To the editor,

A 67-year-old glaucoma man fell on level ground with left sided tripod fracture (Figure 1). He suffered from both eyes primary open angle glaucoma, but failed pharmacological treatment and trabeculectomy surgery. His visual field (VF) loss is extensive, (Figure 2), so left eye Baerveldt glaucoma implant, followed by right eye Ahmed glaucoma valve were implanted for intraocular pressure control.

Primary glaucoma, being a top cause of blindness worldwide, is generally more prevalent in elderly (1). Secondary glaucoma like angle closure, phacomorphic glaucoma are particularly related to aging cataract lens. Fall in geriatric glaucoma patients is not rare, and occasionally causes serious sequelae (2).

Vision assessment not only counts on visual acuity (VA), but also contrast sensitivity, colour vision and VF. In geriatric patients, both near and distance VA should be assessed, as uncorrected presbyopia is common cause for poor vision, where management is simply a pair of glasses. VA charts’ testing with black letters on white background is under high contrast, thus possibly missing early diagnosis of glaucoma patients who suffered slight decrease in contrast sensitivity only (3). Loss in contrast sensitivity is associated with increased falls in elderly, and sometimes explain discrepancy between reasonable acuity in clinic, but poor functional vision in dimly lit elderly home (4). Vistech chart, Pelli-Robson chart or Cambridge chart are possible testing tools for contrast sensitivity, and aiding diagnosis of low vision and glaucoma. Most optic neuropathies give characteristic red-green colour deficiency, however in early glaucoma, blue-yellow colour deficiency is detected instead (5).

VF testing helps detecting and monitoring diseases of optic nerve and intracranial visual pathway. Normal VF is 50, 60, 70 and 90-degree respectively over superior, nasal, inferior and temporal directions. However, refractive status, VA, presence of dermatochalasis, senile ptosis and tremor in old people could hinder a reliable interpretation of VF defect. In clinic, simplest qualitative method for peripheral VF is by confrontation, whereas central 10-degree by Amsler grid. For more accurate and detailed quantification, perimetry could be used. Kinetic perimetry is based on a moving stimulus of known luminance from a non-seeing area to a seeing area. In contrast, static perimetry involves a static on-off stimuli of variable luminance presented throughout the potential field. Automated static perimetry is commonly used for glaucoma progression analysis, (Figure 2) yet patient’s cooperation and concentration is of paramount importance, which sometimes is difficult for the elderly.

Mobility helps people to navigate, driving and continue to use public transport with confidence. Elderly mobility is particularly affected by inferior and central field defects, and geriatricians should bear in mind for assessing rehabilitation potential. In glaucoma patients, common visual field defects include blind spot enlargement, nasal stepping, or paracentral scotoma in early stage; progressing to arcuate scotoma later, subsequently enlarging to become altitudinal field defects in late stage. Eventually, only residual temporal or central island of vision left form dense constriction of peripheral fields (Figure 2), before complete blindness occurs.

In conclusion, contrast sensitivity and VF are important parameters for vision assessment in elderly, coincidentally glaucoma causes loss in both.

Peer-review: Externally peer-reviewed.

Authorship Contributions

Concept: S.C.L.A.U., Design: S.C.L.A.U., Data Collection or Processing: S.C.L.A.U., Analysis or Interpretation: S.C.L.A.U., Literature Search: S.C.L.A.U., Writing: S.C.L.A.U., S.T.C.K.

Conflict of Interest: Authors have declared no conflicts of interest.

Financial Disclosure: The authors declared that this study received no financial support.