Costantino Schiavi

Effect of citicoline on visual acuity in amblyopia: preliminary results

Abstract•Background: Citicoline has been used to improve consciousness levels in cerebral trauma and as a complement for levodopa in Parkinsons disease. It has also been shown that severe glaucomatous visual field deficits improve for at least 4 months with the use of citicoline. In this paper, preliminary results are presented of an open and a double-blind study on the effect of citicoline in amblyopia.•Methods: The open study was started in 1991. Fifty patients with amblyopia were treated with citicoline (1000 mg i.m. daily for 15 days). They were selected from an age group beyond the plastic period of the visual system. Occlusion or other types of anti-amblyopic treatment were never used at the same time as citicoline. A double-blind study was conducted on 10 more patients, randomly assigned to a treatment or placebo group and followed for 6 months. A statistical test for repeated measures was performed on all the results.•Results: A statistically significant improvement in visual acuity was found both for the amblyopic and the sound eye in 46 of the 50 patients (92%). The behaviour was different for normal and amblyopic eyes. The improvement remained stable for at least 4 months. These results have been substantiated by the double-blind study. No side effects were observed.•Conclusion: Citicoline improves visual acuity, at least temporarily, in amblyopic patients beyond the plastic period of the visual system. Our results suggest that trials of citicoline as a medical treatment of amblyopia are warranted.

Cytidin-5′-diphosphocholine enhances the effect of part-time occlusion in amblyopia

Cytidin-5′-diphosphocholine (CDP-choline) has been shown to improve visual acuity (VA), Contrast Sensitivity and Visual Evoked Responses at least temporarily, in amblyopic patients beyond the plastic period of the visual system. In this paper results are presented of a study conducted on forty-five patients with amblyopia in one eye, aged 5–9 years and followed for one year. Of them, 15 (Group A) were treated with CDP-choline (500 mg daily for 10 days every six months); 15 (Group B) were treated with CDP-choline plus one hour of occlusion daily; 15 (Group C) were treated with one hour of occlusion daily. The final VA values were statistically different from the initial ones, for all three groups. Eleven of the Group A patients showed an improvement in VA after the first treatment; a gradual deterioration took place in 6 patients at the end of the fourth month; VA further improved in 9 patients after the second treatment. At the end of the year, VA was higher than at the beginning in 12 of the 15 patients. Group B had an improvement of VA in 13 patients, starting 10 days from the beginning of treatment. This improvement continued throughout the observation period. Group C had an improvement after one month, which continued for 8 months, without deteriorating. In conclusion CDP-choline enhances the effect of part-time occlusion. CDP-choline could be employed also in younger patients. Longer observation periods are still needed and better means of administration have to be found.

Surgical management of anomalous head posture because of horizontal gaze palsy or acquired vertical nystagmus.

AbstractPurpose To confirm the effectiveness of the Kestenbaum–Anderson principle in the surgical management of compensatory head posture because of horizontal gaze palsy and acquired vertical nystagmus.Methods Nine patients with anomalous head posture because of horizontal gaze palsy, and four patients with acquired vertical nystagmus and oscillopsia and compensatory torticollis underwent surgery according to the Kestenbaum–Anderson principle. As in the treatment of congenital nystagmus, the eyes have to be shifted in the orbits, in the direction of anomalous head posture. Homonymously based prisms were used preoperatively to assess the potential benefit of surgery. At the time of surgery, the clinical conditions of the patients had been stable for at least 1 year.Results After surgery, compensatory head posture and visual performances improved in all cases and the results remained stable for at least 2 years.Conclusions Contrary to what is generally believed, the ocular condition of the patients with compensatory head posture secondary to neurological causes can be often improved with surgery. The aim of surgery is obviously not to modify ocular motility, but rather to improve the head position.

Further evidence for the role of proprioception in space perception

In this paper results are presented of errors in spatial localization found after encircling procedures for retinal detachment both in the operated and in the normal eye. Also changes in spatial localization were found in strabismus patients in which a stretch on the operated muscle was exerted after an adjustable recession. In both groups of patients a manipulation of the eye muscle was performed without inducing an eye muscle imbalance in the retinal detachment patients and without modifying the eye position in the strabismus patients in which a stretch was exerted. These data provide further evidence in favour of the role of proprioceptive information in space perception.

