Safety and Efficacy of Microinvasive Glaucoma Surgery

Microinvasive glaucoma surgery (MIGS) is emerging as a new therapeutic option for glaucoma patients who wish to reduce their medication burden and avoid the postoperative complications of conventional glaucoma filtration surgery. These devices differ in terms of their efficacy and safety profile. Schlemm’s canal devices have the most favorable safety profile at the compromise of modest efficacy, while subconjunctival and suprachoroidal devices are potentially more effective at lowering the intraocular pressure at the expense of a higher rate of complications. This review consolidates the latest evidence on the efficacy and safety of the MIGS devices in clinical use and provides an overview on upcoming devices which would likely also become viable treatment options in the near future. These clinical data would assist a glaucoma surgeon in selecting the most appropriate MIGS device for each patient based on the glaucoma severity and patient expectations

Complications and outcomes of primary phacotrabeculectomy with mitomycin C in a multi-ethnic asian population.

PURPOSE:To determine the occurrence of intraoperative and postoperative complications up to three years after primary phacotrabeculectomy with intraoperative use of Mitomycin C (MMC) in primary open angle (POAG) and primary angle closure glaucoma (PACG) patients, and the effect of postoperative complications on surgical outcome. METHODS:Retrospective review of 160 consecutive patients with POAG (n = 105) and PACG (n = 55), who underwent primary phacotrabeculectomy with MMC at the National University Hospital, Singapore, from January 1, 2008 to December 31, 2010. Data was collected using a standardized form that included patient demographic information, ocular characteristics and postoperative complications, including hypotony (defined as intraocular pressure < 6 mmHg), shallow anterior chamber (AC) and hyphema. RESULTS:The mean age ± standard deviation (SD) of patients was 68.2 ± 8.2 years. No patient lost light perception during duration of follow-up. 77% of the postoperative complications occurred within the first month only. The commonest complications were hypotony (n = 41, 25.6%), hyphema (n = 16, 10.0%) and shallow AC (n = 16, 10.0%). Five patients (3.1%) required reoperation for their complications. Early hypotony (defined as hypotony < 30 days postoperatively) was an independent risk factor for surgical failure (hazard ratio [HR], 5.1; 95% CI, 1.6-16.2; p = 0.01). Hypotony with another complication was also a risk factor for surgical failure (p < 0.02). CONCLUSIONS:Hypotony, hyphema and shallow AC were the commonest postoperative complications in POAG and PACG patients after phacotrabeculectomy with MMC. Most complications were transient and self-limiting. Early hypotony within the first month was a significant risk factor for surgical failure

Anterior segment optical coherence tomography angiography following trabecular bypass minimally invasive glaucoma surgery

To assess anterior segment optical coherence tomography angiography (AS-OCTA) imaging of the episcleral vessels before and after trabecular bypass minimally invasive glaucoma surgery (MIGS).Published versionThis work was supported by Singapore Imaging Eye Network (SIENA), project no. NMRC/CG/C010A/2017_SERI and SERINTU Advanced Ocular Engineering (STANCE) Program

Summary of all postoperative complications up to and including 3 years after surgery.

<p>AC = anterior chamber; early = less than or equal to one month from operation; early and late = occurring at least once in each; late = more than one month from operation; PVD = posterior vitreous detachment.</p><p>*Data presented as number (percentage).</p><p>Summary of all postoperative complications up to and including 3 years after surgery.</p

Logistic regression analysis of the risk factors for hypotony, hyphema and shallow anterior chamber^*.

<p>AC = anterior chamber; CI = confidence interval; IOP = intraocular pressure; OR = odds ratio; PACG = primary angle closure glaucoma; POAG = primary open angle glaucoma; preop = preoperative.</p><p>*Hypotony, hyphema and shallow AC were the top three commonest complications (in descending order).</p><p>^†Other Asians excluding Chinese, Malays and Indians.</p><p>Logistic regression analysis of the risk factors for hypotony, hyphema and shallow anterior chamber^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118852#t003fn002" target="_blank">*</a>}.</p

Baseline characteristics of patients with primary open angle glaucoma and primary angle closure glaucoma.

<p>CDR = cup-disc ratio; IOP = intraocular pressure; IQR = interquartile range; LogMAR = logarithm of the minimum angle of resolution; PACG = primary angle closure glaucoma; POAG = primary open angle glaucoma; SD = standard deviation.</p><p>*Data presented as mean (standard deviation) or number (percentage), unless otherwise specified.</p><p>^†Data presented as median (interquartile range).</p><p>^‡p-values were calculated using chi-square test, independent t-test or Mann-Whitney U test as appropriate.</p><p>^§p-value for race was calculated using Chinese and non-Chinese as categorical variables (chi-square test).</p><p>Baseline characteristics of patients with primary open angle glaucoma and primary angle closure glaucoma.</p

Glaucoma in myopia:diagnostic dilemmas

Myopic eyes have an increased risk of glaucoma. However, glaucomatous changes in a myopic eye are often difficult to detect. Classic structural and functional investigations to diagnose glaucoma may be confounded by myopia. Here, we identify some of the common pitfalls in interpreting these structural parameters, and the possible solutions that could be taken to overcome them. For instance, in myopic eyes, we discuss the limitations and potential sources of error when using neuroretinal rim parameters, and retinal nerve fibre layer and ganglion cell-inner plexiform layer thickness measurements. In addition, we also review new developments and potential adjuncts in structural imaging such as the assessment of the retinal nerve fibre layer texture, and the examination of the microcirculation of the optic nerve head using optical coherence tomography angiography. For the functional assessment of glaucoma, we discuss perimetric strategies that may aid in detecting characteristic visual field defects in myopic glaucoma. Ultimately, the evaluation of glaucoma in myopia requires a multimodal approach, to allow correlation between structural and functional assessments. This review provides overview on how to navigate this diagnostic dilemma

