Case report: Management of recurrent pupillary optic capture with sutureless surgical technique using 7-0 polypropylene flange.

Background: To report a novel surgical technique for recurrent pupillary optic capture after flanged intraocular lens (IOL) fixation. Methods: In this retrospective case series, we detail our use of two parallel 7-0 polypropylene sutures passed between the iris plane and the optic of scleral-fixated IOL to address pupillary optic capture. Flanges were created using ophthalmic cautery to secure it to the sclera without suture. Results: Two eyes with pupillary optic capture underwent a sutureless surgical technique using 7-0 polypropylene flanges. No recurrences of pupillary optic capture were observed during the 1-year follow-up. Conclusion: Our sutureless surgical technique using a 7-0 polypropylene flange was an effective, efficient, and less invasive approach for treating recurrent pupillary optic capture.

Real-time in vivo monitoring of intraocular pressure distribution in the anterior chamber and vitreous chamber for diagnosis of glaucoma.

Glaucoma causes irreversible vision loss due to optic nerve damage and retinal cell degeneration. Since high intraocular pressure (IOP) is a major risk factor for glaucoma development, accurate IOP measurement is crucial, especially intravitreal IOP affecting the optical nerve and cells. However, conventional methods have limits in selectively and directly detecting local retina pressure. Here, we present continuous measurements of local IOP values in the anterior chamber and vitreous chamber of living animals using minimally invasive probes with pressure-sensitive transistors. After inducing glaucoma in animal models, we compared the local IOP distribution between normal and glaucomatous eyes. We also compared IOP values detected in the cornea using tonometry measurements. Our findings revealed that glaucoma induced higher IOP in the vitreous chamber than in the anterior chamber, indicating that measuring IOP in the vitreous chamber is key to the glaucoma model. This progress offers future directions for diagnosis and treatment of glaucoma.

Relative Risks for Dementia among Individuals with Glaucoma: A Meta-Analysis of Observational Cohort Studies.

PURPOSE: To investigate the relative risks (RRs) for dementia among individuals with glaucoma. METHODS: We conducted a search of PubMed, Web of Science, Scopus, and Cochrane databases for observational cohort studies examining the association between glaucoma and dementia until March 2023. Two authors independently screened all titles and abstracts according to predefined inclusion and exclusion criteria. Pooled RR and 95% confidence intervals (CIs) were generated using random-effect models. RESULTS: The meta-analysis included 18 cohort studies conducted in eight countries and involving 4,975,325 individuals. The pooled RR for the association between glaucoma and all-cause dementia was 1.314 (95% CI, 1.099-1.572; I2 = 95%). The pooled RRs for the associations of open-angle glaucoma with Alzheimer dementia and Parkinson disease were 1.287 (95% CI, 1.007-1.646; I2 = 96%) and 1.233 (95% CI, 0.677-2.243; I2 = 73%), respectively. The pooled RRs for the associations of angle-closure glaucoma with all-cause dementia and Alzheimer dementia were 0.978 (95% CI, 0.750-1.277; I2 = 17%) and 0.838 (95% CI, 0.421-1.669; I2 = 16%), respectively. No evidence of publication bias was detected in the Begg-Mazumdar adjusted rank correlation test (p = 0.47). CONCLUSIONS: Based on current observational cohort studies, there is evidence supporting that glaucoma is a risk factor for dementia in the adult population.

Association between psychological vulnerability and glaucoma progression: Protocol for a multicenter prospective cohort study in South Korea.

