Piggyback IOL, reverse optic capture may mitigate postop negative dysphotopsia

IOL design, IOL material and posterior chamber depth were not associated with patient reports of a dark shadow in the temporal visual field.

Samuel Masket

Surgical intervention eliminated or reduced symptoms of negative dysphotopsia in patients who had undergone anterior capsulorrhexis with in-the-bag IOL implantation, a study found.

Resolution of negative dysphotopsia symptoms depended on IOL coverage of the anterior capsule edge rather than collapse of the posterior chamber alone.

Negative dysphotopsia is characterized as a patient-reported dark shadow in the temporal visual field after cataract surgery with in-the-bag implantation of a posterior chamber IOL.

“What a patient will most often do is either say it’s similar to wearing horse blinders or they’ll put their hands just up outside the temporal aspect of their eyes,” Samuel Masket, MD, the corresponding author of the study, said in an interview with Ocular Surgery News. “It’s as though there’s a blockage of part of their vision on the temporal side.”

Negative dysphotopsia is unpredictable and difficult to diagnose.

“We have no testing device, so we rely solely on patient-reported complaints,” he said.

The etiology of negative dysphotopsia has been poorly understood. However, ray tracing analysis has confirmed that negative dysphotopsia can be attributed to overlap of the anterior capsulotomy on the optic surface, Dr. Masket said.

“Primarily it is the anterior circular capsulotomy that seems to be creating the negative shadow,” he said. “We’ve come to that conclusion because no patient has ever developed negative dysphotopsia when the intraocular lens is on top of the capsule — only when the intraocular lens is below the capsule.”

The study was published by Dr. Masket and co-author Nicole R. Fram, MD, in the Journal of Cataract and Refractive Surgery.

Patients and procedures

The retrospective study included 14 procedures performed in 12 eyes of 11 patients with negative dysphotopsia. Piggyback IOL implantation was performed in seven cases, reverse optic capture in three cases, in-the-bag IOL exchange in three cases and iris suture fixation of the capsular bag-IOL complex in one case.

The primary outcome measure was resolution of negative dysphotopsia symptoms 3 months postoperatively. A secondary outcome measure was evaluation of posterior chamber anatomy and the correlation with negative dysphotopsia symptoms in selected patients as ultrasound biomicroscopy became available.

Piggyback IOL implantation involved placement of a three-piece IOL in the ciliary sulcus, anterior to the IOL-capsular bag complex. Lens power ranged from –1 D to +1.5 D and varied with associated ametropia. The lenses implanted were the AQ5010V IOL (STAAR Surgical) and the Clariflex IOL (Abbott Medical Optics).

Patients who underwent reverse optic capture had received a single-piece toric or aspheric AcrySof IOL (Alcon). Symptoms were improved for these patients.

Two patients who underwent in-the-bag IOL exchange had received three-piece and one-piece AcrySof IOLs. The three-piece IOL was exchanged for an SI-40NB IOL (AMO). The one-piece IOL was replaced with a three-piece silicone lens (AQ2010V, STAAR Surgical). The third patient who underwent IOL exchange also had a one-piece acrylic IOL replaced with a three-piece silicone lens, the authors said. None of these IOL exchanges resulted in improved symptoms.

The patient who underwent iris suture fixation of the capsular bag-IOL complex had a one-piece AcrySof acrylic IOL replaced with a three-piece silicone IOL. The IOL-capsular bag complex was affixed to the iris with 10-0 polyester sutures; the haptics of the IOL were incorporated. Posterior chamber depth was markedly reduced after surgery, but symptoms were unimproved.

Outcomes and observations

Symptoms of negative dysphotopsia were partially or completely resolved in the 10 patients who underwent reverse optic capture or piggyback IOL implantation.

No improvement was observed in the four patients who underwent in-the-bag IOL exchange or iris suture fixation of the capsular bag-IOL complex.

“There are only two effective treatments that I’m aware of,” Dr. Masket said. “That is placing the lens in the sulcus, removing it from the bag and replacing it in the sulcus or just bringing the optic edge anterior to the bag and leaving the loops in the bag, or putting a piggyback lens on top of the existing in-the-bag lens.”

Study results showed that negative dysphotopsia was not associated with IOL material or design. The phenomenon was associated with a variety of lens types and superior as well as temporal incision placement, Dr. Masket said.

In addition, posterior chamber depth did not appear to play a contributing role.

“We have some patients who have a very shallow posterior chamber but still have very symptomatic negative dysphotopsia,” he said.

Dr. Masket indicated that symptoms of negative dysphotopsia increased with pupil constriction and decreased with dilation.

Dr. Masket further said that femtosecond laser-assisted capsulotomy has not been investigated with regard to the rate of negative dysphotopsia.

In addition to a reliance on subjective patient observations, limitations of the study included retrospective study design, small sample size, and lack of age and gender matching, the authors said. – by Matt Hasson

Reference:

• Masket S, Fram NR. Pseudophakic negative dys-photopsia: Surgical management and new theory of etiology. J Cataract Refract Surg. 2011;37(7):1199-1207.

• Samuel Masket, MD, can be reached at Advanced Vision Care, 2080 Century Park East, Suite 911, Los Angeles, CA 90067; 310-229-1220; email: avcmasket@aol.com.
• Disclosure: Dr. Masket has no relevant financial disclosures.

William B. Trattler

Sam Masket’s paper “Pseudophakic negative dysphotopsia: Surgical management and new theory of etiology” is an important paper for clinicians, as it provides clinical evidence that the anterior edge of the capsule plays a pivotal role in negative dysphotopsia symptoms. It allows clinicians to explain to patients who experience this phenomena that the symptom is not related to the particular lens model that was chosen, as the temporal dark shadow symptom can occur with any lens material and will not resolve with an IOL exchange. It allows the surgeon to explain that if the negative dysphotopsia symptom does not improve on its own with time, there is a simple therapy that should be effective at eliminating the symptoms. The treatment includes repositioning the optic in front of the anterior capsule or potentially even YAG treatment at the edge of the anterior capsule that is overlying the optic. With these options, clinicians are armed with new therapeutic treatment options for helping patients with these symptoms.

–William B. Trattler, MD
OSN SuperSite Board Member
Disclosure: Dr. Trattler has no relevant financial disclosures.