20-MHz ultrasound and its value in imaging of lacrimal plugs

BACKGROUND: High-frequency B scan ultrasonography is a proven method for the assessment of anterior segment diseases. Only few studies have used sonography to examine the lacrimal drainage system. We examined the proximal lacrimal drainage system by high-resolution 20-MHz ultrasound to verify the possibility to identify intracanalicular lacrimal plugs. METHODS: Eight patients who had received 12 lacrimal plug implants were examined by high-resolution ultrasound. A 20-MHz sector scanner was used for detection and localization of 2 types of intracanalicular plugs (Herrick) lacrimal silicone plug, Smart trade mark acrylic polymer plug) and 1 punctum plug. Ultrasound examinations were performed 1-24 months after plug placement. Cross-sections of the lacrimal canaliculi were obtained. RESULTS: The various intracanalicular implants were successfully viewed using the 20-MHz ultrasound sector scanner. Intracanalicular plugs were located at the appropriate position as intended. The silicone plugs could be seen as areas of higher reflectivity. In contrast, acrylic polymer plugs were seen as low-reflective inner structures. In a longitudinal echogram, the interface between the acrylic polymer plug and the lacrimal canaliculus produced a strong acoustic impedance. In patients with an intracanalicular acrylic polymer plug, the caliber of the plug could be ascertained and the diameter measured. CONCLUSION: High-resolution ultrasound with a 20-MHz sector scanner is helpful in detecting intracanalicular plugs and is a valuable tool to assess the migration of lacrimal plugs through lacrimal canaliculi. A 20-MHz sector scanner can be used to identify and locate lacrimal plugs in the proximal drainage system even if biomicroscopic signs or clinical data are absent.     

Evidence of lacrimal plugs via high resolution ultrasound

BACKGROUND: The practical value of high-frequency ultrasound (transducer frequency of 20 MHz) for studying lacrimal plugs positioned into canaliculi was proved. MATERIALS AND METHODS: Twelve patients with twenty intracanalicular plugs and two punctum plugs were examined via high-frequency B-scan ultrasonography using 20 MHz transducer (model I3 Sacramento, USA). Detection and localisation of the intracanalicular plugs was made by a 20 MHz sector scanner. The ultrasound examinations were performed 1 - 24 month after the placement of lacrimal plugs. After patient's head positioning, the high-frequency ultrasound investigation was done via immersion fluid (2 % methylcellulose). RESULTS: All patients with dry eye treated by lacrimal plug implant showed echographic structure in the lacrimal canaliculus. In transversal echograms it was possible to image both canaliculi together when the lids were half-closed. Contrary to the normal state, it was not necessary to inject viscous fluid into the canaliculus. High-resolution ultrasound was able to differentiate the normal canaliculus from the findings after plug placement. The echograms can vary from one plug type to another. Highly reflective structures were found after the placement of silicone intracanalicular plugs, e. g. HERRICK-Plug. In contrast, the ultrasonic image taken through acrylic polymer intracanalicular plugs showed homogeneous small reflective inner structure, e. g. SMART-Plug. However, smooth and flat acoustic interface between acrylic polymer plug and the lacrimal canaliculus produced strong echoes. CONCLUSIONS: 20 MHz ultrasound seems to be well suited for the detection and localisation of intracanalicular plugs. By use of 20 MHz ultrasound scans it is possible to get high-quality images of the intracanalicular plug and around lacrimal canaliculus. Compared with UBM, the depth of penetration is much higher with negligible resolution. On the whole, we believe that 20 MHz ultrasound can become a useful tool for evaluating the placement of intracanalicular plugs after insertion.     

