Schizophrenia and Orthoptic Conditions: A Literature Review

Purpose

A narrative review of the literature reporting ocular abnormalities in patients with schizophrenia was undertaken to determine the types and prevalence of orthoptic conditions in this patient cohort.

Methods

A systematic search of multiple databases yielded 1,974 studies published between January 1992 and January 2022. All were screened for relevance based on their title and abstract.

Results

Seventeen studies were included in the final review. Ocular abnormalities reported in schizophrenia included a high incidence of strabismus, reduced visual acuity and reduced stereopsis compared to controls. Additionally, eye movement abnormalities (including reduced smooth pursuit gain and increased prosaccade latency) were frequently reported. Reduced visual acuity was associated with negative symptoms and reduced quality of life in schizophrenia.

Conclusions

Orthoptists and eye care professionals should be aware that a higher incidence of strabismus, reduced visual acuity, reduced stereoacuity, and eye movement abnormalities are reported in patients with schizophrenia. Further research is required to determine whether, or to what extent, ocular abnormalities and visual disturbances influence or exacerbate the symptoms of schizophrenia, and whether there is an effect of schizophrenia medication on these orthoptic conditions.

Strabismus Surgery for Psychosocial Reasons-A Literature Review

Introduction

Strabismus surgery may be undertaken for visual benefit, to improve or eliminate diplopia symptoms, or to restore or improve binocular single vision (BSV). In patients without visual symptoms or expected visual benefit, strabismus surgery may still be undertaken if the presence of strabismus causes the patient psychosocial symptoms. To evaluate strabismus surgery undertaken for psychosocial reasons, evidence of postoperative outcomes in this specific cohort is needed.

Methods

A systematic search of the literature was conducted (1946-2023) to identify evidence where postoperative outcomes were reported for adult patients (age 18 years and above) who had undergone strabismus surgery for psychosocial reasons.

Results

Sixty-nine papers were included in the literature review. Most sources of evidence included patients within heterogeneous cohorts of strabismus surgery outcomes, with a range of symptoms and differing surgical aims.

Discussion

In adults who underwent strabismus surgery for psychosocial reasons, improved postoperative ocular alignment and/or improved health related quality of life (HRQoL) were common. Strabismus surgery outcomes appeared to be measured satisfactorily at three months postoperatively. Additional surgical outcomes, including an expanded field of vision, unexpected BSV, improved binocular summation, improved task performance and improved eye movements have been reported, but not fully investigated. There was a lack of consensus on how postoperative success should be defined and measured. A core outcome set for strabismus has been suggested and there is potential to add to the available evidence by investigating which outcome measures are most relevant to those with strabismus and psychosocial symptoms. There is a growing need for robust evidence in this specific subgroup of patients due to a lack of evidence specifically reporting postoperative outcomes in adults with strabismus and psychosocial symptoms.

Minimal reporting guideline for research involving eye tracking (2023 edition)

A guideline is proposed that comprises the minimum items to be reported in research studies involving an eye tracker and human or non-human primate participant(s). This guideline was developed over a 3-year period using a consensus-based process via an open invitation to the international eye tracking community. This guideline will be reviewed at maximum intervals of 4 years.

Evaluation of the Nystagmus Information Pack

Introduction:

In response to the need for easily accessible, high-quality information about nystagmus, the Nystagmus Information Pack was created and made freely available online in 2017. This study was undertaken to evaluate the content and accessibility of the Nystagmus Information Pack.

Methods:

Clinicians, eye clinic liaison officers (ECLOs), teachers, patients, families, and any person with an interest in nystagmus were invited to complete an online questionnaire about the content and accessibility of the Nystagmus Information Pack.

Results:

One hundred and sixty respondents completed the questionnaire. Respondents who had previously accessed the Nystagmus Information Pack (n = 49, 30.6%) reported the content was appropriate (86%), of sufficient detail (94%), and easy to understand (88%). Minor suggestions were made to improve the content. Respondents who had not accessed the Nystagmus Information Pack (n = 111, 69.4%) reported not being aware of the resource (90%) but had already accessed nystagmus information from a wide range of sources. Poor vision was a barrier to accessing the resource for a small number of respondents (4.5%).

