Twenty-Four-Month Outcome of Gonioscopy-Assisted Transluminal Trabeculotomy (GATT) in Eyes With Prior Corneal Transplant Surgery

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.

Open-angle glaucoma and Fuchs dystrophy

A 62-year-old woman with a history of moderate myopia, long-standing open-angle glaucoma (OAG), and Fuchs dystrophy in both eyes was referred for consultative care. She had prior trabeculectomy in 1984 and 1992 in the left and right eyes, respectively. She is 3 months post-Descemet-stripping endothelial keratoplasty (DSEK) in the left eye, now referred with uncontrolled intraocular pressure (IOP) despite maximum tolerated medical therapy. Current medical therapy for IOP consists of acetazolamide 250 mg by mouth 2 times a day, brimonidine 2 times a day in the left eye, dorzolamide 2 times a day in the left eye, and timolol 2 times a day in the left eye. The patient has a history of presumed steroid response; however, her corneal surgeon has requested that the steroid be continued for the next several months because of the recent DSEK. The IOP in the left eye has ranged from the mid-20s to mid-30s since DSEK. The right eye has consistently had pressure in the low teens and below for many years without topical antihypertensive medications. Examination revealed stable visual acuity at 20/30 and 20/40 in the right and left eyes, respectively, IOP was 12 mm Hg in the right eye and 25 mm Hg in the left eye by Goldman applanation, irregular but reactive pupils without afferent defect, and full confrontational visual fields. Slitlamp examination showed superior low avascular bleb, moderate-to-severe guttae, and posterior chamber IOL in the right eye. The left eye showed superior low diffuse bleb, clear DSEK graft, quiet chamber, superonasal iridectomy, and posterior chamber IOL with an open posterior capsule. The conjunctiva was moderately scarred but a repeat trabeculectomy or Xen Gel stent (Abbvie) appeared possible. The angles were wide open in each eye. Fundus examination was normal aside from myopic, anomalous-appearing nerves with an approximate cup-to-disc ratio of 0.90 in both eyes. Humphrey visual field showed nonspecific changes on the right and moderate nasal defect on the left eye, stable to previous examinations dating back to 2018 (Figure 1JOURNAL/jcrs/04.03/02158034-202407000-00018/figure1/v/2024-07-10T174240Z/r/image-tiff and Figure 2JOURNAL/jcrs/04.03/02158034-202407000-00018/figure2/v/2024-07-10T174240Z/r/image-tiff). Optical coherence tomography (OCT) of the retinal nerve fiber layer (RNFL) revealed moderated thinning in both eyes that was also stable to prior examinations (Figure 3JOURNAL/jcrs/04.03/02158034-202407000-00018/figure3/v/2024-07-10T174240Z/r/image-tiff). Her axial length measured 25.23 and 26.34 mm in the right and left eyes, respectively. Central corneal thickness was 553 μm in the right eye and 563 μm in the left eye before her DSEK procedure. What would be your approach to management of this patient's left eye, addressing the following: Rationale for your procedure of choice? Would you over-rule the corneal surgeon and stop the steroid in an attempt to obviate the need for glaucoma surgery? Does the age of onset of glaucoma affect your surgical decision making? Note that patient age at the time of trabeculectomy was 22 years. Are some procedures better suited for patients after DSEK surgery?

Is GATT the Answer?

How to cite this article: Bhartiya S, Aktas Z, Ichhpujani P. Is GATT the Answer? J Curr Glaucoma Pract 2023;17(4):167-168.

Outcomes of XEN Stent in Patients With Glaucoma and Previous Corneal Transplantation

PRCIS

The XEN stent safely and effectively controls intraocular pressure in select patients with history of corneal transplantation.

PURPOSE

Glaucoma is a common complication after corneal transplantation and can be difficult to manage in these patients. This study reports outcomes of XEN stent implantation in eyes with glaucoma in the setting of previous corneal transplantation.

PATIENTS AND METHODS

Noncomparative retrospective case series including eyes with a history of corneal transplantation and subsequent XEN stent implantation by a single glaucoma surgeon in Surrey, British Columbia, between 2017 and 2022. The analysis included patient demographics, pre and postoperative intraocular pressure (IOP), pre and postoperative glaucoma medications, peri and postoperative complications and interventions, and incidence of repeat corneal transplantation and additional glaucoma procedures to control IOP.

RESULTS

Fourteen eyes with previous cornea transplantation underwent XEN stent implantation. Mean age was 70.1 years (range: 47-85 y). Mean follow-up was 18.2 months (range: 1.5-52 mo). The most common glaucoma diagnosis was secondary open angle glaucoma (50.0%). There was a significant reduction in IOP and the number of glaucoma agents at all postoperative time points ( P < 0.05). IOP decreased from 32.7 ± 10.0 mm Hg at baseline to 12.5 ± 4.7 mm Hg at the most recent follow-up. Glaucoma agents decreased from 4.0 ± 0.7 to 0.4 ± 1.0. Two eyes required additional glaucoma surgery to control IOP, with an average time to reoperation of 7 weeks. Two eyes underwent repeat corneal transplantation, with an average time to reoperation of 23.5 months.

CONCLUSIONS

In selected patients with previous corneal transplants and refractory glaucoma, the XEN stent was safely implanted and effectively reduced IOP in the short term.

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.

The case for standalone micro-invasive glaucoma surgery: rethinking the role of surgery in the glaucoma treatment paradigm

PURPOSE OF REVIEW

To highlight progress in glaucoma therapy challenging the traditional medication-first approach and present evidence supporting early standalone surgery in the era of micro-invasive glaucoma surgery (MIGS).

RECENT FINDINGS

Medical therapy is limited by well documented poor adherence that compromises the quality of intraocular pressure reduction. Results from modern clinical trials demonstrate advantages of selective laser trabeculoplasty and MIGS procedures in terms of both IOP control and progression risk.

SUMMARY

The MIGS options for pseudophakic or precataractous patients are limited by regulatory rules that require the performance of some procedures only at the time of cataract surgery. These include the iStent/iStent Inject and the Hydrus implants. Nonbleb-forming procedures currently available for standalone use in eyes with mild-moderate primary open-angle glaucoma include gonioscopy-assisted transluminal trabeculotomy (which lowers IOP by 28-61% and medication use by 38-73% in various studies), trabecular ablation with the Trabectome (23-39% and 21-43%, respectively), excisional goniotomy with the Kahook Dual Blade (15-36% and 15-40%, respectively), ab interno canaloplasty (35% and 57%, respectively), and combined canaloplasty and trabeculotomy using the OMNI system (39-40% and 64-73%, respectively). For patients who would benefit from early standalone surgery, these procedures offer meaningful reductions in both IOP and medication burden.