Visual function, disability, and psychological impact of glaucoma

Multiple medications and quality of life of Nigerians with primary open angle glaucoma

PURPOSE

To determine the impact of multiple medications on the quality of life of primary open angle glaucoma (POAG) patients on medical treatment at Guinness Eye Centre Onitsha, Nigeria.

MATERIALS AND METHODS

Adult patients diagnosed with POAG who were undergoing medical therapy were selected through systematic sampling. They were asked to provide information on socio-demographic background, the number and types of glaucoma medications they were using and any adverse effects encountered while using these medications. The patients' quality of life was assessed by utilizing the National Eye Institute Visual Function Questionnaire-25 (NEI-VFQ-25) and all patients completed ocular examination. Data analysis was with Statistical Package for Social Sciences (SPSS) version 23.

RESULTS

One hundred and seventy-one patients, aged 40-83 years, mean 59.1 ± 11.1 were studied; there were 79(46.2%) males and 92(53.8%) females. One hundred and nine (63.7%) patients were on multiple medications. Side effects of treatment increased with increasing number of medications. The mean quality of life score in monotherapy group and double therapy group were 89.3 ± 15.8 and 80.2 ± 21.1 respectively; while that in ≥ triple therapy group was 78.9 ± 18.8. This decrease in mean quality of life score with increasing number of medications was statistically significant in bivariate analysis (P < 0.01), however, multiple regression analysis showed that the number of medications did not significantly affect the quality of life scores after adjusting for confounding variables(p = 0.881).

CONCLUSION

Among the patients studied, use of multiple medications, unlike visual acuity (VA) and severity of glaucoma, was not an independent predictor of quality of life.

Predicting visual field global and local parameters from OCT measurements using explainable machine learning

Glaucoma is characterised by progressive vision loss due to retinal ganglion cell deterioration, leading to gradual visual field (VF) impairment. The standard VF test may be impractical in some cases, where optical coherence tomography (OCT) can offer predictive insights into VF for multimodal diagnoses. However, predicting VF measures from OCT data remains challenging. To address this, five regression models were developed to predict VF measures from OCT, Shapley Additive exPlanations (SHAP) analysis was performed for interpretability, and a clinical software tool called OCT to VF Predictor was developed. To evaluate the models, a total of 268 glaucomatous eyes (86 early, 72 moderate, 110 advanced) and 226 normal eyes were included. The machine learning models outperformed recent OCT-based VF prediction deep learning studies, with correlation coefficients of 0.76, 0.80 and 0.76 for mean deviation, visual field index and pattern standard deviation, respectively. Introducing the pointwise normalisation and step-size concept, a mean absolute error of 2.51 dB was obtained in pointwise sensitivity prediction, and the grayscale prediction model yielded a mean structural similarity index of 77%. The SHAP-based analysis provided critical insights into the most relevant features for glaucoma diagnosis, showing promise in assisting eye care practitioners through an explainable AI tool.

Structure-function relationship of reading performance in patients with early to moderate glaucoma

PURPOSE

To assess reading performance in patients with mild to moderate primary open-angle glaucoma (POAG), and to determine the relationship between reading ability and visual field (VF), microperimetry, and optical coherence tomography (OCT) parameters.

METHODS

Reading performance of 30 POAG patients examined by the Minnesota Reading Acuity Chart (MNREAD) was compared to that of 21 age-matched controls collected from Ankara University in Turkey. Humphrey Field Analyzer (HFA) 24-2 SITA Standard and 10-2 patterns, and microperimetry were used for VF measurements. All subjects underwent OCT analysis for retinal nerve fiber layer thickness (RNFLT), optic nerve head (ONH) measurements, and ganglion cell inner plexiform layer thickness (GCIPLT). The linear relationship between reading parameters and VF, microperimetry, and OCT parameters was investigated. Univariate and multiple logistic regression models were used to identify the risk factors for glaucoma.

RESULTS

In POAG patients, maximum reading speed (MRS) had a significant association with average rim area, mean cup-to-disc ratio (CDR), and cup volume (p < 0.05, for all). Decreased MRS was associated with thinner average GCIPLT and inferotemporal, superior, and inferior GCIPLT quadrants (p < 0.05, for all). Global index values for the HFA 24-2/10-2 tests, microperimetry, and ONH/RNFLT parameters had no correlation with reading performance. After accounting for the better and worse eyes, gender, education, age, and visual acuity of the glaucoma patients, MRS score was 23 units lower in the worse eye (p = 0.009), critical print size (CPS) was 0.21 units larger in the better eye (p = 0.03) and 0.25 units larger in the worse eye (p < 0.001), reading accesibility index (ACC) was 0.11 units lower in the better eye (p = 0.02) and 0.13 units lower in the worse eye (p = 0.002), and RA was 0.13 units higher in the worse eye (p = 0.003) of POAG patients.

CONCLUSION

POAG had significantly lower reading performance when compared to healthy subjects. Reading speed was associated with decreased macular GCIPLT indicating that reading performance may be affected in the earlier stages of the disease.

Abilities of circumpapillary retinal nerve fiber layer thickness and vascular density to discriminate stages in primary open-angle glaucoma

PURPOSE

To clarify the abilities of circumpapillary retinal nerve fiber layer thickness (cpRNFLT) obtained by optical coherence tomography (OCT) and circumpapillary vessel density (cpVD) measured by OCT-angiography to distinguish different stages in primary open-angle glaucoma determined by 24-2 or 30-2 static visual field (VF) testing.

METHODS

This retrospective study includes 25 healthy normal eyes of 25 subjects and 87 primary open-angle glaucoma eyes of 87 patients. Areas under the receiver operating characteristic curves (AUROC) were evaluated for determining glaucoma stages using cpRNFLT and cpVD. The absolute errors of the estimated mean total deviation (mTD) using optimal models with cpRNFLT and cpVD were also compared.

