Gonioscopy-assisted Transluminal Trabeculotomy (GATT) combined phacoemulsification surgery: Outcomes at a 2-year follow-up

Surgery Outcomes of Prolene Suture Gonioscopy-Assisted Transluminal Trabeculotomy (GATT): Up to 4 Years Follow-Up and Prognostic Factors

PRCIS

Long-term success was achievable after GATT. GATT performed at early stage of glaucoma had better surgery outcomes. Trabeculoplasty may compromise surgery success.

PURPOSE

To evaluate the long-term effectiveness of prolene suture gonioscopy-assisted transluminal trabeculotomy (GATT) and identify factors that may affect surgical outcomes.

PATIENTS AND METHODS

This is a retrospective cohort study of adult patients with prolene suture GATT performed by a single surgeon at 1 medical center.

RESULTS

Of the 145 eyes from 124 patients studied, intraocular pressure was reduced from 22.1±7.8 to 15.1±3.2 and 15.1±3.5 mm Hg, and the number of glaucoma medications was reduced from 3.2±1.1 to 1.3±1.4 and 1.4±1.5 at postoperative years 3 and 4, respectively. Ninety-three and 71 eyes completed a 3- and 4-year follow-up, with 44% of the eyes at year 4 remaining medication free. Compared with eyes with combined GATT/cataract extraction (CE), eyes with GATT alone had significantly more preoperative medications and a higher reoperation rate (31% vs. 16.5%). Eyes with prior trabeculoplasty had a higher reoperation rate (28.8%) than those without (16.1%). Kaplan-Meier survival analysis revealed that GATT/CE eyes without trabeculoplasty had a longer median time to failure (48 mo) than GATT/CE eyes with trabeculoplasty (18 mo), and GATT eyes with or without trabeculoplasty (9 and 12 mo, respectively).

CONCLUSION

Prolene suture GATT successfully reduced IOP. Eyes with more preoperative medications responded less well to GATT. Prior laser trabeculoplasty was associated with poorer outcomes. Further study is needed to verify these findings.

Gonioscopy-Assisted Transluminal Trabeculotomy Outcomes Under Different Levels of Glaucoma Severity: A Multicenter, Comparative Study

PURPOSE

To evaluate the outcomes of gonioscopy-assisted transluminal trabeculotomy (GATT) under different levels of glaucoma severity.

DESIGN

Retrospective, multicenter, before-and-after study.

METHODS

One eye from all primary open-angle glaucoma patients who underwent GATT combined with cataract surgery (Phaco-GATT) or GATT stand-alone with 12 months of follow-up were included and divided according to glaucoma severity (mild = GI, moderate = GII, and advanced = GIII) and the outcomes compared.

RESULTS

A total of 270 eyes were included: 90 in GI, 75 in GII, and 105 in GIII. The IOP was reduced from 18.6 ± 6.0 mm Hg in GI, 19.7 ± 6.4 mm Hg in GII, and 21.0 ± 7.9 mm Hg in GIII, preoperatively, to 11.9 ± 2.6 mm Hg in GI, 11.8 ± 2.1 mm Hg in GII, and 11.9 ± 3.0 mm Hg in GIII at 12 months postoperatively (P < .001 for all). The number of hypotensive ocular medications were reduced from 2.7 ± 1.0 in GI, 3.1 ± 0.8 in GII, and 3.2 ± 1.2 in GIII to 0.6 ± 0.9 in GI, 1.0 ± 1.1 in GII, and 1.2 ± 1.1 in GIII at the last postoperative visit (P < .001 for all). Relative success was achieved, at 1 year, in 93.8% of the eyes in GI, 89.0% in GII, and 88.1% in GIII (P = .3). Complete success was achieved in 61.8% of the eyes in GI, 43.8% in GII, and 37.6% in GIII (P = .007). No serious adverse event was observed in any group.

CONCLUSIONS

GATT is a safe and effective procedure in glaucoma, regardless of its preoperative severity.

