Risk factors for intraocular pressure elevation in a six-month period after ab interno trabeculotomy using a Kahook Dual Blade

Trabeculotomy Using the Kahook Dual Blade for Exfoliation Glaucoma and Primary Open Angle Glaucoma: Comparison of Outcomes According to Incision Range

PRCIS

Large amount of trabeculotomy with Kahook Dual Blade (KDB) confers better intraocular pressure (IOP) lowering.

PURPOSE

We compared the postoperative outcomes of trabeculotomy using the KDB in patients with exfoliation glaucoma (EXG) and primary open angle glaucoma between the 120-degree incision and the 210- to 240-degree incision groups.

PATIENTS AND METHODS

We retrospectively analyzed the postoperative outcomes of trabeculotomy performed using the KDB in 101 eyes with EXG and primary open angle glaucoma, who received 120- and 210- to 240-degree incisions at Kumamoto University Hospital between April 25, 2018, and August 11, 2021. Kaplan-Meyer survival curves were used to assess the outcomes. Surgical failure was defined as IOP ≥21 mm Hg (criterion A) and ≥19 mm Hg (criterion B), or an IOP ≤4 mm Hg in either criterion and the need for additional glaucoma surgery.

RESULTS

In total, 64 and 37 eyes were included in the 120 and 210- to 240-degree groups, respectively. The 210- to 240-degree group had a higher 1-year success rate compared with the 120-degree group, both when considering all eyes and when considering only those with EXG (P<0.05).

CONCLUSIONS

In trabeculotomy with KDB, a 210- to 240-degree incision was more effective than a 120-degree incision in lowering IOP in EXG cases.

Surgical Outcomes of Ab Interno Trabeculotomy Without Phacoemulsification

Purpose

The aim of this study was to evaluate ab interno trabeculotomy outcomes without phacoemulsification.

Methods

This retrospective study evaluated 118 eyes of patients aged 18 and above who underwent ab interno trabeculotomy between December 2017 and August 2022. When surgeries were performed in both eyes, only the eye undergoing the initial surgery was evaluated. Prior to and after surgery, the intraocular pressure (IOP) and mean number of IOP-lowering medications were compared. An IOP of ≤21 mmHg (A) and ≤18 mmHg (B) along with a ≥20% reduction in the preoperative IOP was defined as survival. Cases that required reoperation for glaucoma were defined as surgical failure. The Kaplan-Meier method was used to evaluate the survival rates. A Cox proportional hazards model was used to analyze the preoperative factors that influenced survival rates.

Results

At 36 months postoperatively, the 13.4 ± 2.8 mmHg average IOP was significantly decreased from the preoperative 23.5 ± 9.8 mmHg value (P < 0.0001). Moreover, a significant decrease in the mean number of the IOP-lowering medications to 2.3 ± 1.4 at 36 months was found versus the initial 3.9 ± 1.1 preoperative value (P < 0.0001). The survival rates for criteria A and B at 36 months postoperatively were 28% and 25%, respectively. Only the preoperative IOP was identified by multivariate analysis as a factor influencing survival rates (P < 0.0001). Hyphema in 36 eyes (30.5%) and an IOP spike in 20 eyes (16.9%) were the only observed complications. Additional glaucoma surgery was required in 27 eyes (22.9%) during the follow-up period.

Conclusion

Utilization of ab interno trabeculotomy effectively lowered the IOP and reduced the number of IOP-lowering medications. Patients with higher preoperative IOP exhibited better postoperative outcomes.

Outcomes of iStent Inject Versus Kahook Dual Blade Surgery in Glaucoma Patients Undergoing Cataract Surgery

PRCIS

iStent Inject implantation (iStent) or Kahook Dual Blade goniotomy (KDB) in combination with phacoemulsification have a similar IOP-lowering effect in all stages of glaucoma, and medications are significantly reduced, especially after KDB.

PURPOSE

To compare the 2-year efficacy and safety of iStent or KDB in combination with phacoemulsification in eyes with mild to advanced open angle glaucoma.

METHODS

A retrospective chart review of 153 patients that received iStent or KDB in combination with phacoemulsification at a single center between March 2019 and August 2020. The main outcome parameters at 2 years were: (1) intraocular pressure (IOP)-reduction ≥20%, with a postoperative IOP ≤18 mm Hg, and (2) a reduction of ≥1 medication. Results were stratified by glaucoma grade.

RESULTS

After 2 years, mean IOP was reduced from 20.3±6.1 to 14.2±4.1 mm Hg in the phaco-iStent group ( P <0.001) and from 20.1±6.1 to 14.7±3.6 mm Hg in the phaco-KDB group ( P <0.001). The mean number of medications was reduced from 3.0±0.9 to 2.6±1.1 in the Phaco-iStent group ( P =0.001) and from 2.3±1.0 to 1.5±1.3 in the Phaco-KDB group ( P <0.001). Success regarding IOP-reduction ≥20% with a postoperative IOP ≤18 mm Hg was met by 46% in the phaco-iStent group and by 51% in the phaco-KDB group. A reduction of ≥1 medication was met by 32% in the phaco-iStent group and by 53% in the phaco-KDB group ( P =0.013). Eyes with mild to moderate and advanced glaucoma responded equally well to the success criteria.

CONCLUSIONS

iStent and KDB, in combination with phacoemulsification, both lowered IOP effectively in all stages of glaucoma. More medications were reduced after KDB, suggesting that it may be a more effective procedure compared with iStent.