Glaucomatous visual fields and neurocognitive function are independently associated with poor lane maintenance during driving simulation

Vision rehabilitation in glaucoma patients

PURPOSE OF REVIEW

Vision rehabilitation services are important but underutilized resources for patients with glaucoma. Glaucoma and its impact on vision can affect patients' abilities to read and drive, two activities of daily living that are associated with quality of life and functional independence. In this review, we provide an overview of low vision, discuss barriers to vision rehabilitation, and outline various strategies and interventions to optimize visual function and quality of life in patients with glaucoma.

RECENT FINDINGS

Studies have shown that glaucoma negatively impacts reading, driving and overall quality of life. Decreased visual acuity, visual field loss and reduced contrast sensitivity play a role. Low vision services and interventions can help patients maximize visual function and improve their quality of life. Barriers to receiving these services exist at multiple levels and an increased awareness and integration into routine ophthalmic care are needed to deliver comprehensive care.

SUMMARY

Glaucoma is one of the leading causes of low vision. Ophthalmologists who treat glaucoma often tend to focus on objective measures to monitor progression and disease severity, but the functional impact of glaucoma should also be addressed. Low vision services can benefit patients, particularly for reading and driving, and should be considered as an essential component of patient care.

Peripheral visual field loss and activities of daily living

PURPOSE OF REVIEW

Peripheral visual field (VF) loss affects 13% of the population over 65. Its effect on activities of daily living and higher order visual processing is as important as it is inadequately understood. The purpose of this review is to summarize available literature on the impact of peripheral vision loss on driving, reading, face recognition, scene recognition and scene navigation.

RECENT FINDINGS

In this review, glaucoma and retrochiasmal cortical damage are utilized as examples of peripheral field loss which typically spare central vision and have patterns respecting the horizontal and vertical meridians, respectively. In both glaucoma and retrochiasmal damage, peripheral field loss causes driving difficulty - especially with lane maintenance - leading to driving cessation, loss of independence, and depression. Likewise, peripheral field loss can lead to slower reading speeds and decreased enjoyment from reading, and anxiety. In glaucoma and retrochiasmal field loss, face processing is impaired which impacts social functioning. Finally, scene recognition and navigation are also adversely affected, impacting wayfinding and hazard detection leading to decreased independence as well as more frequent injury.

SUMMARY

Peripheral VF loss is an under-recognized cause of patient distress and disability. All peripheral field loss is not the same, differential patterns of loss affect parameters of activities of daily living (ADL) and visual processing in particular ways. Future research should aim to further characterize patterns of deranged ADL and visual processing, their correlation with types of field loss, and associated mechanisms.

A Novel Approach to Measuring Binocular Visual Fields in Glaucoma

PRECIS

Combined average visual field index (VFI) is a simple, novel tool for binocular visual field which agrees with the existing binocular integrated visual field (IVF) model, as well as patient reported activity limitation in glaucoma.

PURPOSE

The aim was to determine the correlation between novel models of binocular visual field with the existing IVF and glaucoma activity limitation (GAL-9).

MATERIALS AND METHODS

IVFs were calculated from the monocular visual fields of 58 patients with primary glaucoma and the novel binocular visual field models termed binocular summation visual field index (BiSumVFI) and combined average visual field index (CaVFI) were derived from the VFIs of both fields. GAL-9 questionnaire was administered to the patients. The relationship between IVF and the 2 newer models of binocular fields were determined and the correlation of IVF, BiSumVFI, and CaVFI with GAL-9 was estimated.

RESULTS

A very strong correlation was seen between IVF and BiSumVFI (r=-0.913, P<0.001, confidence interval: -0.958 to -0.821) and also between IVF and CaVFI (r=-0.896, P<0.001, confidence interval: -0.947 to -0.802). Linear regression analysis showed a significant R2 of 0.902 (P<0.001) to predict IVF from BiSumVFI and R2 of 0.847 (P<0.001) to predict IVF from CaVFI. IVF, BiSumVFI, and CaVFI correlated moderately and significantly with GAL-9 with correlation coefficients of 0.481, -0.499, and -0.505, respectively.

CONCLUSION

The binocular summation VFI and combined average VFI models of binocular visual field are good predictors of IVF in glaucoma. They correlate well with the existing IVF model in estimating patients' perception of activity limitation in glaucoma.

Vision, attention, and driving

Safe driving demands the coordination of multiple sensory and cognitive functions, such as vision and attention. Patients with neurologic or ophthalmic disease are exposed to selective pathophysiologic insults to driving-critical systems, placing them at a higher risk for unsafe driving and restricted driving privileges. Here, we evaluate how vision and attention contribute to unsafe driving across different patient populations. In ophthalmic disease, we focus on macular degeneration, glaucoma, diabetic retinopathy, and cataract; in neurologic disease, we focus on Alzheimer's disease, Parkinson's disease, and multiple sclerosis. Unsafe driving is generally associated with impaired vision and attention in ophthalmic and neurologic patients, respectively. Furthermore, patients with ophthalmic disease experience some degree of impairment in attention. Similarly, patients with neurologic disease experience some degree of impairment in vision. While numerous studies have demonstrated a relationship between impaired vision and unsafe driving in neurologic disease, there remains a dearth of knowledge regarding the relationship between impaired attention and unsafe driving in ophthalmic disease. In summary, this chapter confirms-and offers opportunities for future research into-the contribution of vision and attention to safe driving.