Comparative outcomes of trabeculotomy ab externo versus trabecular ablation ab interno for open angle glaucoma

Ab interno removal of malpositioned ex-press glaucoma device combined with bleb needling

PURPOSE

We present an ab interno removal technique combined with a needling procedure for a malpositioned Ex-PRESS glaucoma shunt.

STUDY DESIGN

Retrospective case series.

METHODS

This study examined four cases of malpositioned Ex-PRESS shunts. Needle bleb revision was performed to expand the space under the scleral flap and bleb area. Clinical data, including corneal endothelial cell density (ECD), intraocular pressure (IOP), and anterior segment optical coherence tomography images (AS-OCT), were retrieved from clinical records.

RESULTS

All four cases underwent ab interno shunt removal combined with needle bleb revision without any serious complications. In three cases of anterior shunt malposition, a reduction in ECD was apparent before surgery but remained relatively stable after surgery. In one patient with posterior shunt malposition, shunt occlusion was suspected before surgery, but bleb formation and IOP improved after surgery. IOP was 8 mmHg to 21 mmHg (median, 10.5 mmHg) before surgery and 5 mmHg to 17 mmHg (median, 10 mmHg) 12 months after surgery. No additional glaucoma surgery was required within the first 12 months; however, after 12 months, two patients required additional glaucoma surgery.

CONCLUSION

Ab interno Ex-PRESS device removal combined with bleb needling is an important procedure in patients with malpositioned Ex-PRESS devices.

Historical and Contemporary Debates in Schlemm's Canal-Based MIGS

Glaucoma is one of the primary causes of blindness worldwide. Canal opening surgery, a type of minimally invasive glaucoma surgery (MIGS) applied in cases of mild to moderate glaucoma, has gained increasing popularity in recent years due to its efficacy in reducing the intraocular pressure, its safety profile, the simplicity of its technique, and the reduced likelihood of compromised vision. Nevertheless, the existing body of histopathological studies remains insufficient for a comprehensive understanding of post-surgical wound healing. Consequently, debates persist among researchers regarding the mechanism through which Schlemm's canal opening surgery reduces the intraocular pressure, as well as the surgical techniques that may impact the outcomes and the factors influencing surgical success. As the history of MIGS is relatively short and lacks sufficient systemic reviews or meta-analyses evaluating the influence of individual factors, this review was conducted to illuminate the disparities in researchers' opinions at the current stage of research.

Intrascleral intraocular lens fixation with ab interno trabeculotomy in patients with exfoliation glaucoma with lens subluxation

PURPOSE

To evaluate the surgical outcomes of intrascleral intraocular lens (IOL) fixation using ab interno trabeculotomy (LOT) in patients with exfoliation glaucoma with lens subluxation.

STUDY DESIGN

Retrospective case series.

METHODS

Twenty eyes of 18 patients with exfoliation glaucoma and lens or IOL subluxations were included. Three success criteria were based on postoperative intraocular pressure (IOP) (A, ≤15 mmHg; B, ≤18 mmHg; C, ≤21 mmHg). The IOP, number of glaucoma medications, and visual acuity were compared before and after surgery. Success probability was analyzed using Kaplan-Meier survival curves. Cox proportional hazards' regression models were used to examine prognostic factors for surgical failure.

RESULTS

The mean follow-up period was 23.4 ± 7.8 months. The mean IOP significantly decreased from 23.2 ± 6.8 mmHg preoperatively to 14.0 ± 4.4 mmHg at 1 year postoperative (P<0.001). Postoperative hyphema and vitreous hemorrhage were observed in seven and 15 eyes, respectively, and washout in the anterior chamber or vitreous cavity was performed in four eyes. Postoperative IOP spikes and hypotony were observed in four eyes each. Glaucoma reoperation was performed in two eyes. The success rates at 12 months were 65%, 85%, and 90% using criteria A, B, and C, respectively. The IOP at 1 month after surgery was a significant prognostic factor for surgical failure according to criterion A (hazard ratio: 1.08; P=0.034).