RESULTS

The AUROCs for discriminating glaucomatous eyes from normal eyes was significantly higher for cpRNFLT than the respective AUROCs for cpVD (0.969 [95% CI 0.939 to 0.998] vs. 0.872 [95% CI 0.806 to 0.938], p = 0.006), whereas cpVD had significantly higher AUROC for discriminating severe glaucoma eyes from moderate glaucoma eyes than cpRNFLT (0.771 [95% CI 0.655 to 0.886] vs. 0.578 [95% CI 0.420 to 0.736], p = 0.022). The mean absolute error in estimating mTD using both cpRNFLT and cpVD was significantly less than the error using cpRNFLT alone (4.56 ± 3.76 dB vs. 5.39 ± 4.00 dB, p = 0.027).

CONCLUSION

Our results suggest that cpVD is better for follow-ups after moderate stage. The combination of cpRNFLT and cpVD may improve VF estimation compared to cpRNFLT alone.

Does the sampling frequency of an eye tracker affect the detection of glaucomatous visual field loss?

PURPOSE

Evidence suggests that eye movements have potential as a tool for detecting glaucomatous visual field defects. This study evaluated the influence of sampling frequency on eye movement parameters in detecting glaucomatous visual field defects during a free-viewing task.

METHODS

We investigated eye movements in two sets of experiments: (a) young adults with and without simulated visual field defects and (b) glaucoma patients and age-matched controls. In Experiment 1, we recruited 30 healthy volunteers. Among these, 10 performed the task with a gaze-contingent superior arcuate (SARC) scotoma, 10 performed the task with a gaze-contingent biarcuate (BARC) scotoma and 10 performed the task without a simulated scotoma (NoSim). The experimental task involved participants freely exploring 100 images, each for 4 s. Eye movements were recorded using the LiveTrack Lightning eye-tracker (500 Hz). In Experiment 2, we recruited 20 glaucoma patients and 16 age-matched controls. All participants underwent similar experimental tasks as in Experiment 1, except only 37 images were shown for exploration. To analyse the effect of sampling frequency, data were downsampled to 250, 120 and 60 Hz. Eye movement parameters, such as the number of fixations, fixation duration, saccadic amplitude and bivariate contour ellipse area (BCEA), were computed across various sampling frequencies.

RESULTS

Two-way ANOVA revealed no significant effects of sampling frequency on fixation duration (simulation, p = 0.37; glaucoma patients, p = 0.95) and BCEA (simulation, p = 0.84; glaucoma patients: p = 0.91). BCEA showed good distinguishability in differentiating groups across different sampling frequencies, whereas fixation duration failed to distinguish between glaucoma patients and controls. Number of fixations and saccade amplitude showed variations with sampling frequency in both simulations and glaucoma patients.

CONCLUSION

In both simulations and glaucoma patients, BCEA consistently differentiated them from controls across various sampling frequencies.

Deep Learning Estimation of 10-2 Visual Field Map Based on Macular Optical Coherence Tomography Angiography Measurements

PURPOSE

To develop deep learning (DL) models estimating the central visual field (VF) from optical coherence tomography angiography (OCTA) vessel density (VD) measurements.

DESIGN

Development and validation of a deep learning model.

METHODS

A total of 1051 10-2 VF OCTA pairs from healthy, glaucoma suspects, and glaucoma eyes were included. DL models were trained on en face macula VD images from OCTA to estimate 10-2 mean deviation (MD), pattern standard deviation (PSD), 68 total deviation (TD) and pattern deviation (PD) values and compared with a linear regression (LR) model with the same input. Accuracy of the models was evaluated by calculating the average mean absolute error (MAE) and the R2 (squared Pearson correlation coefficients) of the estimated and actual VF values.

RESULTS

DL models predicting 10-2 MD achieved R2 of 0.85 (95% confidence interval [CI], 74-0.92) for 10-2 MD and MAEs of 1.76 dB (95% CI, 1.39-2.17 dB) for MD. This was significantly better than mean linear estimates for 10-2 MD. The DL model outperformed the LR model for the estimation of pointwise TD values with an average MAE of 2.48 dB (95% CI, 1.99-3.02) and R2 of 0.69 (95% CI, 0.57-0.76) over all test points. The DL model outperformed the LR model for the estimation of all sectors.

CONCLUSIONS

DL models enable the estimation of VF loss from OCTA images with high accuracy. Applying DL to the OCTA images may enhance clinical decision making. It also may improve individualized patient care and risk stratification of patients who are at risk for central VF damage.

Accuracy of pattern deviation in estimating the glaucomatous damage in the central 10° visual field in eyes with glaucoma and cataract

BACKGROUND/AIMS

The accuracy of pattern deviation (PD) in estimating the damage to the glaucomatous visual field (VF) in the central 10° in eyes with glaucoma and cataract is unclear.

METHODS

This retrospective study includes 63 eyes of 52 glaucoma patients who successfully underwent cataract surgery or cataract surgery plus iStent implantation. Using the Humphrey Field Analyser 10-2 test, VF was measured within 6 months preoperatively and postoperatively (VFpre and VFpost, respectively). The mean total deviation values in VFpost (mTDpost) indicates glaucomatous damage without cataract and the difference between this value and mean PD values in VFpre (mPDpre) was evaluated (εmPD). The effect of cataract was then evaluated as the difference between mTDpost and mTDpre (ΔmTD), while the effects of mTDpost and ΔmTD on εmPD were also assessed. In addition, based on preoperative visual acuity (VApre) and VFpre, the optimal model for predicting mTDpost was identified. The error of this method (εOptimalModel) was estimated as the difference against mTDpost, which was compared with εmPD.

RESULTS

Compared with mTDpre, there was a significant improvement in mTDpost (p=0.028). A significant difference was observed between mPDpre and mTDpost (p<0.001). Further, εmPD significantly increased with the increase of mTDpost or ΔmTD (p<0.001 and p=0.0444, respectively). The absolute εOptimalModel was significantly smaller than the absolute εmPD (p<0.001).

