Yanin Suwan

Peripapillary perfused capillary density in primary open-angle glaucoma across disease stage: an optical coherence tomography angiography study

Aims To assess peripapillary perfused capillary density (PCD) in primary open-angle glaucoma (POAG) across stage of disease. Methods In this observational, cross-sectional study, 60 eyes with varying stages of POAG and 24 control eyes were imaged on a spectral domain optical coherence tomography angiography system (AngioVue, Optovue, Fremont, California, USA) generating images centred on the optic nerve head. Major blood vessels were removed using custom automated software. PCD was calculated as a percentage as the ratio of pixels associated with perfused capillaries to the total number of pixels in the corresponding region-of-interest (ROI). Analysis of covariance was used to compare PCD among the subject groups and control for possible covariates. Area under the receiver operating characteristic curve (AROC) and sensitivity at 95% specificity were calculated to assess the capability of PCD to distinguish mild glaucoma from control. The Pearsons product-moment correlation coefficient was used to assess correlations between PCD and circumpapillary retinal nerve fibre layer thickness (cpRNFLT) and visual field mean deviation (MD). Results PCD demonstrated a progressive stepwise decrease from control eyes throughout worsening POAG stage at all ROIs. PCD demonstrated AROC and sensitivity values comparable to cpRNFLT and visual field parameters and exhibited significant correlations with cpRNFLT and MD at all corresponding ROIs. Conclusions PCD displayed significant correlations with morphological and functional indices and exhibited diagnostic capabilities comparable to currently employed clinical variables. Our preliminary results suggest that PCD analysis may prove to be a useful tool in monitoring POAG across stage and identifying early POAG.

Pattern of peripapillary capillary density loss in ischemic optic neuropathy compared to that in primary open-angle glaucoma

Purpose Both non-arteritic anterior ischemic optic neuropathy (NAION) and primary open-angle glaucoma (POAG) damage retinal ganglion cell axons, which are perfused by the radial peripapillary capillaries. To evaluate the pattern of ischemia, we compared peripapillary capillary density (PCD) in NAION eyes to POAG eyes matched for visual field mean deviation and retinal nerve fiber layer thickness. Methods 31 chronic NAION (>6 months after the acute event) and unaffected fellow eyes (31 subjects), 42 moderate and severe POAG eyes (27 subjects), and 77 control eyes (46 healthy subjects) were imaged with a commercial optical coherence tomography angiography system (AngioVue, Avanti RTVue-XR, Optovue, CA) at two academic institutions. Two concentric circles of diameters 1.95mm (inner) and 3.45mm (outer) were manually placed on images centered on the optic nerve head, producing an annular region-of-interest. Image analysis with major vessel removal was performed using a custom program. Whole-image, whole-annulus, and sectoral PCDs were measured. Results Whole-image and whole-annulus PCDs in NAION and moderate and severe POAG eyes were significantly decreased compared to unaffected fellow eyes and control eyes (all P<0.001). Superior and temporal PCD values were affected more than other sectors in both NAION and POAG groups compared to control group. Whole-image and whole-annulus PCDs were not statistically different between NAION and POAG eyes (both P = 0.99). However, of all peripapillary sectors, the inferior sector PCD value was less affected in POAG eyes compared to NAION eyes (P = 0.001). Univariate analysis results also revealed a significant positive correlation between superior and inferior PCDs and corresponding RNFL thicknesses. The inferior sector correlation was greater in POAG than NAION eyes. Conclusion While the whole PCD values were not different in chronic NAION and POAG, the greater correlation of inferior PCD with corresponding RNFL sectors in POAG compared to NAION suggests greater susceptibility of the inferior radial peripapillary capillary in the pathogenesis of POAG.

Hidden mechanisms beyond the pupillary block in acute angle closure: ultrasound biomicroscopic study

To evaluate the mechanisms of acute angle closure (AAC) other than the pupillary block using ultrasound biomicroscopy.

Epstein-Barr virus-associated iris smooth muscle tumor with epithelioid morphology in AIDS patients: a case report.

Importance Report of an acquired immunodeficiency syndrome (AIDS) patient with Epstein–Barr virus (EBV)-associated iris smooth muscle tumor. Observations A 14-year-old African American female diagnosed with AIDS developed a painless iris mass in the right eye for 10 months. Iridocyclectomy was performed, and the pathology indicated EBV-associated iris smooth muscle tumor with epithelioid morphology. Immunohistochemical stains and in situ hybridization for EBV-encoded ribonucleic acid are very useful diagnostic tools for definite diagnosis. At 14-month follow-up, the patient did not have any tumor recurrence. Conclusion This is the case report of EBV-associated iris smooth muscle tumor in a person diagnosed with AIDS with a unique epithelioid morphologic feature.

Pseudophakic angle-closure from a Soemmering ring

BackgroundReport of three patients with pseudophakic angle-closure from a Soemmering ring. Three mechanisms of the Soemmering ring induced pseudophakic angle-closure in three patients were demonstrated by meticulous anterior segment examination and ultrasound biomicroscopic (UBM) analysis.Case presentationIn the first case, the Soemmering-capsule-IOL complex caused relative pupillary block similar to a phakic eye and was successfully treated with laser iridotomy alone. In the second case, an enlarged Soemmering ring provided posterior iris support in apposition to the anterior chamber angle. We performed a laser capsulotomy through the iridotomised hole. The last, a protruding Soemmering content causing absolute pupillary block became resolved after laser iridotomy and total Soemmering ring content removal.ConclusionAngle-closure in pseudophakic eyes is uncommon. Several causes have been reported in the literatures including Soemmering ring. This is the first report on three different mechanisms of Soemmering ring related angle-closure in pseudophakic eyes. Ultrasound biomicroscopic analysis plays a crucial role as a diagnostic tool.