CONCLUSION

Intrascleral IOL fixation combined with microhook LOT is a promising option in cases of exfoliation glaucoma with subluxated lens/IOL; however, the high rate of postoperative hyphema and vitreous hemorrhage should be noted.

[Trabeculotomy (ab externo) as primary intervention for open-angle glaucoma : 5-year results]

BACKGROUND

The published results of trabeculotomy ab externo (TOT), as an outflow channel surgery in adults with open-angle glaucoma, are underrepresented in comparison with other pressure-lowering glaucoma procedures.

OBJECTIVE

To determine the long-term pressure lowering effect and complications of TOT as a stand-alone procedure or in combination with phacoemulsification with intraocular lens implantation (PIT) as a primary pressure-lowering procedure in adult patients with forms of chronic open-angle glaucoma.

METHOD

This was a retrospective analysis of 121 eyes of 106 patients wherby 90 eyes underwent TOT and 31 eyes underwent PIT. The follow-up period was 5 years. Follow-up was performed in the same center under standardized conditions. Preoperative as well as postoperative best-corrected distance visual acuity, intraocular pressure, pressure-lowering medication, and complications were recorded. For success criterion 1, the intraocular pressure was not allowed to exceed 17 mm Hg at any control. For success criterion 2, the intraocular pressure was allowed to be above 17 mm Hg at 1 control throughout the follow-up period.

RESULTS

Preoperative intraocular pressure in the TOT group was 25.92 mm Hg (SD 6.58) and 26.32 mm Hg (SD 6.06) in the PIT group. The annual cumulative success rates with pressure-lowering medications for success criterion 1 were 92.8%, 82.5%, 70.5%, 52.7% and 26.1%. For success criterion 2 these were 97.9%; 94.9%, 93.2%, 91.3%, and 89%. We found no relevant difference in pressure reduction between TOT and PIT. Without pressure-lowering medications, success rates were significantly lower for both success criteria. No serious complications occurred. The most common postoperative complication was spontaneously resorbable hyphema.

CONCLUSION

Performing TOT or PIT as a primary glaucoma procedure for chronic open-angle glaucoma in adults is reasonable, has a significant pressure-lowering effect and very low complication rate.

Characteristics of Eyes Requiring Trabeculotomy for Glaucoma With Steroid Treatment: Atopic Dermatitis and Factors Affecting Surgical Outcomes

PURPOSE

The aim is to analyze the surgical outcomes of glaucomatous patients with steroid treatment and investigate the factors, including atopic dermatitis, associated with the surgical success rate.

MATERIALS AND METHODS

We retrospectively enrolled participants who required first trabeculotomy for glaucoma with steroid treatment between May 2005 and February 2018 and then compared the postoperative outcomes according to the history of atopic dermatitis or surgical procedures. Surgical success was defined as postoperative IOP ≤ 21 mmHg, ≥20% reduction from baseline, and absence of reoperation. The factors influencing the surgical success rates were investigated using mixed-effects Cox regression.

RESULTS

The study included 70 eyes of 46 patients (18 eyes of 12 patients with atopic dermatitis). Postoperative intraocular pressure was not significantly different between eyes with and without atopic dermatitis (12 months after the surgery: patients without atopic dermatitis, 15.4 ± 3.6 mmHg; patients with atopic dermatitis, 16.1 ± 3.9 mmHg; P = 0.65). Twelve months after the surgery, the number of postoperative medications was higher in patients with atopic dermatitis than in those without (2.8 ± 1.3 vs. 2.0 ± 1.7; P = 0.060). However, no significant differences were noted in surgical success rates between patients with atopic dermatitis and those without (P = 0.54). Mixed-effects Cox regression of surgical success rate indicated that only the number of preoperative medications significantly influenced surgical success (P = 0.03).

CONCLUSIONS

Regardless of the presence of atopic dermatitis, patients taking many preoperative glaucomatous medications might require reoperation.

