Intrasession repeatability and agreement of the anterior corneal assessment provided by a multidiagnostic device

CLINICAL RELEVANCE

Multidiagnostic systems have recently appeared on the market. Knowledge of the repeatability and validity of any instrument is mandatory before its introduction in clinical practice.

BACKGROUND

The aim of this work is to examine the intrasession repeatability of anterior pole measurements provided by the multidiagnostic device Wave Analyzer Medica 700 (WAM700) and agreement with Pentacam measurements in normal eyes.

METHODS

In the right eyes of 113 participants, three repeat measurements of central keratometry, central corneal thickness, anterior chamber depth and corneal eccentricity were made with the WAM700 and Pentacam in random order. Intrasession repeatability and agreement were determined.

RESULTS

Employing WAM700, intrasession repeatability for keratometry, central corneal thickness and anterior chamber depth was good (ICCs ≥ 0.992; CV 0.48-0.98%), yet worse than the values obtained for the Pentacam (ICCs ≥ 0.998; CV 0-0.33%). WAM700 showed excellent intrasession repeatability when used to measure the anterior chamber depth (Sw 0.03 mm). However, the repeatability of this device was inferior for central corneal thickness (Sw 4.24 μm) and keratometry measurements (Sw < 0.21 D) and was poor for corneal eccentricity (Sw 0.07; ICC 0.908; CV 14.58%). Agreement between WAM700 and Pentacam showed a high ICC for the keratometry measurements, central corneal thickness and anterior chamber depth (>0.972) but lower for corneal eccentricity (ICC 0.762).

CONCLUSIONS

In healthy eyes, the WAM700 multidiagnostic device showed good intrasession repeatability for keratometry, central corneal thickness and anterior chamber depth measurements. Agreement between WAM700 and Pentacam was good for the anterior chamber depth measurement. However, these instruments cannot be considered interchangeable for keratometry, central corneal thickness and eccentricity readings.

Content development for a new item-bank for measuring multifocal contact lens performance

BACKGROUND

Presbyopia is an age-related condition that causes a decreased ability to focus on nearby objects. Multifocal contact lenses are commonly used to address this issue. However, there seems to be a notable dissatisfaction among multifocal contact lens wearers. The absence of a reliable instrument to measure the patient's perspective, despite the widespread use of this method, highlights the need for further research in this area.

OBJECTIVE

The objective of this study is to develop an item-bank integrating all domains necessary to assess the patient's perspective on multifocal contact lens performance, offering a comprehensive measure. The item-bank will ensure a high level of content validity, be self-administered, and will initially be available in Spanish. The aim of this tool is to serve as a valuable resource for research and optometric clinics, facilitating the follow-up of patients with presbyopia who wear multifocal contact lenses or those who are newly starting to use them.

METHODOLOGY

The MCL-PRO item bank, followed a systematic and step-wise inductive approach to gather information, following the recommendations outlined in the COSMIN guidelines and similar studies. The process involved the following steps: (1) Literature review and relevant existing items identification (2) Social media review, (3) Semi-structured focus groups, (4) performing qualitative analysis, (5) refining and revising the items, and (6) generating the content of the item bank.

RESULTS

A total of 575 items were included in the item-bank hosted under 8 different domains that were found to be important for presbyopic population: visual symptoms (213), activity limitation (111), ocular symptoms (135), convenience (36), emotional well-being (33), general symptoms (16), cognitive issues (21) and economic issues (10).

CONCLUSION

The item-bank created has followed standardised methodology for its development and encloses all the aspects for MCL performance evaluation from patients perspective.

Spanish Cross-Cultural Adaptation, Rasch Analysis and Validation of the Ocular Comfort Index (OCI) Questionnaire

The Ocular Comfort Index (OCI) assesses ocular surface irritation and grades the severity of dry eye disease. This study sought to adapt the OCI questionnaire into Spanish, and then to assess the psychometric performance and validity of the new adapted version (OCI-versión española, OCI_VE). The questionnaire was translated, back translated, and then cross-culturally adapted for use with Spanish-speaking individuals. The OCI_VE was completed by 450 participants, including 53 subjects that were diagnosed with dry eye disease. Through a Rasch analysis, the psychometric properties of item fit, targeting, person separation, reliability, and differential item functioning (DIF) were assessed. To test the convergent validity, we examined the correlation between the OCI_VE and the Computer Vision Symptom Scale (CVSS17). Validity was tested in a subgroup of participants with and without dry eye, and test-retest repeatability was determined in a subset of 151 individuals. We also compared, via DIF, the performance of the OCI_VE with that of the original OCI. Our Rasch analysis revealed a good model fit, high accuracy, good targeting, unidimensionality, and no DIF according to gender. The validity and repeatability were good. The OCI_VE shows comparable psychometric properties to the original English version, making it a valid tool for measuring dry eye symptoms in Spanish adults.