A Prospective Comparison of 180 Versus 360-Degree Gonioscopy-Assisted Transluminal Trabeculotomy Outcomes in Pseudoexfoliation Glaucoma

PRCIS

Analysis of surgical success and intraocular pressure (IOP), best-corrected visual acuity (BCVA), and antiglaucomatous medication (AGM) changes between segmental 180-degree and 360-degree gonioscopy-assisted transluminal trabeculectomy (GATT) in patients with pseudoexfoliation glaucoma (PEXG) showed no significant difference.

OBJECTIVE

To compare surgical outcomes of segmental 180-degree and 360-degree GATT in patients with PEXG.

MATERIALS AND METHODS

Prospective, comparative study of 65 PEXG eyes, who underwent segmental 180-degree GATT (GATT 180-degree group, 31 eyes) and 360-degree GATT (GATT 360-degree group, 34 eyes) in a tertiary academic center over a 12-month of follow-up. Primary outcome was qualified and complete surgical success rates for criterion A (IOP <18 mm Hg and >30% reduction) and criterion B (IOP <15 mm Hg and >30% reduction). Secondary outcome measures included IOP reduction, BCVA change, AGM use, and postoperative complications.

RESULTS

The probabilities of qualified and complete success rates both for criteria A and B did not significantly differ between the groups ( P > 0.05). IOP and BCVA levels were similar at each time point ( P > 0.05). IOP reduction was 59.3 ± 9.5% in the GATT 180-degree group and 55.8 ± 18.1% in the GATT 360-degree group ( P = 0.33). No significant difference in the mean number of AGM was present at the 12-month visit (1.2 ± 1.1 in GATT 180-degree group vs 1.5 ± 1.2 in GATT 360-degree group, P = 0.25). Significantly higher incidences of postoperative hyphema and IOP spikes were observed in the GATT 360-degree group ( P = 0.01 and P = 0.008, respectively).

CONCLUSION

Both segmental 180-degree and 360-degree GATT similarly reduced IOP and AGM with comparable surgical success rates in patients with PEXG at the end of 12 months. Postoperative hyphema and IOP spike rates were significantly higher after 360-degree GATT. Segmental 180-degree GATT may be sufficient to adequately modulate IOP with a lower incidence of postoperative complications in PEXG.

Intraocular pressure spikes after gonioscopy-assisted transluminal trabeculotomy (GATT)

PURPOSE

Intraocular pressure (IOP) spikes (IOP > 30 mmHg or > 10 mmHg above baseline IOP) are a common and worrisome complication of gonioscopy-assisted transluminal trabeculotomy (GATT). The purpose of this study is to identify risk factors for IOP spikes and to describe their characteristics, management, and clinical course in a large cohort of patients.

METHODS

A retrospective, single-center study which included 217 consecutive eyes of patients that underwent GATT between December 2019 and April 2022 with follow-up of at least 90 days.

RESULTS

IOP spikes occurred in 52 of 217 (24%) eyes. Spikes occurred in 15.5% of patients in whom pre-operative IOP-lowering medications were continued after surgery (90 eyes), and in 29.9% in whom IOP-lowering medications were stopped after surgery (127 eyes). Spikes were diagnosed at a mean of 7.7 ± 6.5 days after surgery. All IOP spikes occurred within the first month of surgery. The mean duration of a spike was 4.9 ± 5.4 days. Management of IOP spikes included adding a mean of 3.13 ± 1.7 groups of glaucoma medications. Thirty-seven (72.5%) eyes were treated with oral carbonic anhydrase inhibitor, 11 (21.6%) were treated with IV mannitol, and anterior chamber paracentesis was performed in 16 (31.4%). Six (11.8%) eyes underwent additional glaucoma surgery to control IOP. Patients that continued their pre-operative IOP-lowering medications after surgery were 2.3 times less likely to develop a spike as compared to patients who discontinued their medications (P = 0.016). Spikes were found to be a risk factor for failure of GATT.

CONCLUSIONS

IOP spikes are a common occurrence after GATT. They most commonly appear during the first two post-operative weeks and usually resolve with topical and systemic IOP-lowering treatment. The continuation of IOP-lowering medications after GATT is recommended to lower the risk of IOP spikes.

