Prolonged preoperative prismatic treatment in alternating convergent squint.

Our 10-year retrospective study includes 178 children below the age of 10 years, operated for alternating convergent squint. Inclusion criteria were: Absence of amblyopia and an angle of squint less than 45 pdpt so that alignment of the eyes in only one operation could be expected. One hundred children received preoperatively a prismatic correction of the distance deviation for a period of 6-15 months; 78 cases were treated with glasses and occlusion. In the prism-treated group a significantly better alignment (p = 0.0001) with a motorial gain of 7-8 pdpt was observed 6 months after surgery; also better sensorial results with significantly (p = 0.0001) more cases of stable NRC or harmonious ARC and improved binocularity were achieved. Unlike the type of esotropia, the preexisting retinal correspondence significantly influenced the motorial outcome (p < 0.05). Fewer reoperations were necessary in the prism-treated group (p = 0.001). Our results indicate that a prolonged prismatic correction is an effective preoperative treatment in patients with alternating convergent squint.

Influence of existing retinal correspondence on the results of squint operations in alternating convergent strabism.

In our study we examined the influence of existing retinal correspondence on the result of squint operations for alternating convergent strabism. 157 patients under 10 years of age at the time of their first or only operation were included. They were divided into groups, depending on their age at the onset of squint and subgroups according to their type of retinal correspondence. The development of distance and near deviation was investigated separately. Covariance analysis demonstrated that the preoperative sensorial state is a predictor for the motor outcome of surgery with regard to postoperative distance deviation. Statistically we found at least noticeable results (p < 0.15) in all groups of patients--for acquired esotropia a significant result (p < 0.01). With regard to the postoperative near deviation we found a significant influence of the preoperative sensorial state only in the group of patients with a late onset of squint (p = 0.05). For patients with an earlier onset (before the 30th month) of strabismus, the preoperative angle of near deviation proved to have a significant impact on the postoperative development of near deviation (p < 0.05). Sensorio-motorial adaptational phenomena in esotropia are presumed to be the major cause for this difference.

Effect of levodopa on contrast sensitivity and scotomas in human amblyopia.

The neurotransmitter dopamine (DA) is involved in several visual functions. Visual deprivation decreases retinal DA concentration in chickens and monkeys. In animals with deprivation amblyopia, several studies suggest that neurotransmitters are involved in visual-cortical plasticity and can restore partial visual acuity in adult cats. We investigated in a cross-over, double-masked study the influence of levodopa on contrast sensitivity and binocular suppression in human adult strabismic and amblyopic patients. After one single administration of levodopa, a significant increase in contrast sensitivity and decrease of the size of the fixation point scotoma was found. No changes could be detected after placebo administration. Levodopa did not induce changes in contrast sensitivity in the dominant eyes of the patients or in normal subjects. In conclusion, we found a short-term effect of levodopa on contrast sensitivity and fixation point scotomas in amblyopic eyes of adult patients.

[Decreased reading speed and rapid fatigue as signs of disordered visual function]. / Verminderte Lesegeschwindigkeit und rasche Ermüdbarkeit als Zeichen der gestörten Sehfunktion.

Monocular and binocular reading curves of 20 patients (4 with cataract, 5 with glaucoma, 11 with maculopathy) were recorded by infrared oculography. Reading speed was found to be directly proportional to the visual acuity of the eye tested. However, the same visual acuity in both eyes does not always mean that the subject reads at the same speed with both eyes. For example, paracentral visual field defects impair reading ability and eyes which appear to have good vision may easily become tired. Twelve of 16 examined eyes with maculopathy showed a significant decrease in reading speed during a reading test lasting no more than 2 minutes. In tests of the same duration cataract patients did not tire; their reading speed increased. Binocular vision helps improve reading speed in cases of maculopathy, and even more so in cases of glaucoma with visual field defects. Attention is drawn to Mackensen's suggestion that measurement of reading speed is a valuable function test, and to the fact that in certain cases fatigue of an eye during reading is a new and measurable criterion of the degree of visual impairment.

[Disorders of eye movements in point fixation of the dominant eye in unilateral deprivation amblyopia, squint amblyopia and unilateral organ damage]. / Störungen der Okulomotorik während Punktfixation des führenden Auges bei einseitiger Deprivationsamblyopie, Schielamblyopie und einseitigem Organschaden.

