Retained Lens Fragments
During cataract extraction, lens fragments may remain in the anterior chamber angle or in the posterior chamber behind the iris, or they may migrate into the vitreous cavity when zonular dehiscence or posterior capsule rupture occurs. Retained lens fragments are thought to occur more frequently in the anterior segment with phacoemulsification than with ECCE; the reported postoperative prevalence is 0.45%–1.70%, but the actual rates may be higher because of unrecognized cases. During phacoemulsification, intraocular turbulence may force small lens fragments to lodge in the angle or behind the iris, out of the surgeon’s view. Femtosecond laser–assisted cataract surgery can also create many small nuclear fragments, some of which may be retained behind the iris. Dispersive OVDs may trap and retain more lens fragments than cohesive OVDs.
Patients with retained lens fragments present with varying degrees of inflammation, depending on the size of the lens fragment, the type of lens material, the time elapsed since surgery, and the patient’s individual response. Clinical signs of retained lens material include uveitis, elevated IOP, corneal edema, and vitreous opacities. With persistent post-operative inflammation but no lens fragment seen on slit-lamp examination, gonioscopy is indicated to look for a retained lens particle.
Retained cortical lens material or nuclear fragments do not necessarily require surgical intervention. In general, cortical material is better tolerated and more likely to be reabsorbed over time than is nuclear material, which, even in small amounts, persists longer and is more likely to incite a significant inflammatory reaction, corneal edema, or elevated IOP.
Inflammation can be controlled with corticosteroid and nonsteroidal anti-inflammatory drops. Elevated IOP can be treated with aqueous suppressants. Surgical intervention may be necessary to remove residual lens fragments in the following situations:
presence of a large or visually significant amount of lens material
increased inflammation not readily controlled with topical medications
medically unresponsive elevated IOP resulting from inflammation
associated retinal detachment or retinal tears
For retained lens fragments in the anterior chamber with an intact posterior capsule, simple irrigation/aspiration or viscoexpression of the residual material may be performed through the original phacoemulsification incision.
The reported incidence of intravitreal retained lens fragments is between 0.1% and 1.6%. When lens material has migrated into the vitreous cavity through a defect in the zonular fibers or posterior capsule, referral to a vitreoretinal surgeon for pars plana vitrectomy and removal of the lens material is indicated. If necessary, the vitreoretinal surgeon can delay intervention for more than a week after cataract surgery without jeopardizing a successful outcome.
Modi YS, Epstein A, Smiddy WE, Murray TG, Feuer W, Flynn HW Jr. Retained lens fragments after cataract surgery: outcomes of same-day versus later pars plana vitrectomy. Am J Ophthalmol. 2013;156(3):454-459.e1
Vanner EA, Stewart MW. Vitrectomy timing for retained lens fragments after surgery for age-related cataracts: a systematic review and meta-analysis. Am J Ophthalmol. 2011;152(3): 345–357.e3.
Excerpted from BCSC 2020-2021 series: Section 11 - Lens and Cataract. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.