Spanish Cross-Cultural Adaptation and Rasch Analysis of the Convergence Insufficiency Symptom Survey (CISS)

Purpose

To culturally and linguistically adapt the Convergence Insufficiency Symptom Survey (CISS) to Spanish and assess the psychometric performance of the new version through Rasch analysis and classical test theory methods.

Methods

The Spanish version of the CISS (CISS_VE) was completed by 449 subjects (9–30 years old) from the general population. The validity and reliability of CISS_VE were assessed through Rasch statistics (precision, targeting, item fit, unidimensionality, and differential item functioning). To test construct validity, we calculated the coefficients of correlation between the CISS_VE and the Computer-Vision Symptom Scale (CVSS17) or Warwick–Edinburgh Mental Well-Being Scale (WEMWBS). We determined test–retest reliability in a subset of 229 subjects. We used differential item functioning (DIF) to compare the CISSS_VE and the CISS after administering the CISS to 216 English children.

Results

After applying exclusion criteria, the responses of 420 participants (mean age, 18.62 years; female, 54.95%) revealed good Rasch model fit, good precision (person separation = 2.33), and suboptimal targeting (–1.37). There was some evidence of multidimensionality, but disattenuated correlations between the Rasch dimension and a possible secondary dimension were high, suggesting they were measuring similar constructs. No item bias according to gender or age was detected. Spearman's correlation was 0.34 (P < 0.001) for CISS_VE–CVSS17 and non-significant for CISS_VE–WEMWBS. The limits of agreement for test–retest reliability were 9.67 and –8.71. Rasch analysis results indicated no difference between CISS and CISS_VE.

Conclusions

According to our results, CISS_VE is a valid and reliable tool for measuring the symptoms assessed by CISS in Spanish people 9 to 30 years of age.

Translational Relevance

CISS_VE can measure convergence insufficiency symptoms in Spanish-speaking subjects.

Symptoms associated with reading from a smartphone in conditions of light and dark

Asthenopia symptoms were investigated in visually-normal subjects without computer-related vision symptoms after prolonged reading from: smartphone versus hardcopy under photopic conditions, and smartphone in conditions of ambient versus dark room illumination. After reading from the smartphone, total symptom scores and nine out of ten questionnaire symptoms were significantly worse than for the hardcopy ("blurred vision while viewing the text, "blurred distance vision after the task", "difficulty in refocusing from one distance to another", "irritated or burning eyes", "dry eyes", "eyestrain", "tired eyes", "sensitivity to bright lights" and "eye discomfort"). Mean total symptom scores and scores for "irritated or burning eyes" and "dry eyes" were significantly higher for the dark versus photopic conditions. In conclusion, prolonged smartphone reading could cause worse asthenopic symptoms than reading from a hardcopy under similar conditions. Symptoms could be even worse when reading from a smartphone in the dark.

Gaining insight into the photophysical properties of a coumarin STP ester with potential for bioconjugation

The photophysical properties of a coumarin 392 4-sulfotetrafluorophenyl ester, C392STP (sodium (E/Z)-4-(4-(2-(6,7-dimethoxycoumarin-3-yl)vinyl)-benzoyl)-2,3,5,6-tetrafluoro-benzenesulfonate), an amine reactive coumarine with potential for bioconjungation, have been studied in different solvents.

The Computer-Vision Symptom Scale (CVSS17): development and initial validation

PURPOSE

To develop a questionnaire (in Spanish) to measure computer-related visual and ocular symptoms (CRVOS).