Identification of retained intracanalicular plugs with ultrasound biomicroscopy

BACKGROUND: Punctal plugs may be associated with complications, the most common being secondary epiphora due to canalicular obstruction. Simple lacrimal irrigation will diagnose an obstruction within the canaliculus but will not determine whether the plug is still present at the site of the obstruction. We performed a study to determine the feasibility of imaging retained intracanalicular plugs with ultrasound biomicroscopy (UBM). METHODS: We performed in vitro evaluation of an EagleVision punctal plug and a Herrick intracanalicular plug to obtain information about the UBM characteristics of the two plugs. We then performed UBM in two patients with suspected intracanalicular plugs, one with prolapse of an EagleVision punctal plug into the canaliculus and one with bilateral epiphora secondary to inserted intracanalicular Herrick plugs. RESULTS: In both cases, UBM enabled location of the plugs within the canalicular system at the level of obstruction. INTERPRETATION: UBM is a useful diagnostic tool in determining the presence and location of a presumed retained intracanalicular plug, either placed directly within the canaliculus or prolapsed into the canaliculus from a punctal position.     

Lodged intracanalicular plugs as a cause of lacrimal obstruction

PURPOSE: To evaluate the complications and success of treatment of migrated or lodged intracanalicular and punctal plugs. METHODS: A retrospective chart review of all cases having either a dacryocystorhinostomy or surgical removal of an intracanalicular or punctal plug from 1992 to 2006, in a single physician referral oculoplastics practice, was performed to identify cases in which a retained lacrimal plug required surgical intervention. Patients presented with symptoms of tearing, infection, or granuloma formation. The charts of 998 surgical cases were reviewed, from which 66 eyes (6.6%) were determined to have had lodged lacrimal plugs that required surgical removal, thus qualifying them for inclusion in this study. Patients were followed after surgery until reconstructive silicone tubing was removed (range, 6 weeks to 6 months), and each patient was questioned regarding symptoms. A comparison group of 336 eyes that had collared punctal plugs placed served as the control group. RESULTS: All cases were noted to have complications from intracanalicular plugs. No complications were noted from other forms of lacrimal plugs. All eyes in this series required a canaliculotomy or a dacryocystorhinostomy after office irrigation failed to dislodge the plug. Five eyes presented with canaliculitis, 28 eyes presented with epiphora, and 29 eyes presented with dacryocystitis. Four of 66 eyes (6%) in this cohort presented with a pyogenic granuloma. Five eyes (8%) presented with canaliculitis. Forty-nine of 66 eyes (74%) were asymptomatic following treatment, with no observable infection or epiphora. Seven of 66 eyes (11%) had some improvement in symptoms and another 10 of 66 eyes (15%) had no change in symptoms after treatment. No complications requiring surgical intervention were encountered in the control group of collared punctal plugs. CONCLUSIONS: Intracanalicular-type plugs may lodge in the lacrimal outflow system. This may result in epiphora, canaliculitis, or dacryocystitis that may require major reconstructive surgery. Despite surgical intervention, these symptoms do not always resolve (26% of eyes in this study had persistent epiphora). Intracanalicular plugs were observed to be associated with a higher rate of granulation tissue formation in the lacrimal outflow tract when compared with other forms of punctal plugs. As a result of the increased number of complications seen with intracanalicular plugs, caution is advised with respect to use of these devices. The relative infrequency of complications seen with collared punctal plugs suggests a safer alternative. Data from this study lead the authors to advocate the consideration of other forms of lacrimal occlusion due to the high number of complications noted with intracanalicular plugs, and the availability of other reversible forms of punctal occlusion.     

Punctal plugs in the management of dry eyes

Punctal plugs appear to be a relatively safe, effective, and reversible method of preserving aqueous and artificial tears on the ocular surface to reduce the signs and symptoms of dry eye. An absorbable plug may be used temporarily to assess the effectiveness of this therapy prior to insertion of a longterm nonabsorbable plug (Freeman-type, Herrick Lacrimal Plug, or SmartPlug) or cautery. Indications and contraindications for use of punctal plugs are discussed, as are features of various plugs, techniques of insertion and removal, complications, and outcomes.     