CONCLUSIONS

This study warns clinicians that PD of the central 10° VF might underestimate the glaucomatous VF damage with the progression of glaucoma and overestimate it as a cataract progresses.

Deep Learning Estimation of 10-2 Visual Field Map Based on Circumpapillary Retinal Nerve Fiber Layer Thickness Measurements

PURPOSE

To estimate central 10-degree visual field (VF) map from spectral-domain optical coherence tomography (SD-OCT) retinal nerve fiber layer thickness (RNFL) measurements in glaucoma with artificial intelligence.

DESIGN

Artificial intelligence (convolutional neural networks) study.

METHODS

This study included 5352 SD-OCT scans and 10-2 VF pairs from 1365 eyes of 724 healthy patients, patients with suspected glaucoma, and patients with glaucoma. Convolutional neural networks (CNNs) were developed to estimate the 68 individual sensitivity thresholds of 10-2 VF map using all-sectors (CNNA) and temporal-sectors (CNNT) RNFL thickness information of the SD-OCT circle scan (768 thickness points). 10-2 indices including pointwise total deviation (TD) values, mean deviation (MD), and pattern standard deviation (PSD) were generated using the CNN-estimated sensitivity thresholds at individual test locations. Linear regression (LR) models with the same input were used for comparison.

RESULTS

The CNNA model achieved an average pointwise mean absolute error of 4.04 dB (95% confidence interval [CI] 3.76-4.35) and correlation coefficient (r) of 0.59 (95% CI 0.52-0.64) over 10-2 map and the mean absolute error and r of 2.88 dB (95% CI 2.63-3.15) and 0.74 (95% CI 0.67-0.80) for MD, and 2.31 dB (95% CI 2.03-2.61) and 0.59 (95% CI 0.51-0.65) for PSD estimations, respectively, significantly outperforming the LRA model.

CONCLUSIONS

The proposed CNNA model improved the estimation of 10-2 VF map based on circumpapillary SD-OCT RNFL thickness measurements. These artificial intelligence methods using SD-OCT structural data show promise to individualize the frequency of central VF assessment in patients with glaucoma and would enable the reallocation of resources from patients at lowest risk to those at highest risk of central VF damage.

The development of a glaucoma-specific health-related quality of life item bank supporting a novel computerized adaptive testing system in Asia

Background

A glaucoma-specific health-related quality of life (HRQoL) item bank (IB) and computerized adaptive testing (CAT) system relevant to Asian populations is not currently available. We aimed to develop content for an IB focusing on HRQoL domains important to Asian people with glaucoma; and to compare the content coverage of our new instrument with established glaucoma-specific instruments.

Methods

In this qualitative study of glaucoma patients recruited from the Singapore National Eye Centre (November 2018-November 2019), items/domains were generated from: (1) glaucoma-specific questionnaires; (2) published articles; (3) focus groups/semi-structured interviews with glaucoma patients (n = 27); and (4) feedback from glaucoma experts. Data were analyzed using the constant comparative method. Items were systematically refined to a concise set, and pre-tested using cognitive interviews with 27 additional glaucoma patients.

Results

Of the 54 patients (mean ± standard deviation [SD] age 66.9 ± 9.8; 53.7% male), 67 (62.0%), 30 (27.8%), and 11 (10.2%) eyes had primary open angle glaucoma, angle closure glaucoma, and no glaucoma respectively. Eighteen (33.3%), 11 (20.4%), 8 (14.8%), 12 (22.2%), and 5 (9.3%) patients had no, mild, moderate, severe, or advanced/end-stage glaucoma (better eye), respectively. Initially, 311 items within nine HRQoL domains were identified: Visual Symptoms, Ocular Comfort Symptoms, Activity Limitation, Driving, Lighting, Mobility, Psychosocial, Glaucoma management, and Work; however, Driving and Visual Symptoms were subsequently removed during the refinement process. During cognitive interviews, 12, 23 and 10 items were added, dropped and modified, respectively.

Conclusion

Following a rigorous process, we developed a 221-item, 7-domain Asian glaucoma-specific IB. Once operationalised using CAT, this new instrument will enable precise, rapid, and comprehensive assessment of the HRQoL impact of glaucoma and associated treatment efficacy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41687-022-00513-3.

Predicting 10-2 Visual Field From Optical Coherence Tomography in Glaucoma Using Deep Learning Corrected With 24-2/30-2 Visual Field

Purpose

To investigate whether a correction based on a Humphrey field analyzer (HFA) 24-2/30-2 visual field (VF) can improve the prediction performance of a deep learning model to predict the HFA 10-2 VF test from macular optical coherence tomography (OCT) measurements.

Methods

This is a multicenter, cross-sectional study. The training dataset comprised 493 eyes of 285 subjects (407, open-angle glaucoma [OAG]; 86, normative) who underwent HFA 10-2 testing and macular OCT. The independent testing dataset comprised 104 OAG eyes of 82 subjects who had undergone HFA 10-2 test, HFA 24-2/30-2 test, and macular OCT. A convolutional neural network (CNN) DL model was trained to predict threshold sensitivity (TH) values in HFA 10-2 from retinal thickness measured by macular OCT. The predicted TH values was modified by pattern-based regularization (PBR) and corrected with HFA 24-2/30-2. Absolute error (AE) of mean TH values and mean absolute error (MAE) of TH values were compared between the CNN-PBR alone model and the CNN-PBR corrected with HFA 24-2/30-2.

Results

AE of mean TH values was lower in the CNN-PBR with HFA 24-2/30-2 correction than in the CNN-PBR alone (1.9dB vs. 2.6dB; P = 0.006). MAE of TH values was lower in the CNN-PBR with correction compared to the CNN-PBR alone (4.2dB vs. 5.3 dB; P < 0.001). The inferior temporal quadrant showed lower prediction errors compared with other quadrants.

Conclusions

The performance of a DL model to predict 10-2 VF from macular OCT was improved by the correction with HFA 24-2/30-2.

Translational Relevance

This model can reduce the burden of additional HFA 10-2 by making the best use of routinely performed HFA 24-2/30-2 and macular OCT.