Combining OCT and OCTA for focal structure-function modeling in early primary open-angle glaucoma

PURPOSE. To investigate modeling of the focal visual field (VF) loss by combining structural measurements and vascular measurements in eyes with early primary open-angle glaucoma (POAG). METHODS. In this cross-sectional study, subjects with early glaucoma (VF mean deviation, ≥−6 dB) underwent optical coherence tomography (OCT) imaging, optical coherence tomography angiography (OCTA) imaging, and Humphrey 24-2 VF tests. Capillary perfusion densities (CPDs) were calculated after the removal of large vessels in the OCTA images. Focal associations between VF losses at the individual VF test locations, circumpapillary retinal nerve fiber layer (RNFL) thickness measurements from OCT, and CPDs were determined using nerve fiber trajectory tracings. Linear mixed models were used to model focal VF losses at each VF test location. RESULTS. Ninety-seven eyes with early POAG (VF mean deviation, −2.47 ± 1.64 dB) of 71 subjects were included. Focal VF modeling using a combined RNFL-CPD approach resulted in a median adjusted R2 value of 0.30 (interquartile range [IQR], 0.13-0.55), whereas the RNFL-only and CPD-only approaches resulted in median values of 0.22 (IQR, 0.10-0.51) and 0.26 (IQR, 0.10-0.52), respectively. Seventeen VF locations with the combined approach had an adjusted R2 value greater than 0.50. Likelihood testing at each VF test location showed that the combined approach performed significantly better at the superior nasal VF regions of the eyes compared with the univariate approaches. CONCLUSIONS. Modeling of focal VF losses showed improvements when structural thickness and vascular parameters were included in tandem. Evaluation of VF defects in early glaucoma may benefit from considering both RNFL and OCTA characteristics.Agency for Science, Technology and Research (A*STAR)Nanyang Technological UniversityNational Medical Research Council (NMRC)National Research Foundation (NRF)Published versionSupported by grants from the National Medical Research Council (CG/C010A/2017_SERI, OFIRG/0048/2017, OFLCG/004c /2018, TA/MOH-000249-00/2018, and MOH-OFIRG20nov0014); National Research Foundation Singapore (NRF2019- THE002-0006 and NRF-CRP24-2020-0001); A*STAR (A20H4- b0141); the Singapore Eye Research Institute & Nanyang Technological University (SERI-NTU Advanced Ocular Engineering [STANCE] Program); the Duke-NUS Medical School (Duke-NUS-KP(Coll)/2018/0009A); and the SERI-Lee Foundation (LF1019-1)

Investigating the macular choriocapillaris in early primary open-angle glaucoma using swept-source optical coherence tomography angiography

Introduction: There has been a growing interest in the role of vascular factors in glaucoma. Studies have looked at the characteristics of macular choriocapillaris in patients with glaucoma but with conflicting results. Our study aims to use swept-source optical coherence tomography angiography (SS-OCTA) to evaluate macular choriocapillaris metrics in normal participants and compare them with patients with early primary open-angle glaucoma (POAG) (mean deviation better than −6dB). Methods: In this prospective, observational, cross-sectional study, 104 normal controls (157 eyes) and 100 patients with POAG (144 eyes) underwent 3 mm × 3mm imaging of the macula using the Plex Elite 9000 (Zeiss Meditec, Dublin, CA, USA). Choriocapillaris OCTA images were extracted from the device’s built-in review software and were subsequently evaluated for the density and size of choriocapillaris flow deficits. Results: After adjusting for confounding factors, the density of flow deficits was independently higher in those aged 53 years and above (P ≤ 0.024) whereas the average flow deficit size was significantly larger in those aged 69 years and above (95% CI = 12.39 to 72.91; P = 0.006) in both normal and POAG patients. There were no significant differences in the density of flow deficits (P = 0.453) and average flow deficit size (P = 0.637) between normal and POAG participants. Conclusion: Our study found that macular choriocapillaris microvasculature on SS-OCTA is unaltered by subjects with POAG. This suggests that OCTA macular choriocapillaris may not be potentially helpful in differentiating early glaucoma from healthy eyes.Agency for Science, Technology and Research (A*STAR)Nanyang Technological UniversityNational Medical Research Council (NMRC)National Research Foundation (NRF)Published versionThis work was funded by grants from the National Medical Research Council (CG/C010A/2017_SERI; OFLCG/004c/2018- 00; MOH-000249-00; MOH-000647-00; MOH-001001-00; MOH-001015-00; MOH-000500-00; and MOH-000707-00), National Research Foundation Singapore (NRF2019- THE002-0006 and NRF-CRP24-2020-0001), A∗ STAR (A20H4b0141), Singapore Eye Research Institute, Nanyang Technological University [SERI-NTU Advanced Ocular Engineering (STANCE) Program], and SERI-Lee Foundation (LF1019-1) Singapore