Purpose: We hypothesized that a recently introduced epibulbar micro-shunt (PRESERFLO, P) produces nycthemeral (24h) intraocular pressure (IOP) profiles different from ab-interno trabeculectomy (Trabectome, T). P is a flow restrictor that drains fluid into the sub-tenon space. In contrast, T increases conventional outflow, which is limited by episcleral venous pressure. Methods: In this prospective cohort, we analyzed 68 patients (34 P and 34 T) who presented for 24-h IOP monitoring 6 to 12 months after surgery. IOP and tonographic outflow facility were measured in the habitual position using a pneumatonometer. The IOP variation was considered the primary outcome measure. Glaucoma medications were also compared. Results: P had a higher baseline IOP than T (24.8±10.0 vs. 17.3±7.9 mmHg, p=0.001). Postoperatively, P and T had similar nycthemeral IOP profiles, but IOP in P was significantly lower than in T, except at 4 pm. P had a lower absolute IOP variation than T (5.8±2.6 vs. 7.1±2.7 mmHg, p=0.049). The relative IOP variation was similar in both (34.8±13.2 vs. 37.2±13.1, p=0.45) as was the tonographic outflow facility (0.35±0.23 vs. 0.26±0.18 µl/min/mmHg, p=0.097). Conclusion: Nycthemeral IOP profiles of P and T were similar, but P had lower IOPs and less variation than T. This could reflect how T, unlike P, is more impacted by habitual, positional factors, especially at night.

Purpose: To compare ab interno trabeculectomy by trabecular meshwork excision to plasma-mediated ablation in primary open-angle glaucoma. Methods: Retrospectively collected data of TrabEx+ (TEx, n=56) and Trabectome (T, n=99) were compared by coarsened exact matching to reduce confounding and matched based on baseline IOP and age. Primary outcomes were IOP and number of glaucoma medications. Complications and need for additional glaucoma surgery were assessed. Patients were followed for up to one year. Results: 53 TEx could be matched to T. Baseline IOP was 16.5±4.6 mmHg in both; age was 73.7±8.8 and 71.5±9.9 years in TEx and T, respectively. TEx were taking more medications than T (p<0.001). IOP was reduced to 14.8±4.3 in TEx and to 13.4±3.4 in T at 6 months, and to 14.9±6.0 (p=0.13) in TEx and to 14.1±3.8 mmHg (all p<0.05) in T at 12 months. Medications were reduced at both 6 and 12 months (p< 0.05). No differences were seen between TEx and T at 6 and 12 months. In TEx, only one serious complication occurred, and two patients required further glaucoma surgery. Conclusion: Although both groups had a baseline IOP considered low for ab-interno trabeculectomy, IOP and medications were reduced further at 6 and 12 months. IOP reduction did not reach significance in TEx at 12 months. The inter-group comparison did not reveal any significant differences. Both had a low complication rate.

Purpose: To create a highly balanced comparison of ab interno trabeculectomy (Trabectome, AIT) and trabecular bypass stenting (iStent, TBS).Setting: Eye and Ear Institute, Pittsburgh, Ross Eye Institute, Buffalo, and Glaucoma Associates of Texas, Dallas, USA.Design: Retrospective Exact Matching analysis.Methods: AIT and TBS patients were included from three large glaucoma practices. The primary outcome measure was the unmedicated IOP ≤ 21 mmHg at 2-year follow-up visit. A secondary measure was unmedicated IOP reduction ≥ 20% at 2 years. Patients were matched by baseline IOP, the number of glaucoma medications and glaucoma type using Exact Matching and by age using Nearest Neighbor matching. Patients without a close match were excluded. All surgeries were combined with phacoemulsification. Results: 154 AIT and 110 TBS eyes were analyzed. 48 AIT patients were exactly matched to 48 TBS patients. Both groups had a baseline IOP of 15.3±3.1 mmHg. At 24 months, the mean IOP was 13.9±3.3 for AIT versus 16.8±2.8 mmHg for TBS (p=0.04), while the number of medications was 0.7±1.0 for AIT versus 1.7±1.2 for TBS (p=0.04). The proportion of subjects achieving IOP ≤ 21 mmHg without medications at 24 months was 53% in AIT versus 16.6% in TBS (P < 0.05). At 24-month follow up 17.6% of patients in AIT had ≥ 20% IOP reduction without medication versus no patient in TBS. Conclusions: An Exact Matching comparison of AIT and TBS demonstrated greater IOP reduction with fewer medications in AIT.

Purpose: To evaluate the efficacy and survival rates of same session ab interno trabeculectomy with the trabectome and Ahmed glaucoma valve implant (AT) in comparison to the Ahmed glaucoma valve alone (A). Method: A total of 107 eyes undergoing primary glaucoma surgery were enrolled in this retrospective comparative case series, including 48 eyes which underwent AT and 59 eyes which received A alone. Participants were identified using the procedural terminology codes, and their medical records were reviewed. The primary outcome measure was surgical success, defined as intraocular pressure (IOP) > 5 mmHg, ≤ 21 mmHg, and IOP reduction ≥ 20% from baseline at two consecutive visits after three months, no reoperation for glaucoma. Secondary outcome measures were IOP, the number of glaucoma medications, incidence of a hypertensive phase, and best corrected visual acuity (BCVA). Results: The cumulative probability of success at one year was 70% in AT, and 65% in A (p=0.85). IOP decreased significantly from 26.6 ± 10.1 mmHg at baseline to 14.7 ± 3.3 mmHg at the final follow-up in AT (p= 0.001). The corresponding numbers for A were 28.8 ± 10.2 and 16.7 ± 4.9, respectively (p= 0.001). The final IOP was significantly lower in AT (p= 0.022). The number of medications at baseline was comparable in both groups (2.6 ± 1.2 in AT and 2.5 ± 1.3 in A, p=0.851). Corresponding number at 1 year visit was 1.2±2 in AT and 2.8±1.8 in A (p=0.001). The incidence of a hypertensive phase was 18.7% in AT and 35.5% in A (p=0.05). HP resolved in only 30% of eyes. The criteria for HP resolution were fulfilled in 9 eyes (30%). There was no difference in the rate of resolution of the hypertensive phase between AT and A (33.3% and 28.5%, respectively, p=0.67). Conclusion: Ahmed glaucoma valve implant with same session trabectome surgery significantly decreased the rate of the hypertensive phase and postoperative IOP as well as the number of glaucoma medications.

