Light scattering and light transmittance in a series of calcified single-piece hydrophilic acrylic intraocular lenses of the same design

Abstract

Light scattering was extremely high and transmittance was significantly reduced in calcified IOLs. Differences in transmittance observed in the 290 to 350 nm region between IOLs with different expiration dates were related to use of different hydrophilic acrylic raw material suppliers in the manufacture of the IOLs, highlighting the complexity of IOL calcification investigations.

Effects of Intraocular Lens Opacification on Light Scatter, Stray Light, and Overall Optical Quality/Performance

“…None of the hydrophilic acrylic lenses included has a hydrophobic coating/surface modification. 3,16,17 The explanted and control silicone lenses were represented by the Chiroflex C10UB (Chiron Vision, Emeryville, CA, USA). Two of the explanted PMMA lenses were represented by model UVL-304-01 (Ioptex, Irwindale, CA, USA).…”

“…16,17 A customized threepiece dark eye model with a PMMA cornea was used to hold the IOLs under immersion in BSS. Care was taken to prevent the presence of air bubbles inside of the eye model during loading and assembly.…”

“…This is a measure of brightness or intensity of reflected (scattered) light. 16,17 According to the operator's manual, the raw pixel density level of the device ranges from 0 to 255 without background correction.…”

“…Results were expressed as percent light transmittance (%T) in the visible light spectrum (400-700 nm). 16,17 RESULTS Figure 1 shows representative gross photographs of the lenses explanted because of clinically significant optic opacification. Gross and light microscopy of the explanted hydrophilic acrylic lenses showed calcified deposits, which were predominantly located within the optic substance (N ¼ 9) or on the surface/subsurface of the lenses (N ¼ 4).…”

“…[13][14][15] In previous studies, we evaluated light scattering and light transmission in IOLs explanted because of clinically significant postoperative opacification. 16,17 Very high levels of light scattering and a potential for decrease in light transmittance were found. However, only back scattered light was measured with a Scheimpflug camera (dispersion of light reflected out of the eye that can be seen by an external observer).…”