Factors associated with 1-year outcomes and transient intraocular pressure elevation in minimally invasive glaucoma surgery using Kahook Dual Blades

In this retrospective case-control study, we aimed to investigate the mid- to long-term outcomes and factors involved in minimally invasive glaucoma surgery using the Kahook Dual Blade. Of the 229 cases since 2018 in which the dual blades were used for glaucoma surgery at the Tenri Hospital, 133 eyes of 98 patients who followed up for more than 3 months were included. Intraocular pressure (IOP), number of drops score, and need for reoperation were evaluated on day 1 and at 1, 3, 6, 9, and 12 months postoperatively. Intraocular pressure spikes occurred in 25 patients postoperatively (18.8%), occurring at approximately 4.5 days (1-10.25). The preoperative number of eye drops used and ocular axial length were found to be associated with the occurrence of spikes (OR = 1.45, 95% CI 1.02-2.06; P = 0.025 and OR = 1.41, 95% CI 0.98-1.25; P = 0.072, respectively). At the 12-month mark, no significant relationship was found between the presence of spikes or incisional extent scores and the amount of change in IOP and number of drops scores. Patients with severe visual field impairment, high preoperative IOP and drop scores, and long ocular axial length may require more frequent follow-ups after surgery to check for spikes.

Outcomes of standalone ab interno trabeculotomy in the treatment of open-angle glaucoma in eyes with high myopia

BACKGROUND

We retrospectively evaluate the long-term efficacy and safety of trabeculotomy glaucoma surgery in treating open-angle glaucoma (OAG) in eyes with high myopia (HM).

METHODS

This study included 20 eyes with HM (axial length ≥ 26.5 mm) and OAG; age, preoperative IOP (intraocular pressure), and sex-matched 20 non-HM eyes (axial length < 26.5 mm) served as controls. Each eye underwent standalone ab interno trabeculotomy using a Kahook dual blade. A follow-up examination was performed 36 months after surgery. The main outcome measure was the operative success rate (i.e., a ≥ 20% pre- to post-operative reduction in IOP with or without IOP-lowering medication). Kaplan-Meier analysis was employed as a measure of surgical success. The secondary outcome measures were postoperative IOP, the number of glaucoma medications, and postoperative complications.

RESULTS

IOP and the number of glaucoma medications were statistically significantly reduced at all postoperative follow-up examinations. The Kaplan-Meier analysis demonstrated that the probability of postoperative success at 36 months was 45% and 65% for HM and non-HM eyes, respectively. In the HM group, the presence of pathological myopia was statistically significant risk factor for surgical failure. No critical postoperative complications were detected.

CONCLUSIONS

In our study, the long-term efficacy of ab interno trabeculotomy in HM eyes with OAG was inferior to that in non-HM eyes with OAG. Our findings suggest that surgical indications for trabeculotomy in HM should be determined based on the presence of pathological myopia.

Prediction of trabecular meshwork-targeted micro-invasive glaucoma surgery outcomes using anterior segment OCT angiography

We performed a prospective, longitudinal study to investigate the association between the preoperative intrascleral vasculature assessed using anterior segment (AS)-optical coherence tomography angiography (OCTA) and surgical outcomes of trabecular meshwork-targeted micro- or minimally invasive glaucoma surgery (MIGS). We included 37 patients with primary open-angle glaucoma. Preoperative AS-OCTA images of the sclero-conjunctiva of the nasal corneal limbus were acquired in the superficial (conjunctival) and deep (intrascleral) layers. The vessel densities (VDs) of each layer were measured separately in the entire area, limbal side, and fornix area. Surgical success was determined by postoperative intraocular pressure (IOP) and IOP reduction. Twenty-three and 14 eyes were classified as having successful and unsuccessful outcomes, respectively. The deep VDs of the entire area and fornix area were significantly lower in the successful group (P = 0.031 and P = 0.009). The success rate was significantly higher for eyes with a lower deep VD than for eyes with a higher deep VD. A greater IOP reduction was significantly associated with lower deep VD in the fornix area (P = 0.022) and higher preoperative IOP (P < 0.001). These results indicate that intrascleral vasculature assessed using preoperative AS-OCTA was negatively correlated with surgical success and IOP reduction resulting from trabecular meshwork-targeted MIGS. AS-OCTA images might help predict MIGS outcomes.