INTRODUCTION: Mental health is a significant concern for patients diagnosed with glaucoma, as visual impairment can have a profound impact on psychological well-being. Conversely, psychological vulnerability in glaucoma patients can negatively influence treatment adherence to ocular hypotensive therapy, thereby potentially exacerbating disease progression in a vicious cycle. The study protocol proposed herein aims to explore the impact of psychological states such as anxiety, depression, and stress on both medication adherence and progression of glaucoma. MATERIALS AND METHODS: This study is to be a prospective multicenter study conducted at four tertiary medical centers. Patients recently diagnosed with glaucoma and not yet treated will be enrolled. Anxiety, depression, and stress scales will be administered at baseline, one year, and two years, along with glaucomatous assessments to be performed every six months. Validated questionnaires (Generalized Anxiety Disorder Assessment [GAD-7], Patient Health Questionnaire [PHQ-9], and Perceived Stress Scale-10 [PSS-10]) will assess anxiety, depression, and stress, respectively. The primary objective is to correlate post-diagnosis psychological status with medication adherence and disease progression. The effects of pre- and post-diagnosis changes in anxiety, depression, and stress on disease progression will be analyzed. Kaplan-Meier survival analysis and logistic regression will be performed to identify clinical characteristics associated with increased risk of developing anxiety, depression, and stress in glaucoma patients.

XEN Gel Stent for Conjunctiva with Minimal Mobility Caused by Scleral Encircling: A Case Report.

This case report describes the successful use of a XEN gel stent for controlling intraocular pressure (IOP) in a patient who had previously undergone scleral encircling for rhegmatogenous retinal detachment. The patient had very limited mobile conjunctiva due to scarring caused by the earlier surgery, which limited their options for glaucoma surgery. The XEN gel stent, a minimally invasive glaucoma surgery (MIGS) procedure that does not require opening the conjunctiva, was implanted in the subconjunctival space using an ab interno approach. Postoperative blebs were imaged using anterior segment optical coherence tomography, and IOP was monitored over six months. This study found that the XEN gel stent effectively controlled the IOP, and there were no complications during or after surgery. This case report may expand the indication for the XEN gel stent, which could be considered a viable option for patients who have undergone scleral buckling and have limited mobile conjunctiva.

Management of Steroid-Induced Glaucoma in a Patient with Pyoderma Gangrenosum.

Pyoderma gangrenosum (PG) is an uncommon inflammatory skin disorder typically presenting as painful skin ulcers, which may also exhibit extracutaneous findings. PG can occur at the site of trauma or surgery, which is known as the pathergic phenomenon. A 36-year-old man developed bilateral steroid-induced glaucoma after prolonged systemic immunosuppressive treatment for cutaneous pyoderma gangrenosum. After successful Ahmed glaucoma valve implantation surgery with donor scleral patch graft in the right eye, the same surgery failed repeatedly in the left eye and complicated with the prolonged conjunctival necrosis and the exposure of the donor scleral patch graft. Under the impression of ocular involvement of PG, microinvasive glaucoma surgery (MIGS) with XEN® Gel Stent was performed in the left eye; the conjunctival bleb was successfully formed without conjunctival necrosis, and intraocular pressure was well maintained. Ophthalmic surgery can be complicated in patients with PG, and the surgical option should be selected prudently to minimize surgical trauma. MIGS, as a minimally invasive surgical technique, could offer an advantage for patients with PG.

Long-term surgical outcomes of Ahmed valve implantation in refractory glaucoma according to the type of glaucoma.

