Case Report: Microincision Vitreous Surgery Induces Bleb Failure in Eyes With Functional Filtering Bleb.

Purpose: To investigate the effect of microincision vitreous surgery (MIVS) on intraocular pressure (IOP) control in glaucomatous eyes with functional filtering bleb. Methods: We enrolled 18 patients (15 males; median age, 73 years) who previously had filtering surgery and underwent MIVS with functional filtering bleb. Kaplan-Meier method was used to calculate the survival rate with defined the failure as when more number of preoperative antiglaucoma medication was started or additional glaucoma surgery including bleb revisions were performed, and IOP increase of 20% (criteria 1) and 30% (criteria 2) from preoperative levels after 2 weeks of MIVS. Results: The median follow-up duration was 970 days. Preoperative IOP was 13.3 ± 3.8 mmHg (mean ± SD). Postoperative IOP were 14.7 ± 4.9 (P=0.365), 15.2 ± 3.5 (P=0.137), 16.4 ± 5.6 (P = 0.073), 17.6 ± 6.1(P = 0.020), and 14.5 ± 4.0 (P = 0.402) mmHg at 3, 6, 12, and 15 months and final visit, respectively (compared to preoperative IOP). The number of antiglaucoma medications was a median of 1.0 (range 0-4) preoperatively and 0 (0-4) at the final visit (P = 0.238). The survival rates were 55%/61% at 3 months, 50%/61% at 6 months, and 38%/55% at 12 months with criteria 1 and 2, respectively. Four eyes (22%) received additional glaucoma surgery during follow-up. Conclusion: After several months of MIVS, IOP was likely to increase. We should focus on IOP control by conducting long-term follow-ups.

Effect of Manual Upper Eyelid Elevation on Intraocular Pressure Measurement by Four Different Tonometers.

SIGNIFICANCE: This study is the first to show that the manual upper eyelid elevation (manual UEE) that is commonly used to prevent disruption of the IOP measurement due to blinking or upper eyelid contact with the tip of the tonometer does not affect the IOP values. PURPOSE: We investigated whether manual UEE affects the IOP readings using three rebound tonometers (Icare TA01i, Icare PRO, and Icare ic100) and Goldmann applanation tonometry (GAT). METHODS: One eye was measured for 101 patients (56 eyes of primary open-angle glaucoma patients and 45 healthy subjects). The IOPs were measured without and with manual UEE. Each IOP was measured twice; the measurement order using the tonometers was randomly selected. In addition, palpebral fissure height (distance between the upper and lower eyelids) was measured. RESULTS: The IOPs without manual UEE were 12.1 ± 2.9, 13.3 ± 2.7, 11.7 ± 2.9, and 16.0 ± 3.2 mmHg (Icare TA01i, Icare PRO, Icare ic100, and GAT), and those with manual UEE were 12.3 ± 3.0, 13.3 ± 2.8, 11.7 ± 2.9, and 16.0 ± 3.3, respectively. No significant difference was found between the IOP without and with manual UEE (IOP difference; all, P > .50; paired t test). Multiple linear regression analyses revealed that palpebral fissure height did not affect IOP difference for any of the tonometers. CONCLUSIONS: Simple manual UEE when measuring the IOP has little effect on the IOP obtained using all current rebound tonometers and GAT.

Comparison of the Intraocular Pressure Measured Using the New Rebound Tonometer Icare ic100 and Icare TA01i or Goldmann Applanation Tonometer.

