Electrical activity of the orbicularis muscles before and after installation of ocular prostheses

Effect of Rehabilitation with a New Ocular Prosthesis on Electromyography of the Occipitofrontalis, Temporal, Masseter, and Sternocleidomastoid

Objectives  The aim of this study was to verify during facial expressions (“happy,” “sad,” “fearful,” “angry,” “surprised,” and “disgusted”) if: (1) there would be difference in the electromyography (EMG) of the occipitofrontalis, temporal, masseter, and sternocleidomastoid muscles on the normal side (NS) compared with the affected side (AS) (without the use of an ocular prosthesis) in individuals with unilateral absence of the eyeball, and (2) the rehabilitation with a new ocular prosthesis would affect the EMG of the muscles studied on the AS in these individuals.

Materials and Methods  Thirteen individuals, without temporomandibular disorder, with good health, with unilateral absence of the eyeball (the eye must have been removed by evisceration or enucleation), and users or nonusers of an ocular prosthesis were included. EMG of the occipitofrontalis, temporal, masseter, and sternocleidomastoid muscles was performed during rest and facial expressions (“happy,” “sad,” “fearful,” “angry,” “surprised,” and “disgusted”) before (T0) and 90 days after (T1) rehabilitation with a new ocular prosthesis. The analyses were performed in T0 on NS and AS (without the use of an ocular prosthesis), and in T1 on AS with the new ocular prosthesis.

Statistical Analysis  All data were submitted to the Student's t -test with p  < 0.05.

Results  There was no statistically significant difference comparing the AS with the NS in T0 for all muscles studied, during all facial expressions evaluated ( p  > 0.05). There was no statistically significant difference comparing the AS in T0 with itself in T1 for all muscles studied, during all facial expressions evaluated ( p  > 0.05).

Conclusion  Eye loss did not affect the EMG of studied muscles when comparing NS with AS (without the use of an ocular prosthesis). The rehabilitation with ocular prosthesis was not capable of changing the EMG on AS.

Prostetic Rehabilitation of an Eye Globe: Case Report

Introduction

The lack of an eye has an immediate and long-term impact on a patient's life.

Aim

The aim of this study is to show a case of prosthetic rehabilitation of an eyeball.

Case report

Male patient, 60 years old, sought care at the Oral Oncology Center of the São Paulo State University "Júlio de Mesquita Filho", for the rehabilitation of the orbital cavity with an acrylic eye prosthesis. This prosthesis was made with thermopolymerizable acrylic resin and hand painted iris with oil paint on cardboard. The prosthesis was installed after finishing and polishing and the hygiene and general care instructions were explained.

Conclusion

In the present case, the patient was satisfied with the aesthetics and comfort of the prosthesis, which demonstrates the success of the treatment.

Trigeminal brainstem modulation of persistent orbicularis oculi muscle activity in a rat model of dry eye

Altered corneal reflex activity is a common feature of dry eye disease (DE). Trigeminal sensory nerves supply the ocular surface and terminate at the trigeminal interpolaris/caudalis (ViVc) transition and spinomedullary (VcC1) regions. Although both regions contribute to corneal reflexes, their role under dry eye conditions is not well defined. This study assessed the influence of local inhibitory and excitatory amino acid neurotransmission at the ViVc transition and VcC1 regions on hypertonic saline (HS) evoked orbicularis oculi muscle activity (OOemg) in urethane-anesthetized male rats after exorbital gland removal (DE). HS increased the magnitude of long-duration OOemg activity (OOemgL, >200ms) in DE compared to sham rats, while short-duration OOemg activity (OOemgS, <200ms) was similar for both groups. Inhibition of the ViVc transition by muscimol, a GABAA receptor agonist, greatly reduced HS-evoked OOemgL activity in DE rats, whereas injections at the VcC1 region had only minor effects in both groups. Blockade of GABAA receptors by bicuculline methiodide at the ViVc transition or VcC1 region increased HS-evoked OOemgL activity in DE rats. Blockade of N-methyl-D-aspartate (NMDA) receptors at either region reduced HS-evoked OOemgL activity in DE and sham rats. GABAαβ3 receptor density was reduced at the ViVc transition, while NMDA receptor density was increased at both regions in DE rats. Loss of GABAergic inhibition at the ViVc transition coupled with enhanced NMDA excitatory amino acid neurotransmission at the ViVc transition and the VcC1 region likely contribute to altered corneal reflexes under dry eye conditions.

Rehabilitation of atrophic anophthalmic cavity with orthostatic ocular prosthesis: A clinical report

The absence of the eyeball can generate psychosocial and facial harmony changes, such as atrophy of the muscles around it. In these cases, the use of an orthostatic prosthesis with expanding function fosters distension of the tissues for subsequent rehabilitation. This technique consists of making individual ocular prostheses with gradual enlargement of size. The aim of this following clinical report was to describe the technique used in the standing prosthetic rehabilitation of a patient, 73 years old, who underwent enucleation of the right eye as a result of glaucoma. Clinical and laboratory procedures were performed such as impression, adjusting curvature of the sclera, centering the pupil area and processing in heat-cured acrylic resin three prostheses made according to the expansion of the anophthalmic cavity. At the end of treatment, there was a considerable increase of the cavity, allowing for volume replacement similar to that existing in the patient's contralateral orbit, thus generating a satisfactory facial harmony.