Work

Evaluating Slit-Lamp Performance in Diagnosing Anterior Uveitis: A Simulated Model Approach – Are All Slit-Lamps the Same, and Does it Matter?

Year: 2026

Type: article

Abstract: Background/Objectives: Anterior uveitis is diagnosed by detecting inflammatory cells in the anterior chamber using slit lamp biomicroscopy. Available slit lamps can vary significantly in illumination quality, potentially affecting diagnostic accuracy. This study evaluates device-to-device variability in slit lamp illumination within a tertiary ophthalmic centre and assesses its impact on anterior uveitis detection. Subjects/Methods: 43 Haag-Streit BQ900 slit lamps (21 tungsten, 22 LED) were evaluated. Lux emissions were quantified using a calibrated photometer under standardised conditions. Simulated anterior chambers were developed using particles (~15 μm diameter) suspended in ethanol, targeting cell concentrations according to Standardisation of Uveitis Nomenclature (SUN) criteria grades 0-4+. Thirteen masked observers graded each chamber under standardised settings, comparing the dimmest tungsten and LED lamps. Statistical analyses included coefficient of variation (CV), independent and paired t-tests and Bland-Altman. Results: All slit lamps demonstrated variability in lux output, even among identical models. LED slit lamps exhibited a markedly higher maximum brightness (some >200,000 lux) than tungsten models (max 126,400 lux). Under diagnostic conditions (1 × 1 mm beam, 45°), LED slit lamps emitted significantly higher and more consistent lux compared to tungsten lamps (LED mean: 1275 ± 503 lux; tungsten mean: 793 ± 438 lux; p = 0.0017). In anterior chamber simulations, LED illumination improved detection at lower SUN grades (0.5+: LED mean = 2.23 cells, tungsten = 0.77 cells, p = 0.00006; 1+: LED = 5.77, tungsten = 4.15, p = 0.0403). Conclusions: Slit lamp illumination varies substantially. In a simulated model, lower illuminance was associated with reduced detection of low-grade inflammation. Routine illumination auditing and equipment standardisation, considering the broader adoption of LED slit lamps, may improve the reliability of uveitis assessment.

Source: British and Irish Orthoptic Journal

DOI: 10.22599/bioj.577

Authors: Kwok Kit Johnny Ma, Martin Rhodes, Joe Baxter, Thomas Evans, Jessy Choi

Institutions: University of Sheffield, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield Children's NHS Foundation Trust

Language: English

Topic: Ocular Diseases and Behçet’s Syndrome

Subfield: Ophthalmology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: diamond

OpenAlex ID: W7225224109