Iatrogenic complications related to the use of Herrick Lacrimal Plugs

PURPOSE: To report a series of lacrimal complications associated with a specific type of lacrimal plug (Herrick Lacrimal Plug; Lacrimedics Incorporated, Rialto, CA.) DESIGN: Retrospective, noncomparative case series and survey. METHODS: Members of the American Society of Ophthalmic Plastic and Reconstructive Surgery were asked to submit personally treated cases of patients referred for treatment of complications after placement of a Herrick Lacrimal Plug. MAIN OUTCOME MEASURES: Failure of the device to be removed by simple lacrimal irrigation. RESULTS: The clinical courses of 41 patients were analyzed. Patients ranged in age from 19 to 81 years, and all had symptomatic epiphora related to the presence of the lacrimal plug. Several interventions were used to treat lacrimal obstruction. Nasolacrimal duct probing with irrigation was used in 15 lacrimal systems, whereas six systems were probed and subsequently stented with silicone tubing. Eyelid margin cutdown was used in eight cases. Balloon dacryoplasty was performed in three systems, dacryocystorhinostomy in 18 instances, and conjunctivodacryocystorhinostomy in two patients. CONCLUSIONS: The Herrick lacrimal occlusion device sometimes cannot be removed by simple irrigation and is capable of inducing permanent, irreversible, symptomatic lacrimal drainage system obstruction.     

Corneal topographical study of the effect of lacrimal punctum occlusion on corneal surface regularity in dry eye patients.

PURPOSE: To compare topographic indices of surface regularity in dry eye patients and in normal subjects (controls) and to investigate the short-term effect of lacrimal punctal plugs on these indices in dry eye patients. METHODS: The surface regularity index (SRI) and surface asymmetry index (SAI) of the TMS-2 corneal topographic modelling system were used to evaluate corneal surface regularity in 20 eyes of 10 dry eye patients before and after the insertion of Herrick silicon lacrimal plugs (Lacrimedics, Rialto, CA, USA) and in 24 eyes of 12 normal subjects as controls. RESULTS: SRI and SAI were significantly lower in controls than dry eye patients (p=0.00). Median SRI was 1.72 in dry eye patients before punctal occlusion and 0.525 in the control group. Median SAI was 1.305 in dry eye patients and 0.240 in controls. After lacrimal punctal occlusion, Schirmer test results and fluorescein breakup time increased in nine patients and remained the same in one patient. After occlusion, the SRI decreased in 9 eyes, and increased in 11 (p=0.970); SAI decreased in 13 eyes and increased in 7 (p=0.135). CONCLUSIONS: No significant change in topographic indices of corneal surface irregularity could be detected in severe dry eye patients with lacrimal punctal plugs in the short-term follow-up.     

Preventive effect of lacrimal occlusion on topical timolol-induced bronchoconstriction in asthmatics

AIM: To evaluate the potential preventive role of lacrimal occlusion on the topical timolol-induced bronchoconstriction in asthmatics. METHODS: This was a prospective and single-masked study. Fourteen volunteer subjects with asthma were included. Collagen plugs were inserted into both canaliculi on one side to inhibit lacrimal drainage. The effect of lacrimal occlusion on lung function tests was measured before and 60 min after the instillation of a timolol drop in unplugged and plugged eyes. The spirometric measurements include forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC, and mid expiratory flow-rate (FEF25-75). RESULTS: The timolol (0.5%) drop administration into the eye caused a significant decrease in pulmonary functions in patients with asthma in whom the lacrimal punctae had not been occluded by collagen plug. P values were 0.008 for FVC and 0.001 for FEV1 and FEF25-75. The occlusion of the lacrimal duct by intracanalicular plugs significantly reduced this decrease in pulmonary function. P values were 0.6 for FVC, 0.8 for FEV1, and 0.5 for FEF25-75. The lacrimal occlusion did not affect heart rate and blood pressures. Three subjects complained of epiphora. CONCLUSIONS: Lacrimal occlusion with intracanalicular collagen plugs may almost completely prevent the bronchoconstriction caused by topical timolol in asthmatics by inhibiting or decreasing systemic absorption of the medication.     

