February 6, 2018
According to the World Health Organization (WHO), approximately one in 10 babies born in the world each year are preterm, which is before 37 weeks gestation. Of the preterm infants, those born before 31 weeks are at an even higher risk of developing lifelong challenges such as retinopathy of prematurity (ROP), the leading cause of childhood blindness.
According to the National Eye Institute, ROP occurs when abnormal blood vessels grow and spread throughout the retina, the tissue that lines the back of the eye. These atypical blood vessels are fragile and can leak, scarring the retina and pulling it out of position. This causes a retinal detachment, which is the primary cause of ROP visual impairment and blindness.
Field of view (FOV) screenings, one of the most critical components in the retinal diagnosis of newborn babies, is complicated by ROP as initial indicators appear at the very edge of the retina, making it extremely difficult to correctly diagnose and treat ROP. However, with the use of wide-field imaging systems, such as the Visunex PanoCam LT Ophthalmic Imaging System, physicians may be able to view the edges of the retina to help provide a diagnosis.
UL technical experts in Suzhou, China, tested Visunex’s claim that the ophthalmic device provides a 130° field of view. Paul B. Zhang (Paul Z.), engineer project associate with UL China, developed the verification methodology by first researching the field of ophthalmic imaging.
Next, he looked to the International Electrotechnical Commission (IEC) and the International Organization for Standardization (ISO) to see if sufficient FOV measurement criteria already existed for ophthalmic imaging devices. Then, as the Food and Drug Administration (FDA) had awarded a clearance in 2015 for the Visunex PanoCam LT Imaging system, he studied all of the FDA’s available information.
“We had to face a situation known as ‘Product Prior to Standard’ and develop a testing protocol based on fundamental physics and correlated standards,” says Paul Z. “We maintained a positive spirit while developing the process in a scientifically rigorous manner.”
Paul Z. spent approximately six weeks to research, design and perform the testing. “We needed to consider the fundamental physical optics and the relative refraction factors because the artificial material used is not only different from the human eye but offers different viewing distances over the objective lens,” he says.
Luke Zhang (Luke Z.), operations manager for UL China, adds that “by verifying their marketing claim, the customer gained a greater understanding of their product, which helped distinguish themselves in the space and win bids by giving their buyers more confidence in choosing the Visunex product.” he explains.
“UL Marketing Claim Verifications can be highly customized for our customers,” explains Ryan Zhang, business development manager for UL Greater China. “We work closely with the customer to verify claims that help differentiate the customer to build their own unique value position in the competitive market.”
“Even without a published methodology, our technical experts were able to find a way to help our customer demonstrate the truth behind their marketing claim,” says Luke Z, “and we now have a robust and repeatable Verification program so that physicians and hospitals purchasing these` types of products can have confidence that they will be able to see a 130° field of view as promoted.”