Comparison of 12-month surgical outcomes of ab interno trabeculotomy with phacoemulsification between spatula-shaped and dual-blade microhooks

The effect of axial length on the short-term outcomes of cataract surgery combined with ab interno trabeculotomy

PURPOSE

Minimally invasive glaucoma surgery is safer and effective surgical modality for patients with glaucoma. To compare the effect of axial length (AL) on the surgical outcomes of combined cataract surgery and ab interno trabeculotomy (phaco-LOT), a retrospective, non-randomized comparative study was performed.

METHODS

In total, 458 eyes of 458 open-angle glaucoma patients who underwent phaco-LOT and were followed-up without any intervention for at least 6 months were enrolled. All were divided into a long-AL group (AL ≥ 26.0 mm, 123 eyes) and a not-long-AL group (AL < 26.0 mm, 335 eyes). The principal outcomes were the changes in intraocular pressure (IOP) and medication scores. We also sought a correlation between postoperative IOP spike and hyphema.

RESULTS

Significant postoperative reductions in IOP and medication scores were apparent in all subjects. The IOP reductions were significant at all timepoints in the not-long-AL group, but not until 1 month postoperatively in the long-AL group, and the IOP change was significantly lower in the long-AL group from postoperative day 1 to 3 months. On subanalysis of subjects by age, the microhook used, the pre-operative IOP, and the medication score, a significantly higher incidence of IOP spike was observed in the long-AL group in weeks 1 and 2 (both p < 0.05), but this did not correlate with hyphema status, implying that a different mechanism was in play.

CONCLUSION

Phaco-LOT was effective regardless of AL, but the postoperative IOP decrease was lower and the early postoperative incidence of IOP spike was higher in long-AL eyes.

Twelve-month outcomes of Kahook dual blade goniotomy combined with cataract surgery in Latino patients

PURPOSE

To evaluate 12 month surgical outcome of Kahook Dual Blade (KDB) goniotomy in combination with cataract surgery in Latino patients with open angle glaucoma (OAG) and ocular hypertension (OHT).

METHODS

This retrospective study included 45 eyes of 40 patients who underwent KDB goniotomy combined with cataract extraction from January 2016 to September 2020 at two centers in South America. Primary outcome was surgical success defined as ≥ 20% intraocular pressure (IOP) reduction or ≥ 1 medication reduction from preoperative without additional IOP-lowering procedures and an IOP ≥ 5 mmHg or ≤ 21 mmHg. Additionally, we used 2 cutoffs values for success of IOP ≤ 18 and ≤ 15 mmHg. Secondary outcomes included: IOP, medication use, best corrected visual acuity, complications and failure-associated factors.

RESULTS

Success rates at 12 months with cutoff limits of 21, 18 and 15 mmHg were 84.3%, 75.6% and 58.7%, respectively. At 12 months, mean preoperative IOP significantly decreased from 19.23 ± 0.65 mmHg on 2.3 ± 1.0 medications to 14.33 ± 0.66 mmHg on 0.6 ± 0.9 medications (p < 0.001) , with 62% of eyes free of hypotensive medication. Eyes that developed postoperative IOP spikes showed a higher risk for failure using the cutoff limit of IOP ≤ 18 mmHg with a hazard ratio of 3.6 (95% confidence interval [CI], 1.80-7.13; p < 0.001). There were no serious ocular adverse events.

CONCLUSIONS

KDB combined with cataract extraction showed safety and efficacy for decreasing IOP in OAG and OHT Latino patients. Additionally, dependence on medications was reduced significantly after surgery.

A Retrospective Study of Risk Factors Affecting Long-Term Outcomes Following Ab Interno Trabeculotomy and Goniotomy Concomitant with Phacoemulsification

Purpose

To examine the potential risk factors affecting the long-term outcomes following a combination of phacoemulsification with ab interno trabeculotomy with the microhook (μLOT-Phaco) and goniotomy with the Kahook Dual Blade (KDB-Phaco).