Predicting the central 10 degrees visual field in glaucoma by applying a deep learning algorithm to optical coherence tomography images

We aimed to develop a model to predict visual field (VF) in the central 10 degrees in patients with glaucoma, by training a convolutional neural network (CNN) with optical coherence tomography (OCT) images and adjusting the values with Humphrey Field Analyzer (HFA) 24–2 test. The training dataset included 558 eyes from 312 glaucoma patients and 90 eyes from 46 normal subjects. The testing dataset included 105 eyes from 72 glaucoma patients. All eyes were analyzed by the HFA 10-2 test and OCT; eyes in the testing dataset were additionally analyzed by the HFA 24-2 test. During CNN model training, the total deviation (TD) values of the HFA 10-2 test point were predicted from the combined OCT-measured macular retinal layers’ thicknesses. Then, the predicted TD values were corrected using the TD values of the innermost four points from the HFA 24-2 test. Mean absolute error derived from the CNN models ranged between 9.4 and 9.5 B. These values reduced to 5.5 dB on average, when the data were corrected using the HFA 24-2 test. In conclusion, HFA 10-2 test results can be predicted with a OCT images using a trained CNN model with adjustment using HFA 24-2 test.

Predicting the Glaucomatous Central 10-Degree Visual Field From Optical Coherence Tomography Using Deep Learning and Tensor Regression

PURPOSE

To predict the visual field (VF) of glaucoma patients within the central 10° from optical coherence tomography (OCT) measurements using deep learning and tensor regression.

DESIGN

Cross-sectional study.

METHODS

Humphrey 10-2 VFs and OCT measurements were carried out in 505 eyes of 304 glaucoma patients and 86 eyes of 43 normal subjects. VF sensitivity at each test point was predicted from OCT-measured thicknesses of macular ganglion cell layer + inner plexiform layer, retinal nerve fiber layer, and outer segment + retinal pigment epithelium. Two convolutional neural network (CNN) models were generated: (1) CNN-PR, which simply connects the output of the CNN to each VF test point; and (2) CNN-TR, which connects the output of the CNN to each VF test point using tensor regression. Prediction performance was assessed using 5-fold cross-validation through the root mean squared error (RMSE). For comparison, RMSE values were also calculated using multiple linear regression (MLR) and support vector regression (SVR). In addition, the absolute prediction error for predicting mean sensitivity in the whole VF was analyzed.

RESULTS

RMSE with the CNN-TR model averaged 6.32 ± 3.76 (mean ± standard deviation) dB. Significantly (P < .05) larger RMSEs were obtained with other models: CNN-PR (6.76 ± 3.86 dB), SVR (7.18 ± 3.87 dB), and MLR (8.56 ± 3.69 dB). The absolute mean prediction error for the whole VF was 2.72 ± 2.60 dB with the CNN-TR model.

CONCLUSION

The Humphrey 10-2 VF can be predicted from OCT-measured retinal layer thicknesses using deep learning and tensor regression.

Deep learning model to predict visual field in central 10° from optical coherence tomography measurement in glaucoma

BACKGROUND/AIM

To train and validate the prediction performance of the deep learning (DL) model to predict visual field (VF) in central 10° from spectral domain optical coherence tomography (SD-OCT).

METHODS

This multicentre, cross-sectional study included paired Humphrey field analyser (HFA) 10-2 VF and SD-OCT measurements from 591 eyes of 347 patients with open-angle glaucoma (OAG) or normal subjects for the training data set. We trained a convolutional neural network (CNN) for predicting VF threshold (TH) sensitivity values from the thickness of the three macular layers: retinal nerve fibre layer, ganglion cell layer+inner plexiform layer and outer segment+retinal pigment epithelium. We implemented pattern-based regularisation on top of CNN to avoid overfitting. Using an external testing data set of 160 eyes of 131 patients with OAG, the prediction performance (absolute error (AE) and R² between predicted and actual TH values) was calculated for (1) mean TH in whole VF and (2) each TH of 68 points. For comparison, we trained support vector machine (SVM) and multiple linear regression (MLR).

RESULTS

AE of whole VF with CNN was 2.84±2.98 (mean±SD) dB, significantly smaller than those with SVM (5.65±5.12 dB) and MLR (6.96±5.38 dB) (all, p<0.001). Mean of point-wise mean AE with CNN was 5.47±3.05 dB, significantly smaller than those with SVM (7.96±4.63 dB) and MLR (11.71±4.15 dB) (all, p<0.001). R² with CNN was 0.74 for the mean TH of whole VF, and 0.44±0.24 for the overall 68 points.

CONCLUSION

DL model showed considerably accurate prediction of HFA 10-2 VF from SD-OCT.

Usefulness of data augmentation for visual field trend analyses in patients with glaucoma

AIM

To investigate the usefulness of data augmentation in visual field (VF) trend analyses in patients with glaucoma.

METHOD

This study included 6380 VFs from 638 eyes of 417 patients with open-angle glaucoma. Various affine transformations were applied to augment the VF data: (1) rotation, (2) scaling, (3) vertical and horizontal shift and (4) a combination of these different transformations. Using pointwise linear regression (PLR), the total deviation (TD) values of a patient's 10th VF were predicted using TD values from shorter VF series (from first to third VFs (VF1-3) to first to ninth VFs (VF1-9)) with and without VF data augmentation, and the root mean squared error (RMSE) was calculated.

RESULTS

With PLR, mean RMSE without VF augmentation averaged from 3.95 (VF1-3) to 19.01 (VF1-9) dB. The RMSE was significantly improved by applying the different transformations: (1) rotation (from VF1-3 to VF1-7), (2) scaling (from VF1-3 to VF1-6), (3) vertical and horizontal shifts (from VF1-3 to VF1-4) and (iv) a combination of these (from VF1-3 to VF1-7). Progression rates in VF1-10 had better agreement with those in shorter VF series when a combination of affine transformation was applied. The differences in rates were between 1.9 (VF1-3) and 0.39 (VF1-9) dB if augmentation was used, which was significantly smaller than that observed when augmentation was not applied (from 2.6 with VF1-3 to 0.26 dB with VF1-9).