Effects of lacrimal occlusion with collagen and silicone plugs on patients with conjunctivitis associated with dry eye

PURPOSE: To determine whether canalicular occlusion with collagen and silicone plugs reduces the severity of symptoms in patients with conjunctivitis secondary to dry eye. METHODS: 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. RESULTS: 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. CONCLUSIONS: Progressive lacrimal occlusion with collagen and silicone plugs was of clinical benefit to patients with dry eye and conjunctivitis.     

Determination of relative contribution of the superior and inferior canaliculi to the lacrimal drainage system in health using the drop test

PURPOSE: The aim of this study was to explore the use of the 'drop test' as a method of assessing maximal lacrimal outflow capacity, and to measure the relative contribution of the superior and inferior canaliculi to the drainage capacity in normal subjects. METHOD: The drop test involves instilling measured aliquots of normal saline over 3-min periods to raise the tear lake medially. Both eyes were assessed; however, for the right lacrimal drainage system only, sequential insertion and then removal of silicone punctal plugs was performed. After each stage the maximal lacrimal drainage capacity was measured. no punctal plugs were placed in the puncta on the left side. RESULTS: Complete data were collected from 20 subjects with a mean age of 35.6 years. The intraclass correlation coefficient for the five left eye readings was 0.98 (CI 0.96-0.99) and the limits of agreement of a single reading were -22.6 to +93.0 micro L/3 min. Without intervention, no statistically significant difference was found in the mean lacrimal outflow between the left and right eyes (P = 0.16). A statistically significant reduction in outflow resulted from punctal occlusion (P < 0.05). Presenting the proportion of lacrimal outflow as a percentage of the combined values of the superior and inferior canaliculi, 59.9% of outflow occurred through the inferior canaliculus. CONCLUSION: The drop test was found to provide a simple and repeatable method of assessing lacrimal drainage in a minimally invasive manner in the clinical setting. In healthy volunteers in the supine position 60% of maximal lacrimal outflow capacity occurs through the inferior canaliculus.     

Perforated punctal plug in the treatment of partial punctal stenosis.

BACKGROUND: Epiphora is a common finding among elderly patients. Common etiologies of epiphora include lid-globe appositional abnormalities, ocular surface disorders, and lacrimal excretory obstruction. CASE REPORT: A patient reported with symptoms of unilateral, nonpainful epiphora. The cause was determined to be punctal stenosis and the patient was managed with a perforated punctal plug. CONCLUSION: Punctal stenosis is one of several disorders that may cause a lacrimal excretory obstruction. Common methods of treatment include repeated dilation and irrigation, as well as various surgical procedures described in the literature. Eye care practitioners should be aware of the availability of perforated punctal plugs and their usefulness in treatment of the partially stenosed punctum.     

Silicone punctal plug extrusion resulting from spontaneous dissection of canalicular mucosa: A clinical and histopathologic report

PURPOSE: To report on an uncommon, previously unidentified, progressive silicone punctal plug extrusion. DESIGN: Small, retrospective case series. PARTICIPANTS: Five cases of punctal plug extrusion were identified among a series of 424 consecutive implantations. Histopathologic analysis was obtained in one case. One additional referred case was included in this report. RESULTS: The plugs were completely extruded from the punctal lumen 6 to 14 months after insertion after an otherwise uncomplicated postoperative course. All plugs were retained at the punctal margin by an encircling band of vascularized mucosal tissue originating from the canalicular lumen. The band consisted of connective tissue of canalicular mucosal origin, attached just below the junction of the punctal and canalicular epithelium. Mild mononuclear infiltration was present in the connective tissue component of the punctal region. There was no cytologic or architectural evidence of abnormal epithelium or connective tissue or of pyogenic granuloma. CONCLUSIONS: These observations suggest that progressive lacrimal punctal plug extrusion may relate to mucosal dissection by the plug edges. We speculate that mechanical stress induced by eyelid closure on an improperly sized or placed implant may result in plug tilt. Subsequent epithelial hyperplasia further enhances the tilt, and the sharper edge of the conical bulb promotes separation of the canalicular mucosa from its distal luminal aspect. At the completion of the extrusion, the mucosal surface is separated from its connective tissue base, at a proximal subpunctal level, causing formation of an encircling tissue band.     

