Silicone versus collagen plugs for treating dry eye: results of a prospective randomized trial including lacrimal scintigraphy. SmartPlug versus silicone punctal plug therapy for dry eye: a prospective randomized trial. Effects of lacrimal occlusion with collagen and silicone plugs on patients with conjunctivitis associated with dry eye. Lacrimal punctum occlusion in the treatment of severe keratoconjunctivitis Sicca caused by Sjögren syndrome: a uniocular evaluation. Vitrectomy with silicone oil or perfluoropropane gas in eyes with severe proliferative vitreoretinopathy: results of a randomized clinical trial. Silicone Study Report 2.
To compare the short-term efficacy of collagen and silicone plugs for treating dry eye using quantitative lacrimal scintigraphy.
                Prospective randomized clinical trial.
                In this institutional study, 24 dry eye patients were evaluated in two groups: group I (n = 22 eyes) received collagen plugs and group II (n = 26 eyes) received silicone plugs. Comparisons were made with normal control subjects (n = 22 eyes). Data for the Schirmer I test, tear break-up time, and ocular surface staining with rose bengal dye were recorded before and after punctal occlusion. Lacrimal scintigraphy was performed at each time point, and the time to half maximum activity on the ocular surface (T(1/2)), and the percentage retention of activity on the ocular surface at the end of the dynamic study (RI) were recorded.
                In both patient groups, Schirmer I results, tear break-up times, and rose bengal staining scores improved significantly after plug insertion. Mean T(1/2) values and RI values increased significantly in both groups (P < .0001 for both). The differences for these values between groups I and II was statistically insignificant (P > .05).
                Collagen and silicone plugs both resulted in significant increases in aqueous tear volume, half-life of nuclear material on the ocular surface, and percentage of nuclear material retention. The groups' post-insertion values for all parameters were similar. These results suggest that these two plug types have similar efficacy as treatments for dry eye in the short term. Further studies evaluating long-term results are required. To evaluate the clinical efficacy, retention rates, and complications of SmartPlug insertion compared with silicone punctal plugs in patients with dry eye.
                Thirty-six eyes with subjective symptoms of dry eye in addition to a tear film breakup time (TBUT) <5 seconds and evidence of ocular surface damage on rose Bengal or fluorescein staining were included. Treated eyes were randomized to either a silicone plug or SmartPlug inferior punctal occlusion. Pre- and posttreatment evaluations included subjective symptom scoring, tear meniscus height, TBUT, Schirmer test, fluorescein and rose Bengal staining, and artificial tear use.
                After a mean follow-up period of 11.2 weeks, both the silicone plug- and SmartPlug-treated eyes showed significant improvement in symptom scoring (P = 0.002 and P = 0.005, respectively), TBUT (P = 0.035 and P = 0.009, respectively), and fluorescein (P = 0.024 and P = 0.016, respectively) and rose Bengal (P = 0.008 and P = 0.046, respectively) staining. There was no significant difference in these parameters between the 2 plugs. SmartPlug-, but not the silicone plug-treated eyes showed significant improvement in mean tear meniscus height (P = 0.037). The use of artificial tear supplements was reduced in 10 (55.6%) silicone- and 11 (61.1%) SmartPlug-treated eyes. Minor complications related to plug insertion were experienced in 4 (22%) silicone- and 2 (11%) SmartPlug-treated eyes. Spontaneous plug loss occurred with 6 (33%) silicone plugs.
                This prospective randomized trial shows that SmartPlug insertion has equivalent clinical efficacy to the use of conventional silicone plugs. Both SmartPlug and silicone plug use can reduce dependency on tear supplements in >55% of patients with dry eye. To determine whether canalicular occlusion with collagen and silicone plugs reduces the severity of symptoms in patients with conjunctivitis secondary to dry eye.
                This was a prospective, randomized, double-masked study conducted at a single center in Mexico, in which 61 patients with dry eye/conjunctivitis were assigned to progressive lacrimal occlusion with collagen and silicone plugs or a sham procedural group. Outcome variables included total and individual dry eye and conjunctivitis symptom scores, moisturizing agent usage, best-corrected visual acuity, ocular comfort level, visual performance, corneal/conjunctival fluorescein staining, and incidence of adverse events.