PURPOSE: We evaluated the agreement between the intraocular pressure (IOP) values of new rebound tonometer, Icare ic100, and Icare TA01i or Goldmann applanation tonometer (GAT). METHODS: We studied one eye each of 106 subjects (57 with primary open-angle glaucoma, 49 healthy subjects). IOP was randomly measured twice with the patient in sitting position using the Icare ic100, Icare TA01i, and GAT. Tonometer measurements were evaluated using Bland-Altman analysis. The relationship between IOP difference (Icare ic100-GAT) and age, sex, disease, axial length, central corneal thickness (CCT), and corneal curvature was investigated using multivariate regression analysis. RESULTS: IOPs measured using Icare ic100, Icare TA01i, and GAT were 11.7±3.0 (mean±standard deviation), 12.2±2.9, and 16.0±3.2 mm Hg, respectively (P<0.001, one-way analysis of variance). Icare ic100 showed significantly lower IOPs than GAT (P<0.05), but not than Icare TA01 (P>0.05; Tukey-Kramer test). Bland-Altman analysis revealed that the mean differences between Icare ic100 and Icare TA01i and those between Icare ic100 and GAT were -0.46 and -4.2 mm Hg, respectively (95% limits of agreement, -3.35 to 2.42 and -10.10 to 1.61 mm Hg, respectively). For IOP differences between Icare ic100 and GAT, parameters selected in the optimal model were CCT (coefficient, 20.3, P=0.029), corneal curvature (3.0, P=0.020), and glaucoma-normal (-1.0, P=0.004). CONCLUSIONS: The new rebound tonometer Icare ic100 almost constantly showed IOPs lower than GAT. The difference was affected by CCT, corneal curvature, and disease.

Iris Morphological Features in Patients with 360° Angle-Closure Neovascular Glaucoma: An Anterior Segment Optical Coherence Tomography Study.

PURPOSE: To investigate iris morphological features in 360° angle-closure neovascular glaucoma (NVG) by swept-source anterior segment optical coherence tomography (ASOCT). PATIENTS AND METHODS: In this retrospective, clinic-based, comparative study, 14 patients with 360° angle-closure NVG and 14 healthy age-matched control subjects were enrolled. All patients enrolled had no prior glaucoma surgery but underwent cataract surgery with intraocular lens implantation. Horizontal scanning images of swept-source ASOCT were analyzed using software calipers in temporal and nasal angle areas. The iris thickness at 1 and 2 mm from the pupil edge, iris length, trabecular meshwork length, peripheral anterior synechia (PAS) length, PAS height ratio (PAS length/trabecular meshwork length), and pupil diameter were measured. RESULTS: Between the groups, there were no statistically significant differences in iris length, trabecular meshwork length, and pupil diameter (p > 0.05). However, the iris thickness was significantly reduced in the NVG group compared with the control group in the temporal and nasal areas (0.306 vs. 0.563 mm/0.326 vs. 0.645 mm at 1 mm, 0.278 vs. 0.523 mm/0.282 vs. 0.546 mm at 2 mm, respectively) (mean, all p < 0.001). In the NVG group, PAS height ratios were 1.55 ± 0.45 (mean ± standard deviation) (range, 0.58-2.30) and 1.55 ± 0.78 (range, 0.68-3.68) at the temporal and nasal angles, respectively. CONCLUSIONS: In patients with 360° angle-closure NVG, the iris thickness decreased to about 50% of that in healthy subjects, and the PAS length exceeded the trabecular meshwork length by about 1.5 times.

Iris Thickness and Severity of Neovascular Glaucoma Determined Using Swept-Source Anterior-segment Optical Coherence Tomography.

PURPOSE: To investigate the iris thickness (IT) in neovascular glaucoma (NVG) using swept-source anterior-segment optical coherence tomography (ASOCT). PATIENTS AND METHODS: In this retrospective, clinic-based, comparative study, we enrolled 20 NVG patients [11 with 360-degree angle-closure (AC)-NVG and 9 with NVG without AC] and 14 healthy age-matched controls. Horizontal scanning images of swept-source ASOCT were analyzed using software calipers in temporal and nasal angle areas. ITs at 1 and 2 mm from the pupil edge were measured using ASOCT. The relation between IT and the severity of NVG, the effects of intraocular pressure (IOP), intravitreal antivascular endothelial growth factor (anti-VEGF) injection, and panretinal photocoagulation (PRP) were assessed using linear regression analysis based on the corrected Akaike information criteria index. RESULTS: The IT was thinner in 360-degree AC-NVG patients, followed by NVG patients without AC and controls (0.33 vs. 0.48 vs. 0.57 mm at 1 mm and 0.31 vs. 0.43 vs. 0.49 mm at 2 mm; P<0.001 by ANOVA). Multiple linear regression analysis revealed that 360-degree AC-NVG patients-NVG patients without AC and controls (coefficient: -0.16), NVG patients without AC-control (-0.13) and underwent PRP (0.23) at 1 mm, 360-degree AC-NVG patients-NVG patients without AC and controls (-0.12), NVG patients without AC-controls (-0.08), underwent PRP (0.16), received anti-VEGF injection (0.05) and IOP (-0.001) at 2 mm were selected predictors to explain IT. CONCLUSIONS: IT decreases with the progression of the NVG stage and is thinnest in 360-degree AC-NVG patients. Our study suggests a new morphologic feature of NVG.