CONCLUSION

It is useful to apply VF data augmentation techniques when predicting future VF progression in glaucoma using PLR, especially with short VF series.

The History and Future of Low Vision Services in the United States

This article discusses the history of low vision services in the United States. The field began to gain momentum as the term low vision was conceptualized and coined, and this momentum is rapidly increasing with changes in the demographics of visual impairment.

Mental stress as consequence and cause of vision loss: the dawn of psychosomatic ophthalmology for preventive and personalized medicine

The loss of vision after damage to the retina, optic nerve, or brain has often grave consequences in everyday life such as problems with recognizing faces, reading, or mobility. Because vision loss is considered to be irreversible and often progressive, patients experience continuous mental stress due to worries, anxiety, or fear with secondary consequences such as depression and social isolation. While prolonged mental stress is clearly a consequence of vision loss, it may also aggravate the situation. In fact, continuous stress and elevated cortisol levels negatively impact the eye and brain due to autonomous nervous system (sympathetic) imbalance and vascular dysregulation; hence stress may also be one of the major causes of visual system diseases such as glaucoma and optic neuropathy. Although stress is a known risk factor, its causal role in the development or progression of certain visual system disorders is not widely appreciated. This review of the literature discusses the relationship of stress and ophthalmological diseases. We conclude that stress is both consequence and cause of vision loss. This creates a vicious cycle of a downward spiral, in which initial vision loss creates stress which further accelerates vision loss, creating even more stress and so forth. This new psychosomatic perspective has several implications for clinical practice. Firstly, stress reduction and relaxation techniques (e.g., meditation, autogenic training, stress management training, and psychotherapy to learn to cope) should be recommended not only as complementary to traditional treatments of vision loss but possibly as preventive means to reduce progression of vision loss. Secondly, doctors should try their best to inculcate positivity and optimism in their patients while giving them the information the patients are entitled to, especially regarding the important value of stress reduction. In this way, the vicious cycle could be interrupted. More clinical studies are now needed to confirm the causal role of stress in different low vision diseases to evaluate the efficacy of different anti-stress therapies for preventing progression and improving vision recovery and restoration in randomized trials as a foundation of psychosomatic ophthalmology.

The association between structure-function relationships and cognitive impairment in elderly glaucoma patients

Accurate measurement of visual field (VF) is important in accessing glaucoma, however this may not be achieved in patients with dementia or mild cognitive impairment (CI). We investigated the association between CI and structure-function relationships in elderly glaucoma patients. The study included 94 eyes of 51 glaucoma patients aged ≥75 years with no diagnoses of dementia. CI was assessed using the Mini Mental State Examination (MMSE). Using the leave-one-out cross-validation, the mean deviation (MD) of the Humphrey 30-2 VF was predicted from measurements of optical coherence tomography, and the relationship between the squared prediction error and the MMSE score, together with age, fixation loss (FL), false positive (FP), and false negative (FN) percentages that were analyzed using the linear mixed model. A high prevalence of MCI or dementia was observed in the elderly population. The squared prediction error value of the MD was 17.0 ± 21.1 (mean ± standard deviation). The squared prediction error increased with decreasing MMSE total score, but age, FL, FP, and FN were not related. Careful consideration is needed when interpreting the VF results of these patients, because VF can be over- or underestimated, as suggested by the decreased structure-function relationships.

Developing an Item Bank to Measure Quality of Life in Individuals With Glaucoma, and the Results of the Interview With Patients: The Effect of Visual Function, Visual Field Progression Rate, Medical, and Surgical Treatments on Quality of Life

PURPOSE

To construct a new item bank to measure quality of life (QOL) in glaucoma patients and to evaluate glaucoma patients' QOL using the item bank.

METHODS

An item bank of questions was generated through a literature review of QOL instruments useful for glaucoma patients. Using this item bank, a cognitive survey was performed on 203 patients with glaucoma (112 males and 91 females, 61.9±11.9 y old; mean±SD). The results were then analyzed using the Rasch analysis, and the Rasch-derived disability scores were predicted using linear modelling and the following clinical parameters: age, mean total deviation (mTD) in superior and inferior visual field (mTDsup/mTDinf), mTD progression rate, better visual acuity, worse visual acuity, number of eye drops administered per day, number of trabeculectomy procedures experienced in both eyes.

RESULTS

A total of 23 questionnaires of QOL in glaucoma patients were identified resulting in an item bank of 187 questions related to the following tasks: reading/writing, walking, going out, eating and driving (direct disability) as well as questions concerned with worry/anxiety, social participation, and physical symptoms (indirect disability). In the optimal model for direct disability, age and mTDinf were identified as significant predictors, whereas number of eye drops administered per day and number of trabeculectomy experienced were included in the optimal model for indirect disability.

CONCLUSIONS

A new item bank to measure QOL in glaucoma patients was developed and evaluated. Age and mTDinf were found to be related to direct disability while medical and surgical treatments were related to indirect disability.

Areas of the visual field important during reading in patients with glaucoma

PURPOSE

To determine the areas of the binocular visual field (VF) associated with reading speed in glaucomatous patients with preserved visual acuity (VA).

MATERIALS AND METHODS

Fifty-four patients with glaucoma (mean age ± standard deviation 70 ± 8 years) and 38 visually healthy controls (mean age 66 ± 9 years) had silent reading speeds measured using non-scrolling text on a computer setup. Participants completed three cognitive tests and tests of visual function, including the Humphrey 24-2 threshold VF test in each eye; the results were combined to produce binocular integrated VFs (IVFs). Regression analyses using the control group to correct for cognitive test scores, age and VA were conducted to obtain the IVF mean deviation (MD) and total deviation (TD) value from each IVF test location. Concordance between reading speed and TD, assessed using R (2) statistics, was ranked in order of importance to explore the parts of the IVF most likely to be linked with reading speed.