Methods

For 12 months, we retrospectively examined a total of 100 eyes of 100 patients with primary open-angle glaucoma (POAG) and exfoliation glaucoma (EG) who had previously undergone surgery between December 2016 and December 2020. Patients with a preoperative intraocular pressure (IOP) ˂12 mmHg were excluded. Probability of success was calculated using the Kaplan-Meier method, with surgical failure defined as an IOP >18 mmHg, <20% IOP reduction or additional glaucoma surgery. The Cox proportional hazards model was used to examine the potential risk factors for failure, which included age, gender, type of glaucoma, surgical techniques, preoperative IOP, number and type of preoperative IOP-lowering medications, preoperative visual field mean deviation (MD) value, and axial length.

Results

For the 51 males and 49 females, mean preoperative age was 74.4 ± 9.0 years, with μLOT-Phaco performed in 44 and KDB-Phaco in 56 subjects. The type of glaucoma was POAG in 68 and EG in 32 eyes. Preoperative IOP was 20.5 ± 6.7 mmHg, while postoperative IOPs were 14.4 ± 4.2 mmHg, 13.7 ± 2.8 mmHg, and 14.6 ± 3.9 mmHg, respectively (P < 0.001). Significant decreases from the preoperative number of IOP-lowering medications (3.1 ± 1.2) were observed at 12, 24, and 36 months, respectively (1.2 ± 1.3, 1.6 ± 1.3, and 2.1 ± 1.4 (P < 0.001)). Probability of success at 12, 24, and 36 months postoperatively was 52.0%, 49.6%, and 47.7%, respectively. Lower preoperative IOP was shown to be a potential risk factor for surgical failure.

Conclusion

Long-term follow-ups showed IOP decreased in μLOT-Phaco and KDB-Phaco patients. Results suggest that patients with higher preoperative IOP may have better postoperative outcomes.

Comparison of Mid-Term Outcomes between Microhook ab Interno Trabeculotomy and Goniotomy with the Kahook Dual Blade

This study retrospectively examined the mid-term surgical outcomes between microhook ab interno trabeculotomy (μLOT) and goniotomy when one was using the Kahook Dual Blade (KDB) in combination with phacoemulsification in primary open-angle glaucoma and exfoliation glaucoma patients. Between December 2016 and December 2020, the current study examined 47 μLOT and 52 KDB eyes that underwent surgery. When there was a < 20% reduction in the preoperative intraocular pressure (IOP) or when the IOP was > 18 mmHg (criterion A), the IOP was > 14 mmHg (criterion B) at two consecutive follow-up visits, or when there was a requirement for reoperation, these were all considered to indicate that the surgery failed. A genetic algorithm that used the preoperative IOP was used to determine the score matching. After score matching, a total of 27 eyes were evaluated. In the μLOT and KDB groups, the mean postoperative follow-up periods were 31.2 ± 13.3 and 37.2 ± 16.3 months, respectively. The results for both of the groups show there were significant postoperative reductions in the IOP (p < 0.05) and medication scores (p < 0.05) at 6, 12, 24 and 36 months. At 12, 24, and 36 months, the probabilities of success in the μLOT and KDB groups for criterion A were 70.4% and 48.2%, 61.9% and 48.2%, and 55.0% and 48.2% (p = 0.32; log-rank test), respectively. For criterion B, the results for the two groups were 55.6% and 33.3%, 44.4% and 33.3%, and 44.4% and 33.3% (p = 0.15; log-rank test), respectively. Similar postoperative complications were found between the groups. Comparable mid-term surgical outcomes were found for the uses of μLOT and KDB.

Microhook ab interno trabeculotomy for secondary glaucoma in patients with hereditary transthyretin amyloidosis

PURPOSE

To report surgical outcomes of a Microhook ab interno trabeculotomy (µLOT) procedure for glaucoma secondary to hereditary transthyretin amyloidosis (ATTRv).

STUDY DESIGN

Retrospective case series.

METHODS

Medical records of patients with glaucoma secondary to ATTRv with transthyretin Val30Met variant, who underwent µLOT, were retrospectively reviewed. Surgical success was categorized according to the postoperative intraocular pressures (IOPs, mmHg) as follows: (a) 6 ≤ IOP ≤ 21; (b) 6 ≤ IOP ≤ 18; and (c) 6 ≤ IOP ≤ 15, without light perception loss or additional glaucoma surgery. Secondary outcomes were glaucoma medication scores and postoperative complications.