BACKGROUND: We evaluated the long-term efficacy and surgical outcomes of Ahmed glaucoma valve (AGV) implantation in patients with refractory glaucoma by glaucoma type. METHODS: In total, 135 eyes of 135 patients diagnosed with refractory glaucoma and underwent AGV implantation between 2002 and 2018 were reviewed retrospectively. The best-corrected visual acuity (BCVA), intraocular pressure (IOP), and number of antiglaucoma medications were investigated at baseline and follow-up. The cumulative probability of qualified success according to the glaucoma type was evaluated at 12, 24, 36, and 60 months postoperatively. RESULTS: The mean IOP of all patients was 35.7 ± 11.7 mmHg, which was significantly reduced 12.7 ± 7.0 mmHg at 1 week, 16.2 ± 7.5 mmHg at 2 weeks, 17.6 ± 6.8 mmHg at 1 month, 17.5 ± 6.4 mmHg at 3 months, 16.1 ± 6.0 mmHg at 6 months, 16.7 ± 8.0 mmHg at 12 months, 16.4 ± 6.6 mmHg at 24 months, 15.6 ± 5.0 mmHg at 36 months, and 15.6 ± 5.6 mmHg at 60 months after surgery (p < 0.001, respectively). The mean number of antiglaucoma medications was 3.7 ± 1.3, which significantly decreased to 0.4 ± 0.9 at 1 week, 0.3 ± 0.8 at 2 weeks, 0.7 ± 0.9 at 1 month, 1.1 ± 1.1 at 3 months, 1.4 ± 1.0 at 6 months, 1.5 ± 1.1 at 12 months, 1.6 ± 1.2 at 24 months, 1.7 ± 1.2 at 36 months, and 1.8 ± 1.3 at 60 months after surgery (p < 0.001, respectively). The mean BCVA significantly improved from postoperative 2 weeks. Although 71 (52.6%) eyes had postoperative complications, the cumulative probability of surgical success was 72.6% at 12 months, 66.7% at 24 months, and 63.7% at 36 and 60 months. According to the glaucoma type, the success rate of AGV implantation was more than 50% even after 60 months follow-up, except subgroup of neovascular glaucoma (NVG) due to retinal vein occlusion (RVO). CONCLUSIONS: AGV implantation in patients with refractory glaucoma was, after long-term follow-up, successful overall. Therefore, AGV implantation can be an effective surgical option to reduce the IOP and number of antiglaucoma medications and to improve visual acuity for various glaucoma types.

Comparison of ocular surface assessment and adherence between preserved and preservative-free latanoprost in glaucoma: a parallel-grouped randomized trial.

Given that nonadherence is related to subject characteristics and drug tolerance and preserved eye drops tend to be more intolerable than preservative-free ones, we conducted a phase 4, parallel-grouped, investigator-blind, active-control, randomized, multicenter study. A total of 51 patients with intraocular pressure (IOP) ≥ 15 mmHg diagnosed with open-angle glaucoma or ocular hypertension were randomly assigned to the preserved latanoprost group (n = 26) and the preservative-free latanoprost group (n = 25). The efficacy variables were corneal/conjunctival staining grade, Ocular Surface Disease Index (OSDI), adherence at 12 weeks after the first administration; corneal/conjunctival staining grade at 4 weeks; and IOP, tear break-up time (TBUT), and hyperemia score at 4 and 12 weeks. The safety variables included visual acuity and drug tolerance questionnaire results. There was no statistically significant difference in corneal/conjunctival staining grade, OSDI, or TBUT between the groups at 4 and 12 weeks. However, the adherence rate was higher and the hyperemia score was lower in the preservative-free group than in the preserved group. The severity and duration of stinging/burning sensation were lower in the preservative-free group than in the preserved group. Overall, preservative-free latanoprost showed better ocular tolerance assessed by hyperemia scores and stinging/burning symptoms following higher adherence than preserved latanoprost.

A soft and transparent contact lens for the wireless quantitative monitoring of intraocular pressure.

Continuous detection of raised intraocular pressure (IOP) could benefit the monitoring of patients with glaucoma. Current contact lenses with embedded sensors for measuring IOP are rigid, bulky, partially block vision or are insufficiently sensitive. Here, we report the design and testing in volunteers of a soft and transparent contact lens for the quantitative monitoring of IOP in real time using a smartphone. The contact lens incorporates a strain sensor, a wireless antenna, capacitors, resistors, stretchable metal interconnects and an integrated circuit for wireless communication. In rabbits, the lens provided measurements that match those of a commercial tonometer. In ten human participants, the lens proved to be safe, and reliably provided accurate quantitative measurements of IOP without inducing inflammation.