Comparison of effectiveness and complications in trabeculotomy with phacoemulsification between ab externo and ab interno using a spatula-shaped microhook

To compare the short-term surgical effectiveness and safety profile of trabeculotomy ab externo and ab interno with microhook in terms of the recovery of visual acuity. A retrospective chart review was performed on patients who underwent trabeculotomy combined with phacoemulsification and lens implantation at Asahi General Hospital, with 6 months of follow-up. The patients treated by trabeculotomy were classified into two groups depending on the surgical procedures: ab interno with Tanito microhook (TMH) and ab externo with rigid probe trabeculotome (LOT). The demographics, preoperative and postoperative intraocular pressure (IOP), number of medications (Med), best-corrected visual acuity (BCVA), surgical-induced astigmatism (SIA), and postoperative complications were analyzed at pre-operation, and 1 week and 1–6 months post-operation. Fifty-two eyes of 38 Japanese patients underwent TMH and 42 eyes of 32 patients underwent LOT. The decreases in IOP and Med from the baseline were significant at all time points in both groups (p < 0.001), but there were no significant differences between the two groups. BCVA improved significantly in TMH and LOT after the operation (p < 0.001). BCVA and SIA significantly improved, mostly at 1 week in TMH, compared with LOT (p = 0.02 and 0.003). Hyphema and IOP spike exceeding 30 mmHg (spike) occurred in 11% and 6% of participants in TMH, and 33% and 26% of participants in LOT, respectively. Hyphema and IOP spike occurred more frequently in the LOT than in the TMH group (p = 0.01 and 0.005). Ab interno trabeculotomy showed similar IOP-lowering effects as ab externo, but had less postoperative complications.

Comparison of Surgical Outcomes Between Ab Interno Suture Trabeculotomy and Ab Externo Metal Trabeculotomy in Adult Patients with Glaucoma

Purpose

To compare the outcomes of ab interno suture trabeculotomy (AbI-TLO) and ab externo metal trabeculotomy (AbE-TLO) in adult patients with glaucoma aged over 40 years.

Patients and Methods

A retrospective chart review was conducted, including adult patients with glaucoma who underwent AbI-TLO or AbE-TLO between January 2015 and June 2019. A single surgeon (YO) performed all the operations. Eighty-one patients (81 eyes) were included in this study. Surgical success was defined as a postoperative intraocular pressure (IOP) of ≤18 mmHg and an IOP reduction of ≥20% from the preoperative IOP, without requiring additional glaucoma surgery. Success rates were assessed using Kaplan-Meier survival curves and log-rank (Mantel-Cox) tests, while risk factors were analyzed using the Cox proportional hazards model.

Results

Forty-nine patients who underwent AbI-TLO and 32 patients who underwent AbE-TLO were studied; the preoperative IOPs were 27.9 ± 7.3 (mean ± standard deviation) mmHg and 25.6 ± 8.1 mmHg in the AbI-TLO and AbE-TLO groups, respectively (p=0.217). The 12-month postoperative IOPs were 15.8 ± 4.0 mmHg and 16.3 ± 4.2 mmHg in the AbI-TLO and AbE-TLO groups, respectively (p=0.724). The surgical success rates at 12 months were 77.6% and 62.5% in the AbI-TLO and AbE-TLO groups, respectively (p=0.144). Postoperative hyphema with level formation and ocular hypertension over 30 mmHg were observed in 22.4% and 26.5% of patients in the AbI-TLO group and 18.8% and 12.5% of those in the AbE-TLO group, respectively. Stepwise multivariate Cox regression analysis showed that a longer axial length was a risk factor for surgical failure (hazard ratio: 2.030; p=0.042).

Conclusion

AbI-TLO and AbE-TLO had similar surgical outcomes and postoperative complications. A longer axial length was associated with an insufficient IOP reduction.

