We have read with great interest the article by Suzuki and associates entitled “Outbreak of Late-onset Toxic Anterior Segment Syndrome After Implantation of One-piece Intraocular Lenses.” The article describes the occurrence of late-onset ocular inflammation caused by intraocular lenses (IOLs) that had become contaminated with aluminum as a result of a damaged instrument used in the IOL factory. The authors have, therefore, recommended that companies that produce IOLs should be aware of the risk of contamination by heavy metals such as aluminum and should exercise extreme caution in manufacturing the IOLs. We thank the authors for their excellent work and would like to make some contributions with respect to heavy metal toxicity of the retina, which can be seen together with toxic anterior segment syndrome (TASS) caused by these metals.
First, the authors report that none of the patients had any fundus abnormalities on the fundus examination even though vitreous opacities were found in 21.5% of the patients. However, it has been reported that aluminum toxicity can cause a toxic retinopathy that can be detected by an electrophysiological examination such as an electroretinogram (ERG). Also, the literature that is currently available provides little knowledge about aluminum toxicity of the retina. Therefore, it is important to determine whether aluminum toxicity could affect the retinas in patients with IOLs that had been contaminated with aluminum. Since the study by Suzuki and associates uses data collected from questionnaires that were issued directly to the 183 clinical centers where the contaminated IOLs had been used, the authors might not have been able to obtain electrophysiological findings for all the patients. However, the difference between the initial and final best-corrected visual acuities of the patients who underwent surgical treatment, which reduced the levels of aluminum in their eyes, can be compared to the values of the patients who had received only medical treatment. This might provide a proof of aluminum toxicity of the retina. If the statistical results provide a clue to the retinal toxicity, an electroretinographic examination might be required for all the patients who had only medical treatment. If the electroretinographic results for the eyes with the IOLs that had been contaminated with aluminum indicate pathologic findings in patients who had only medical treatment, these patients might be followed through ERGs to rule out ongoing retinal damage from the aluminum as well.
In addition, this article also contains a minor inconsistency in terms of the patients’ genders. It states that there were 89 male patients (89 affected eyes) and 162 female patients (162 affected eyes). However, this is not what is shown in Table 1.
Finally, we would like to congratulate the authors for this most interesting study and hope that our scientific contribution will provide a further contribution to the literature, especially in terms of TASS caused by heavy metals.