RESULTS

This study included 18 eyes (13 patients, 6 men). The mean follow-up period was 25.2±9.8 months (7-38 months). Kaplan-Meier analysis indicated success rates of (a) 1.00 at 6, 1.00 at 12, and 0.43 at 24 months; (b), 1.00 at 6, 0.93 at 12, and 0.43 at 24 months; (c) 0.94 at 6, 0.75 at 12, and 0.27 at 24 months after operation. Postoperative IOPs were significantly reduced from the baseline of 25.2±5.8 mmHg to 11.5±2.7 at 3, 12.3±4.1 at 6, and 13.8±3.9 at 12 months (Dunnett's test). Medication scores were also improved at 3 and 6 months but without a significant reduction at 12 months. There were no severe complications requiring surgical intervention except for additional glaucoma surgery.

CONCLUSION

µLOT for secondary glaucoma in ATTRv is safe and effective 1 year after surgery, but the effects diminish after 2 years.

The number of examinations required for the accurate prediction of the progression of the central 10-degree visual field test in glaucoma

The purpose of the study was to investigate the number of examinations required to precisely predict the future central 10-degree visual field (VF) test and to evaluate the effect of fitting non-linear models, including quadratic regression, exponential regression, logistic regression, and M-estimator robust regression model, for eyes with glaucoma. 180 eyes from 133 open angle glaucoma patients with a minimum of 13 Humphrey Field Analyzer 10-2 SITA standard VF tests were analyzed in this study. Using trend analysis with ordinary least squares linear regression (OLSLR), the first, second, and third future VFs were predicted in a point-wise (PW) manner using a varied number of prior VF sequences, and mean absolute errors (MAE) were calculated. The number of VFs needed to reach the minimum 95% confidence interval (CI) of the MAE of the OLSLR was investigated. We also examined the effect of applying other non-linear models. When predicting the first, second, and third future VFs using OLSLR, the minimum MAE was obtained using VF1-12 (2.15 ± 0.98 dB), VF1-11 (2.33 ± 1.10 dB), and VF1-10 (2.63 ± 1.36 dB), respectively. To reach the 95% CI of these MAEs, 10, 10, and 8 VFs were needed for the first, second and third future VF predictions, respectively. No improvement was observed by applying non-linear regression models. As a conclusion, approximately 8-10 VFs were needed to achieve an accurate prediction of PW VF sensitivity of the 10-degree central VF.

Three-dimensional heads-up surgery in ab-interno trabeculotomy: Image processing-assisted trabeculotomy

Purpose

We compared the visibility and surgeon posture between image-processing-assisted trabeculotomy (IP-LOT) using the NGENUITY^® 3D visual system and conventional microsurgery (microscope-assisted trabeculotomy; MS-LOT).

Methods

IP-LOT was performed for five pig eyes. The visibility of the trabecular mesh work was evaluated on images of the trabecular mesh work and the posterior surface of the cornea (Cor) obtained under three different conditions. Images were then analyzed using ImageJ^® to measure differences in luminance between the trabecular mesh work and Cor. IP-LOT was also performed for eleven human eyes, and the data were analyzed using the same approach as that used for the pig eyes. The length from the surgeon’s abdomen to the operative eye (working distance) during MS-LOT and IP-LOT was measured for 12 different surgeons and compared to evaluate surgeon posture.

Results

Image processing significantly increased the difference in luminance between the trabecular mesh work and Cor in both pig and human eyes (p < 0.05). Moreover, the working distance in IP-LOT was significantly shorter than that in MS-LOT (p < 0.05).

Conclusion

Our findings suggest that the NGENUITY^® 3D visual system provides better trabecular mesh work visibility than a normal microscope in conventional surgical methods, and it allows surgeons to operate without moving far from the operative eye.