Efficacy and safety of Usights UC100 illuminated microcatheter in microcatheter-assisted trabeculotomy

AIM

To evaluate the efficacy and safety of Usights UC100 illuminated microcatheter in microcatheter-assisted trabeculotomy (MAT).

METHODS

Totally 10 eyes of 10 patients with primary open angle glaucoma (POAG) who underwent MAT facilitated by Usights UC100 (5 eyes) or iTrack (5 eyes) were reviewed. The success of this surgery was defined as intraocular pressure (IOP) <22 mm Hg with >30% reduction, without oral glaucoma medications, or additional glaucoma surgery.

RESULTS

The mean pre-operative IOP was 25.38±10.22 mm Hg in the Usights UC100 group and 19.98±3.87 mm Hg in the iTrack group. MAT was achieved in all eyes in both groups. The success rates for the Usights UC100 group and iTrack groups were in all and 4 eyes, respectively. Both microcatheters produced a statistically significant reduction in IOP, and eyes using Usights UC100 achieved a lower IOP than the iTrack group at 3mo follow-up (12.58±1.52 and 14.84±1.89 mm Hg, respectively), but no statistical significance was there. No severe side effects were observed in either group.

CONCLUSION

MAT using Usights UC100 or iTrack both achieve significant pressure reduction in cases of POAG, and Usights UC100 is as safe as iTrack.

Influence of Goniotomy Size on Treatment Safety and Efficacy for Primary Open-Angle Glaucoma: A Multicenter Study

PURPOSE

To compare the efficacy and safety of 120-, 240-, and 360-degree goniotomy (GT) with or without phacoemulsification with intraocular lens implantation (PEI) for patients with primary open-angle glaucoma (POAG).

DESIGN

Multicenter, retrospective, comparative, nonrandomized interventional study.

METHODS

Patients diagnosed with POAG who underwent GT with or without PEI were included, and divided into 6 groups: 1) standalone 120-degree GT (120GT); 2) standalone 240-degree GT (240GT); 3) standalone 360-degree GT (360GT); 4) PEI + 120GT; 5) PEI + 240GT; and 6) PEI + 360GT. Data on intraocular pressure (IOP), the number of ocular hypotensive medications, and complications were collected and compared. Success was defined as a postoperative IOP within the range of 6 to 18 mm Hg and a 20% reduction from baseline without further glaucoma surgery. Complete success and qualified success were defined as the above without and with ocular hypotensive medications, respectively.

RESULTS

Three hundred eight eyes of 231 patients were included with a mean follow-up of 14.4 ± 8.6 months (6.0-48.0 months). There were no significant differences in the reductions in IOP and number of medications and cumulative survival probability for complete and qualified success rates among the 3 groups of standalone GT and PEI + GT. The 360GT group had the highest proportion of hyphema with or without PEI.

CONCLUSIONS

120GT, 240GT, and 360GT with or without PEI showed similar efficacy in reducing IOP and medications used in POAG. 360GT with or without PEI was more likely to cause hyphema compared with 120GT or 240GT. 120GT with or without PEI was sufficient for treating POAG with or without cataract..

Hemi-GATT combined with phacoemulsification in patients with moderate-severe primary open-angle glaucoma: 2-year outcomes

PURPOSE

To describe the outcomes of inferior hemisphere 180° gonioscopy-assisted transluminal trabeculotomy (hemi-GATT) in patients with moderate-severe stage primary open-angle glaucoma (POAG).

METHODS

This single center, retrospective study identified patients with POAG who had undergone combined inferior hemi-GATT with phacoemulsification. Patients with moderate-severe staged POAG were included in the study. Outcome measures included surgical success, intraocular pressure (IOP), number of topical IOP-lowering drops, best-corrected visual acuity (BCVA), visual field mean deviation (MD) and complications. Success was defined using two criteria: Criterion A (IOP <17 mmHg and >20% reduction) and Criterion B (IOP <12 mmHg and >20% reduction).

