Pseudophakic Pupillary Block after Toxic Anterior Segment Syndrome

PURPOSE: We report a case of pseudophakic pupillary block after toxic anterior segment syndrome (TASS). CASE SUMMARY: An 84-year-old woman underwent phacoemulsification and intraocular lens implantation in the posterior chamber. Six days after surgery, anterior chamber inflammation was seen. Twenty-five days after surgery, a sudden increase in intraocular pressure (IOP) associated with pupillary block was observed. Despite the use of IOP-lowering medication, the IOP was not controlled. Peripheral laser iridotomy failed. After surgical peripheral iridectomy, IOP decreased significantly and was controlled. CONCLUSIONS: Despite the rarity of TASS combined with pseudophakic pupillary block, clinicians must be aware of this condition in patients showing prolonged inflammatory state and IOP elevation after surgery.

Additive Role of Optical Coherence Tomography Angiography Vessel Density Measurements in Glaucoma Diagnoses

PURPOSE: This study compared the glaucoma diagnostic abilities of optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). In addition, the possibility of enhancing diagnostic capability by combining the two modalities was investigated. METHODS: A total of 131 healthy eyes and 113 glaucomatous eyes were imaged by both OCT and OCTA. In OCT, glaucoma was defined as when the color of the superior or inferior quadrant of the peripapillary retinal nerve fiber layer thickness map was yellow (borderline, <5%) or red (outside normal limits, <1%). In OCTA, glaucoma was determined using the cut-off value of the superior or inferior peripapillary vessel density, calculated after receiver operating characteristic curve analysis. Sensitivity and specificity were determined by OCT alone, by OCTA alone, or by OCT and OCTA combined. RESULTS: The sensitivity of OCT (86.7%) was better than that of OCTA (74.3%), whereas the specificity of OCTA (87.0%) was better than that of OCT (67.9%). When these two modalities were combined, both sensitivity and specificity were enhanced (90.3% and 92.4%, respectively). Among the 131 eyes, 32 were misdiagnosed as glaucomatous by OCT but accurately diagnosed as normal by OCTA. These eyes were myopic, with a longer axial length and a thinner and temporally displaced peak of peripapillary retinal nerve fiber layer thickness, causing the false positive result in OCT. CONCLUSIONS: When OCTA was combined with OCT, the specificity of glaucoma diagnoses were enhanced. OCTA may compensate for the shortcomings of OCT in the diagnosis of glaucoma.

Effects of Choroidal Thickness on Refractive Outcome Following Cataract Surgery in Primary Angle Closure

PURPOSE: To identify the preoperative biometric factors, including subfoveal choroidal thickness (CT), associated with refractive outcome after cataract surgery in eyes with primary angle closure (PAC). METHODS: This study included 50 eyes of 50 PAC patients who underwent uneventful cataract surgery. Preoperatively, anterior segment parameters including anterior chamber depth (ACD) and lens vault were determined by anterior segment optical coherence tomography. Subfoveal CT was measured by spectral domain optical coherence tomography enhanced depth imaging before and at one month after surgery. Mean refractive error (MRE) was calculated as the difference in spherical equivalent between actual postoperative refraction determined one month postoperatively and that predicted using each of three IOL calculation formulas (SRK/II, SRK/T, and Haigis). Regression analyses were performed to investigate potential associations between MRE and putative factors. RESULTS: Mean ACD was 1.9 ± 0.4 mm, and preoperative subfoveal CT was 250.8 ± 56.9 µm. The SRK/T (MRE, 0.199 ± 0.567 diopters [D]) and Haigis (MRE, 0.190 ± 0.727 D) formulas showed slight hyperopic shift, while the SRK/II formula demonstrated a myopic shift (MRE, −0.077 ± 0.623 D) compared with that expected after cataract surgery. Mean absolute refractive error was not significantly different between formulas. Higher preoperative lens vault and shallower ACD were associated with a hyperopic shift in all formulas, but not in a statistically significant manner. Thicker preoperative subfoveal choroid was associated with a myopic shift after cataract surgery in all formulas (SRK/II: β = −0.511, p < 0.001; SRK/T: β = −0.652, p < 0.001; Haigis: β = −0.671, p < 0.001). Greater postoperative reduction of subfoveal CT was associated with a myopic shift after cataract surgery in all formulas (SRK/II: β = −0.511, p < 0.001; SRK/T: β = −0.652, p < 0.001; Haigis: β = −0.671, p < 0.001). CONCLUSIONS: Our results indicate that preoperative subfoveal CT and the difference between pre- and postoperative subfoveal CT are significant factors for predicting refractive error after cataract surgery in PAC patients. These findings should be considered when performing cataract surgery to optimize visual outcomes.

Factors Associated with Outcomes of Combined Phacoemulsification and Ahmed Glaucoma Valve Implantation

PURPOSE: To evaluate outcomes and factors associated with surgical failure in patients who underwent combined phacoemulsification and Ahmed glaucoma valve (AGV) implantation. METHODS: This retrospective and longitudinal study enrolled 40 eyes (38 patients) that underwent combined phacoemulsification and AGV implantation. Visual acuity, intraocular pressure (IOP), and number of antiglaucoma medications were evaluated preoperatively and postoperatively. Complete success was defined as a last follow-up IOP of 6 to 21 mmHg without medication, qualified success as an IOP of 6 to 21 mmHg with medication, and failure as an IOP of >21 or <6 mmHg. RESULTS: The mean follow-up period was 18 ± 10 months. Preoperative diagnoses were chronic angle closure glaucoma (35.0%), neovascular glaucoma (22.5%), uveitic glaucoma (17.5%), primary open-angle glaucoma (15.0%), and other (10.0%). IOP decreased from a mean of 30.5 ± 8.7 to 14.5 ± 3.7 mmHg at the last follow-up visit (p < 0.001). Treatment was classified as qualified success in 18 eyes (45%), complete success in 15 (37.5%), and failure in seven (17.5%). Twenty-two eyes (55%) showed improvement in visual acuity. The most common postoperative complication was a transient hypertensive phase (five eyes, 12.5%). Tube-iris touch was associated with surgical failure (hazard ratio, 8.615; p = 0.008). CONCLUSIONS: Combined phacoemulsification and AGV implantation is an effective and safe surgical option for patients with refractory glaucoma and cataract. Postoperative tube-iris touch is an indicator of poor prognosis.

Comparison of Cytotoxic Effects on Rabbit Corneal Endothelium between Preservative-free and Preservative-containing Dorzolamide/timolol

PURPOSE: To evaluate and compare the toxic effects of eyedrops containing a fixed combination of 2.0% dorzolamide and 0.5% maleate timolol with or without preservatives on rabbit corneal endothelium. METHODS: This study was performed with 22 eyes of New Zealand white rabbits. Dorzolamide/timolol eyedrops with preservative (Cosopt group) or without preservative (Cosopt-S group) were diluted with a balanced salt solution at a 1 : 1 ratio. We injected 0.1 mL of diluted Cosopt into the anterior chamber of left eyes and an equal volume of diluted Cosopt-S into the anterior chamber of right eyes. Corneal thickness, corneal haze, and conjunctival injection were measured before and 24 hours after treatment. Endothelial damage was compared between both eyes by vital staining (alizarin red/trypan blue staining), live/dead cell assay, TUNEL assay, and scanning electron microscopy. RESULTS: Corneal endothelial damage was severe in the Cosopt group. Cosopt-treated eyes exhibited remarkable corneal edema and prominent apoptosis of endothelial cells. In addition, the live/dead cell assay revealed many dead cells in the endothelium, and scanning electron microscopy analysis showed that corneal endothelial cells exhibited a partial loss of microvilli on the surface as well as extensive destruction of intercellular junctions. However, in the Cosopt-S group, corneal edema was mild and the damage to the corneal endothelium was minimal. CONCLUSIONS: The main cause of corneal endothelial toxicity was due to the preservative in the dorzolamide/timolol fixed combination eyedrops, and not the active ingredient. Thus, it appears to be safer to use preservative-free eyedrops during the early postoperative period.

Postoperative Stabilization of the Strabismic Angle in Intermittent Exotropia

PURPOSE: To analyze the postoperative strabismic angle for five years or more and to investigate when the angle stabilized in intermittent exotropia. METHODS: We retrospectively reviewed the clinical records of 89 patients who had undergone surgery for intermittent exotropia. The postoperative strabismic angles measured were analyzed at one-year intervals up to five years postoperatively. We divided them into two groups according to their age at the time of surgery. Group 1 was less than 5 years of age, while Group 2 participants were 5 years of age or older. RESULTS: For our 89 total patients, average exo-angles were 7.8 +/- 7.26, 7.9 +/- 7.51, 9.5 +/- 7.05, 10.1 +/- 6.87, and 9.4 +/- 6.90 prism diopters at one, two, three, four, and five years postoperatively, respectively. Average exo-angles between postoperative year one and year three, as well as between postoperative year two and year three, were statistically significant (p = 0.015, 0.022). However, the angles were not statistically significant between postoperative year three and year four or between years three and five, respectively (p = 0.707, p = 0.948). The stabilization characteristics of the angle were somewhat different according to age group. In Group 1, the average exo-angle in postoperative years one and three were statistically significant (p = 0.016), but the angle in the same period was not statistically significant in Group 2 (p = 0.203). CONCLUSIONS: There was no significant interval change after three years postoperatively in intermittent exotropia, but if the patient's age at surgery was 5 years or higher, no significant change of exo-angle was found following postoperative year one in this study.

The Ocular Fatigue of Watching Three-Dimensional (3D) Images

PURPOSE: To compare ocular fatigue, non-ocular symptoms, and ocular surface changes, such as tear break-up time (BUT) and ocular surface temperature, after watching 2-dimensional (2D) and 3-dimensional (3D) images. METHODS: Fourteen volunteers were enrolled in the present study. Subjects watched 2D as well as 3D images and answered questions regarding ocular fatigue and general symptoms such as headache. Before and after watching images, the spherical equivalent, degree of conjunctival injection, tear BUT, and ocular surface temperature were measured and the amount of change was analyzed. While watching images, subjects answered questions regarding ocular fatigue and the time when they began to feel definitive symptoms. RESULTS: Watching 3D images induced a greater degree of ocular fatigue, headache, and decreasing concentration than watching 2D images (p = 0.038, 0.003, and 0.045, respectively). While watching images, 3D images induced a greater degree of ocular fatigue than 2D images and caused subjects to feel earlier ocular fatigue (3D: 54.86 min, 2D: 78.57 min, p = 0.002). Spherical equivalents became more myopic after watching 3D images. CONCLUSIONS: After watching 3D images, a greater degree of ocular fatigue, headache, and decreasing concentration was induced and a shorter time to feel definitive ocular fatigue was observed than after watching 2D images. In addition, spherical equivalents changed myopically after watching 3D images.