Minimally Invasive Glaucoma Surgery: A Critical Appraisal of the Literature

Micro- or minimally invasive glaucoma surgeries (MIGS) have been the latest addition to the glaucoma surgical treatment paradigm. This term refers not to a single surgery, but rather to a group of distinct procedures and devices that aim to decrease intraocular pressure. Broadly, MIGS can be categorized into surgeries that increase the trabecular outflow [Trabectome, iStent (first and second generations), Hydrus microstent, Kahook Dual Blade and gonioscopy-assisted transluminal trabeculotomy], surgeries that increase suprachoroidal outflow (Cypass microstent and iStent Supra), and conjunctival bleb-forming procedures (Xen gel stent and InnFocus microshunt). Compared to traditional glaucoma surgeries, such as trabeculectomy and glaucoma drainage device implantation (Ahmed, Baerveldt, and Molteno valves), MIGS are touted to have less severe complications and shorter surgical time. MIGS represent an evolving field, and the efficacy and complications of each procedure should be considered independently, giving more importance to high-quality and longer-term studies.

Factors associated with achieving intraocular pressure lower than 15 mmHg by Trabectome surgery in primary open-angle glaucoma

To assess good prognostic factors of Trabectome surgery in primary open-angle glaucoma (POAG), clinical records of patients with POAG who underwent Trabectome surgery with/without cataract surgery as the first additive therapy to eye drops between January 2015 and March 2018 were retrospectively reviewed. Overall, data of 79 eyes (79 patients; 50 men; mean age, 68.0 years) up to postoperative 24 months were analyzed. Their mean intraocular pressure (IOP) was 20.4 ± 6.0 mmHg at baseline. Forty-two eyes (53.2%) achieved an IOP < 15 mmHg and ≥ 20% reduction from baseline without additional treatments. Phakic eyes had a better survival probability than pseudophakic eyes after adjusting for age, sex, baseline IOP, best-corrected visual acuity, and eye drop score (hazard ratio 3.096; 95% confidence interval [95% CI] 1.367–7.013; P = 0.007). Phakic eyes treated with combined Trabectome and cataract surgeries (mean survival time, 22.250 months; 95% CI 17.606–26.894) had a better survival probability than pseudophakic eyes treated with Trabectome surgery only (mean survival time, 12.111 months; 95% CI 8.716–15.506; P = 0.009) after the adjustment. Among the eyes treated with Trabectome surgery only, phakic eyes required significantly less additional treatments than pseudophakic eyes (P = 0.04). Trabectome surgery may be indicated for phakic eyes with POAG in addition to eye-drop therapy.

Viscotrabeculotomy versus trabeculectomy in the surgical treatment of open angle glaucoma: a single center, randomised controlled trial

PURPOSE

The aim of the study was to compare the effect of viscotrabeculotomy and the effect of trabeculectomy on the intraocular pressure (IOP) in cases of open angle glaucoma (OAG).

STUDY DESIGN

Prospective comparative study.

PATIENTS AND METHODS

The study was conducted on 148 eyes of 148 patients (87 men) presenting with and operated upon for OAG at Mansoura Ophthalmic center of Mansoura University in Mansoura, Egypt from 2012 to 2016. Patients were randomized into viscotrabeculotomy and trabeculectomy groups. Postoperative follow up visits were scheduled at weeks 1 and 2 then months 1, 2, 3, 6, 9, 12, 15, 18, 21 and 24. Complications were noted and managed according to needs. The primary outcome measure was IOP.

RESULTS

The study was conducted on 148 eyes (74 right) of 148 patients (87 men). The mean ± SD (range, median) age of the study patients was 50.1 ± 11.5 (20-67, 53) and 51.1 ± 10.0 (27-65, 54.5) years respectively. The mean ± SD (range, median) IOP of the study eyes on maximal tolerated IOP lowering therapy was 23.15 ± 2.31 (19-30, 23.0) and 23.64 ± 1.87 (20-28, 23.0) mmHg respectively and at the end of the 24 months of follow up was 14.91 ± 2.4 (12-23, 14) and 16.64 ± 2.8 (14-25, 16) mmHg respectively (p =  < 0.0005). Notable complications included a mild hyphema in the viscotrabeculotomy group and an IOP spike in the trabeculectomy group.

