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. Long-term efficacy of adding a sharp posterior optic edge to a three-piece silicone intraocular lens on capsule opacification: five-year results of a randomized study. Long-term results of sealed capsule irrigation using distilled water to prevent posterior capsule opacification: a prospective clinical randomised trial. Vitrectomy with silicone oil or sulfur hexafluoride gas in eyes with severe proliferative vitreoretinopathy: results of a randomized clinical trial. Silicone Study Report 1. Effect of optic material on posterior capsule opacification in intraocular lenses with sharp-edge optics: randomized clinical trial.
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). To compare the intensity of capsule opacification with the sharp and the round optic edge variant of an open-loop hydrophobic silicone intraocular lens (IOL).
                Randomized, controlled, double-blind clinical trial with intraindividual comparison.
                Fifty-one patients with bilateral age-related cataract were included (102 eyes). Each patient had had cataract surgery in both eyes and received a Microsil IOL with a sharp optic edge design (model S) in one eye and a Microsil IOL with a round optic edge design (model R) in the fellow eye. Both IOLs had an identical haptic design (nonangulated polymethylmethacrylate) and silicone optic material. The patients were examined at the slit lamp, best-corrected visual acuity was assessed, and standardized high-resolution digital retroillumination images of the posterior capsule were taken 5 years after surgery. The intensity of regeneratory posterior capsule opacification (rPCO), fibrotic PCO (fPCO), and anterior capsule opacification (ACO) was assessed subjectively at the slit lamp, and of rPCO, objectively using automated image analysis software (AQUA). The need for an Nd:YAG laser capsulotomy (Nd:YAG-LCT) was noted.
                The mean AQUA PCO score was 1.2 for the model S and 2.4 for the model R lens (P = .001). The model S lens also led to less peripheral fPCO (P = .003). Concerning ACO, there was no significant difference between both IOL groups (P = .72). Whereas no capsulotomy was required with the model S, four cases (16%) had been performed in the model R group.
                Five years postoperatively, the sharp-edged silicone IOL showed less rPCO and fPCO than the round-edged IOL. However, regarding ACO, there was no significant difference between both IOL styles. We investigated long-term safety and efficacy of sealed capsule irrigation (SCI) during cataract surgery to prevent posterior capsule opacification (PCO).
                One eye of each of 17 patients (mean age: 70.1+/-9.7 years) who presented with bilateral cataracts was randomly chosen for SCI treatment. After phacoemulsification, the capsular bag was vacuum sealed with the PerfectCapsule device (Milvella) followed by SCI using distilled water for two minutes. No vacuum loss occurred during irrigation. Each patient's fellow eye served as a control. One hydrophilic acrylic intraocular lens model was implanted in all eyes. Five patients had to be excluded due to deep anterior chamber, small pupil or unilateral surgery. Follow-up examinations took place one day and one, three, six, 12 and 24 months after surgery. We evaluated safety parameters, anterior capsule (AC) overlapping and PCO.
                Postoperatively, mean best corrected visual acuity, pachymetry, endothelial cell count, intraocular pressure, AC overlapping and PCO showed no statistically significant difference between SCI and the control group (p>0.05, Wilcoxon test).
                SCI is a safe procedure and enables the specific pharmacological targeting of lens epithelial cells inside the capsular bag. Using distilled water, however, it is not possible to reduce PCO development significantly. Thus, alternative substances should be evaluated. Between September 1985 and September 1987, 101 eyes with rhegmatogenous retinal detachment and severe (with a classification of at least C-3) proliferative vitreoretinopathy but without prior vitrectomy were treated with vitrectomy and randomized to either a mixture of 20% sulfur hexafluoride gas and air or to 1000 centistokes of silicone oil. Between 50% and 60% of eyes that received silicone oil had visual acuity better than or equal to 5/200 compared with 30% to 40% of the eyes that received sulfur hexafluoride gas (P less than .05). Macula attachment was more frequent in eyes that received silicone oil than in those that received sulfur hexafluoride gas (80% vs 60%, P less than .05). Hypotony was more prevalent in eyes with a detached macula (40% to 50% for sulfur hexafluoride gas vs 25% to 30% for silicone oil) when compared with those with attached maculas (less than 5% for either modality). Keratopathy was more prevalent in eyes with detached maculas (about 55% to 60% for either modality) compared with eyes with attached maculas (25% to 30% for sulfur hexafluoride gas vs 10% to 15% for silicone oil). In a companion article, we show that these differences between a gas tamponade and silicone oil are not found for perfluoropropane gas. Comparison of the intensity of posterior capsule opacification (PCO) between a silicone intraocular lens (IOL) and a hydrophobic acrylic IOL, both of them 3-piece and open-loop and having truncated optics with sharp edges.
                Randomized, controlled, patient- and examiner-masked trial with intrapatient comparison.
                One hundred six eyes of 53 patients with age-related bilateral cataract.
                Each patient had cataract surgery in both eyes and received a silicone IOL in one eye and a hydrophobic acrylic IOL in the fellow eye. Follow-up examinations were at 1 and 3 years after surgery. The patients were examined at the slit lamp, visual acuity (VA) was assessed, and standardized high-resolution digital retroillumination images of the posterior capsule were taken. The amount of PCO was assessed subjectively at the slit lamp and objectively using automated image analysis software. Data of 56 eyes of 28 patients, who were examined at each follow-up, were analyzed.
                Posterior capsule opacification intensity at 3 years as measured with automated image analysis.
                At 1 and 3 years after surgery, PCO did not differ between the silicone (1.6 and 1.9 [image analysis scores, 0-10 scale], respectively) and acrylic IOLs (1.7 and 2.2) (P > 0.24). Furthermore, there was no significant difference in best-corrected VA, rhexis/IOL overlap, capsular folds, and amount of anterior capsule opacification during the follow-up period. In each group, one neodymium:yttrium-aluminum-garnet (YAG) laser capsulotomy was performed during the entire study duration.
                Silicone and hydrophobic acrylic are similarly effective in inducing the PCO-inhibiting effect of a rectangular, sharp optic edge. Three years after surgery, the PCO intensity and the YAG rate were low with both IOL models.
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.