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Illumination levels in commonly used ophthalmic devices.

ABSTRACT: Pupil diameter is a key parameter for corneal and multifocal intraocular lens surgery. Many devices are dedicated to measure the pupil size, but do not specify the illumination during capture. The aim of this study was to present illumination levels in routinely used ophthalmic devices which present pupil sizes. To obtain measurements, the lux meter was placed in the chin rest in the corneal plane and the room was completely dimmed. Ten measurements were taken for each device. The illumination levels for white and red Placido disk corneal topographers were 1253.1 ± 0.2 and 329.0 ± 0.2 lux, respectively (both photopic conditions). Scheimpflug corneal tomography should be considered as a mesopic measurement (14.5 ± 0.1 lux). Optical coherence tomography and autorefractometry are scotopic measurements (0.4-0.6 lux). We postulate that producers should provide illumination levels of their devices measuring pupil size. Moreover, when mentioning a pupil size, one should consider presenting to what lighting conditions it refers to.

SUBMITTER: Kanclerz P

PROVIDER: S-EPMC10907405 | biostudies-literature | 2024 Mar

REPOSITORIES: biostudies-literature

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Illumination levels in commonly used ophthalmic devices.

Kanclerz Piotr P Bazylczyk Natasza N

Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie 20230807 3

Pupil diameter is a key parameter for corneal and multifocal intraocular lens surgery. Many devices are dedicated to measure the pupil size, but do not specify the illumination during capture. The aim of this study was to present illumination levels in routinely used ophthalmic devices which present pupil sizes. To obtain measurements, the lux meter was placed in the chin rest in the corneal plane and the room was completely dimmed. Ten measurements were taken for each device. The illumination l ...[more]

PMID: 37548670

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Project description:BackgroundSeveral validated scales have been developed to measure frailty, yet the direct relationship between these measures and their scores remains unknown. To bridge this gap, we created a crosswalk of the most commonly used frailty scales.MethodsWe used data from 7070 community-dwelling older adults who participated in National Health and Aging Trends Study (NHATS) Round 5 to construct a crosswalk among frailty scales. We operationalized the Study of Osteoporotic Fracture Index (SOF), FRAIL Scale, Frailty Phenotype, Clinical Frailty Scale (CFS), Vulnerable Elder Survey-13 (VES-13), Tilburg Frailty Indictor (TFI), Groningen Frailty Indicator (GFI), Edmonton Frailty Scale (EFS), and 40-item Frailty Index (FI). A crosswalk between FI and the frailty scales was created using the equipercentile linking method, a statistical procedure that produces equivalent scoring between scales according to percentile distributions. To demonstrate its validity, we determined the 4-year mortality risk across all scales for low-risk (equivalent to FI <0.20), moderate-risk (FI 0.20 to <0.40), and high-risk (FI ≥0.40) categories.ResultsUsing NHATS, the feasibility of calculating frailty scores was at least 90% for all nine scales, with the FI having the highest number of calculable scores. Participants considered frail on FI (cutpoint of 0.25) corresponded to the following scores on each frailty measure: SOF 1.3, FRAIL 1.7, Phenotype 1.7, CFS 5.3, VES-13 5.5, TFI 4.4, GFI 4.8, and EFS 5.8. Conversely, individuals considered frail according to the cutpoint of each frailty measure corresponded to the following FI scores: 0.37 for SOF, 0.40 for FRAIL, 0.42 for Phenotype, 0.21 for CFS, 0.16 for VES-13, 0.28 for TFI, 0.21 for GFI, and 0.37 for EFS. Across frailty scales, the 4-year mortality risks between the same categories were similar in magnitude.ConclusionOur results provide clinicians and researchers with a useful tool to directly compare and interpret frailty scores across scales.

Project description:BACKGROUND:Hypernatraemia is common in inpatients and is associated with substantial morbidity. Its differential diagnosis is challenging, and delayed treatment may have devastating consequences. The most important hormone for the regulation of water homeostasis is arginine vasopressin, and copeptin, the C-terminal portion of the precursor peptide of arginine vasopressin, might be a reliable new parameter with which to assess the underlying cause of hypernatraemia. METHODS:In this prospective, multicentre, observational study conducted in two tertiary referral centres in Switzerland, 92 patients with severe hyperosmolar hypernatraemia (Na+ > 155 mmol/L) were included. After a standardised diagnostic evaluation, the underlying cause of hypernatraemia was identified and copeptin levels were measured. RESULTS:The most common aetiology of hypernatraemia was dehydration (DH) (n = 65 [71%]), followed by salt overload (SO) (n = 20 [22%]), central diabetes insipidus (CDI) (n = 5 [5%]) and nephrogenic diabetes insipidus (NDI) (n = 2 [2%]). Low urine osmolality was indicative for patients with CDI and NDI (P < 0.01). Patients with CDI had lower copeptin levels than patients with DH or SO (both P < 0.01) or those with NDI. Copeptin identified CDI with an AUC of 0.99 (95% CI 0.97-1.00), and a cut-off value ≤ 4.4pmol/L showed a sensitivity of 100% and a specificity of 99% to predict CDI. Similarly, urea values were lower in CDI than in DH or SO (P < 0.05 and P < 0.01, respectively) or NDI. The AUC for diagnosing CDI was 0.98 (95% CI 0.96-1.00), and a cut-off value < 5.05 mmol/L showed high specificity and sensitivity for the diagnosis of CDI (98% and 100%, respectively). Copeptin and urea could not differentiate hypernatraemia induced by DH from that induced by SO (P = 0.66 and P = 0.30, respectively). CONCLUSIONS:Copeptin and urea reliably identify patients with CDI and are therefore helpful tools for therapeutic management in patients with severe hypernatraemia. TRIALS REGISTRATION:ClinicalTrials.gov, NCT01456533 . Registered on 20 October 2011.

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Illumination levels in commonly used ophthalmic devices.

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Illumination levels in commonly used ophthalmic devices.

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