and z axis. Cycloposition of the eyes was recorded first in a seated position (both eyes open, test 1), then in a supine position (right eye closed, test 2), occlusion of both eyes (test 3), both eyes open (test 4). Cyclovergence was calculated as the difference between the right and the left eye positions. Results: The range of cyclotorsion of the right and left eye in all four tests was between 1.13° excyclotorsion and 0.34° incyclotorsion. There was no statistically significant difference of the median values for torsion for the four test situations. Concerning the influence of body position on cyclotorsion, a statistically significant difference between the different test positions and settings did not exist. Median values for right/left torsion/cyclovergence were: 0.17/0.04/0.02 (test 1), −0.31/−0.71/−0.16 (test 2), −1.09/−0.60/0.82 (test 3), 0.28/0.28/−0.82 (test 4). Conclusions: Cyclotorsion does not significantly change between seated and supine position in subjects with normal binocular vision and stable fixation. In these subjects, an erroneous refractive surgery due to incorrect measurement of the axis of astigmatism in the seated position and performing the refractive surgery in the supine position, is very unlikely.

Heilungsverlauf und Komplikationen nach Augenmuskeloperationen

Hintergrund: Zur Inzidenz operativer und postoperativer Komplikationen bei Augenmuskeloperationen liegen unterschiedliche Mitteilungen vor. Ziel der vorliegenden Studie war es, sowohl Komplikationen als auch geringfügige pathologische Veränderungen des vorderen und hinteren Augenabschnittes nach unterschiedlichen Augenmuskeloperationen zu quantifizieren. Patienten und Methode: Es wurden prospektiv alle Patienten erfaßt, bei denen im Zeitraum Januar bis Mai 1998 an der Augenklinik für Schielbehandlung und Neuroophthalmologie Gießen eine Augenmuskeloperation durchgeführt wurde. In die Studie konnten 500 Augen von 377 Patienten im Alter von 2 bis 82 Jahren einbezogen werden. Das Spektrum der durchgeführten Eingriffe umfaßte Rücklagerungen, Resektionen, Faltungen, kombinierte Operationen, Transpositionen, Fadenoperationen und Revisionsoperationen an allen geraden und schrägen Augenmuskeln. Die Patienten wurden am Tag vor der Operation und postoperativ am ersten Tag, nach einer Woche und nach drei Monaten untersucht. Alle Komplikationen des vorderen und hinteren Augenabschnittes wurden dokumentiert und quantitativ erfaßt, teilweise erfolgte eine Gradeinteilung (0–3). Ergebnisse: Am ersten postoperativen Tag war bei 30% der Augen eine zumeist diskrete Lidschwellung auffällig. Die Bindehautschwellung und -injektion waren meist gering bis mäßig, nach einer Woche häufig nur noch gering. Der Reizzustand der Bindehaut war geringer nach Faltung als nach Resektion eines horizontalen M. rectus. Bei den Hornhautveränderungen dominierte am ersten postoperativen Tag eine Epitheliopathie (1,6%), nach 1 Woche standen diskrete Fuchssche Dellen (4,3%) im Vordergrund, die unter lokaler Therapie abheilten. Mikroskopisch erkennbare Bindehautfalten wurden überwiegend zur 3-Monats-Kontrolle (14,3%) dokumentiert, ebenso Bindehautnarben (91,3%), die i.d.R. sehr gering waren. Perforationen oder schwerwiegende Komplikationen kamen nicht vor. Schlußfolgerungen: Eine Augenmuskeloperation ist ein komplikationsarmer Eingriff, der nur selten einen erneuten Eingriff wegen organischer pathologischer Veränderungen erfordert. Zur Erkennung von Fuchsschen Dellen ist eine Kontrolluntersuchung 4–7 Tage postoperativ wichtig. Faltung eines horizontalen M. rectus führt zu weniger Bindehautreiz als Resektion.Background: Varying reports on the incidence of operative and postoperative complications following eye muscle surgery have been published. The purpose of this study was to quantify complications after various types of eye muscle surgery as well as minor pathological changes of the anterior and posterior segment. Patients and methods: This prospective study included all patients who underwent eye muscle surgery at the Department of Strabismology and Neuroophthalmology, Giessen, from January to May 1998. Five hundred eyes of 377 patients aged 2–82 years were included. The spectrum of procedures comprised: recessions, resections, tucks, R&R procedures, transpositions, bimedial retroequatorial myopexies, and revisions of rectus and oblique muscles. All patients were examined 1 day preoperatively and 1 day, 1 week, and 3 months postoperatively. Any complications and even minor pathological changes of the anterior and posterior segment were documented. Some changes were assessed by means of a score (0–3). Results: One day postoperatively, 30% of eyes had inflammatory pseudoptosis, most of them mild. Conjunctival swelling and injection were frequently mild and moderate, after 1 week mostly mild. Conjunctival irritation was more pronounced following resection than tucking. Punctate epithelial keratopathy was noted in 1.6% of cases (first postoperative day), dellen in 4.3% (first postoperative week). Three months postoperatively, 14.3% of eyes had biomicroscopically visible conjunctival folds and 91.3% had minimal conjunctival scars. None of the patients had a scleral perforation or other serious complication. Conclusions: Eye muscle surgery rarely entails complications. Revisions due to organic pathological changes are extremely rare. Possible development of dellen requires check-up 4–7 days postoperatively. Tucking of rectus muscles causes less conjunctival irritation than resection.

