Nov 1, 2014
James M. Osher, MD, identifies the patient characteristics and reviews some of the complications with small-gauge vitrectomy for vitreous floaters.
Cincinnati—Small-gauge pars plana vitrectomy (PPV) for symptomatic floaters is associated with few but potentially serious complications, said James M. Osher, MD, on behalf of the Vitrectomy for Floaters Study Group (VFSG).
“Floaters most commonly result from posterior vitreous detachment (PVD) or vitreous syneresis,” explained Dr. Osher, who began this study with Michael Lai, MD, PhD, during his surgical retina fellowship at Retina Group of Washington/Georgetown University. Dr. Osher is now assistant professor of ophthalmology at the Cincinnati Eye Institute/University of Cincinnati.
“Vitrectomy for symptomatic vitreous floaters has become more widespread with the use of small-gauge instrumentation, which affords a higher safety profile,” he added.
To that end, the VFSG initiated a study to identify risk factors for symptomatic vitreous floaters and to analyze the intraoperative and postoperative complications of small-gauge PPV. The retrospective interventional case series included 204 eyes of 153 patients who underwent 23- or 25-gauge PPV for vitreous floaters over a 45-month period at a single private retina practice.
Preoperative data recorded included length of symptoms, visual acuity, IOP, lens status, and IOL type. Premium IOL patients were considered those with multifocal or accommodating lenses (toric lenses were not considered premium for the purposes of this study).
Intraoperatively, the group evaluated vitrectomy gauge, PVD induction, and presence of retinal tears. Finally, postoperative data included visual acuity, IOP, cataract development, and complications.
In short, Dr. Osher said “premium IOL patients may be more symptomatic from vitreous floaters and, therefore, elect surgical intervention sooner than patients with monofocal, toric, or crystalline lenses.”
What the study found
The mean age of the patients was 62.8 years (40 to 88) and mean follow-up was 8.7 months (1 to 41). Sixty-four percent (n = 131) of eyes were pseudophakic, with 15% (n = 19) of IOLs being either multifocal or accommodating. Most eyes (94.1%) underwent 25-gauge PPV.
Intraoperative PVD was present in 191 eyes (78.3%). PVD induction was performed in the remaining 13 eyes. Intraoperative retinal tears were identified in 7 eyes, 2 of which had PVD induction (p < 0.05).
Postoperative complications included one case each of endophthalmitis and retinal detachment; 15 eyes had a transient hypotony of less than 5 mm Hg, and 14 eyes had a transient IOP of more than 25 mm Hg.
Thirty-four percent of phakic eyes underwent cataract surgery during the follow-up period, with the mean time to surgery of 8.5 months. Forty-five percent of phakic eyes showed no progressive lens changes.
Postoperative visual acuity in pseudophakic eyes remained stable at 20/25 at postoperative months 3 and 6, but decreased slightly from 20/25 to 20/30 (p = 0.01) in phakic eyes from month 3 to month 6. The time interval between symptom onset and PPV was shorter for patients with premium IOLs than other patients (mean 13.8 versus 23.6 months). However, the difference did not reach statistical significance (p = 0.22) (Figure 1 and 2)
“There are three possibilities for the increased symptoms in the premium lens patients,” Dr. Osher said.
“First, there may be an actual optical difference in premium IOLs compared [with] monofocal IOLs that makes floaters more symptomatic,” he said. “Second, patients who are more likely to opt for a premium IOL have higher expectations and therefore are more bothered by/sensitive to any imperfections in their vision.
“And, finally, the personality of patients who select premium IOLs by nature may also predispose them to become more bothered by floaters,” Dr. Osher said.
Because intraoperative retinal tears are more common if a PVD is induced (an almost five-fold increase compared with eyes with a pre-existing PVD), Dr. Osher recommends a complete scleral-depressed exam at the conclusion of surgery to check for tears in the retina.
For the cataract surgeon who may implant the premium lens, Dr. Osher said “our observation of increased symptoms with premium IOLs should prompt the cataract surgeon to discuss this possibility with the patient, especially if large floaters are observed on the preoperative exam.”
Referral to a retina specialist or an ophthalmologist comfortable with performing a scleral-depressed retina exam should take place with any new onset of floaters to evaluate for retinal tears. Patient should be referred for possible surgical intervention when the symptoms interfere with aspects of the patient's life and are more than a nuisance. Similar referral patterns should be considered for a phakic patient, he noted.
One of the biggest strengths of this study was the number of cases—it is the largest study to date that examined small-gauge PPV for floaters, according to Dr. Osher.
“We believe that small-gauge vitrectomy for floaters is a viable option in the symptomatic patient,” he said. “While the complication rate is very low, vision-threatening complications do occur and patients should be made aware of this prior to moving forward with surgery.”
Pseudophakic patients or eyes with PVD may be better candidates for small-gauge PPV, he noted.
James M. Osher, MD
This article was adapted from Dr. Osher’s presentation at the 2014 meeting of the American Society of Retina Specialists.