Sir,

We read with interest the recent report by Shonibare and Lochhead1 describing a patient with visual confusion who suffered troublesome visual ghosting following primary implantation of a near-infrared (NIR)-transmitting black IOL. Secondary implantation of a NIR-blocking Artisan black IOL abolished the patient’s symptoms.

Simultaneously—and independently—we reported an identical experience in a patient with intractable diplopia who required a secondary NIR-blocking Artisan IOL to suppress debilitating visual ghosting.2

NIR light is assumed imperceptible to humans, yet perception of light is almost universal in patients following NIR-transmitting black IOL implantation.3 In all, 91% of patients perceived light post-operatively, the remainder had acquired optic neuropathies with impaired long-wavelength spectral sensitivity and consequently could not perceive NIR light.3

Taken together, these observations suggest that careful and systematic evaluation of both patient factors and black IOL properties are necessary to identify the optimal primary black IOL implant pre-operatively in each patient to minimize the risk of treatment failure.

First, patient factors should be considered including the necessity of posterior segment monitoring, need for absolute light occlusion, scotopic pupil size, lens status, and optic nerve pathology (Table 1). Second, the properties of each black IOL, including optimum surgical configuration, occlusive optic size, and utility in primary and secondary IOL implantation must then be considered (Table 2). Black intraocular lenses are variably occlusive to NIR light and may be usefully categorized by this property.4

Table 1 Summary of patient factors relevant to primary Black IOL selection in eligible patients
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Table 2 Technical details of all black intraocular lenses in clinical use
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High levels of post-operative satisfaction have been reported with NIR-transmitting black IOL implantation,5 although emerging reports of treatment failure do advise some caution.1, 2, 3 Predicting this risk pre-operatively is critical to the long-term efficacy of surgical intervention. Design of a NIR-transmitting black contact lens would permit a therapeutic trial to determine pre-operative NIR light sensitivity where uncertainty exists. Primary implantation of a NIR-blocking IOL would be advised if troublesome ghosting occurred.

SLO/OCT posterior segment imaging remains a distinct clinical advantage in patients with NIR-transmitting black IOLs and may improve long-term safety. However, informed consent in this context must raise the possibility of treatment failure and need for secondary NIR-blocking IOL implantation in this patient group.