Vergleich von Landoltring- und ETDRS-Buchstaben-Sehschärfe bei Augengesunden und Patienten mit unterschiedlichen Augenerkrankungen

PURPOSE Results of visual acuity determination can differ depending on the stimuli being used, even if their critical details appear under the same visual angle. In this study, visual acuity measured with the Landolt C was compared to acuity measured with ETDRS charts in subjects with and without visual disorders. PATIENTS AND METHODS One hundred patients (age 8 to 90 years) with strabismus amblyopia (39), refractive amblyopia (5), cataract (24) and maculopathy (32) as well as 13 healthy volunteers (age 18 to 33 years) were examined. Retro-illuminated ETDRS 1, 2 and R charts (Lighthouse) and a retro-illuminated Landolt C chart with the same arrangement of optotypes (Precision Vision) were used. Three out of 5 optotypes in each line had to be correctly identified. In the patient group, the eyes with the lower visual acuity were tested, while the right eyes of the healthy subjects were monitored. Wrong answers were monitored and the results were noted in interpolated logMAR. RESULTS Differences between Landolt C (LC) and ETDRS acuity were only small and statistically not significant. LogMAR values (SEM in parentheses) for LC /ETDRS 1 were: entire group: 0.60 (0.04)/ 0.55 (0.04), strabismus amblyopia: 0.85 (0.08)/ 0.80 (0.08), refractive amblyopia: 0.27 (0.04)/ 0.23 (0.05), cataract: 0.57 (0.07)/ 0.51 (0.07), retinal disease: 0.67 (0.06)/ 0.61 (0.06), healthy eyes: -0.17 (0.03)/ -0.17 (0.02). The mean difference between LC and ETDRS 1 was 0.49 lines in the entire group and 0.51 lines in strabismus amblyopia in favour of ETDRS 1 values. ETDRS 2 and R charts yielded similar results. CONCLUSIONS In healthy subjects and in patients with various eye disorders including strabismus amblyopia, there was only a slight difference between visual acuity measured by ETDRS charts compared to the Landolt C. Comparing data of different settings it must be considered that in the lower visual acuity range (< 0.32), the mean ETDRS acuity of adults overestimates the Landolt C acuity by 0.5 and 1.0 line.

Reproducibility of Visual Acuity Assessment in Normal and Low Visual Acuity

Purpose To assess the reproducibility of measurements of visual acuity in both the upper and lower range of visual acuity. Materials and methods The retroilluminated ETDRS 1 and ETDRS 2 charts (Precision Vision) were used for measurement of visual acuity. Both charts use the same letters. The sequence of the charts followed a pseudorandomized protocol. The examination distance was 4.0 m. When the visual acuity was below 0.16 or 0.03, then the examination distance was reduced to 1 m or 0.4 m, respectively, using an appropriate near correction. Visual acuity measurements obtained during the same session with both charts were compared. A total of 100 patients (age 8–90 years; median 60.5) with various eye disorders, including 39 with amblyopia due to strabismus, were tested in addition to 13 healthy volunteers (age 18–33 years; median 24). At least 3 out of 5 optotypes per line had to be correctly identified to pass this line. Wrong answers were monitored. The interpolated logMAR score was calculated. In the patients, the eye with the lower visual acuity was assessed, and for the healthy subjects the right eye. Differences between ETDRS 1 and ETDRS 2-acuity were compared. Results The mean logMAR values for ETDRS 1 and ETDRS 2 were -0.17 and -0.14 in the healthy eyes and 0.55 and 0.57 in the entire group. The absolute difference between ETDRS 1 and ETDRS 2 was (mean ± standard deviation) 0.051 ± 0.04 for the healthy eyes and 0.063 ± 0.05 in the entire group. In the acuity range below 0.1 (logMAR > 1.0), the absolute difference (mean ± standard deviation) between ETDRS 1 and ETDRS 2 of 0.072 ± 0.04 did not significantly exceed the mean absolute difference in healthy eyes (p = 0.17). Regression analysis (|ETDRS 1 – ETDRS 2| vs. ETDRS 1) showed a slight increase of the difference between the two values with lower visual acuity (p = 0.0505; r = 0.18). Discussion Assuming correct measurement, the reproducibilty of visual acuity measurements in the lower acuity range is not significantly worse than in normals.