In four juvenile patients with unilateral deprivation amblyopia three types of involuntary eye movement were identified by simultaneous binocular infrared reflection oculography (IROG). During apparent steady-point fixation of the dominant eye three cases showed sinusoidal pendular movements (type 1) of the amblyopic eye mainly in a horizontal and slightly in a vertical direction, amplitude (A) 1 to 4 degrees, frequency (F) 0.25-0.4 Hz; only one patient had similar movements with smaller deviations even in the fixing eye. In three cases disturbed fixation of the dominant eye was found, a lateral drift (type 2) up to 3 degrees followed by slow correcting movement (F 0.05-0.1 Hz). At the same time there were disjugate movements of the amblyopic eye, the movements of the two eyes resulting in variations in squint angle of up to 6-7 degrees. These movements of the weaker eyes were clinically observed by Ohm (1958) and were termed pendular flutter to distinguish them from nystagmus. This paper presents the first objectively recorded curves of these movements, and differentiates them according to the various types of movement. Type 3 is a fine jerky or pendular nystagmus (A = max. 1 degree, F = 1.0-2.8 Hz), which was also present in three cases. Two patients had a combination of all three types of motility disturbance. Four cases with unilateral organ lesions, either congenital or acquired in early infancy, were observed and compared. All these cases showed excessive pendular flutter (type 1)--horizontal in the case of the fixing eye and horizontal and vertical in the case of the weaker eye.(ABSTRACT TRUNCATED AT 250 WORDS)

[Disorders of binocular vision in amblyopic patients working at computer terminals]. / Störung des Binokularsehens Amblyoper bei der Bildschirmarbeit.

For the first time two cases are described with disturbances of binocular vision caused by subjective perception of positive scotomata in the amblyopic eye. The visual strain of working at a terminal leads to a slight increase in the squint angle; as a result, a paracentral scotoma may shift into the middle of the binocular visual field and impair the image quality of the fixing eye. Amblyopic subjects presenting with these symptoms are disqualified from working at VDUs. However, not every amblyopic is affected.

[Measurement of coaxial position in lens implants]. / Messung der Koaxialposition bei Linsenimplantaten.

Intraocular lens implantation occasionally causes binocular diplopia resistant to prismatic correction. Present methods of examination cannot determine the cause of this incurable diplopia. Therefore, a new method based on keratometry has been invented to allow qualitative and quantitative analysis of biomicroscopically undetectable decentration of intraocular lens implants producing asthenopic complaints. The present study investigates the type and frequency of intraocular lens decentration relative to the visual axis.

[Vital staining of the conjunctiva for prevention of epithelial implantation cysts]. / Vitalfärbung der Bindehaut zur Prophylaxe epithelialer Implantationszysten.

Selective vital staining with 1% toluidine blue makes short-term intraoperative differentiation of the conjunctiva from Tenon's capsule possible. It is used with advantage in operations where the anatomical situation is unclear to avoid displacement of conjunctival epithelium into deeper tissues and subsequent growth of cysts. Examples of its application are reoperations with excessive scars after squint or detachment surgery, wound dehiscence after enucleations, lacerated wounds after accidents, and as an aid for beginners in ophthalmic surgery.

[Comparative vision tests using objective and subjective testing methods in amblyopia]. / Vergleichende Visusuntersuchungen mit objektiven und subjektiven Prüfmethoden bei Amblyopen.

In 20 amblyopic eyes without reading ability a comparison was made between the visual acuity found by subjective tests and with the Catford Visual Acuity Apparatus, Kotowski's Visumeter and Lotmar's Moiré Visometer. These instruments all work on the basis of different physiological functions. The Kotowski Visumeter seems to be the best instrument for an expertise on the visual acuity of an amblyopic eye. With the test pattern moving from nasal to temporal the results corresponded to the patients reading ability in 16 cases (80%); 4 patients had poorer vision. With the checkerboard pattern moving temporonasally the average results were better than the patients' actual vision. The Catford apparatus gave results corresponding to the subjective reading test only in 12 cases (60%). Apparatus with interferometric scales are not suitable for objective visual testing of amblyopic subjects; the results they give are always much better than the actual vision of the patient.

[Squint operation in presbyopic patients]. / Schieloperationen an presbyopen Patienten.

Since it is well known that the eye musculature undergoes degenerative alterations in old age, the question arises whether squint operations are effective in presbyopic and elderly persons. Twenty-four patients with horizontal squint (average age 63 years) wanted the operation because of diplopia, asthenopia and, in a few cases, for cosmetic reasons; 5 patients were aphakic. The operation was successful in 20 cases. The principles of dosing the operation are essentially the same as for juvenile patients. However, specific difficulties in treating elderly patients arise from: (1) lack of accommodative convergence, as a result of which the squint angle difference between distance and near fixation is usually greater; (2) increasing rigidity of the eye muscles, which diminishes the range of fusion; as a result, the patient is unable spontaneously to compensate for minor squint deviations; (3) senile organic lesions of the bulbs further impair fusion. It is advisable to treat convergent squint by correcting the average deviation between distance and near fixation, preferably shortening the external recti. Cases of divergent squint should preferably be treated by correcting the smaller squint angle, with resection of the external recti. The older the patient is and the worse his fusion, the more precisely the operation has to be dosed. Orthoptic training helps in old patients too.