A technique for preventing spontaneous loss of lacrimal punctal plugs

PURPOSE: To describe a technique for the prevention of spontaneous loss of lacrimal punctal plugs. DESIGN: Interventional case series. METHODS: Four consecutive patients (10 puncta in seven eyes) with severe dry eyes who experienced repeated spontaneous plug loss underwent punctal occlusion by suturing plugs with 10-0 polypropylene sutures. RESULTS: All punctal plugs were fitted to lacrimal puncta by anchoring the sutures. Plug retention rate was 80% at 6 months after the procedure. CONCLUSION: Suturing punctal plugs is effective in the production of long-term punctal closure in patients with repeated spontaneous plug loss.     

不同硅胶管置管方式治疗儿童泪小管断裂的临床疗效

目的:探讨不同硅胶管置管方式治疗儿童泪小管断裂的临床疗效.方法:回顾性分析我院2014-01/2015-12收治的儿童泪小管断裂患者42例42眼.根据入院时间顺序分为两组,单路泪道留置硅胶管组20例20眼,环形留置硅胶支撑管组22例22眼,对比分析两组患者的治疗效果.结果:术后2wk~1mo,单路泪道留置硅胶管组有4眼患者由于护理不当,不慎将硅胶管脱落,再次手术处理.环形留置硅胶管组患者无硅胶管脱落者,两组比较差异有统计学意义(P<0.05).单路泪道留置硅胶管组中,治愈16眼,好转1眼,无效3眼,均为术后2wk~1mo硅胶管脱落患者(1眼为犬咬伤患者,2 眼为放炮炸伤患者),治疗有效率为85%.环形留置硅胶管组中,治愈20眼,好转2眼,治疗有效率为100%.两组患者治疗有效率比较,差异有统计学意义(P<0.05).结论:儿童泪小管断裂需及时手术治疗,合理的手术治疗多能获得较好的手术效果,采用环形留置硅胶管较单路泪道留置硅胶管稳定性好,并发症少,临床治疗效果好.     

Complications associated with silicone intracanalicular plugs.

PURPOSE: To assess American Society of Ophthalmic Plastic and Reconstructive Surgery (ASOPRS) member physicians' experiences with complications associated with silicone intracanalicular plugs and publicize risks associated with this device. METHODS: Two case reports are presented. A survey was sent to 420 ASOPRS member physicians, questioning them on their experiences with complications associated with silicone intracanalicular plugs. RESULTS: We present two case reports of complications associated with migration of intracanalicular plugs. In the first case, a 41-year-old man underwent serial insertion of seven intracanalicular plugs in one eye over several years, he had a 3-month relapsing course of Nocardia asteroides canaliculitis, dacryocystitis, and cellulitis requiring systemic antibiotics and multiple surgeries. In the second case, a 72-year-old woman had acute dacryocystitis, eventually necessitating dacryocystorhinostomy; at surgery, an intracanalicular plug was discovered in the lacrimal sac. One hundred fifty-nine usable survey responses were obtained. Sixty-one percent of respondents reported various complications including tearing, canaliculitis, and dacryocystitis. Fifty-one percent of respondents performed surgery to treat complications associated with silicone intracanalicular plugs. CONCLUSIONS: Silicone intracanalicular plugs may be difficult to remove and may be associated with significant lacrimal complications.     