RESULTS

No significant association between IVF MD value and reading speed was observed (p = 0.38). Ranking individual thresholds indicated that the inferior left section of the IVF was most likely to be associated with reading speed.

CONCLUSIONS

Certain regions of the binocular VF impairment may be associated with reading performance even in patients with preserved VA. The inferior left region of patient IVFs may be important for changing lines during reading.

Impact of better and worse eye damage on quality of life in advanced glaucoma

The purpose of the study was to investigate the influence of VF and the VA on vision related quality of life (VRQoL) in advanced glaucoma. Subjects consist of 50 glaucoma patients with mean deviation (MD) less than −20 dB in at least one eye. Patients' VRQoL was assessed using the ‘Sumi questionnaire’. The impact of seven visual measures on VRQoL were compared using principal component regression: MDs of better and worse eyes with 10-2 and 24-2 Humphrey VFs, LogMAR VAs of better and worse eyes and the Esterman score. The root mean of the squared prediction error (RMSE) was calculated using leave-one-out cross validation. Better eye summary measurements were much more influential on VRQoL than corresponding worse eye measurements and Esterman score in every VRQoL task. In conclusion, in advanced glaucoma, VF parameters of the better eye are important for the VRQoL of the patient.

Quality of life of glaucoma patients in China: sociodemographic, clinical, and psychological correlates-a cross-sectional study

PURPOSE

To assess vision-related quality of life (VRQoL) in Chinese glaucoma patients and explore its sociodemographic, clinical and psychological correlates, and determine which of them explain the largest variation.

METHODS

This cross-sectional study included 508 Chinese glaucoma patients. Chinese-version Glaucoma Quality of Life-15 questionnaire (CHI-GQL-15) and Hospital Anxiety and Depression Scales were administered to all participants to evaluate their VRQoL and psychological distresses. Visual functions (habitual-corrected visual acuity (HCVA), intraocular pressure, and mean defect (MD) of visual field) were assessed through clinical examinations by professionals. Sociodemographic information and other treatment histories were collected via interviews and chart review. Stepwise multiple linear regression analyses were performed to identify sociodemographic, clinical, and psychological predictors of VRQoL.

RESULTS

The mean summary score for CHI-GQL-15 was 28.79 ± 12.74. Patients exhibited the greatest difficulty in activities involving glare and dark adaptation (28.19 ± 22.86), followed by central and near vision (26.18 ± 26.56), peripheral vision (18.03 ± 21.37), and the least difficulty for outdoor mobility (15.06 ± 24.57). Moderate and heavy economic burden, HCVA and MD of both the better and the worse eyes, number of glaucoma surgeries in the treatment history and the presence of depression were independent predictors for VRQoL of glaucoma patients. Clinical factors explained the largest variation.

CONCLUSION

VRQoL of glaucoma patients is multifactorial and was primarily determined by clinical indices. VRQoL assessment could be informative when adopted as a complement to objective visual measures in clinical practice.

Comparison of resource utilization in the treatment of open-angle glaucoma between two cities in Finland: is more better?

INTRODUCTION

Glaucoma is a progressive optic neuropathy associated with neural rim loss of the optic disc and the retinal nerve fibre layer typically causing visual field (VF) deterioration. Generally, glaucomatous lesions in the eye and in the visual field progress slowly over the years. In population-based cross-sectional studies, the percentage of unilateral or bilateral visual impairment varied between 3-12%. In screening studies, 0.03-2.4% of patients have been found to suffer visual impairment. Glaucoma has previously been associated with substantial healthcare costs and resource consumption attributable to the treatment of the disease. The disease also causes reduction in health-related quality of life (HRQoL) in patients with glaucoma.

OBJECTIVE AND METHODS

This study compares patients with diagnosed open-angle glaucoma from two geographically different regions in Finland. A total of 168 patients were examined, 85 subjects from an area with higher per patient treatment costs (Oulu) and 83 patients from a region with lower per patient treatment costs (Turku). All patients had a history of continuous glaucoma medication use for a period of 11 years. For each patient, the total direct costs from glaucoma treatment were calculated and the total amount of resource consumption was determined from registries and patient records. Each patient underwent a clinical examination with visual field assessment and fundus photography. These data were used to determine the current stage of disease for each patient. Health-related quality of life questionnaire (15D) was used in determining each patient's subjective HRQoL score.

RESULTS

When applying the current diagnostic criteria for open-angle glaucoma, a total of 40% of patients did not to display any structural or functional damage suggesting glaucoma after 11 years of continuous medical treatment and follow-up. Patients with higher glaucoma stage (worse disease) were found to have statistically higher treatment costs compared with those at lower disease stages. Resource consumption was also greater in the patients in higher glaucoma stage. Patients in the Oulu district consumed more resources, and glaucoma treatment was more expensive than in the Turku area. The total treatment cost in Oulu and Turku was 6010 € and 4452 €, respectively, for the whole 11-year period. There was no statistically significant difference in quality-of-life scores between the two areas. No difference was noted between the higher-spending and lower-spending areas in this respect. However, when the population was analysed as a whole, patients with higher glaucoma stage were found to have lower vision-based 15D scores compared with those at lower disease stages. This observation was made also at both districts independently.

CONCLUSIONS

Major cost source in open-angle glaucoma treatment is medication, up to 74% of annual costs. In addition, it seems that higher resource consumption and higher treatment costs do not increase the patients' HRQoL as assessed by the 15D instrument.

Identifying areas of the visual field important for quality of life in patients with glaucoma

PURPOSE

The purpose of this study was to create a vision-related quality of life (VRQoL) prediction system to identify visual field (VF) test points associated with decreased VRQoL in patients with glaucoma.