Purpose: To analyze the five-year results of Trabectome ab interno trabeculectomy of a single glaucoma center. Method: In this retrospective interventional single-center case series, data of 93 patients undergoing ab interno trabeculotomy between September 2010, and December 2012 were included. Kaplan-Meier analysis was performed using success criteria defined as postoperative intraocular pressure (IOP) ≤21 mm Hg, or >20% reduction from preoperative IOP, and no need for further glaucoma surgery. Risk factors for failure were identified using Cox proportional hazards ratio (HR). Results: The retention rate for five years follow-up was 66%. The cumulative probability of success at 1, 2, 3, 4 and 5 years was 82.6%, 76.7%, 73.9%, 72.3%, and 67.5%. Risk factors for failure were lower baseline IOP (HR=0.27, P=0.001), younger age (HR=0.25, P=0.02), and higher central corneal thickness (HR=0.18, P= 0.01). Pseudoexfoliation was associated with a higher success rate (HR= 0.39, P=0.02). IOP was decreased significantly from 20.0±5.6 mmHg at baseline to 15.6±4.6 mmHg at 5-year follow-up (P=0.001). The baseline number of glaucoma medications was 1.8±1.2, which decreased to 1.0±1.2 medications at 5 years. Conclusion: Trabectome surgery was associated with a good long-term efficacy and safety profile in this single-center case series with a high retention rate. A higher baseline IOP, older age, thinner cornea, and pseudoexfoliation glaucoma were associated with a higher success rate.

Purpose: To evaluate the efficacy and survival rates of trabectome-mediated ab interno trabeculectomy combined with non-fenestrated Baerveldt glaucoma implants (BT) in comparison to Baerveldt glaucoma implant alone (B).Method: A total of 175 eyes undergoing primary glaucoma surgery (60 eyes BT and 115 B) were enrolled in this retrospective comparative case series. Participants were identified using the procedural terminology codes. Groups were then matched using Coarsened Exact Matching (51 eyes in each group). The primary outcome measure was surgical success, defined as 5 mmHg < IOP ≤ 21 mmHg, and IOP reduction ≥ 20% from baseline, and no reoperation for glaucoma. Secondary outcome measures were intraocular pressure, the number of glaucoma medications, and best corrected visual acuity (BCVA).Results: The cumulative probability of success at one year was 61% in BT, and 50% in B. IOP decreased significantly from 23.5±2.4 mmHg at baseline to 14.1±2.7 mmHg at the final follow up in BT (P= 0.001). The corresponding numbers for B were 23.2± 2.0 and 13.9± 1.6, respectively (P= 0.001). There was no significant difference in IOP at the final follow-up (P=0.56). The number of medications at baseline was 2.3±0.3 in both groups. However, BT needed significantly fewer drops at all postoperative time intervals and used 1.1±0.3 (BT) and 2.0±0.4 eye drops (B) at the final follow-up visit (P= 0.004). No dangerous hypotony or hypertension occurred in BT.Conclusion: Similar rates of success and IOP reduction were observed in BT and B. BT needed significantly fewer glaucoma medications. Tube fenestration was not necessary in BT resulting in less postoperative hypotony and hypertension.

Objective: To evaluate three different microincisional ab interno trabeculectomy procedures in a porcine eye perfusion model. Methods: In perfused porcine anterior segments, 90 degrees of trabecular meshwork (TM) were ablated using the Trabectome (T; n = 8), Goniotome (G; n = 8), or Kahook device (K; n = 8). After 24 hours, additional 90 degrees of TM were removed. Intraocular pressure (IOP) and outflow facility were measured at 5 µL/min and 10 µL/min perfusion to simulate an elevated IOP. Structure and function were assessed with canalograms and histology. Results: At 5 µL/min infusion rate, T resulted in a greater IOP reduction than G or K from baseline (76.12% decrease versus 48.19% and 47.96%, P = 0.013). IOP reduction between G and K was similar (P = 0.420). Removing another 90 degrees of TM caused an additional IOP reduction only in T and G but not in K. Similarly, T resulted in the largest increase in outflow facility at 5 µL/min compared with G and K (first ablation: 3.41 times increase versus 1.95 and 1.87; second ablation: 4.60 versus 2.50 and 1.74) with similar results at 10 µL/min (first ablation: 3.28 versus 2.29 and 1.90 (P = 0.001); second ablation: 4.10 versus 3.01 and 2.01 (P = 0.001)). Canalograms indicated circumferential flow beyond the ablation endpoints. Conclusions: T, G and K significantly increased the outflow facility. In this model, T had a larger effect than G and K.