Early referral for dropped lens is best, subspecialist says

Inflammation often leads to emergency vitrectomy. Earlier referral improves the prognosis.

Issue: September 1, 2001

NUREMBURG, Germany — The best device for handling dropped lens material during cataract surgery is probably the telephone, a retinal subspecialist said here. A prompt referral for vitrectomy will provide the best possible outcome and decrease the potential for retinal detachment, he said.

“Refer early; we are very friendly,” said David Wong, FRCOphth, a retinal specialist from Liverpool, England.

Although uncommon, lens material in the vitreous is a potentially serious complication of cataract surgery, Mr. Wong told physicians at the Deutsche Ophthalmochirurgen meeting here.

A dropped lens can swiftly lead to uveitis and high intraocular pressure (IOP) poorly responsive to medical intervention. An emergency vitrectomy then becomes necessary to control the inflammation and reduce the IOP. Vitrectomy performed on the same day as the cataract surgery or very shortly thereafter is the best treatment, he said.

Don’t try too hard

“Part of the problem is that when we drop a nucleus, we don’t know what to say to the patient afterward. Cataract is such a successful operation today that all patients expect a perfect operation. And cataract surgeons, I think, try too hard because they don’t want to disappoint the patient,” Mr. Wong said.

In England, fewer cataract surgeons tend to wait out the inflammation and high IOP. Quick referral is the trend. Additionally, patient informed consent has become even more detailed.

“We are now very careful to explain all the things that can occur. So if things happen, you can be a little more relaxed and more honest with the patient. The best solution at this point is to have good cooperation between cataract surgeon and vitreoretinal surgeon. If you do a cataract operation and you drop a nucleus, don’t try too hard. And the American experience is the same; they attribute their improving results to not trying too hard,” he said.

Hiding patients

Referral for vitrectomy more than 21 days after cataract surgery was associated with poorer visual prognosis, Mr. Wong said. In a study of 109 cases of dropped lenses referred to his center over a 4-year period, roughly a third of these were referred after 28 days. Often, these were emergency cases characterized by uveitis, high IOP, corneal edema and retinal microaneurysm. Of the 109 cases, almost half presented this clinical picture upon referral.

“In other words, the cataract surgeons had been hiding these patients,” he said.

“We all know from the literature that if the referral is early, then the results are likely to be good,” he said. “But most people choose to believe that patients who are operated on early do well, but the ones who have a later vitrectomy also do well.”

Even small lens particles can quickly swell and initiate uveitis, Mr. Wong noted. Inflammatory cells in the trabeculum make IOP control difficult.

“The answer is to refer early,” he said. “Do not hide these patients. Your vitreoretinal colleague can help; not necessarily to operate right away, but to watch the IOP very carefully. In fact, if you work in a big hospital and you have a retinal surgeon next door, vitrectomy on the same day, in fact, gives very good results. This is perfectly possible if the cataract surgeon finishes the operation, you ask the patient to sit up, have a cup of tea and then give them another local anesthetic and do the vitrectomy.”

Other factors

Mr. Wong’s study sought to explain why some patients had a better prognosis than others. In addition to referral beyond 21 days, three other independent risk factors were identified: existing eye disease, fragmentation of the lens particles by performing phacoemulsification in the posterior chamber and retinal detachment. Retinal detachment occurred in a quarter of his vitrectomies, with nearly 50% of detachments occurring before vitrectomy and the other half occurring thereafter.

Factors that had no bearing on prognosis included whether or not an IOL was implanted, type of IOL, whether there was residual vitreous in the anterior chamber or whether there was a high IOP following surgery.

“It may be surprising to some, but these factors did not influence the visual prognosis,” he said.

“We collected many data, including how long we waited between phacoemulsification and vitrectomy, what the pressure was like, what the inflammation was like, whether the implant was put in, what type of implant, how it was put in and so on.

“We also looked at the anterior vitrectomy done by the cataract surgeon and whether a lot of vitreous was left in the anterior chamber. And, of course, we asked ourselves whether or not we used the best method for removing these lens particles that dropped into the vitreous cavity,” he said.

For Your Information:

David Wong, FRCOphth, can be reached at Royal Liverpool University, Hospital Broadgreen and Liverpool, Prescot Street, Liverpool, L78XP, Great Britain; (44) 151-706-3969; fax: (44) 151-706-5861.