Novel glaucoma model in rats using photo-crosslinked azidobenzoic acid-modified chitosan.

An experimental model of pressure-induced optic nerve damage promises to greatly expand understanding of the cellular events leading to retinal ganglion cell (RGC) death and of how they are influenced by intraocular pressure (IOP) and other risk factors associated with glaucoma. In this work, we propose a novel strategy employing photo-crosslinkable azidobenzoic acid-modified chitosan (Az-CH) for long-term, persistent elevation of IOP. For this purpose, a solution of Az-CH was injected into the anterior chamber of experimental rat eyes, which were subsequently irradiated with ultraviolet (UV) light to form an Az-CH gel that hindered aqueous outflow and effected prolonged IOP elevation thereby. The control eyes were treated as follows: (1) intracameral injection of Az-CH without UV irradiation, (2) intracameral injection of saline solution without UV irradiation or (3) no injection with UV irradiation. A significant IOP increase was observed in the experimental eyes, which was continuously higher for the whole testing period of 12 weeks after one-time treatment with Az-CH injection and UV irradiation. Also, a more significant loss of RGCs, one of the major features of glaucoma, was observed in experimental eyes than in the control eyes. Therefore, the strategy presented herein can be a novel experimental model to study the mechanism of RGC damage by elevated IOP over the course of a prolonged period.

Smart contact lens and transparent heat patch for remote monitoring and therapy of chronic ocular surface inflammation using mobiles.

Wearable electronic devices that can monitor physiological signals of the human body to provide biomedical information have been drawing extensive interests for sustainable personal health management. Here, we report a human pilot trial of a soft, smart contact lens and a skin-attachable therapeutic device for wireless monitoring and therapy of chronic ocular surface inflammation (OSI). As a diagnostic device, this smart contact lens enables real-time measurement of the concentration of matrix metalloproteinase-9, a biomarker for OSI, in tears using a graphene field-effect transistor. As a therapeutic device, we also fabricated a stretchable and transparent heat patch attachable on the human eyelid conformably. Both diagnostic and therapeutic devices can be incorporated using a smartphone for their wireless communications, thereby achieving instantaneous diagnosis of OSI and automated hyperthermia treatments. Furthermore, in vivo tests using live animals and human subjects confirm their good biocompatibility and reliability as a noninvasive, mobile health care solution.

Evaluation of ocular surface disease in elderly patients with glaucoma: expression of matrix metalloproteinase-9 in tears.

PURPOSE: To evaluate the symptoms and signs of ocular surface disease (OSD) and tear-film matrix metalloproteinase-9 (MMP-9) overexpression using point-of-care testing (InflammaDry test) in patients with primary open-angle glaucoma (POAG). METHODS: This prospective, case-control study included 67 patients diagnosed with POAG and 47 healthy control subjects. The OSD assessment included Schirmer-I test, the Oxford corneal stain scale, tear breakup time (TBUT), and the five-item dry eye questionnaire (DEQ-5). Measurement of extracellular MMP-9 level was performed using the InflammaDry test. The OSD parameters and MMP-9 expression levels were compared between the POAG group and the control group. Additional subgroup analysis in POAG group was performed according to number of topical glaucoma medications (Bottle 1, 2, or 3 medications). RESULTS: There were significant differences between the control and POAG groups for all OSD parameters. MMP-9 overexpression was observed in 71.6% of POAG group, whereas only 31.9% of control group showed MMP-9 overexpression. The subgroup analysis revealed that DEQ-5, Oxford stain score, Schirmer-I, and MMP-9 overexpression demonstrated no significant difference among the three groups. Abnormal TBUT (≤5 s) was observed in 37.5%, 59.1%, and 76.2% for each subgroup according to number of bottles (1, 2, and 3), and strong MMP-9 overexpression were also detected in 25.0%, 40.9%, and 61.9%, respectively (P = 0.032, P = 0.043). CONCLUSIONS: The use of preservative-containing medications may affect the ocular surface in patients with POAG. Graded measurement of tear-film MMP-9 could provide more information on OSD and might be a more useful marker for inflammation than then conventional results obtained by using an MMP-9 kit.