Association of Myopia With Peripapillary Perfused Capillary Density in Patients With Glaucoma: An Optical Coherence Tomography Angiography Study

Importance This study used optical coherence tomographic angiography to assess for impaired blood flow in myopic eyes with or without open-angle glaucoma. Objective To compare the peripapillary perfused capillary density (PCD) between eyes with and without glaucoma. Design, Setting, and Participants In this cross-sectional study at a tertiary glaucoma referral practice, we recruited patients with myopic eyes of spherical equivalent of more than −3.0 diopters with and without open-angle glaucoma, patients with nonmyopic eyes with glaucoma, and patients with no disease from February 2016 to October 2016. We obtained 4.5 × 4.5-mm optical coherence tomographic angiography images of the optic nerve head and calculated PCD as the ratio of pixels associated with capillaries to the number of pixels in the region of interest after large blood vessel removal. Both eyes of each patient were used in the analysis. Continuous variables were assessed by analysis of variance and Tukey tests. A marginal model of generalized estimating equations was performed to adjust for confounding factors and intraclass correlations. Main Outcomes and Measures Mean PCD. Results We matched 87 patients with myopic eyes with glaucoma (of whom 39 [45%] were women), 17 with myopic eyes without glaucoma (of whom 10 [59%] were women), and 93 with non-myopic eyes with glaucoma (of whom 55 [59%] were women) for visual field defects and included 51 control participants (or whom 38 [75%] were women). Mean (SD) ages were 67.5 (12.0) years for patients with myopia and glaucoma, 48.2 (19.0) years for those with myopia without glaucoma, 67.3 (11.0) years for those with glaucoma without myopia, and 64.7 (8.9) years in control participants. Global PCD demonstrated a progressive decrease from the control group (mean [SD], 41.0 [4.2]) to those with myopia without glaucoma (38.4 [5.8]) to those with glaucoma without myopia (31.9 [7.5]) to those with both (28.2 [6.0]; all P < .001). The mean difference in global PCD between the 3 groups and control group, adjusted for age and axial length, was greatest in those with myopia and glaucoma (−11.1; 95% CI, −14.0 to −8.1; P < .001), followed by those with glaucoma without myopia (−8.6; 95% CI, −10.9 to −6.3; P < .001) and those with myopia without glaucoma (−2.8; 95% CI, −6.9 to 1.2; P = .17). No interaction was found between glaucoma and myopia. Conclusions and Relevance These findings demonstrate peripapillary microvascular attenuation to a greater extent in open-angle glaucoma than myopia. The cross-sectional design means we cannot determine if this association is a cause and/or is associated with other confounding factors.

Qualitative and quantitative evaluation of acute angle-closure mechanisms

BackgroundTo evaluate ocular biometric parameters in different subtypes of acute angle closure and compared to fellow eyes of AAC and PACS eyes.MethodsThis is a retrospective chart review study. A total of 167 eyes (96 patients) consisting of 71 AAC eyes, 71 fellow eyes of AAC, and 25 PACS eyes were recruited. All patients underwent ocular examination and biometry. The mechanism of AAC was confirmed by ultrasound biomicroscopy. We then subdivided AAC eyes into four subgroups: crowded-angle (CR), lens subluxation (LS) pupillary block (PB), and plateau iris syndrome (PL). Outcome variables included anterior chamber depth (ACD), lens thickness (LT), vitreal length (VL), axial length (AL), lens position and relative lens position (LP and RLP, respectively), and lens axial length factor (LAF).ResultsAmong the three groups, ACD was shallower in AAC eyes than fellow eyes of AAC and PACS eyes (p < 0.01 for both) and AAC eyes demonstrated a lesser LP and RLP. The LT, VL, AL, and LAF were not significantly different among the three groups. Among the four subgroups, LS displayed the most shallow ACD (p = 0.01). The lens position in PL was greater than in CR and LS (p < 0.05 and <0.01, respectively).ConclusionsAAC eyes had a more anterior lens position than fellow eyes and PACS eyes, though lens thickness did not differ among the groups. As such, an anterior lens position may offer more sensitive prognostication regarding future development of AAC compared to lens thickness.

Brown–McLean syndrome: the role of iridodonesis

Purpose The aim of this study was to report a case series of Brown–McLean syndrome (BMS). Methods The charts of 28 patients with BMS at Ramathibodi and Rutnin Hospital from 1981 to 2015 were reviewed. Results BMS is a rare condition with corneal edema involving the peripheral cornea with orange-brown pigment deposition underlying the edematous area. The edema typically starts inferiorly and advances circumferentially to superior cornea. Central cornea remains clear in most patients. We report 28 patients with BMS that occurred either spontaneously or after various intraocular procedures. Ultrasound biomicroscopy was performed to demonstrate the iridocorneal relationship. Conclusion Iridocorneal relationship from the ultrasound biomicroscopy study in four patients did not support previous hypothesis about the role of iridodonesis impact on corneal endothelium. Patients with BMS can rarely progress to corneal decompensation; however, they should be periodically monitored and made aware of early clinical signs of their complications.

Ebstein-Barr Virus-Associated Iris Leiomyosarcoma in an AIDS Patient : A Case Report

Importance: Report of an AIDS patient with Ebstein-Barr virus (EBV)-associated iris leiomyosarcoma.Observations: A 19-year-old AIDS patient presented with a painless rapidly growing mass in the right iris. EBVassociated leiomyosarcoma was confirmed by an immunohistochemical study of the excisional biopsy.Conclusion: This is the second case report on immunohistochemically proven EBV-associated iris leiomyosarcoma in AIDS.