METHODS

A pilot questionnaire was created by consulting the literature, clinicians, and video display terminal (VDT) workers. The replies of 636 subjects completing the questionnaire were assessed using the Rasch model and conventional statistics to generate a new scale, designated the Computer-Vision Symptom Scale (CVSS17). Validity and reliability were determined by Rasch fit statistics, principal components analysis (PCA), person separation, differential item functioning (DIF), and item-person targeting. To assess construct validity, the CVSS17 was correlated with a Rasch-based visual discomfort scale (VDS) in 163 VDT workers, this group completed the CVSS17 twice in order to assess test-retest reliability (two-way single-measure intraclass correlation coefficient [ICC] and their 95% confidence intervals, and the coefficient of repeatability [COR]).

RESULTS

The CVSS17 contains 17 items exploring 15 different symptoms. These items showed good reliability and internal consistency (mean square infit and outfit 0.88-1.17, eigenvalue for the first residual PCA component 1.37, person separation 2.85, and no DIF). Pearson's correlation with VDS scores was 0.60 (P < 0.001). Intraclass correlation coefficient for test-retest reliability was 0.849 (95% confidence interval [CI], 0.800-0.887), and COR was 8.14.

CONCLUSIONS

The Rasch-based linear-scale CVSS17 emerged as a useful tool to quantify CRVOS in computer workers. : Spanish Abstract.

[Benchmarking in the emergency unit process in 7 hospitals from different autonomous communities]

OBJECTIVE

To identify and to share the results among hospitals regarding the process of attention at the Emergency Unit, and to detect the practices that explain the differences.

MATERIAL AND METHOD

SETTING

7 hospitals of different regions in Spain.

PERIOD OF STUDY

2005-2007. Firstly the comparability criteria were defined assuring the homotecia in the «emergency process». In order to fulfil the study objectives, 11 criteria were selected and every center sent the information of each one. 7 indicators were identified to compare hospitals processes'. Data regarding all the attentions provided during the study period was analyzed, establishing the benchmark among the centers. Finally, a questionnaire was elaborated for the process analysis, considering all the stages of the process, the resources and the procedures used in every stage, to be fulfilled in each hospital.

RESULTS

The homotecia has been verified in the 7 hospitals, with some differences between centers. 7 indicators have been analyzed in the different hospitals, corresponding to 1,526,890 patients attended in the study period. A benchmark has been identified, with the best results in four of seven indicators: % of admissions from urgencies: 8.3%, emergency pressure: 56.14%, emergency length of stay: 2 hs 20min, and % of patients with length stay > 24h: 0.05%. Differences between the stages of the process, resources and procedures used in every stage in the benchmark center have been analyzed.

CONCLUSIONS

A set of indicators to compare Emergency Departments has been identified, letting us establish the benchmark.

[Synovial chondromatosis. A study of 39 patients]

OBJECTIVE

To study the clinical manifestations, use of diagnostic imaging techniques and outcome of patients with synovial chondromatosis in our health area.

PATIENTS AND METHODS

POVISA Hospital provides health services to a population of 127,000 inhabitants. The clinical histories of all the patients in this area who were histologically diagnosed with synovial chondromatosis between January 1992 and December 2003 were reviewed.

RESULTS

There were 38 cases of joint chondromatosis, all monoarticular, and one case of extra-articular chondromatosis in 20 men and 19 women aged 56.5±12.7 years (mean±SD) at diagnosis (range: 16-79 years). The main joint affected was the knee (15; 39.5%), followed by the hip (8; 21%) and the temporomandibular joint and elbow, both of these in three patients (7.9%). Previous arthropathy was recorded in 18 patients (18/38, 47.4%). Symptom duration prior to diagnosis was 25.4±34 months. The most frequent clinical manifestations were joint pain (100%), restricted movement (77%) and swelling (57%). Plain radiographs were carried out in all patients and suggested the diagnosis in 20 (51.3%). Magnetic resonance imaging findings led to a diagnosis in 12 out of 15 patients in whom this procedure was required (80%). In all patients loose bodies were removed and synovectomy was performed by arthroscopic procedures in six. In 16 patients (42%) total joint replacement was required. The mean postoperative follow-up was 23.7±5.3 months. No cases of chondrosarcoma were identified and the recurrence rate was low (7.9%).

CONCLUSIONS

In our setting, almost half (47.4%) of the cases of synovial chondromatosis occurred in a previously damaged joint: the correct diagnosis was delayed by more than 2 years and total arthroplasty was required in 42% of the patients.