Association between esodeviation and primary open-angle glaucoma: the 2010-2011 Korea National Health and Nutrition Examination Survey.

BACKGROUND/AIMS: To evaluate the association between strabismus and primary open-angle glaucoma (POAG) in a representative Korean population. METHODS: A total of 11 114 participants aged 20 years or older in the Korea National Health and Nutrition Examination Survey database for the years 2010 through 2011 were reviewed. A standardised protocol was used to interview every participant and to perform comprehensive ophthalmic examinations. Glaucoma diagnosis was based on fundus photography and frequency-doubling technology perimetry results, according to the International Society of Geographical and Epidemiological Ophthalmology criteria. Ocular alignment was evaluated using the alternate prism and cover test, and clinically significant horizontal strabismus was defined as exodeviation of ≥15 prism dioptres (PD) and esodeviation of ≥10 PD. Univariate and multivariate regression analyses were used to evaluate the potential risk factors for POAG. RESULTS: In the Korean population, subjects with clinically significant esodeviation had a much higher prevalence of POAG (12.32%) than those without clinically significant esodeviation (3.14%, p=0.016). After adjusting for age and intraocular pressure, clinically significant esodeviation was independently associated with POAG (OR 7.61, p=0.002). CONCLUSION: Esodeviation was independently associated with POAG in the Korean population. This could be the result of, at least in part, ocular-adduction-induced greater strain on the temporal optic nerve head and peripapillary tissues, which makes eyes with esodeviation more vulnerable to POAG.

Risk factors for disease progression in low-teens normal-tension glaucoma.

BACKGROUND/AIMS: To investigate the risk factors for disease progression of normal-tension glaucoma (NTG) with pretreatment intraocular pressure (IOP) in the low-teens. METHODS: One-hundred and two (102) eyes of 102 patients with NTG with pretreatment IOP≤12 mm Hg who had been followed up for more than 60 months were retrospectively enrolled. Patients were divided into progressor and non-progressor groups according to visual field (VF) progression as correlated with change of optic disc or retinal nerve fibre layer defect. Baseline demographic and clinical characteristics including diurnal IOP and 24 hours blood pressure (BP) were compared between the two groups. The Cox proportional hazards model was used to identify the risk factors for disease progression. RESULTS: Thirty-six patients (35.3%) were classified as progressors and 66 (64.7%) as non-progressors. Between the two groups, no significant differences were found in the follow-up periods (8.7±3.4 vs 7.7±3.2 years; p=0.138), baseline VF mean deviation (-4.50±5.65 vs -3.56±4.30 dB; p=0.348) or pretreatment IOP (11.34±1.21 vs 11.17±1.06 mm Hg; p=0.121). The multivariate Cox proportional hazards model indicated that greater diurnal IOP at baseline (HR=1.609; p=0.004), greater fluctuation of diastolic BP (DBP; HR=1.058; p=0.002) and presence of optic disc haemorrhage during follow-up (DH; HR=3.664; p=0.001) were risk factors for glaucoma progression. CONCLUSION: In the low-teens NTG eyes, 35.3% showed glaucoma progression during the average 8.7 years of follow-up. Fluctuation of DBP and diurnal IOP as well as DH were significantly associated with greater probability of disease progression.

Intraocular Pressure Monitoring Following Islet Transplantation to the Anterior Chamber of the Eye.