Conclusion:

Some improvements to the content and accessibility of the Nystagmus Information Pack should be considered, in particular the format options in which it is available, to enable access in preferred formats and with poor vision. The availability of the Nystagmus Information Pack should be promoted and shared more widely, as the majority of respondents were unaware of the resource despite having an association with or interest in nystagmus.

Is a Depth Camera in Agreement with an Electromagnetic Tracking Device when Measuring Head Position?

Introduction

Clinicians typically observe and describe abnormal head postures (AHPs) and may also measure them. Depth cameras have been suggested as a reliable measurement device for measuring head position using face-tracking technology. This study compared a depth camera (Microsoft Kinect) to a gold standard electromagnetic tracking system (Polhemus device) to measure head position.

Method

Twenty healthy volunteers (mean age 21 years) had their head position simultaneously recorded using the depth camera (Kinect) and the electromagnetic tracking system (Polhemus). Participants were asked to make 30-degree head movements into chin up, chin down, head turn and head tilt positions. The head movement made and the stability of the head at each position were recorded and analysed.

Results

Compared to the electromagnetic tracking system (Polhemus), the depth camera (Kinect) always measured a smaller head movement. Measurements with the two devices were not statistically significantly different for turn right (P = 0.3955, p > 0.05), turn left (P = 0.4749, p > 0.05), tilt right (P = 0.7086, p > 0.05) and tilt left (P = 0.4091, p > 0.05) head movements. However, the smaller depth camera measurement of chin up and chin down head movements were statistically significant, chin up (P = 0.0001, p < 0.01) and chin down (P = 0.0005, p < 0.001). At each eccentric position, the depth camera (Kinect) recordings were more variable than the electromagnetic tracking system (Polhemus).

Conclusions

Compared to the electromagnetic tracking system (Polhemus), the depth camera (Kinect) was comparable for measuring head turns and tilts but was less accurate at measuring chin up and chin down head positions. Further research is needed before the depth cameras are considered for clinical recordings of head position.

How Does Vertical Reading Affect Reading Speed?

PURPOSE

Vertical reading is an adaptive reading strategy sometimes used in homonymous hemianopia. This study aimed to measure horizontal and vertical reading speeds in visually normal volunteers using the Radner Reading Chart.

METHODS

Fifteen orthoptic students, mean age 19.7 years, took part in this repeated measures study. Participants read sentences aloud from the Radner Reading Chart horizontally and rotated vertically, to read up and down the line. Words read correctly and the time taken to read each sentence were recorded.

RESULTS

Reading speeds were calculated (words read correctly per second) for horizontal text (2.95 words per second) and for vertical text, reading up the line (1.73 words per second) and reading down the line (1.57 words per second). Reading horizontal text was significantly faster than reading vertical text. Reading horizontal text was 1.22 words per second faster than reading text vertically up (p < 0.0001) and 1.38 words per second faster than text vertically down (p < 0.0001). There was no statistically significant difference between reading text vertically up the line and vertically down the line (0.16 words per second, p = 0.42).

CONCLUSION

Horizontal reading speed, measured with the Radner Reading Chart, was significantly faster than both vertical reading speeds. There was no significant difference between reading vertically up the line and reading vertically down the line. The slower time taken to read the vertically orientated sentences had a greater effect on reading speed than the number of errors made.

The Impact of Diplopia on Reading

Aim:

To compare the effect of induced vertical diplopia (small and large separation) on reading speed and accuracy.

Methods:

The Radner Reading Chart (RRC) was used to measure reading speed (correct words per minute (wpm)) and accuracy (percentage). Accuracy was measured using two different methods: ‘accuracy-omission’ where only the omission of a word reduced the score, and ‘accuracy-addition and omission’ where any error reduced the score. Three viewing conditions were created using Fresnel prisms on plano glasses: a control condition without diplopia (6 prism dioptres (Δ) base up (BU) over each eye), small separation vertical diplopia (3Δ BU right eye and 3Δ base down (BD) left eye) and large separation vertical diplopia (6Δ BU right eye and 6Δ BD left eye). Viewing conditions were counterbalanced to minimise order effects.

