AUG 05, 2011
This small case series reports on the utility of different surgical techniques for treating patients with pseudophakic negative dysphotopsia. Patients who underwent piggyback IOL implantation or reverse optic capture experienced at least partial resolution of symptoms, but those treated with in-the-bag IOL exchange or iris suture fixation of the capsular bag-IOL complex did not improve.
The authors, Sam Masket, MD, and colleagues, conclude that symptom resolution depends on IOL coverage of the anterior capsule edge rather than on collapse of the posterior chamber alone, backing his hypothesis implicating the anterior capsulorhexis.
The study included 11 patients (12 eyes) treated at one private practice. All but one of the 14 procedures they underwent were performed by the same surgeon. The 10 patients treated with piggyback IOL implantation or reverse optic capture experienced partial or complete resolution of symptoms by three months. No patient who had in-the-bag IOL exchange (n = 3) improved despite alteration of IOL material or edge design. Iris suture fixation of the capsular bag-IOL complex (n = 1) also was not successful despite ultrasound biomicroscopy confirmation of posterior chamber collapse.
These outcomes, which are in keeping with the existing literature, show that negative dysphotopsia symptoms can be improved by sulcus placement of the IOL (primarily or after IOL exchange), with secondary piggyback IOL implantation and by reverse optic capture of the IOL optic.
On the other hand, they conclude that the lack of effectiveness of reducing posterior chamber depth or in-the-bag IOL exchange for an IOL of different material suggest that negative dysphotopsia is likely induced at the interface of the anterior capsulotomy and the front surface of the posterior chamber IOL, with a reflection of the anterior capsulotomy edge projected onto the nasal peripheral retina. They add that negative dysphotopsia can be considered a complication of anterior capsulorhexis with in-the-bag implantation of an IOL and suggest that new IOL designs might preclude negative dysphotopsia symptoms.