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Ripcord removal after Baerveldt implantation ‘reasonable’ in some patients
Scheduled Baerveldt ripcord removal results in similar IOP decrease and success rates as spontaneous removal.
The scheduled removal of a surgically implanted ripcord in a Baerveldt glaucoma drainage device resulted in similar recovery outcomes as in patients whose tubes opened spontaneously, according to a study published in Journal of Glaucoma.
“If one is facing elevated IOP in a post-Baerveldt patient at 3 weeks postoperatively, it is reasonable to remove the ripcord,” study co-author Leon W. Herndon, MD, told Ocular Surgery News. “There are some patients in whom waiting an additional 3 to 4 weeks for spontaneous opening of the tube might be of concern, so it is reassuring to see that these tubes can be ‘opened’ earlier.”
Patients and procedure
Eighty-one patients underwent superotemporal placement of a Baerveldt 350 mm2 implant (Johnson & Johnson Vision) with a piece of 6-0 Prolene suture positioned under the temporal conjunctiva, where it could be accessed as a “ripcord” by the surgeon during clinical follow-up. These patients were randomly assigned to either ripcord removal at week 3 or observation. Of patients in the intervention group, seven crossed over to the observation group, mostly due to hypotony. Two patients with high IOP in the control group crossed over to the intervention group and underwent ripcord removal.
Subanalysis of these “as treated” groups included 39 patients in the intervention group and 42 controls. Demographic data of the two groups were similar at baseline.
At the 3-week follow-up visit, patients in the intervention group were given a subconjunctival injection of lidocaine and epinephrine, Healon (sodium hyaluronate, Johnson & Johnson Vision) was injected into the anterior chamber, and the ripcord was removed by Herndon using jeweler’s forceps.
Results
Mean IOP at baseline was 23.7 mm Hg in the intervention group and 22 mm Hg in the control group. At 6 months’ follow-up, mean decrease in IOP was 9.31 mm Hg and 7.71 mm Hg, respectively, with no statistically significant difference between the groups.
Fifty-nine percent of cases in the intervention group and 64% in the control group were deemed to be successes, which was defined as a final IOP greater than 5 mm Hg and less than or equal to 15 mm Hg without further surgical intervention.
Median visual acuity in the intervention group preoperatively was 20/50 compared with 20/40 in the control group. The intervention group lost on average 2.3 lines of vision; the control group lost 0.4 lines (P = .028). The study authors said the difference was possibly attributable to faster progression of disease in patients with more advanced disease at baseline. There was a statistically significant difference in stage of disease between the two groups at baseline.
There was also a statistically significant difference between the groups regarding mean number of preoperative glaucoma medications, both preoperatively and at the end of the study. Mean number of medications at baseline was 2.9 in the intervention group vs. 2.2 in the control group (P = .03). At month 6, these numbers were decreased by 1.4 medications in the intervention group vs. 0.5 in the control group (P = .0077).
The rate of total complications was not significantly different between the two groups, and the reintervention rate was lower than that seen in other studies, the authors said.
Lessons learned
In the observation group, an absorbable suture that ligates the Baerveldt tube is expected to dissolve by week 5 or 6 postoperatively while a fibrous capsule forms around the implant. Herndon said capsule formation in the intervention group was seen earlier than expected, as early as 3 weeks after surgery. Also noted was the lower rate of tube fibrin obstruction in the intervention group.
Spontaneous opening of the tube can lead to sudden IOP decrease and consequent complications.
“One advantage of removing the ripcord earlier is that the surgeon controls the time of tube opening, rather than having the tube open when the patient is performing activities of daily living, including bending, stooping or straining,” Herndon said. “One disadvantage of removing the ripcord is that the procedure to remove the ripcord takes some time and will slow the flow of clinic.” – by Robert Linnehan
- Reference:
- An SJ, et al. J Glaucoma. 2019;doi:10.1097/IJG.0000000000001133.
- For more information:
- Leon W. Herndon, MD, can be reached at Department of Ophthalmology, Duke University, Box 3802 Med Center, Durham, NC 27710; email: leon.herndon@duke.edu.
Disclosure: Herndon reports no relevant financial disclosures.