聚乳酸可降解泪道塞的初步实验研究

目的:自主开发研制出一种可降解泪道塞。方法:选择聚乳酸为原材料,经过加热塑形裁切得到泪道塞;采取摘除主泪腺、摘除第三眼睑、摘除Harder氏腺,得到兔干眼动物模型;观察植入泪道塞前后,泪液分泌试验、热原实验;观察泪道塞组织相容性及降解时间。结果:泪道塞植入后,能明显改善兔干眼模型泪液分泌试验观察指标,无热原反应,组织相容性佳,完全降解时间约为2mo。结论:广泛用于生物医学领域的聚乳酸材料制备的可降解泪道塞对兔无毒害作用,具有极好的安全性及生物相容性,成本低,具有进一步研究价值及临床应用前景。     

泪小管断裂吻合置管术的疗效分析

目的:观察显微镜下用直接发现法行泪小管断裂吻合置管术的临床效果。方法:在手术显微镜下沿泪小管断端在复原伤口后找泪小管断离鼻侧断端,以硬膜外麻醉导管作为泪小管内支撑,吻合泪小管断端。结果:患者60例其中1例术后因置管部分脱出,自行还纳时致泪小点及远端泪小管豁开,经手术修复治愈,1例拔管后随访泪道不通畅,其余均痊愈。结论:显微镜下直接发现法找到泪小管鼻侧断端的成功率较高,且行吻合修复术后恢复泪道排泪功能效果肯定。     

泪小管断裂Ⅰ期吻合17例临床分析

目的:讨论外伤致泪小管断裂I期吻合术的时机选择,手术方式及术后泪道功能重建效果。方法:回顾性分析2006-03/2007-06在我院行泪小管断裂I期吻合的17例患者,选用AS-E型硬膜外麻醉导管(内径约0.5mm)作支撑,断端吻合的手术方法并观察术后效果。结果:手术后随访4～16mo,泪道通畅8例(47%),泪道狭窄5例(29%),泪道阻塞4例(24%)。结论:以AS-E型硬膜外麻醉导管作支撑,行泪小管断端I期吻合,可有效重建泪道引流功能。     

Two cases of lacrimal gland agenesis in the same family--clinicoradiologic findings and management

BACKGROUND: Lacrimal gland agenesis is extremely rare. This condition is occasionally associated with salivary gland agenesis and abnormalities in the lacrimal drainage system, particularly occlusions of the lacrimal puncta and canaliculi. The detailed presentation of clinicoradiologic findings and treatment modality has not been previously reported. METHODS: A 6-year-old boy was presented to our department complaining of severe foreign-body sensations in both eyes. Punctate epithelial erosions and mucous filaments were noted in both eyes. His tear break-up time (TBUT) was less than 1 second, and a Schirmer's test (both eyes) detected less than 1 mm of wetting in 5 minutes. His mother had similar complaints dating back to childhood. RESULTS: Orbital computed tomography (CT) scan and magnetic resonance imaging (MRI) revealed the absence of both lacrimal glands and all major salivary glands. After the insertion of a lacrimal punctal plug, punctate epithelial erosions and mucous filaments decreased remarkably within 2 weeks. MRI scans of the patient's mother confirmed the absence of both lacrimal glands and salivary glands. She had been using artificial tears for a long time. INTERPRETATION: The absence of lacrimal glands can be confirmed by clinicoradiologic findings, and the punctal plug may be an effective tool for the treatment of patients who retain a patent lacrimal drainage system.     

Silicone versus collagen plugs for treating dry eye: results of a prospective randomized trial including lacrimal scintigraphy

PURPOSE: To compare the short-term efficacy of collagen and silicone plugs for treating dry eye using quantitative lacrimal scintigraphy. DESIGN: Prospective randomized clinical trial. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.