Intraocular islet transplantation was investigated as a new procedure to treat diabetes. The development of this procedure requires close monitoring of the function of both eye and islet graft. We developed a soft, smart contact lens to monitor the intraocular pressure and applied this for noninvasive monitoring in association with the intraocular islet transplantation in diabetes. A strain sensor inside the lens can detect detailed changes in intraocular pressure by focusing the strain only in the desired, selective area of the contact lens. In addition, this smart contact lens can transmit the real-time value of the intraocular pressure wirelessly using an antenna. The wireless measurement of intraocular pressure that was obtained using this contact lens had a high correlation with the intraocular pressure measured by a rebound tonometer, thereby proving the good accuracy of the contact lens sensor. In the initial period, a slight elevation of intraocular pressure was observed, but the pressure returned to normal in the initial period after the transplantation. This type of monitoring will provide important information on potential changes in the intraocular pressure associated with the transplantation procedure, and it enables appropriate clinical safety steps to be taken, if needed.

Predicting the Therapeutic Efficacy of Laser Peripheral Iridotomy for Individuals With Asymptomatic Narrow Angle: The Triple Hump Sign.

PURPOSE: To evaluate the clinical efficacy of a novel screening sign [ie, the triple hump (TH) sign] for prediction of laser peripheral iridotomy (LPI)'s intraocular pressure (IOP)-lowering effectiveness in subjects with asymptomatic narrow angles. METHODS: This cross-sectional study was conducted from 2010 to 2015 in a hospital setting. Eighty-four eyes of 84 primary angle-closure suspect (PACS) patients were imaged before LPI using anterior segment optical coherence tomography. The "positive-TH sign" was defined, on anterior segment optical coherence tomography-generated cross-sectional scans, as the characteristic configuration formed by the angulations between the crystalline lens's central anterior surface and both sides of the iris pigment epithelium. After LPI, the extent of IOP reduction was compared between the positive- and negative-TH groups. RESULTS: The positive-TH eyes did not significantly differ from the negative-TH ones in pre-LPI IOP (P=0.200). In the positive-TH group, IOP decreased significantly after LPI (by 6.42%±17.96%, from 14.07±3.11 to 12.88±2.65 mm Hg, P=0.002). In the negative-TH group, IOP did not change significantly after LPI (by 4.66%±25.97%, from 13.23±2.42 to 13.52±3.01 mm Hg, P=0.624). CONCLUSION: PACS eyes indicating the positive-TH sign showed, at post-LPI 1 month, a greater IOP decrease. On this basis, the TH sign may be a useful screening tool for predicting the effect of LPI and determining the treatment plan in PACS patients.

Temporal Raphe Sign for Discrimination of Glaucoma from Optic Neuropathy in Eyes with Macular Ganglion Cell-Inner Plexiform Layer Thinning.

PURPOSE: To evaluate the potential of the temporal raphe sign on the macular ganglion cell-inner plexiform layer (mGCIPL) thickness map for discriminating glaucomatous from nonglaucomatous optic neuropathy (NGON) in eyes with mGCIPL thinning. DESIGN: Cross-sectional study. PARTICIPANTS: A total of 175 eyes of 175 patients with mGCIPL thinning on Cirrus (Carl Zeiss Meditec, Dublin, CA) high-definition OCT were retrospectively included. Glaucoma specialists and neuro-ophthalmology specialists evaluated the patients' medical records for diagnosis of glaucomatous optic neuropathy (GON) or NGON. Finally, by consensus, 67 eyes with GON and 73 eyes with NGON were enrolled. METHODS: A positive temporal raphe sign was declared in patients in whom there was a straight line longer than one-half of the length between the inner and outer annulus in the temporal elliptical area of the mGCIPL thickness map. Decision tree analysis was performed to formulate a diagnostic model. MAIN OUTCOME MEASURES: Area under receiver operating characteristic curve (AUC) with sensitivity and specificity. RESULTS: The temporal raphe sign was observed in 61 of 67 GON eyes (91.0%), but in only 21 of 73 NGON eyes (28.8%) (P < 0.001; chi-square test). On this basis, the diagnostic ability of the temporal raphe sign for discriminating GON from NGON was judged to be good (AUC, 0.811; 95% confidence interval, 0.749-0.874; sensitivity, 91.0%; specificity, 71.2%). The diagnostic performance of the decision tree-based model (AUC 0.879; 95% confidence interval, 0.824-0.933; sensitivity, 88.1%; specificity, 87.7%) was better than that of the temporal raphe sign or the relative afferent pupillary defect (RAPD) alone (P = 0.005, P < 0.001, respectively; DeLong's test). The decision tree model revealed the following: (1) If the temporal raphe sign is positive and the RAPD is absent, the case should be diagnosed as GON; (2) if the temporal raphe sign is absent regardless of the presence or absence of the RAPD, or both the temporal raphe sign and the RAPD are present, the case should be diagnosed as NGON. CONCLUSIONS: In clinical practice, determining whether the temporal raphe sign appears on OCT macular scans can be a useful tool for discrimination of glaucomatous from nonglaucomatous mGCIPL thinning.