                Total dry eye and conjunctival symptom scores were reduced by 43.7 and 33.7%, respectively 2 weeks after occlusion of all four lacrimal canaliculi with collagen plugs, increasing to 77.4 and 72.1% 2 weeks later following superior canalicular occlusion of both eyes with silicone plugs and inferior placement of collagen plugs. At the 8-week visit (4 weeks after silicone plug implantation of the inferior canaliculi of both eyes), the reduction in total dry eye and conjunctival symptom scores further increased to 94.2 and 93.0%, respectively, accompanied by a marked decline in each of the seven individual symptom scores (dryness, watery eyes, itching, burning, foreign body, fluctuating vision, and light sensitivity). In concert with these changes, moisturizing agent usage and corneal/conjunctival fluorescein staining decreased in a progressive fashion over the 8-week study period, and best-corrected visual acuity, ocular comfort, and visual performance improved in the absence of any treatment-related adverse events except for one case of epiphora. The response of patients to lacrimal occlusion can be sharply contrasted with the sham procedure group, which remained relatively unchanged from baseline at each of the study visits.
                Progressive lacrimal occlusion with collagen and silicone plugs was of clinical benefit to patients with dry eye and conjunctivitis. A controlled uniocular study to evaluate the short-term efficacy of lacrimal punctum occlusion in the treatment of severe dry eye caused by Sjögren syndrome.
                Uniocular punctum occlusion by punctum plug in the upper and lower puncta in 1 eye was performed in 20 patients with severe keratoconjunctivitis Sicca caused by Sjögren syndrome. To overcome possible interindividual variability between patients, the other eye, in the same patient, was not occluded and served as a control eye. The eye to be occluded was randomly selected. The patients were instructed to continue using their dry eye medications. Tear function tests (Schirmer test, rose Bengal test, and debris in de cul-de-sac) were performed in both eyes. Subjective complaints (discomfort) were registered for both eyes. All the above-mentioned data were collected before starting the treatment and at least 6 weeks later. The above-mentioned parameters were compared and statistically analyzed in both eyes.
                Of the 20 patients, 7 patients dropped out. The remaining 13 patients completed the final analysis. In the occluded eye, we found a significant improvement in both the subjective complaints and the rose Bengal score, but the Schirmer test and the tear mucus score did not change.
                Punctum occlusion therapy in a short-term study improved the rose Bengal score and discomfort score in our patients and thus may be helpful in the treatment of severe dry eye caused by Sjögren syndrome. Between September 1987 and October 1990, 265 eyes with rhegmatogenous retinal detachment and severe (with a classification of at least C-3) proliferative vitreoretinopathy were treated with vitrectomy and randomized to treatment with perfluoropropane gas or silicone oil; 131 eyes had undergone no prior vitrectomy (group 1) while 134 eyes had undergone vitrectomy with intraocular gas tamponade (group 2). At the last examination, there were no differences between perfluoropropane gas and silicone oil in achieving visual acuity greater than or equal to 5/200 (43% vs 45% for group 1, 38% vs 33% for group 2) and complete posterior retinal reattachment (73% vs 64% for group 1, 73% vs 61% for group 2). For group 1 eyes followed up for at least 18 months, there was an advantage favoring perfluoropropane gas in achieving complete posterior retinal reattachment (83% vs 60% at 36 months, P = .045). The rates of reoperation and keratopathy were similar, while hypotony was more prevalent in eyes randomized to perfluoropropane gas (group 2). Regardless of tamponade, groups 1 and 2 had similar anatomic and visual success. However, hypotony was twice as prevalent in group 2 (perfluoropropane), and the prevalence of keratopathy increased with follow-up in group 2 (either tamponade). Either tamponade produced better results than those seen with sulfur hexafluoride gas (Silicone Study Report 1).
This systematic review shows a relative scarcity of controlled clinical trials assessing the efficacy of punctal occlusion therapy in dry eye. Although the evidence is very limited, the data suggest that silicone plugs can provide symptomatic relief in severe dry eye. Moreover, temporary collagen plugs appear similarly effective to silicone plugs on a short-term basis.