[Prescription of weak corrective lenses (author's transl)]. / Uber die verordnung von Brillen mit geringfügiger Korrektionswirkung.

Ophthalmological examinations of patients with asthenopic complaints should include measurement of fusion in addition to retinoscopy under cycloplegia and testing for heterophoria. If fusion is poor in the absence of heterophoria it is advisable to correct even small refractive errors up to 0.5 D; 63% of such patients are cured of complaints as a result and there is an improvement in almost all the others. On the other hand, only 22% of heterophoric patients are cured of their asthenopia by "weak" glasses, although 64% show an improvement.

[Eight years' prismatic treatment of convergent alternating squint (author's transl)]. / Acht Jahre Prismenbehandlung des Strabismus convergens alternans.

Two groups of 178 Children, treated and untreated by prisms, were examined 1 year after strabotomy. The advantage of prism treatment is clear from the 22% normalization of binocularity (compared with 11%), 51% normalization of retinal correspondence (compared with 22%), and 93% good cosmetic result (compared with 68%). However, in spite of prism treatment, binocular vision remains defective in 71% of cases of squint. A reexamination of the same persons 3.6 years on average after the operation shows the same tendency in both groups (with and without prism treatment): impairment of binocularity, decrease on angle of squint, increase in number of persons with good cosmetic result but defective binocular vision (77% of prism patients).

[Soft contact lenses with black center for occlusion treatment of amblyopia with excentric fixation and latent normal retinal correspondence (author's transl)]. / Zentrale okklusion mittels geschwärzter weicher Kontaktlinsen bei Amblyopen mit excentrischer Fixation und latenter normaler Netzhautkorrespondenz.

Soft contact lenses with a central black zone 6.5-8 mm in diameter were used for occlusion treatmnt in nine cases of severe amblyopia with excentric fixation, incurable by direct occlusion or pleoptics. All the patients, aged between five and 14 years, had latent normal retinal correspondence. The new principle of this treatment is to interrupt only bifoveal retinal rivalry but not the existing binocularity of peripheral retinas. Therefore, an existing angle of squint has to be corrected by prisms. After treatment lasting five to 18 months one case had normal vision, four had sufficient visual acuity to cope with daily reading requirements, while improvement was insufficient in four cases. Treatment is continuing.

[Cycloplegia with cyclopentolate for testing-refraction of children (author's transl)]. / Zykloplegie mit Cyclopentolat bei Refraktionsbestimmungen im Kindesalter.

A comparative study of the cycloplegic effect of 1% cyclopentolate and atropine or homatropine was done by means of Lindner's method of retinoscopy. In 53% of 1.5- to 6-year-old strabismic patients the hypermetropic refraction was higher (average 0.6 dpt) under the use of atropine, and in 27% of 6- to 11-year-old children cyclopentolate was more effective than homatropine (average 0.5 dpt). Therefore, atropine should be used for children with convergent squint up to 6 years, in order to get full correction of hypermetropia. In other cases cyclopentolate is preferable because of its rapid and strong efficiency of brief duration.

[Disturbing physiologic diplopia (author's transl)]. / Störende physiologische Diplopie.

Spontaneously observed physiologic diplopia seems to be a pathologic condition caused by a disturbance of high cerebral functions, especially of attention. In a personally observed case an organic psychosyndrome was present. The aetiology and an effective therapy are still unknown. Further studies of similar cases may promote explanation.

[Disturbances of fusion after extensive retinal haemorrhages in new-born infants (author's transl)]. / Fusionsstörungen nach ausgedehnten Netzhautblutungen bei Neugeborenen.

Follow-up examinations of 21 non-squinting children aged six revealed, that most children who had had extensive bilateral post-partum retinal hemorrhages had a significantly higher incidence of impaired range of fusion (25 degrees max.) as compared to the cases without perinatal hemorrhages. Not a single case of impaired fusion could be improved by orthoptic treatment. The disorder is assumed to be due to a discrete perinatal impairment of the cerebral optomotor centers.

[Spontaneous improvement of visual fusion by correction of minor anisometropia (author's transl)].

It is shown from two examples that spectacle correction of minor grades of anisometropia in children can be sufficient to allow them to fuse normally and to avoid asthenopic complaints caused by partial suppression of the image from one eye.