METHOD

VRQoL score was surveyed in 164 patients with glaucoma using the 'Sumi questionnaire'. A binocular VF was created from monocular VFs by using the integrated VF (IVF) method. VRQoL score was predicted using the 'Random Forest' method, based on visual acuity (VA) of better and worse eyes (better-eye and worse-eye VA) and total deviation (TD) values from the IVF. For comparison, VRQoL scores were regressed (linear regression) against: (i) mean of TD (IVF MD); (ii) better-eye VA; (iii) worse-eye VA; and (iv) IVF MD and better- and worse-eye VAs. The rank of importance of IVF test points was identified using the Random Forest method.

RESULTS

The root mean of squared prediction error associated with the Random Forest method (0.30 to 1.97) was significantly smaller than those with linear regression models (0.34 to 3.38, p<0.05, ten-fold cross validation test). Worse-eye VA was the most important variable in all VRQoL tasks. In general, important VF test points were concentrated along the horizontal meridian. Particular areas of the IVF were important for different tasks: peripheral superior and inferior areas in the left hemifield for the 'letters and sentences' task, peripheral, mid-peripheral and para-central inferior regions for the 'walking' task, the peripheral superior region for the 'going out' task, and a broad scattered area across the IVF for the 'dining' task.

CONCLUSION

The VRQoL prediction model with the Random Forest method enables clinicians to better understand patients' VRQoL based on standard clinical measurements of VA and VF.

Eye movements during visual search in patients with glaucoma

Background

Glaucoma has been shown to lead to disability in many daily tasks including visual search. This study aims to determine whether the saccadic eye movements of people with glaucoma differ from those of people with normal vision, and to investigate the association between eye movements and impaired visual search.

Methods

Forty patients (mean age: 67 [SD: 9] years) with a range of glaucomatous visual field (VF) defects in both eyes (mean best eye mean deviation [MD]: –5.9 (SD: 5.4) dB) and 40 age-related people with normal vision (mean age: 66 [SD: 10] years) were timed as they searched for a series of target objects in computer displayed photographs of real world scenes. Eye movements were simultaneously recorded using an eye tracker. Average number of saccades per second, average saccade amplitude and average search duration across trials were recorded. These response variables were compared with measurements of VF and contrast sensitivity.

Results

The average rate of saccades made by the patient group was significantly smaller than the number made by controls during the visual search task (P = 0.02; mean reduction of 5.6% (95% CI: 0.1 to 10.4%). There was no difference in average saccade amplitude between the patients and the controls (P = 0.09). Average number of saccades was weakly correlated with aspects of visual function, with patients with worse contrast sensitivity (PR logCS; Spearman’s rho: 0.42; P = 0.006) and more severe VF defects (best eye MD; Spearman’s rho: 0.34; P = 0.037) tending to make less eye movements during the task. Average detection time in the search task was associated with the average rate of saccades in the patient group (Spearman’s rho = −0.65; P < 0.001) but this was not apparent in the controls.

Conclusions

The average rate of saccades made during visual search by this group of patients was fewer than those made by people with normal vision of a similar average age. There was wide variability in saccade rate in the patients but there was an association between an increase in this measure and better performance in the search task. Assessment of eye movements in individuals with glaucoma might provide insight into the functional deficits of the disease.

Emotional well-being and adjustment to vision loss in later life: a meta-synthesis of qualitative studies

PURPOSE

To review perceived emotional well-being in older people with visual impairment and perceived factors that inhibit/facilitate psychosocial adjustment to vision loss.

METHOD

The databases of MEDLINE, EMBASE, PsycINFO and CINAHL were searched for studies published from January 1980 to December 2010, which recruited older people with irreversible vision loss, and used qualitative methods for both data collection and analysis. Results sections of the papers were synthesised using a thematic-style analysis to identify the emergent and dominant themes.

RESULTS

Seventeen qualitative papers were included in the review, and five main themes emerged from the synthesis: 1) the trauma of an ophthalmic diagnosis, 2) impact of vision loss on daily life, 3) negative impact of visual impairment on psychosocial well-being, 4) factors that inhibit social well-being, and 5) factors that facilitate psychological well-being. We found the response shift model useful for explaining our synthesis.

CONCLUSIONS

Acquired visual impairment can have a significant impact on older people's well-being and make psychosocial adjustment to the condition a major challenge. Acceptance of the condition and a positive attitude facilitate successful psychosocial adjustment to vision loss as well as social support from family, friends and peers who have successfully adjusted to the condition.

Choosing appropriate patient-reported outcomes instrument for glaucoma research: a systematic review of vision instruments

PURPOSE

To identify vision Patient-Reported Outcomes instruments relevant to glaucoma and assess their content validity.

METHODS

MEDLINE, MEDLINE in Process, EMBASE and SCOPUS (to January 2009) were systematically searched. Observational studies or randomised controlled trials, published in English, reporting use of vision instruments in glaucoma studies involving adults were included. In addition, reference lists were scanned to identify additional studies describing development and/or validation to ascertain the final version of the instruments. Instruments' content was then mapped onto a theoretical framework, the World Health Organization International Classification of Functioning, Disability and Health. Two reviewers independently evaluated studies for inclusion and quality assessed instrument content.

RESULTS

Thirty-three instruments were identified. Instruments were categorised into thirteen vision status, two vision disability, one vision satisfaction, five glaucoma status, one glaucoma medication related to health status, five glaucoma medication side effects and six glaucoma medication satisfaction measures according to each instruments' content. The National Eye Institute Visual Function Questionnaire-25, Impact of Vision Impairment and Treatment Satisfaction Survey-Intraocular Pressure had the highest number of positive ratings in the content validity assessment.

CONCLUSION

This study provides a descriptive catalogue of vision-specific PRO instruments, to inform the choice of an appropriate measure of patient-reported outcomes in a glaucoma context.

