A recent study published in Ophthalmology and Therapy evaluated the 6-year clinical outcomes of excisional goniotomy with the Kahook Dual Blade (KDB) in the management of various types of glaucoma.
Give me some background.
With the advent of microinvasive glaucoma surgery (MIGS), options for the surgical management of glaucoma have greatly expanded.
Case in point: The KDB (New World Medical Inc.) is an angle-based MIGS device that aims to increase conventional outflow by diverting aqueous egress to the Schlemm’s canal.
- In fact: Previous studies have reported a favorable safety and efficacy profile for KDB goniotomy, with IOP reductions of 20-30% from baseline and a decrease in glaucoma medication burden by 1-3 medications.
Bring it back to this study.
However, when it comes to long-term outcomes, investigators noted that there is only one study in PubMed evaluating 5-year outcomes with the device, and its findings were limited by the inclusion of successful outcomes only.
Consequently: The researchers sought to document clinical safety and efficacy outcomes of KDB goniotomy with or without concomitant phacoemulsification over a 6-year period in a real-world setting.
Now talk about the study.
In this retrospective, noncomparative chart review, investigators included 90 eyes of 53 patients with glaucoma who underwent standalone KDB goniotomy (KDB-alone group, 18 eyes) or KDB goniotomy with concomitant phacoemulsification (KDB-phaco group, 72 eyes).
The surgical time frame: Between October 2015 and October 2017.
And how was surgical success was defined?
- An IOP reduction by ≥ 20% at the last follow-up
- No surgical reinterventions required
- A final IOP ≥ 4 mmHg and ≤ 21 mmHg
They also reported on changes in parameters for up to 72 months, such as:
- Baseline in IOP
- Number of glaucoma medications
- Best-corrected visual acuity (BCVA)
- Visual field parameters
Findings?
At 72 months, the mean (standard deviation [SD]) IOP reduced from:
- KDB-phaco group: 17.5 (5.7) to 13.6 (3.0) mmHg (P < 0.0001)
- 27.4% reduction
- KDB-alone group: 23.3 (5.9) to 15.1 (6.2) mmHg (P = 0.0593)
- 28.8% reduction
Similarly, the mean (SD) number of glaucoma medications was reduced from:
- KDB-phaco group: 1.3 (1.0) to 0.8 (0.9) mmHg (P < 0.0001)
- 38.5% reduction
- KDB-alone group: 1.2 (1.0) to 0.7 (0.8) mmHg (P = 0.3409)
- 41.7% reduction
Note: Only 52 eyes (58%) were available at 72 months.
Anything else?
During the 72-month follow-up period, surgical success was achieved in 24 of the 52 available eyes (46.2%).
- Four eyes underwent a glaucoma surgical intervention by 72 months.
All complications were minor and self-limited, with no severe or sight-threatening complications reported.
Expert opinion?
“KDB goniotomy appears to be a promising long-term therapy for correcting angle-closure and various forms of open-angle glaucoma,” the study authors noted.
Limitations?
These included:
- The retrospective study design did not allow for randomization
- Many patients (42%) were lost to follow-up, affecting overall consistency in the results
- Medication regimens were not standardized
- Various forms of glaucoma were represented in the study
- The KDB-alone group was relatively small (18 vs. 72 eyes)
- Baseline measurements of IOP were not at a standardized time of day
Significance?
These findings suggest that excisional goniotomy with the KDB effectively lowered the IOP (by an average of 28% from baseline) and maintained or further reduced glaucoma medication burdens (by an average of 30.8%) from baseline.
And lastly …
The KDB demonstrated an excellent safety profile, independent of phacoemulsification status, and a favorable success rate for up to 6 years—providing insights into its long-term efficacy as a glaucoma treatment.