Mirrorglasses in patients with Bechterew´s disease
H.-J. Grein1, F. Grehn1, F. J. Stein2
The visual orientation in patients with Bechterew´s disease, who suffer from an advanced kyphosis, is considerably restricted by the forward bend of the head and neck. The patients try to compensate the restricted field of gaze by a maximum supraversion of the eyes. This can cause discomfort and is limited by the orbital rim. Mirrorglases can help the patients to gain a relatively comfortable straight view, despite their fixed bow.
Case report: A 68 year old patient with Bechterew´s disease who had an advanced kyphosis complained a restricted straight ahead field of gaze. The facial plane was bent against the vertical axis by 50 degrees. Only by bending his knees he was able to erect his upper part of the body to gain a straight ahead view. The patient was supplied with special mirrorglases for kyphosis patients (Obrira Ltd., Rathenow). These glases are equipped with a pair of mirrors at one side of the frame. The bigger mirror at the lower rim of the frame projects a picture of the area in front of the patient to the smaler mirror at the upper rim of the frame. The patient can see an upright and non-reversed picture in the upper mirror. The mirrors are adjusted by the manufactoring company with the help of a lateral photography of the patient. A torsion of the head can be considered as well. The mirrorglasses are intended for far vision use. The angle of aperture allows a sufficient field of gaze: 20 degrees vertically by 40 degrees horizontally. If the patient has problems to concentrate on the projected picture, the lens will be frosted except a small central zone, that allows only to see the upper mirror.
After a short period of habituation, the patient continuously wore his mirrorglases for walking. He reported a significantly improved orientation and a higher quality of perception.
Conclusion: Special glases such as the mirrorglases for kyphosis patients can provide a significant improvement of mobility and a higher quality of life for distinct patients. It is important for opthalmologist as well as for opticians to be familiar with these special glases in order to give adequate advice to these patients.
1Department of Ophthalmology, University of Würzburg, Josef-Schneider-Str. 11, D-97080 Würzburg, Germany