Anxiety, depression, and quality of life in Turkish patients with glaucoma

The purpose was to investigate the relationship between anxiety, depression, and quality of life in patients with glaucoma. This case-control study was carried out with 121 participants with glaucoma (M age=64.2, SD=13.2; 68 women, 76.0% married) and 64 controls. The data were collected by using a data collection form involving questions on patients' specific characteristics, the Hospital Anxiety and Depression Scale, and the National Eye Institute Visual Function Questionnaire. Rate of clinical anxiety was 14.0% and depression 57.0% among the participants with glaucoma. The anxiety risk in women with glaucoma was found to be 7.5 times higher than in men. Risk of depression was 2.94 times higher in unmarried compared to married participants. Anxiety scores were higher in unmarried participants and women. The mean Depression score was statistically significantly higher for unmarried participants. The incidence of depression and anxiety increased with decreasing quality of life scores. Quality of life was associated negatively with anxiety and depression in patients with glaucoma. Evaluating quality of life, anxiety, and depression in older individuals who have glaucoma and examining the risk factors are important to provide earlier health care service and preventive psychological treatment.

Shifting from Compensation to Participation: A Model for Occupational Therapy in Low Vision

Older adults with low vision present unique challenges to occupational therapists because they are generally independent in self-care but limited in leisure, productivity and instrumental activities of daily living. This paper presents a review of the needs of older adults with low vision and proposes a model for occupational therapists.

A comprehensive MEDLINE search (1990–2009) of the literature on the interaction between low vision and intrinsic and extrinsic factors was performed. Titles and abstracts were reviewed and all relevant full articles were selected. Additionally, manual searches were conducted of related occupational therapy literature.

The literature review found that low vision rehabilitation focuses on technology and modifying the physical environment, but that there is a great impact on older adults with low vision by intrinsic and extrinsic issues such as cognition, psychology, physiology, spirituality and the social environment. The model proposes expanding occupational therapy with low vision clients to focus comprehensively on participation and integration in the home and community. A sample measurement model for occupational therapy evaluation is provided.

Correlation of visual function with health-related quality of life in glaucoma patients

OBJECTIVES

The purpose of this study was to assess visual impairment and quality of life (QOL), the relationship between visual function and health-related and vision-related QOL, and to identify factors significantly impacting QOL for glaucoma patients.

METHODS

One-on-one interviews of 280 glaucoma patients at a regional hospital in Taiwan from 1 April 2005 to 30 September 2005. Data collected included demographics, clinical examinations and treatment status. QOL data collected utilized the Chinese (Taiwanese) version of the Medical Outcomes Study Short-Form 36 Health Survey (SF-36) and the National Eye Institute Visual Function-25 (NEIVFQ-25).

RESULTS

The majority of study participants had open-angle glaucoma (54.3%) and were classified as moderate stage (33.6%). The higher the health-related QOL scores for both questionnaires, the fewer difficulties experienced by the patients. Moderate correlation was found between the SF-36 and NEIVFQ-25 subscales and visual function. Significant predicting factors for the SF-36 were gender, age, employment status, presence of systemic disease, better-eye visual acuity and better-eye mean defect. For the NEIVFQ-25, these were general vision, near and distance activities, colour vision and peripheral vision scores.

CONCLUSIONS

A combination of demographic data, clinical examination and QOL questionnaires may help clinicians better ascertain the impact of disease severity on glaucoma patients' QOL. This information may help in patient education, treatment compliance and selection of treatment options.

Effect of combat eye protection on field of view among active-duty U.S. military personnel

BACKGROUND

This study was conducted to determine if ballistic protective eyewear issued to U.S. military service members causes functional blind spots in the visual field. The study also investigated whether the use of corrective lenses with these devices contributes to defects in the visual field.

METHODS

Visual fields were measured using the Esterman Binocular Function test on the Humphrey Field Analyzer. Each subject performed the test with no devices and then repeated the test while wearing several combinations of ballistic eyewear (spectacles or goggles) and prescription correction. Mean differences in Esterman scores between each device and baseline were analyzed.

RESULTS

The spectacle devices did not show significant differences in mean Esterman scores from baseline. The goggle systems did show significant reductions in the peripheral field (P < 0.0001). The use of prescription correction with combat eye protection increased the number of missed points in the periphery by an average of 12.2% compared with ballistic devices alone (P < 0.0001).

CONCLUSION

The use of ballistic protective goggles and prescription lens inserts with military combat eye protection causes a significant reduction in the peripheral field. Service members should be educated to replace eye movements with head movements when scanning the periphery.

Innovations in eye surgery

The field of ophthalmology has undergone revolutionary changes during the past few decades. Advancements in understanding the pathophysiology of eye diseases, superior surgical instrumentation and surgeon skills, and cotreatment with medical therapies have enhanced outcomes. The geriatric population, preferentially affected by these illnesses, has seen a meaningful visual benefit from these surgical innovations. Most importantly, these improvements have led to increases in quality-of-life measures and mental and physical well-being of aging patients.

Evaluation of quality of life for patients with glaucoma

PURPOSE

To understand the impact of glaucoma on ability to function and on quality of life to guide therapeutic choices and strategies for improved adherence to therapeutic regimens and to suggest alterations to environments to help the patient to cope better with the effects of the disease.

DESIGN

Review of the published literature on quality-of-life assessments of patients with glaucoma.

METHODS

The published literature on quality-of-life impacts of glaucoma was reviewed with a focus on the design and evolution of quality-of-life instruments, correlations of responses with objective measures of disease progression, and insights that were gained from the analyses of results.

RESULTS

Information about the impact of glaucoma has been derived from responses to general health-related questionnaires, vision-specific questionnaires, and questionnaires that were designed to be glaucoma specific. Responses to glaucoma-specific instruments tend to correlate best with visual field measurements and other objective measures of disease progression, which suggests that such responses reflect the effects of glaucoma rather than the effects of other health-related issues in this patient population. Recent advances in the design of glaucoma-specific instruments and in analysis of the responses to them have provided some interesting insights. For example, patients who have experienced significant (peripheral) visual field loss attach greater importance to their central vision than do patients with less-advanced disease, but these patients seem to have accepted or adapted to their difficulties with outdoor mobility.

CONCLUSION

Continued improvements in the collection and analysis of quality-of-life data should assist health care providers with the effective delivery of therapies to patients with glaucoma.