Introduction

With increasing age a patient may suffer from different visual complaints which the ophthalmologist cannot always explain by evident pathologic findings. If a patient states reduced vision we routinely check the refraction and prescribe new glasses, probably we will operate a cataract, treat a retinal disease or glaucoma; but only exceptionally is blurred vision considered to be a disorder of binocularity. Subsequently, such patients will feel their problems to be unsolved and will change from one doctor to the next. The difficulty in diagnosing the loss of binocularity, caused by a small eye deviation, derives from an absence of diplopia; the subjectively given symptoms are vague and indistinct.

Patients and Clinical Features

Only two essential examples are described.

Patient 1

A chemist, aged 76, complained of bad vision. He had been treated for glaucoma elsewhere; the eye tension was well adapted, the visual fields showed intermediate defects. The best corrected Visual Acuity (VA) monocular was RE: 0.8 - 1.0, LE: 0.7 - 0.8; but the binocular vision deteriorated to 0.6 - 0.8, the test objects seemed to be blurred. Findings like these are a clue to binocular problems. In fact there was a manifest distant deviation of +6° and a latent near angle of +1°. Prisms of 6Δ base out - added to the distance glasses - immediately produced clear vision for distance. The diagnose was: Age-related Distance Esotropia without diplopia, due to visual field defects caused by the glaucoma.

Patient 2

Female, aged 78, suffered from age-related maculopathy L > R, corrected VA: RE 0.6 text, LE no reading ability. The complaints were: Reading only possible when closing the worse eye. Binocular findings: Orthophoria for distant fixation but divergent position of the left eye of -12Δ while reading. A press-on prism 12Δ base in was applied to the left reading glass. Immediately, and both eyes open, the patient had clear vision and could read size 0.6 quickly. Three months later the power of the prismatic folia was reduced to 8Δ.

Diagnostic methods and fitting of prisms are described in previous publications, see literature [1,2].

Conclusions

Restoring of binocularity, even for eyes having reduced vision, is of high importance for the quality of life, not only of elderly patients.

Summary

The onset of a squint position is not uncommon in the later years of life and is easily diagnosed through the symptom of double vision; exceptional cases lacking diplopia are often overlooked. If someone had good binocular vision in former years, a certain sensation makes the patient feel something to be wrong; that may be described as “bad seeing”, “blurred vision”, “seeing of clouds” and “having to close one eye”. In most cases the absence of diplopia is due to limited central or paracentral visual field defects deriving from various eye diseases. The common types of newly developed squint positions we found to be: Age-related Distance Esotropia or Exotropia of the worse eye. In both cases the precise correction of the eye deviation by prisms and thus the restoration of the peripheral fusion will have the sudden effect of regaining clear vision.

Acknowledgements

I would like to thank Irene Manutscheri for copyediting the manuscript.

1. Stangler Zuschrott E. 2016. Geriatric orthoptics and non-paretic diplopia in adults. New York: Nova Science Publishers; 2016. p.126.
2. Stangler Zuschrott E. Diplopia developed in later life, an ophthalmologic approach. Geriatrics Health. UK. IntechOpen Limited; 2018. p. 9-26. https://goo.gl/DFGtZ7