ANTERIOR SEGMENT IMAGING WITH INTRAOCULAR LENS - A NOVEL SMARTPHONE-BASED IMAGING MODALITY VS SLIT-LAMP BASED SMARTPHONE IMAGING

Ophthalmic imaging plays an important role today in patient diagnosis, follow-up, and academic communication. Unfortunately, the current imaging equipment can be costly, unavailable, and non-portable.

Anterior segment photography with intraocular lens (ASPI) -publsihed in 2019 by Chandrakanth et al. (Indian Journal of Ophthalmology) is a smartphone-based imaging tool that claims to overcome these limitations by being cost-effective, portable, easily available, and extremely handy for academic documentation and communication.

This study aims to evaluate the efficacy of the ASPI – anterior segment photography with intraocular lens by comparing it with a tried and tested anterior segment imaging tool – the smartphone-based slit lamp imaging (SLI) using the slit lamp smartphone adapter, to test the ASPI's relevance in modern ophthalmology.

This study was carried out in the OPD of a tertiary eye care center in southern India, with a sample size of 380 eyes.

Design – hospital-based comparative observational study

Informed consent was obtained from all participants before the study. A slit lamp smartphone adapter was attached to the slit lamp to take an anterior segment image followed by the ASPI image. All images were taken using the same slit lamp, same ASPI, same phone, and in the same room with similar lighting conditions, to control as many variables as possible.

All images were then randomly scored by a single third-person examiner who was blinded to the source of the image.

The images were scored on a standardized image scoring scale that takes into account sharpness, noise, contrast, artifacts, blotchy appearance, and diagnostic confidence.

The scores were then tabulated and analyzed. An unpaired t-test was carried out to determine if the outcomes were statistically significant or not.

 

The ASPI had a better score in only 2 categories - contrast and absence of blotchy appearance. SLI had a better average score overall. However, with a p-value of 0.12, this difference was statistically insignificant. 

As the difference between the ASPI and SLI was statistically insignificant, the non-inferiority of the ASPI is established. It can be extremely useful in peripheral establishments, for example, ophthalmic screening camps and so on. It can be used by residents and fellows to store and share images in an easy way. It can also be used to educate the patient about their disease and to document the progression of the disease and the effects of treatment. We found it very useful in patients in a wheelchair - where an initial examination could be done via the ASPI to avoid repeated slit lamp examinations. In the future, it could serve as a potential tool for post-operative follow-up from home. Its integration with artificial intelligence would also further the reach of ophthalmic care. However, it currently lacks slit illumination, cobalt blue light filter, and posterior segment evaluation is not possible. These are some of the drawbacks that need to be worked on.