Cataract surgery causes biomechanical alterations to the eye detectable by Corvis ST tonometry.

PURPOSE: Modern cataract surgery is generally considered to bring about modest and sustained intraocular pressure (IOP) reduction. However, the pathophysiological mechanism for this remains unclear. Moreover, a change in ocular biomechanical properties after surgery can affect the measurement of IOP. The aim of the study is to investigate ocular biomechanics, before and following cataract surgery, using Corvis ST tonometry (CST). PATIENTS AND METHODS: Fifty-nine eyes of 59 patients with cataract were analyzed. IOP with Goldmann applanation tonometry (IOP-G), axial length, corneal curvature and CST parameters were measured before cataract surgery and, up to 3 months, following surgery. Since CST parameters are closely related to IOP-G, linear modeling was carried out to investigate whether there was a change in CST measurements following cataract surgery, adjusted for a change in IOP-G. RESULTS: IOP-G significantly decreased after surgery (mean±standard deviation: 11.8±3.1 mmHg) compared to pre-surgery (15.2±4.3 mmHg, P<0.001). Peak distance (the distance between the two surrounding peaks of the cornea at the highest concavity), maximum deformation amplitude (the movement of the corneal apex from the start of deformation to the highest concavity) and A1/A2 velocity (the corneal velocity during inward or outward movement) significantly increased after cataract surgery (P<0.05) while radius (the central curvature radius at the highest concavity) was significantly smaller following cataract surgery (P<0.05). Linear modeling supported many of these findings, suggesting that peak distance, maximum deformation amplitude and A2 velocity were increased, whereas A2 deformation amplitude and highest concavity time were decreased (after adjustment for IOP change), following cataract surgery. CONCLUSION: Corneal biomechanical properties, as measured with CST, were observed to change significantly following cataract surgery. TRIAL REGISTRATION: Japan Clinical Trials Registry UMIN000014370.

Time Course of Conjunctival Hyperemia Induced by a Rho-kinase Inhibitor Anti-glaucoma Eye Drop: Ripasudil 0.4.

PURPOSE: We investigated the detailed time course of conjunctival hyperemia induced by ripasudil 0.4%, a novel Rho-kinase inhibitor anti-glaucoma eye drop, in healthy subjects. METHODS: We recruited 51 healthy subjects and administered ripasudil 0.4% in their right eye. We evaluated conjunctival hyperemia using slit lamp photography and measured the intraocular pressure (IOP) using the Icare PRO Rebound Tonometer at baseline and after 5, 15, 30, 60, 90, and 120 min. The conjunctival hyperemia score was graded by three independent observers on a scale of 0 (none) to 3 (severe). Additionally, we analyzed the "percent coverage" of conjunctival hyperemia by using an automated hyperemia analysis software program; this program provides the pixel coverage of the conjunctival vessels in the region of interest. Dunnett and Steel multiple comparison tests were used, as appropriate, for the subsequent analyses. RESULTS: The conjunctival hyperemia score and percent coverage increased rapidly after the instillation of ripasudil 0.4%, peaking at 15 min (score: 1.83 ± 0.29 [mean ± SD]) and 5 min (11.6% ± 4.7%), respectively, and then gradually decreasing until 120 min (0.45 ± 0.22 and 4.7% ± 1.8%, respectively), when they reached a level that was not significantly different from the baseline values. The IOP decreased significantly compared to the baseline at 30, 60, and 90 min, based on the Dunnett test. CONCLUSION: Conjunctival hyperemia induced by ripasudil 0.4% peaks rapidly to moderate severity, but subsides relatively quickly.