Results:

Twenty-four participants were included with a mean age of 20.1 years. The mean reading speed in the control condition was 156.90 wpm. Both diplopic conditions significantly reduced the reading speed compared to the control condition, small separation diplopia to 62.75 wpm (p < 0.001) and large separation diplopia to 105.71 wpm (p < 0.001). The mean reading speed with small separation diplopia was significantly slower than the mean reading speed with large separation diplopia (p < 0.01). Median accuracy scores in the control and the large separation diplopia conditions were 100% using both methods of measuring accuracy. The small separation diplopia condition significantly reduced accuracy to 92.86% (accuracy-omission method) and to 57.50% (accuracy-addition and omission method) compared to the control condition (p < 0.01) and the large separation diplopia condition (p < 0.05).

Conclusion:

When vertical diplopia was induced using Fresnel prisms, diplopia of smaller separation resulted in the greatest reduction in reading speed and accuracy, compared to without diplopia and large separation diplopia.

Simulation of Oscillopsia in Virtual Reality

Purpose:

Nystagmus is characterised by involuntary eye movement. A proportion of those with nystagmus experience the world constantly in motion as their eyes move: a symptom known as oscillopsia. Individuals with oscillopsia can be incapacitated and often feel neglected due to limited treatment options. Effective communication of the condition is challenging and no tools to aid communication exist. This paper describes a virtual reality (VR) application that recreates the effects of oscillopsia, enabling others to appreciate the condition.

Methods:

Eye tracking data was incorporated into a VR oscillopsia simulator and released as a smartphone app – “Nystagmus Oscillopsia Sim VR”. When a smartphone is used in conjunction with a Google Cardboard headset, it presents an erratic image consistent with oscillopsia. The oscillopsia simulation was appraised by six participants for its representativeness. These individuals have nystagmus and had previously experienced oscillopsia but were not currently symptomatic; they were therefore uniquely placed to judge the app. The participants filled in a questionnaire to record impressions and the usefulness of the app.

Results:

The published app has been downloaded ~3700 times (28/02/2018) and received positive feedback from the nystagmus community. The validation study questionnaire scored the accuracy of the simulation an average of 7.8/10 while its ability to aid communication received 9.2/10.

Conclusion:

The evidence indicates that the simulation can effectively recreate the sensation of oscillopsia and facilitate effective communication of the symptoms associated with the condition. This has implications for communication of other visual conditions.

Pressure sore incidence: a strategy for reduction

In this article, the author discusses how the Walsgrave Hospitals NHS Trust implemented a strategy to reduce the prevalence of hospital-acquired pressure sores. The role of the tissue viability nurse is emphasised as is the development of a staff education programme.

The levels of pain experienced with lower limb fractures

This paper gives an overview of a small study of practice in Coventry and Warwickshire Hospital. The study set out to discover how long male patients experienced unrelieved pain following admission to hospital with fractures to their lower limbs.

Terminally ill patients' expectations of nurses

This exploratory study was undertaken to discover what nursing behaviours terminally ill patients desire. To rank patients' attitudes and judgements a Q-sort consisting of 70 cards was used. The statements covered three categories: physical and psycho-emotional care of patients and psycho-emotional care of significant other/s. "I would like the nurse to help me remain at home for as long as possible" was the most favoured statement and the least favoured was: "I would like the nurse to talk to me about death and dying." The overall theme was that responsive rather than directive nursing behaviours were desired. Analysis identified five Factors from which a model of responsive nursing care was developed. Interpretation of the Factors indicated patients desired responsive nursing care that enabled them and their families to bring their own resources to the dying process, rather than having imposed upon them care which nurses deemed appropriate.