MKH-Haase Charts of Binocular Vision Measurements: Repeatability and Validity of Associated Phoria and Stereotests

Abstract Introduction: H.J.-Haase developed a systematic set of tests for evaluating binocular vision called the Pola Test. The Pola Test measures associated phoria and stereoacuity at distance and near using a variety of different targets for each. This testing method and interpretation is referred to as MKH-Haase (Measuring and Correcting Methodology after H.J.Haase –the MKH) method. The MKH method is more commonly used in Germany and other European countries than English speaking countries. The MKH-Haase method has been considered a reliable method for prescribing prisms to symptomatic binocular vision patients. Purpose: To investigate the test-retest reliability of binocular vision measurements using the MKH-Haase series of tests that comprise the Pola Test. In addition, I will compare the Pola results with other associated phoria and stereoacuity tests used in North America. Methods: Thirty-four symptomatic and 40 asymptomatic subjects (based on a symptoms questionnaire) participated in this study. Associated phoria and stereoacuity with different tests, including the Pola Test at distance and near, were measured for those subjects on two different sessions. Not all of subjects were tested with all tests. Only 30 subjects in each group completed all of tests. The Pola Test protocol requires the associated phoria and stereoacuity to be measured twice within a session; once with the Polariods oriented with their axes at 45o and 135o and again with the axes switched. Results: Within and between-sessions repeatability of MKH-Haase associated phoria and stereoacuity tests results revealed that most of MKH-Haase associated phoria and stereoacuity tests showed good repeatability within and between-sessions at both distance and near. However, there were a few exceptions to this general finding. Distance horizontal associated phoria values for the Cross Test and Pointer Test at the first session, and the distance Double Pointer Test values at the second session showed some differences between the two views. Between-sessions repeatability of the associated phoria tests did not show any significant differences. For the stereoacuity tests, the differences between the two disparities were statistically significant at the first session for the symptomatic group Line Test and asymptomatic group Step Test. For the second session at distance, the differences were significant with Step Test for both groups. The differences between sessions for both disparities were not significant for most of tests. The symptomatic group’s Step Test for crossed disparity and asymptomatic group's Step Test for uncrossed disparity were exceptions. A repeated measures ANOVA test was conducted to compare different associated phoria tests. Horizontal associated phoria tests without central fusion lock were significantly different from those with central fusion lock at distance and near. Comparison of different stereoacuity tests was conducted by comparing the number of subjects who could identify specific stereothreshold values. Results showed that at both distance and near, there were no significant differences between contour and global stereoacuity tests based on number of subjects who could attain 60 sec of arc or better. Discussion and Conclusion: Most of MKH-Haase associated phoria and stereoacuity charts have reasonable within and between-sessions repeatability. However, some associated phoria tests showed some differences especially with subjects who had higher values. Although there was a significant difference between various horizontal associated phoria tests at distance and near, most of the values differed by around 0.50 . The exception was the difference between the Wesson Card and Disparometer. The Wesson card was more exo by 1.50 than the Disparometer. Vertical associated phoria tests did not show any significant differences. Although MKH-Haase chart can measure local stereothreshold down to 10 sec of arc at distance, the AO Slide is easier to perceive. Random dot stereoacuity can be measured with MKH-Haase charts at distance down to 30 sec of arc. All of the contour stereoacuity tests are comparable at near. However, the MKH-Haase chart was easier to perceive. The Random Dot Randot test would be more useful for fast screening purposes. Random dot MKH-Haase test would be easier than TNO Test to measure random dot stereothreshold at near

Visual Functions in Parkinson’s Disease

Background: Freezing of gait (FOG) is considered to be a motor disorder symptom that affects some Parkinson Disease (PD) patients; however, it is hypothesized that sensory systems may also be involved in FOG. Purpose: The purpose of this thesis is to measure different 2-dimensional (2-D) and 3-dimensional (3-D) clinical visual functions in FOG and non-FOG PD patients. The ability to maintain adequate alignment of the two eyes was assessed by measuring fixation disparity curve. The other objective of this thesis was to look at integrity of autonomic nervous system (ANS) and two non-motor functions mediated by the cholinergic system in FOG and non-FOG PD patients. FOG PD patients may have greater impairment of one, or more, of these functions. Methods: The 2-D visual function measurements included high and low contrast visual acuities using Early Treatment Diabetic Retinopathy Study charts, low spatial frequency contrast sensitivity using Pelli-Robson chart, horizontal and vertical Vernier acuity using The Freiburg Visual Acuity Test. These tests were conducted under photopic, and then under mesopic conditions. The 3-D visual function measurements included local (contour) and global (random dot) stereopsis at near. Local stereoacuity was measured using Circles and MKH-Haase Line tests. Global stereoacuity was measured using the MKH-Haase Steps, TNO, Randot 3, and Butterfly tests. Fixation disparity curves were measured using the Saladin Near Point Card. Constriction and dilation pupil light reflexes (PLRs) were measured by using a handheld monocular pupillometer to evaluate the integrity of ANS. The inspection time (IT) was determined by a simple length discrimination task to evaluate the integrity of the cholinergic system. Twenty-two FOG PD patients, 25 non-FOG PD patients, and 25 aged matched healthy controls (HC) completed all of the measurements in this project. Results: FOG group had worse 2-D visual resolution results than other two groups especially under the mesopic condition. FOG group also had worse stereopsis than the other two groups. An impairment in global stereopsis was more common than local stereopsis in both PD patient groups. The reduction in stereopsis among PD patients was not associated with the fixation disparity. Both PD patient groups showed significant differences from healthy controls in most of PLR constriction parameters. FOG PD patients showed larger deficits than non-FOG PD patients in some of the constriction parameters. Both groups of PD patients had longer dilation latencies than healthy controls. FOG PD patients had slower IT scores than healthy controls. IT scores for the non-FOG PD patients fell in between the FOG and HC results. Conclusions: FOG patients have a greater impairment in both 2-D and 3-D visual functions. Whether these impairments are contributing to the FOG or just associated with FOG is uncertain. FOG patients also had larger impairments in non-dopaminergic mediated functions such as PLRs and IT, which suggests that FOG patients have greater impairment in two functions that involve cholinergic neurotransmitters

Visual resolution under photopic and mesopic conditions in patients with Sjögren's syndrome

AIM: To focus on different visual resolution tasks under photopic and mesopic conditions in Sjögren's syndrome patients compared to age-matched healthy controls. METHODS: The visual resolution measurements included high and low visual acuities and contrast sensitivity functions. These tests were conducted under photopic and then mesopic conditions. Twenty-one Sjögren's syndrome patients and 21 aged-matched healthy volunteers completed all the measurements in this study. RESULTS: Sjögren's syndrome patients have greater impairment in contrast sensitivity than standardized visual acuity. This reduction was significant under the mesopic condition. Also, Sjögren's syndrome patients treated with pilocarpine suffer more than patients without pilocarpine treatment under low light conditions. CONCLUSION: Sjögren's syndrome patients shows greater impairment in different visual resolution tasks due to dry eye symptoms

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely