A Retrospective Comparison of Phaco-Tube vs. Phaco-Trabeculectomy in Glaucoma Patients.

PURPOSE: To compare surgical outcomes of phacoemulsification combined with Baerveldt implantation (phaco-tube) or trabeculectomy with mitomycin-C (MMC) (phaco-trab) in patients without prior incisional ocular surgery. DESIGN: Single-center, retrospective, comparative case series. PARTICIPANTS: A total of 90 patients underwent surgical treatment, including 45 patients in the phaco-tube group and 45 patients in the phaco-trab group. METHODS: Eligible patients were identified using current procedural terminology (CPT) codes, and their medical records were retrospectively reviewed. MAIN OUTCOME MEASURES: The primary outcome measure was the rate of surgical failure (IOP ≤5 mmHg or >21 mmHg or reduced <20% from baseline on two consecutive study visits after 3 months, reoperations for glaucoma, or experienced loss of light perception vision). Patients who had successful surgical outcomes without use of glaucoma medications were classified as complete successes, while those that used glaucoma medications were classified as qualified successes. Secondary outcome measures were visual acuity (VA), visual field mean deviation (VFMD), intraocular pressure (IOP), glaucoma medication use, and complications. RESULTS: The cumulative probability of failure was 6.7% in the phaco-tube group and 32.8% in the phaco-trab group after 3 years (P= 0.005; Restricted Mean Survival Time = 5.9 months, 95% CI = 1.4 to 10.4 months). IOP was 13.1 ± 3.4 mmHg in the phaco-tube group and 13.3 ± 6.2 mmHg in the phaco-trab group at 3 years (P= 0.90), and the number of glaucoma medications was 2.6 ± 1.5 in the phaco-tube group and 1.7 ± 1.3 in the phaco-trab group (P= 0.015). LogMAR VA was 0.39 ± 0.58 in the phaco-tube group and 0.43 ± 0.73 in the phaco-trab group at 3 years (P= 0.82) and VFMD was -18.3 ± 9.0 dB in the phaco-tube group and -14.1 ± 7.0 dB in the phaco-trab group (P= 0.16). Postoperative complications developed in 21 patients (47%) in the phaco-tube group and 15 patients (33%) in the phaco-trab group (P= 0.28). CONCLUSIONS: Phaco-tubes had a significantly lower rate of surgical failure compared to phaco-trabs after 3 years of follow-up. However, phaco-trabs used significantly fewer glaucoma medications at multiple postoperative timepoints and had a higher proportion of complete success.

Chaotic vortex-induced rotation of an elliptical cylinder.

Non-linear oscillations of an elliptical cylinder, which can rotate about an axis that passes through its symmetry axle due to a torsional spring and hydrodynamic torque produced by the flow of a Newtonian fluid, were analyzed in terms of a single parameter that compares vortex shedding frequency with the torsional spring's natural frequency. The governing equations for the flow coupled with a rigid body with one degree of freedom were solved numerically using the lattice-Boltzmann method. The Reynolds number used was Re=200, which, in the absence of torsional spring, produces chaotic oscillations of the elliptical cylinder. When the torsional spring is included, we identified three branches separated by transition regions when stiffness of the restorative torque changes, as in the case of vortex-induced vibrations. However, in this case, several regions presenting chaotic dynamics were identified. Two regions with stable limit cycles were found when both torques synchronized and when stiffness of the torsional spring is big enough so that the ellipse's oscillation is small.

Ocular Surface Squamous Neoplasia Masquerading as Recalcitrant Epithelial Keratitis.

PURPOSE: The purpose of this study was to report a unique case of ocular surface squamous neoplasia that masqueraded as a nonresolving toxic epithelial keratitis. METHODS: This was a case report and review of the literature. RESULTS: A 79-year-old man presented with decreased vision, redness, and a foreign body sensation in his right eye that was refractory to treatment with lubrication and topical nonsteroidal antiinflammatory drops. Before presentation, the referring provider believed that he had medicamentosa-related keratitis and placed him on oral methazolamide. Slitlamp biomicroscopy of the right eye revealed diffuse epitheliopathy with punctate fluorescein staining and subtle underlying corneal epithelial opalescence. A mildly thickened and inflamed pinguecula was noted from 2 to 5 o'clock at the limbus of the right eye. An anterior segment high-resolution optical coherence tomography revealed thickened, hyperreflective epithelium with an abrupt transition. An incisional biopsy confirmed conjunctival and corneal intraepithelial neoplasia. The patient improved after 4 cycles of topical chemotherapy with 1% 5-fluorouracil eye drops with complete resolution of the corneal and conjunctival pathology. CONCLUSIONS: Ocular surface squamous neoplasia can rarely masquerade as a recalcitrant medicamentosa and epithelial keratitis. In subtle cases or in cases with combined ocular surface morbidities, anterior segment high-resolution optical coherence tomography can be helpful to diagnose and direct therapy.

Recent developments in the use of optical coherence tomography for glaucoma.

PURPOSE OF REVIEW: The aim of this article is to summarize findings of recent reports highlighting the utility of novel optical coherence tomography (OCT) parameters in the diagnosis and monitoring of glaucomatous optic neuropathy. RECENT FINDINGS: Optic nerve head (ONH), retinal nerve fiber layer (RNFL), and macular parameters show high levels of diagnostic capability. The Bruch's membrane opening-minimum rim width (BMO-MRW) measurement is a novel ONH parameter obtained using the Spectralis SD-OCT device (Heidelberg Engineering, Inc., Heidelberg, Germany). The inferotemporal BMO-MRW sector shows the highest diagnostic performance for this parameter. Minimum ganglion cell and inner plexiform layer thickness shows the highest diagnostic performance among macular parameters obtained with the Cirrus HD-OCT (Carl Zeiss, Inc., Dublin, CA, USA). Optic nerve head, macular, and retinal nerve fiber layer parameters are not interchangeable across protocols generated by varying OCT manufacturers. Novel machine-learning algorithms show promise with regards to achieving higher levels of diagnostic accuracy using OCT imaging platforms. SUMMARY: Digital imaging in glaucoma continues to evolve with novel parameters of the optic nerve head, retinal nerve fiber layer, and macula. Diagnostic abilities of these parameters are high and complementary to each other.

Separation and thickness measurements of superficial and deep slabs of the retinal nerve fiber layer in healthy and glaucomatous eyes.

Purpose: Describe a new method to analyze retinal nerve fiber layer (RNFL) thickness maps. Design: Cross-sectional study. Subjects: RNFL thickness maps of healthy and glaucomatous eyes. Methods: Optical coherence tomography (OCT) RNFL raster scans from 98 healthy and 50 glaucomatous eyes were analyzed. The RNFL thickness maps were separated into superficial (SNFL) and deep (DNFL) slabs through a partial thickness plane set at the modal thickness (mode). Association between mode and OCT signal strength (SS), age, axial length, and visual field mean deviation (VFMD) was tested (Pearson coefficient, r). Thicknesses of inferior and superior SNFL regions (i-,s-SNFL), and inferior, superior, nasal, and temporal DNFL regions (i-,s-,n-,t-DNFL) were calculated. The regions thicknesses were compared between healthy and glaucomatous eyes (t-test) and between glaucomatous eyes with early, moderate, and severe disease (ANOVA and linear regressions of thickness on VFMD). Diagnostic accuracy and correlation with VFMD of RNFL regions thicknesses were calculated as the area under the receiver operating characteristic curve (AUC) and Pearson r, respectively. P<0.05 was considered significant. Main outcome: Thickness of regions in SNFL and DNFL slabs. Results: The mode was not associated with SS, age, axial length, or VFMD, it circumscribed the thicker RNFL around the optic disc of healthy and glaucomatous eyes, and it was used to separate the SNFL and DNFL slabs of RNFL thickness maps. The thickness of the SNFL slab was less in glaucomatous eyes than in healthy eyes (P<0.001). S-SNFL and i-SNFL thicknesses (respectively) were 86.0±8.2µm and 87.3±9.6µm in healthy eyes vs. 66.1±9.1µm and 63.4±8.2µm in glaucomatous eyes (P<0.001 for both). The thickness of the DNFL slab was similar between groups (P=0.19). T-DNFL thickness was 37.0±5.3µm in healthy eyes vs. 33.9±5.0µm in glaucomatous eyes (P<0.001); thicknesses of all other DNFL regions were similar. The SNFL regions only thinned with progressively worse glaucoma severity, had excellent AUCs (AUC≥0.95, P<0.001), and correlated strongly with VFMD (r≥0.60, P<0.001). Conclusions: Glaucomatous RNFL thinning is predominantly detected within a slab with thickness greater than the mode. SNFL thickness has great AUC and correlation with VFMD in glaucomatous eyes. The usefulness for diagnosis and monitoring of glaucoma needs further study.

Optical Coherence Tomography Angiography Macular and Peripapillary Vessel Perfusion Density in Healthy Subjects, Glaucoma Suspects, and Glaucoma Patients.

Purpose: To evaluate macular and peripapillary vessel perfusion density (VD) in glaucoma suspects (GS) and glaucoma patients; to correlate ganglion cell-inner plexiform layer (GCIPL) and retinal nerve fiber layer (RNFL) thicknesses with macular and peripapillary VD; and to evaluate the diagnostic accuracy of the structural and vascular parameters. Methods: A consecutive series of GS, glaucoma patients, and healthy subjects was prospectively recruited from July 1, 2016, to January 31, 2017. All subjects underwent standard automated perimetry, spectral-domain optical coherence tomography (OCT), and 6 × 6-mm optical coherence tomography angiography (OCT-A) centered on the fovea and optic nerve. Results: Forty controls, 40 GS, and 40 glaucoma patients were enrolled. Peripapillary RNFL, GCIPL, and macular RNFL thicknesses significantly decreased in the glaucoma group compared to controls and GS (P < 0.01). Peripapillary VD in average and in the superior and inferior quadrants decreased in the glaucoma group (P ≤ 0.001); conversely, macular VD was not statistically different across groups (P > 0.05). At the peripapillary area, a correlation between RNFL thickness and VD was found; conversely, no statistically significant correlation was found between GCIPL thicknesses and macular VD (all P > 0.05) in all groups. Peripapillary RNFL and GCIPL showed higher diagnostic capacity compared to peripapillary and macular VDs. Conclusions: Structural damage is evident both in the peripapillary and in macular areas. Vascular damage seems to be less prominent, as it was seen only for the glaucoma group and at the radial peripapillary plexus. Diagnostic abilities are excellent for structural variables, less so but still good for peripapillary VD, and poor for macular VD.

The classical complement cascade mediates CNS synapse elimination.

During development, the formation of mature neural circuits requires the selective elimination of inappropriate synaptic connections. Here we show that C1q, the initiating protein in the classical complement cascade, is expressed by postnatal neurons in response to immature astrocytes and is localized to synapses throughout the postnatal CNS and retina. Mice deficient in complement protein C1q or the downstream complement protein C3 exhibit large sustained defects in CNS synapse elimination, as shown by the failure of anatomical refinement of retinogeniculate connections and the retention of excess retinal innervation by lateral geniculate neurons. Neuronal C1q is normally downregulated in the adult CNS; however, in a mouse model of glaucoma, C1q becomes upregulated and synaptically relocalized in the adult retina early in the disease. These findings support a model in which unwanted synapses are tagged by complement for elimination and suggest that complement-mediated synapse elimination may become aberrantly reactivated in neurodegenerative disease.

SynGAP regulates spine formation.

SynGAP is a brain-specific ras GTPase-activating protein that is an abundant component of the signaling complex associated with the NMDA-type glutamate receptor. We generated mutant mice lacking synGAP to study its physiological role. Homozygous mutant mice die in the first few days after birth; however, neurons from mutant embryos can be maintained in culture. Here, we report that spine and synapse formation are accelerated in cultured mutant neurons, and the spines of mature mutant neurons are significantly larger than those of wild type. Clusters of PSD-95 and subunits of AMPA-type and NMDA-type glutamate receptors accumulate in spines of mutant neurons by day 10 in vitro, whereas in wild-type neurons they are still mostly located in dendritic shafts. The frequency and amplitude of miniature EPSCs are larger in mutant neurons at day 10 in vitro, confirming that they have more functional synapses. At day 21 in vitro, the spines of mutant neurons remain significantly larger than those of wild type. The mutant phenotype at day 10 in vitro can be rescued by introduction of recombinant wild-type synGAP on day 9. In contrast, introduction of mutant synGAP with a mutated GAP domain or lacking the terminal domain that binds to PSD-95 does not rescue the mutant phenotype, indicating that both domains play a role in control of spine formation. Thus, the GAP activity of synGAP and its association with PSD-95 are important for normal regulation of spine and synapse formation in hippocampal neurons.