The Vexing Problem of Retained Lens Fragments
The Vexing Problem of Retained Lens Fragments
Much emphasis has been placed on the timing of surgery to remove lens fragments. It is well known that over time, retained lens fragments are associated with increasing intraocular inflammation, and many have reasoned that removal of the lens fragments earlier would be lead to better outcomes. All studies evaluating this have been retrospective and evaluated slightly different intervals. No randomized controlled trial to determine the best time to remove retained lens particles has been performed.
Early removal is usually defined as either immediate removal or within one week of cataract surgery. Delayed removal is usually defined as removal after one week. Greater than 30 days seems to represent a time interval that many would define as very delayed.
Immediate removal of the lens fragments is possible in some settings where a retina surgeon can be called in to the surgical room soon after the lens fragment fall posteriorly into the vitreous. This is an attractive option, especially if the dislocated lens fragment is large and surgical visibility is good, and often obviates the need for a secondary intervention.
Most studies have not found any significant difference in outcomes related to the timing of surgery to remove retained lens fragments. However, worse outcomes have occurred when the removal of the lens fragments was delayed (> 30 days). Margherio and colleagues looked at 126 eyes that underwent vitrectomy for retained lens particles: 67 (53%) had early removal and 59 (47%) had delayed removal; of the eyes that had delayed removal, about half (31/59, 53%) would be classified as very delayed. Even though visual outcomes in the very delayed removal group showed a higher percentage of eyes with vision of < 20/400, this was not statistically significant. Moreover, there was no difference in IOP, corneal edema, cystoid macular edema, or choroidal effusions among the early vs late removal groups.
Scott and colleagues evaluated 343 eyes that underwent vitrectomy for retained lens particles and also found no significant difference in final visual acuity or high IOP related to the timing of the vitrectomy. Likewise, Merani and colleagues studied 223 eyes and did not find an association between the timing of pars plana vitrectomy and visual outcome, even though there was a significant association between retinal detachment and very delayed removal of retained lens fragments. A meta-analysis of patients with retained lens fragments who underwent vitrectomy more than three days after cataract surgery found that earlier vitrectomies were associated with significantly better visual acuity outcomes and less intraocular inflammation, retinal detachments, and glaucoma.
Because most studies evaluating the timing of vitrectomy were retrospective in nature, when to perform a vitrectomy for retained lens particles should be determined by the surgeon on a case-by-case basis. Surgeons need to take into account lens fragment size, corneal clarity, IOP, and associated retinal findings when deciding.
Timing of Surgery to Remove Lens Fragments
Much emphasis has been placed on the timing of surgery to remove lens fragments. It is well known that over time, retained lens fragments are associated with increasing intraocular inflammation, and many have reasoned that removal of the lens fragments earlier would be lead to better outcomes. All studies evaluating this have been retrospective and evaluated slightly different intervals. No randomized controlled trial to determine the best time to remove retained lens particles has been performed.
Early removal is usually defined as either immediate removal or within one week of cataract surgery. Delayed removal is usually defined as removal after one week. Greater than 30 days seems to represent a time interval that many would define as very delayed.
Immediate removal of the lens fragments is possible in some settings where a retina surgeon can be called in to the surgical room soon after the lens fragment fall posteriorly into the vitreous. This is an attractive option, especially if the dislocated lens fragment is large and surgical visibility is good, and often obviates the need for a secondary intervention.
Most studies have not found any significant difference in outcomes related to the timing of surgery to remove retained lens fragments. However, worse outcomes have occurred when the removal of the lens fragments was delayed (> 30 days). Margherio and colleagues looked at 126 eyes that underwent vitrectomy for retained lens particles: 67 (53%) had early removal and 59 (47%) had delayed removal; of the eyes that had delayed removal, about half (31/59, 53%) would be classified as very delayed. Even though visual outcomes in the very delayed removal group showed a higher percentage of eyes with vision of < 20/400, this was not statistically significant. Moreover, there was no difference in IOP, corneal edema, cystoid macular edema, or choroidal effusions among the early vs late removal groups.
Scott and colleagues evaluated 343 eyes that underwent vitrectomy for retained lens particles and also found no significant difference in final visual acuity or high IOP related to the timing of the vitrectomy. Likewise, Merani and colleagues studied 223 eyes and did not find an association between the timing of pars plana vitrectomy and visual outcome, even though there was a significant association between retinal detachment and very delayed removal of retained lens fragments. A meta-analysis of patients with retained lens fragments who underwent vitrectomy more than three days after cataract surgery found that earlier vitrectomies were associated with significantly better visual acuity outcomes and less intraocular inflammation, retinal detachments, and glaucoma.
Because most studies evaluating the timing of vitrectomy were retrospective in nature, when to perform a vitrectomy for retained lens particles should be determined by the surgeon on a case-by-case basis. Surgeons need to take into account lens fragment size, corneal clarity, IOP, and associated retinal findings when deciding.
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