Hiroyuki MATSUSHIMA, MD, PhD
Assistant Professor, Department of Ophthalmology, Dokkyo Medical University
880 Kitakobayashi, Mibu, Shimotsuga-Gun, Tochigi 321-0293, Japan
Tel. no. +81-282-87-2163
Fax no. +81-282-86-0630
Is glistening and whitening safe?
As highlighted in the EyeWorld article by Tony Realini, MD, MPH, the effect on visual function by opaci cation in hydrophilic acrylic IOLs and glistenings in hydrophobic acrylic IOLs is signicantly different. Although at the slit lamp the deteriorations in optic clarity may appear to be the same in IOLs affected by these conditions, the effect on visual acuity is signicantly different. In the case of the hydrophilic acrylic lenses, opaci cation causes visual acuity to be signicantly diminished; whereas in the case of glistenings in hydrophobic acrylic IOLs, vision may be only slightly impaired. However, the impact on retinal straylight, which causes disability glare, can be signicant.
One wonders if glistening and whitening in hydrophobic acrylic IOLs is safe. In most cases of whitening, there is a reduction of light transmission by 10 to 20 percent. Ken Hayashi, MD PhD, Fukuoka, Japan, has previously reported that whitening and glistening are not signicantly correlated with visual function and optical aberration. However, Shinichiro Yoshida, MD PhD, Hakodate, Japan, and Yuki Hidaka, MD, Tokyo, Japan, have reported on patients who were bothered by visual disturbance because of severe glistening and whitening. In these patients, removal and replacement of the defective IOLs was effective in improving their visual acuities and contrast sensitivities. Other Japanese authors, including myself, have also reported that glistenings in AcrySof (Alcon, Fort Worth, Texas, U.S./Hünenberg, Switzerland) were associated with decreased visual acuity which improved after IOL explantation and replacement with IOLs without glistenings. Interestingly, although all these cases were associated with other ocular conditions including uveitis, macular hole, or diabetic retinopathy (representing eye diseases that could affect retinal function), only exchange of the glistening affected IOL was performed and resulted in improved visual acuity.
George H.H. Beiko, BM, BCh, FRCSC, St. Catharine, Canada, has warned that severe whitening and glistenings in hydrophobic acrylic IOLs can result in decreased visual performance due to increased disability glare. He has suggested that glistenings/whitening may impact patients since they report a trend towards limiting their driving at night and an increase in self-reported motor vehicle accidents when compared to patients who have an IOL without glistenings (iolsafety.com).
The gure illustrates the progression of whitening over time in a 40-year-old patient with a hydrophobic acrylic IOL. It is evident, as has been reported in the past, that this whitening increases incrementally over the course of time (9 years in my case and up to 15 years in previous reports). Since glistenings and whitening are progressive, I disagree with the author of the EyeWorld article who states “In most cases, glistenings can be observed without intervention, as their impact on visual function is usually negligible.” It is my experience that glistenings and whitening does affect vision and so it is necessary to be vigilant.
Editors' note: Dr. Matsushima has no financial interests related to his comment.