Non-inferiority of Microhook to Trabectome: Trabectome vs. ab interno Microhook Trabeculotomy Comparative Study (TramTrac Study)

PURPOSE

To elucidate the non-inferiority of ab interno microhook trabeculotomy (μTLO) using a recently developed reusable stainless spatula-type microhook device to incise the trabecular meshwork to trabectome (TOM) in terms of the 1-year postoperative outcomes of Japanese patients with glaucoma by means of propensity score analyses.

DESIGN

A multicenter retrospective cohort study.

PARTICIPANTS

We enrolled 553 and 392 patients who underwent TOM and μTLO, respectively, between January 2014 and March 2020 at 10 facilities.

METHODS

Logistic regression analysis was conducted to calculate the propensity score, which indicates the likelihood of treatment assignment (TOM or μTLO). We set the following factors as outcome-related covariates: age, sex, facility, glaucoma disease types, preoperative intraocular pressure (IOP), glaucoma drug score, mean deviation of the Humphrey visual field test and antithrombotic drug use, the presence or absence of combined cataract surgery, and incision range of trabecular meshwork (one or two quadrants). We analyzed four different methods (matching, inverse probability of treatment weighting (IPTW), stratification, and regression adjustment) using the propensity score. We set 15% as the non-inferiority margin based on previous trabectome meta-analysis results.

MAIN OUTCOME MEASURES

The primary outcome was surgical success at 1 year postoperatively. We defined surgical success as satisfying all three criteria: (1) IOP within 5-21 mmHg; (2) IOP reduction of ≥20% from preoperative IOP; and (3) no additional glaucoma surgery.

RESULTS

The 95% confidence interval of risk difference of surgical failure in μTLO in reference to TOM was -12.1 to +9.5% in matching, -12.7 to +11.1% in IPTW, -12.2 to +7.0 in stratification, and -9.7 to +8.1% in regression adjustment, all of which fell within the predetermined non-inferiority margin of 15%.

CONCLUSIONS

Surgical success of μTLO at 1-year postoperatively was not inferior to that of TOM.

Fellow-Eye Comparison between Phaco-Microhook Ab-Interno Trabeculotomy and Phaco-iStent Trabecular Micro-Bypass Stent

The aim of this study is to compare the surgical efficacy and safety between microhook ab-interno trabeculotomy (µLOT) and iStent trabecular micro-bypass stent implantation when both were combined with cataract surgery in both eyes of patients. Sixty-four glaucomatous eyes (32 participants; mean age, 75.9 ± 7.6 years; 15 men, 17 women) were included retrospectively. Intraocular pressure (IOP), number of antiglaucoma medications, best-corrected visual acuity (BCVA), anterior chamber flare (ACF) and corneal endothelial cell density (CECD) were evaluated preoperatively, as well as 2, 3, 6, and 12 months postoperatively. Surgical complications and interventions were compared between the procedures. The preoperative IOP and medications with µLOT (18.8 ± 5.7 mmHg and 3.0 ± 1.2, respectively) were higher than with the iStent (15.5 ± 3.4 mmHg and 2.7 ± 1.2, respectively) (p = 0.0001 and p = 0.0437, respectively). At 12 months, the µLOT values (12.6 ± 2.3 mmHg and 2.3 ± 0.9, respectively) were identical to iStent (12.8 ± 2.5 mmHg and 2.3 ± 0.9, respectively) (p = 0.0934 and p = 0.3251, respectively). At 12 months, the IOP decreased more with µLOT (6.2 mmHg, 29.5%) than iStent (2.7 mmHg, 15.6%) (p = 0.0003). The decrease in medications was greater with µLOT (0.7) than iStent (0.4) (p = 0.0437). Survival rate of IOP control ≤15 mmHg and IOP reduction ≥20% was significantly higher after µLOT (40.6% at 12 months) than iStent (18.8%) (p = 0.0277). The frequency of layered hyphema was significantly greater with µLOT (8 eyes, 25%) than iStent (0 eyes, 0%) (p = 0.0048). The increase in the ACF at 2 weeks postoperatively was significantly greater with µLOT than iStent (p = 0.0156), while changes in the BCVA and CECD were identical between groups. The fellow-eye comparison showed that the IOP reduction was greater with µLOT than iStent when combined with cataract surgery.