CONCLUSIONS

Viscotrabeculotomy and trabeculectomy showed efficacy and safety in OAG patients. The former resulted in better IOP reduction.

Turn Back Elevation of Once Reduced IOP After Trabeculotomy Ab Externo and Kahook Dual Blade Surgeries Combined with Cataract Surgery

Purpose

To evaluate the surgical outcome of internal trabeculectomy by Kahook dual blade (KDB) with that of external trabeculotomy, each combined with phaco-lensectomy and intraocular lens implantation (Phaco).

Patients and Methods

This is a retrospective comparative study. The primary and secondary outcome measures are postsurgical intraocular pressure and postsurgical hyphema. One eye each of 76 primary open angle glaucoma (POAG), pseudoexfoliation glaucoma (PEG) and ocular hypertension (OH) patients underwent external phaco-trabeculotomy, and that of 40 POAG, PEG and OH patients underwent phaco-KDB surgery.

Results

Reduction of the intraocular pressure (IOP) by phaco-KDB at one and two years was 28.4 and 27.8%, respectively, and was not significantly different from that by external phaco-trabeculotomy of 32.7% (P=0.256) and 31.5% (P=0.468), respectively. Three months postsurgical IOP after phaco-KDB and external phaco-trabeculotomy was 16.1 and 15.9 mmHg, respectively. There was a significant turn back elevation of once reduced IOP to 17.1 (P=0.0207) and 17.0 mmHg (P=0.0096) at 24 months, respectively. There were no differences in success probability to achieve IOP below 17 mmHg (P=0.120), 21 mmHg (P=0.719) and >20% IOP reduction (P=0.309) with medication(s) at two years between the phaco-KDB and external phaco-trabeculotomy cohorts. Younger age was a significant (P<0.001) risk factor for failure; however, presurgical IOP (P=0.466), the type of surgery (P=0.219) and presence of postsurgical IOP spike (P=0.737) were not significant risk factors by the Cox proportional hazard model. Hyphema and spike of the IOP in phaco-KDB and external phaco-trabeculotomy cohorts were 40% and 88% (P<0.001), and 53% and 41% (P=0.238), respectively.

Conclusion

The IOP reduction by the phaco-KDB was equivalent to that by external phaco-trabeculotomy up to two years. In both cohorts, once reduced postsurgical IOP tend to increase up to 24 months.

Comparison of the short-term effectiveness and safety profile of ab interno combined trabeculotomy using 2 types of trabecular hooks

PURPOSE

To compare the short-term surgical effectiveness and safety profile of ab interno trabeculotomy using 2 types of trabecular hooks.

STUDY DESIGN

Retrospective comparative study.

PATIENTS AND METHODS

A retrospective chart review was performed on Japanese open-angle glaucoma patients who underwent ab interno trabeculotomy with phacoemulsification and who had a 6-month follow-up. Trabeculotomy was performed using 2 kinds of trabecular hooks, the Tanito ab interno Trabeculotomy Micro-hook (TMH) or the Kahook Dual Blade (KDB). The patients' demographics, preoperative and postoperative intraocular pressures (IOPs), medication scores, and occurrence of complications were analyzed and compared.

RESULTS

Fifty-nine eyes with open-angle glaucoma were included in the final analysis. Trabeculotomy was performed using the TMH in 30 eyes (50.8%) and the KDB in 29 eyes (49.2%). Significant decreases in IOP from the baseline (P < 0.001, except for the 1-month time-point in the KDB group, when P < 0.01) after the 1-month time-point and the medication scores (P < 0.001) at all time-points were noted in both groups. However, the percentage changes in the IOP and medication scores from the baseline at each time-point did not differ significantly between the 2 groups, with the exception of the medication score at the 1-month time-point (P < 0.0283). The occurrence of postoperative complications was similar in the 2 groups.

CONCLUSIONS

The present study demonstrates the absence of significant differences in IOP and medication score reductions at almost all time-points between the TMH and KDB groups.

A comparison of the 1-year surgical outcomes of ab externo trabeculotomy and microhook ab interno trabeculotomy using propensity score analysis

Objective

To compare the 1-year outcomes of trabeculotomy ab externo (ab externo TLO) and trabeculotomy ab interno using a microhook (ab interno TLO) for glaucoma patients using propensity score analysis.