RESULTS

One hundred-twelve eyes of 112 patients were included in this study. Of these, 91 patients were followed for 24 months or greater to assess endpoint surgical success. Kaplan-Meier survival analysis for Criterion A demonstrated a 64.8% probability of success without topical IOP-lowering therapy (complete success) and a 93.4% probability of success with or without topical IOP-lowering therapy (qualified success). Probabilities of complete and qualified success using Criterion B were 26.4% and 30.8%, respectively. IOP reduction from baseline (21.9 ± 5.8 mmHg) to 24-month follow-up (13.6 ± 3.9 mmHg) was 37.9% for the overall cohort. The most common complication was transient hyphema, which occurred in 25.9% (29 of 112) of patients. All cases of hyphema resolved spontaneously.

CONCLUSIONS

Combined hemi-GATT with phacoemulsification was associated with favorable outcomes and a low complication rate in this study of patients with moderate-severe POAG. Further studies are required comparing hemi-GATT to the 360° approach.

Evaluation of peripheral anterior synechia formation following gonioscopy-assisted transluminal trabeculotomy surgery

PURPOSE

To quantitatively assess the development of peripheral anterior synechia (PAS) formation rate and PAS locations on gonioscopic examination following gonioscopy-assisted transluminal trabeculotomy (GATT) surgery and investigate the surgical outcomes.

METHODS

A total of 35 eyes from 31 patients with open angle glaucoma who underwent GATT or combined GATT and phacoemulsification surgery were analyzed. Presence of PAS was assessed on gonioscopy in nasal, temporal, superior and inferior quadrants at months 1, 3 and 6 following surgery. Surgical outcomes were also noted.

RESULTS

Frequencies of PAS formation were 38.3%, 25.3%, 17.0% and 19.1% at postoperative 1 month, 34.0%, 26.4%, 17% and 22.6% at postoperative 3 months and 32.3%, 25.8%, 16.1% and 25.8% at postoperative 6 months, in nasal, temporal, superior and inferior quadrants, respectively. The highest amount of PAS involvement was 3 clock hours in the study which was identified only in nasal and inferior quadrants. Frequency of PAS formation did not significantly differ between nasal, temporal, superior and inferior quadrants at all time points (p > 0.05). No significant differences of mean IOP levels were observed between patients who developed PAS and who did not develop PAS at postoperative 1 month (p = 0.72), 3 months (p = 0.21) and 6 months (p = 0.59). The mean IOP and mean number of antiglaucoma medications decreased from 31.5 ± 7.2 mmHg and 3.6 ± 0.6 at baseline to 13.8 ± 3.1 mmHg and 1.6 ± 1.3 at postoperative 6 months, respectively (p < 0.001, for both). Cumulative success rate (95% confidence interval) was 74.3% (69.9-78.6%) at the end of the study. Mild to moderate degrees of hyphema occurred in all cases postoperatively.

CONCLUSION

Although PAS formation was observed to be relatively higher in nasal quadrant, PAS frequency was not statistically different between the angle quadrants.

Ab-interno Trabeculotomy Procedures: A Review

Purpose

To discuss the safety and efficacy of various forms of ab-interno trabeculotomy procedures.

Methods

A comprehensive search in PubMed and Google Scholar was done using the keywords "glaucoma", "microinvasive glaucoma surgery", "complications", "goniotomy", and "trabeculotomy". Publications discussing ab-interno trabeculotomy procedures were selected; furthermore, the relevant references in these articles were gathered and the search was updated during the article preparation. Since gonioscopy-assisted transluminal trabeculotomy was first introduced in 2014, we had no time restriction.

Results

Ab-interno trabeculotomy procedures, as a type of minimally invasive glaucoma surgeries, facilitate the natural trabecular outflow and lower the intraocular pressure (IOP) while preserving the conjunctiva for possible future glaucoma surgeries. It can be done alone or in combination with cataract surgery and effectively lowers the IOP and the number of antiglaucoma medications in various forms of glaucoma.

Conclusion

By appropriate patient selection, ab-interno trabeculotomy could be selected as a safe and effective procedure in the management of various forms of glaucoma either as an isolated procedure or in combination with cataract extraction.