Selective lesions of rabbit extraocular muscles injected with the anti-AChR immunotoxin saporin-mAb 73

Purpose. To evaluate the effects on extraocular muscles of a skeletal muscle-specific immunotoxin, saporin-mAb 73, as an alternative to botulinum toxin to induce a permanent correction of oculo-facial dystonias or some forms of ocular motility disorders. Methods. An immunotoxin was prepared with a monoclonal antibody (mAb 73) against acetylcholine receptors of skeletal muscle, linked to saporin, a type 1 ribosome-inactivating protein (RIP) from Saponaria officinalis. Sixteen New Zealand white rabbits were treated with a single injection of immunotoxin directly into the medial rectus muscle of one eye. Four different dosages of 2, 5, 20, or 50?ng saporin-mAb 73 were used. The rabbits were sacrificed at two, 7 and 14 days post-injection. The medial rectus muscle and the retractor bulbi muscle of both the injected and the fellow eyes were taken and serial sections were examined by light microscopy in a blinded manner. Results. Saporin-mAb 73, even at the dosage of 2 ng, brought about focal damage in the extraocular muscles of rabbits without histological changes in adjacent muscles. The histological examination revealed necrotic/apoptotic lesions restricted to the sites of inoculation and largely infiltrated by macrophages. No evident inflammatory reaction was detected at any time and neutrophils were substantially absent. At 14 days after injection, necrosis/apoptosis was still evident and the sclerotic reaction was minimal. Conclusions. The immunotoxin saporin-mAb 73 injections into the extraocular muscles of rabbits caused focal damage to the muscles. There was no significant inflammatory reaction and muscle fiber loss was present even at the lower doses. Although the lesions were followed for only 14 days, our results suggest that saporin-mAb 73 has potential to cause safe focal muscle damage but longer-term follow-up are needed to investigate the persistence of muscle weakness.

Automated measurement of strabismic deviation.

A new computerized method of performing automated measurements of the angle of strabismus is presented, based on an infrared television camera, an image analyzer, and a commercial computer. This automated system provides a strategy of examination for patients in whom strabismus is suspected and makes possible a qualitative and quantitative diagnosis of the type of strabismus. In the case of a paralytic deviation, the involved muscle can also be identified with this instrument. The raw data from the image processor are saved and enhanced digitally. The image can be retrieved via monitor or printer, and data can be saved on mass memory. With this instrument, it is possible to follow various diagnostic procedures for strabismus step-by-step and to answer the following questions: is strabismus present? Is it convergent, divergent, or vertical strabismus? What is the angle of deviation? Which is the paralytic or paretic muscle in the case of incomitant deviation?

Technique of simultaneous recording of EMG from various extraocular muscles under EOG control.

Abstract• With this technique simultaneous recording of EMG is shown from various extra-ocular muscles. Electrodes are applied in the muscles during surgical procedures and recordings are performed without discomfort in the following days. The electrical signals are acquired at large bandwidth, and various off-line elaborations are possible. Preliminary results as well as technical details are presented.

Personal Approach for Adjustable Sutures Technique

Adjustable sutures were used in 367 strabismus patients. The technique employed by the authors is described. It is based on the principle of leaving unknotted the suture at surgery. In this way an adjust ment is necessary for all cases. However, this approach is more reliable and less time consuming and thus more acceptable for the patients. Adjustable sutures have been used both for muscle recessions and resections. Results for different types of strabismus are analysed. Oblique adjustments of vertical recti are described, which are useful for correcting cyclodeviations.

Visual recognition time in strabismus: small-angle versus large-angle deviation.

Purpose To measure the possible differences in monocular detection time of a threshold visual acuity stimulus (recognition time [RT]) between patients with small-angle and large-angle strabismus. METHODS Ten patients with free alternating esotropia were tested (10 to 18 years old): five with small-angle esotropia (≤7°), five with large-angle esotropia (15° to 20°). Six age-matched normal subjects served as controls. The RT of the threshold stimulus was measured in both eyes sequentially for stimuli presented in the center of a computer monitor (RT 1). Moreover, we measured the time necessary for identifying the same threshold visual acuity stimulus generated on the computer screen in the moment in which fixation is taken up by one eye after occlusion of the second eye (RT 2). Using the same setting, RT was also measured monocularly in all strabismic and normal subjects who were originally looking at a luminous fixation point positioned horizontally at 6.5 and 15 degrees from the center of the monitor (RT 3). Results The multivariate analysis of variance for repeated measures indicated that there was no statistical difference in RT 1 between groups. The mean RT2 was significantly longer (p<0.001) in large-angle strabismic eyes when compared with that of normal control eyes. The mean RT 2 in small-angle strabismic eyes did not differ significantly from that of normal eyes. Finally, RT 3 (both at 6.5° and 15° of eccentricity) did not show any significant difference in the three different study groups. CONCLUSIONS The authors hypothesized that alternating strabismus patients may have a significant advantage in maintaining a small-angle deviation, as a large-angle deviation would require longer RT in the moment the deviated eye takes up fixation. It can be speculated that the extension of re-fixation movement, obviously shorter in small-angle strabismus patients, is the main factor responsible for longer RT occurring in large-angle strabismus patients.

Beta-endorphins in essential blepharospasm

The effect of the administration of adrenergic and serotoninergic substances on beta-endorphins was evaluated in four patients with essential blepharospasm. The lack of beta-endorphin release following administration of adrenergic agents demonstrated that this aminergic action on the hypothalamus-pituitary adrenal axis is modified in the presence of the essential blepharospasm.