Methods and analysis

The medical charts of 65 consecutive patients who underwent ab externo TLO and those of 69 patients who underwent ab interno TLO were reviewed. Logistic regression analysis was conducted to calculate the propensity score using 1:1 matched analysis, which indicates the likelihood of surgical success at 12 months. We set the outcome-related covariates as age, glaucoma type, mean deviation, preoperative intraocular pressure (IOP), the number of preoperative glaucoma eye drops and the presence or absence of combined cataract surgery. Fifty eyes per each surgery group were subsequently compared.

Results

The mean preoperative IOP was 32.5±11.2 mm Hg in the ab externo TLO group and 28.4±7.8 mm Hg in the ab interno TLO group (p=0.08). The mean postoperative IOP at 12 months was 18.3±7.4 mm Hg in the former group and 17.8±6.3 mm Hg in the latter (p=0.91). When surgical success was defined as a postoperative IOP of between 5 and 21 mm Hg with a more than 20% IOP reduction from baseline and no additional glaucoma surgery, the rate at 12 months was 78% in the ab externo TLO group and 74% in the ab interno TLO group (p=1.00).

Conclusion

The 1-year success rate was not significantly different between ab externo and ab interno TLO.

Prospective Studies of Minimally Invasive Glaucoma Surgeries: Systematic Review and Quality Assessment

Glaucoma is a common blinding disease; while there is no cure, effective treatments include medications, laser, and incisional surgery. There is significant interest from patients and doctors to develop safer surgical options throughout the spectrum of disease, to minimize treatment burden in mild glaucoma patients and to minimize risk of complications in patients needing more aggressive treatment. Surgical procedures called Minimally or Micro-Invasive Glaucoma Surgery (MIGS) are growing in popularity. Eighty-seven prospective studies on MIGS were identified and assessed for quality. Most (74%) did not have a control group. Twelve of the highest quality were reviewed. MIGS procedures appeared to have fewer complications, and lowered intraocular pressure, and reduced medication use. Studies were limited by small sample size, narrow spectrum of glaucomatous disease, and/or conflicts of interest. There is a need for high quality, independently funded and performed, comparative studies on the MIGS to help make treatment decisions.

Pilot study assessing the structural changes in posttrabecular aqueous humor outflow pathway after trabecular meshwork surgery using swept-source optical coherence tomography

This study evaluated the morphological change in aqueous humor outflow (AHO) pathways using swept-source optical coherence tomography (SS-OCT) volumetric scans in glaucoma patients before and after glaucoma surgery. In this prospective observational case series, 15 eyes (13 patients) with glaucoma were treated with 120-degree Trabectome or 360-degree suture trabeculotomy and followed up for 3 months. B-scan images of the posttrabecular AHO pathway were reconstructed and the pathway areas were evaluated, before and after surgery. Changes in posttrabecular AHO pathway were qualitatively classified as “increased”, “non-significant change”, and “decreased” on reconstructed B-scan images. Quantitative measurements of the posttrabecular AHO pathway areas were performed pre- and postoperatively. Factors associated with both qualitative and quantitative changes in AHO pathway were investigated. From 30 regions (15 nasal and 15 temporal regions) in the 15 eyes, AHO pathways were analyzable in 20 regions pre- and postoperatively. Qualitative assessments of the pathway changes were “increased” in 8 regions, “non-significant change” in 9 regions, and “decreased” in 3 regions. Quantitative assessments of the average pathway area did not change significantly (from 3155±1633 pixels preoperatively to 3212±1684 pixels postoperatively, P = 0.50). All parameters relating to intraocular pressure changes or the surgical location were not associated with postoperative AHO pathway change. The intrascleral AHO pathway could be well visualized in glaucoma patients pre- and postoperatively using swept-source optical coherence tomography. However, structural changes in the AHO pathway assessed by SS-OCT were not significant after trabecular-targeted glaucoma surgery. Functional assessments of AHO are needed in future studies.