Supplementierungsmedikamente beim Einsatz der Larynxmaske in der Kataraktchirurgie

ZusammenfassungHintergrund. Bei Patienten, die zur Kataraktoperation eine Propofol-Narkose mit Larynxmaske erhalten, verglichen wir den intraokularen Druck (IOD), den Glaskörperdruck und verschiedene anästhesiologische Parameter bei unterschiedlichen Narkoseregimen unter besonderer Berücksichtigung der Wirkung von S-Ketamin, der linksdrehenden Form des Racemats Ketamin. Patienten und Methoden. Vier Gruppen mit je 15 Patienten (randomisiert), Kataraktoperation (Phakoemulsifikation); Narkoseeinleitung und -fortführung mit Propofol, Larynxmaske und möglichst unter Spontanatmung mit Zuführung eines Sauerstoff-Lachgas-Gemisches; Supplementierung mit Propofol (0,6 mg/kg, Gruppe 1), S-Ketamin (0,3 mg/kg, Gruppe 2), Ketamin (0,6 mg/kg, Gruppe 3) oder Fentanyl (0,5 μg/kg, Gruppe 4); IOD-Messung mittels Tonopen XL zu verschiedenen Zeitpunkten und Beurteilung des intraoperativen Glaskörperdrucks (Score von 0–3). Ergebnisse. Sowohl beim IOD als auch beim Glaskörperdruck zeigte keines der verwendeten Medikamente einen signifikanten Unterschied. Das Einsetzen der Larynxmaske führte nicht zu einem signifikanten IOD-Anstieg. Die Spontanatmungsrate lag in der Fentanyl-Gruppe niedriger als in den anderen Gruppen. Hinsichtlich der Aufwach- und Extubationszeiten sowie unerwünschter Nebenwirkungen ergaben sich keine signifikanten Unterschiede. Schlussfolgerung. S-Ketamin hatte in unseren Untersuchungen keinen signifikanten Einfluss auf den IOD und den Glaskörperdruck. S-Ketamin bietet ein sicheres “Handling” der Patienten durch die rasche Rückkehr zur Spontanatmung bei guter Analgosedation. Außerdem ist die Dosisbelastung gegenüber dem Racemat niedriger.AbstractBackground. We compared intraocular pressure (IOP), vitreous pressure and several anaesthesiological parameters for patients who underwent cataract surgery with propofol anaesthesia, laryngeal mask and different supplementations with reference to the effect of S-ketamin in particular. Patients and methods. In 4 groups with 15 patients cataract surgery (phacoemulsification) was carried out using anaesthesia with propofol, laryngeal masks and spontaneous breathing if possible, supplementation with propofol (0.6 mg/kg, group 1), S-ketamin (0.3 mg/kg, group 2), ketamin (0.6 mg/kg, group 3) or fentanyl (0.5 μg/kg, group 4); IOP measurement with tonopen XL and scoring vitreous pressure at different times during anaesthesia (score 0–3). Results. For IOP and vitreous pressure, none of the different supplementations showed a significant difference. Insertion of the laryngeal mask did not cause a rise in intraocular pressure. The number of patients with spontaneous breathing during the operation in group 4 was significantly lower than in groups 1–3. No significant differences were observed between the different anaesthesiological parameters. Conclusion. S-Ketamin had no significant effect on IOP and vitreous pressure during phacoemulsification. It offers a safe “handling” of patients because of a high spontaneous breathing rate and lower concentration compared to Ketamin.