Near and Distance Stereoacuity in Patients With Primary Open-angle Glaucoma.

PURPOSE: To compare near and distance stereoacuity between patients with primary open-angle glaucoma (POAG) and a control group, and to analyze the associations between stereoacuity and POAG severity. METHODS: This cross-sectional study compared near and distance stereoacuity between the POAG and control groups. The data from the POAG group were used to assess the associations between stereoacuity (both near and distance) and the severity of visual field (VF) defects (based on Hodapp-Anderson-Parrish classification and the VF index). RESULTS: The study included 94 eyes of 47 patients with POAG and 80 eyes of 40 control subjects. Near and distance stereoacuity were significantly lower in the POAG group than in the control group (both P<0.001). Near stereoacuity worsened with POAG severity in terms of both the Hodapp-Anderson-Parrish classification and VF index (P=0.007 and P=0.049, respectively). However, distance stereoacuity was not associated with POAG severity for either categorization (P=0.12 and P=0.57, respectively). The proportions of patients with reduced near stereoacuity and those with a lack of distance stereoacuity were higher in the POAG group than in the control group. CONCLUSIONS: Near and distance stereoacuity were significantly lower among patients with POAG than among control subjects. Near stereoacuity worsened with increasing POAG severity but distance stereoacuity did not. However, the proportion of patients with a lack of distance stereoacuity was higher in the POAG group than in the control group.

Safety and Efficacy of a Membrane-Tube-Type Glaucoma Shunt Device: An Animal Trial.

PURPOSE: To evaluate the safety and efficacy of a membrane-tube-type glaucoma shunt device (MT-device), which was developed to control intraocular pressure (IOP) with a lower chance of complications than conventional glaucoma surgery, in a rabbit model. MATERIALS AND METHODS: The MT-device consists of an expanded polytetrafluoroethylene membrane (thickness 0.2 mm, area 2.5 × 2.5 mm2) and a tube (internal diameter 76 µm, external diameter 175.5 µm, length 7 mm) attached to the membrane. The device was implanted into the left eyes of nine New Zealand white rabbits. The tube was placed in the anterior chamber through paracentesis, and the membrane was fixated on the scleral surface; this induces aqueous drainage from the anterior chamber to the subconjunctival space. IOP, filtering bleb morphology, depth and inflammation of the anterior chamber, and possible complications were evaluated periodically for 8 weeks after surgery. Histological sections were analyzed at 2 and 8 weeks after the surgery. RESULTS: Mean IOP decreased from a preoperative value of 8.7 ± 1.2-4.7 ± 0.6 mmHg at postoperative 8 weeks (p < 0.05). The filtering bleb was maintained during the study period. There were no major postoperative complications. Histologic assessment revealed that 2 weeks after the surgery, fibrous encapsulation, inflammatory cells, and fibroblasts were observed around the MT-device; however, 8 weeks after the surgery, minimal inflammation was observed. CONCLUSIONS: The MT-device showed good biocompatibility and effective IOP reduction with a low risk of complications in a rabbit model.