Management of positive and negative dysphotopsia postcataract surgery - A literature review.

The objective of this review was to provide a summary of the literature on the etiologies and management of positive (PD) and negative dysphotopsia (ND) which are optical phenomena that occur after routine cataract surgery. A search of PubMed and Google Scholar identified 36 relevant papers. There is a consensus on the etiology of PD, which is attributed to the edge design of the intraocular lens (IOL). A truncated square edge can cause light of an oblique incidence to reflect onto the retinal surface and cause streaks and haloes in the visual field. Other causes of PD include diffractive multifocal IOLs and IOLs with a high index of refraction. The causes of ND are multifactorial; however, the majority of the evidence from experimental and clinical studies supports the "illumination gap" of the nasal retina which may arise from the anterior capsule overlying the IOL. Other factors such as pupil size, a high-angle kappa, and increased posterior chamber depth may also play a role. Regarding surgical management, ND has been successfully treated with reverse optic capture, neodymium-doped yttrium aluminum garnet laser capsulectomy, nasal IOL optic truncation, piggyback IOL, and an ND ring. Both PD and ND can be surgically managed by replacing the IOL using in-the-bag exchange or bag-to-sulcus exchange. Technological advancements have presented new avenues for developing antidysphotopsia lenses. Novel approaches utilize anterior capsulotomy fixation using IOL phalanges and a recent diffractive spiral lens that provides smooth full-range vision without dysphotopsia.