Purpose:
Implantation of occlusive intraocular lenses (IOL) is a treatment option in patients with intractable diplopia, visual confusion and unsightly leucocoria. However, there are concerns that an inability to visualize the retina may delay or prevent the diagnosis of a primary posterior pole disease. In this study, we attempted to define the transmission spectra of occlusive IOL as a basis for acquiring SLO/OCT images in a recent interventional case report by this group.
Methods:
We included 5 intraocular lenses (IOLs) from 5 different IOL designs in our study; Black small and large PMMA, Black foldable Lotus, Clear PMMA and Clear foldable Lotus IOLs (Morcher GmbH). We placed each IOL between a fluorescent broad spectrum white light source and a spectroradiometer (Ocean Optics USB2000) to generate transmission spectra for each lens, confirming NIR transmission using an 850nm near infra-red (NIR) LED light source.
Results:
We demonstrated high levels of transmission of NIR light by occlusive IOLs, with Black Lotus IOL demonstrating the least attenuation. No transmission was recorded below 720nm in any occlusive lens. We determined using a mathematical model of occlusive lens transmission that most SLO/OCT scanners in clinical use would achieve 99-100% transmission at their operational wavelengths of NIR light.
Conclusions:
These findings demonstrate for the first time the near complete transmission of near infra-red light through occlusive intraocular lenses, suggesting that commercially available SLO/OCT scanners can be used to generate high quality retinal images to detect posterior pole disease in these patients. Occlusive intraocular lens insertion may therefore represent a safer treatment option than previously considered. These data provide a basis for the development of near infra-red based ocular diagnostic and assessment tools such as Snellen charts and perimetry for this group of patients.
Keywords: intraocular lens • imaging/image analysis: clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)