Metagenomic sequencing in various ocular infections: A systematic review of diagnostic utility

Ocular infections are a common cause of visual morbidity worldwide and continue to pose significant diagnostic and therapeutic challenges. Metagenomic next-generation sequencing (mNGS) enables unbiased detection of wide range of pathogens; however, its diagnostic utility in ocular infections warrant further evaluation. We evaluate the diagnostic performance of mNGS, highlighting its advantages, limitations, and future directions for clinical application. Twenty-one studies involving 1219 eyes were included. mNGS positivity rates ranged from 10 % to 94 %. Sensitivity ranged from 15 % to 100 % and specificity from 12 % to 100 %. Viral pathogens were the most frequently detected (15 out of 21 studies), followed by bacteria (14 out of 21), fungi (10 out of 21), and parasites (6 out of 21). A broad spectrum of pathogens at both the genus and species levels was identified. mNGS also helps in assessing AMR-associated genes and mutations linked to therapy susceptibility. mNGS appears to be a valuable tool for pathogen indentification in ocular infections, particularly for organisms undetectable by conventional diagnostic methods, although careful interpretation is required. Overall, mNGS demonstrated promising diagnostic performance across different types of ocular infections. Larger, well-designed studies employing standardized protocols are needed to address current limitations and to enhance the clinical applicability of mNGS in routine clinical practice.