The effect of some treatment variables on long-term results of argon laser trabeculoplasty

Effect of Preoperative Trabecular Meshwork Pigmentation and Other Eye Characteristics on Outcomes of Combined Phacoemulsification/Minimally Invasive Glaucoma Surgery

PURPOSE

To investigate associations between pigmentation of the trabecular meshwork (PTM) and other preoperative eye characteristics and outcomes of minimally invasive glaucoma surgery combined with phacoemulsification (Phaco/MIGS).

DESIGN

Retrospective interventional case series.

PARTICIPANTS

Academic glaucoma clinic patients with symptomatic cataract and glaucoma treated with combined Phaco/MIGS.

METHODS

Analyzing preoperative PTM, intraocular pressure (IOP), IOP-lowering medications and visual acuity (VA) data in relation to Phaco/MIGS outcomes.

MAIN OUTCOME MEASURES

Pigmentation of the trabecular meshwork and other preoperative eye characteristics in relation to Phaco/MIGS success defined as postoperative IOP between 5 and 21 mmHg and IOP reduction of ≥ 20% and/or a reduction of ≥ 1 IOP-medications compared to baseline, and final IOP, IOP-lowering medications and VA.

RESULTS

A total of 265 eyes (172 patients, mean age, 73.5 [standard deviation, 10.0], range 35-95 years, male 40.0%) were identified and categorized with high PTM (108 eyes, 40.8%) or low PTM (157 eyes, 59.2%). The high PTM group, compared with the low PTM group, demonstrated higher preoperative IOP (16.7 [standard error 0.4] vs. 15.2 [0.4] mmHg, P = 0.009), included more eyes with primary open-angle glaucoma (POAG, P = 0.03), fewer eyes with normal-tension glaucoma (NTG, P = 0.01), and fewer eyes with mild stage glaucoma (P = 0.001). Compared to baseline, final IOP decreased by 6.5 [2.4]% and 13.4 [3.0]% (P = 0.075) to 13.5 [0.3] mmHg and 13.6 [0.4] mmHg (P = 0.77) in the low and high PTM groups, respectively, and IOP-lowering medications decreased by 34.6 [4.9]% (n = 116) and 18.1 [7.3]% (n = 85), respectively (P = 0.062). Surgical success was 59.9% and 58.3%, respectively (P = 0.87). It was positively associated with higher preoperative IOP (hazard ratio 1.08 [95% confidence interval 1.04-1.12] P < 0.0001) and higher number of preoperative IOP-medications (1.20 [1.05-1.37] P = 0.007), negatively associated with history of selective laser trabeculoplasty (SLT, 0.40 [0.23-0.68] P = 0.0009) and longer axial length (0.87 [0.80-0.94], P = 0.0006), but was not associated with PTM.

CONCLUSIONS

Higher PTM was associated with POAG rather than NTG, with more severe glaucoma and higher preoperative IOP, but not with Phaco/MIGS success. Surgical success was positively associated with higher preoperative IOP and number of IOP-medications and negatively associated with history of SLT and longer axial length. These findings may help guide glaucoma surgeons in surgical planning and patient counseling.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Predictors of success in selective laser trabeculoplasty for chinese open-angle glaucoma

AIM

To investigate the determinants of success of selective laser trabeculoplasty (SLT) in Chinese open-angle glaucoma patients.

METHODS

This prospective cohort study sequentially recruited Chinese subjects with unilateral or bilateral primary open-angle glaucoma (POAG) or normal tension glaucoma (NTG). All subjects received a single session of 360-degree SLT treatment. Success was defined as IOP reduction ≥20%. The following were analyzed in univariate and multivariate regression analyses for association with SLT success: type of glaucoma, age, sex, lens status, presenting IOP, pre-SLT IOP, day 1 IOP, 1-week IOP, number and type of anti-glaucoma medications, number of SLT shots and energy, retinal nerve fiber layer (RNFL) thickness, Visual Field Index, endothelial cell count, central corneal thickness, Snellen visual acuity, and spherical equivalent.

RESULTS

In 111 eyes of 65 subjects, there were 51 POAG eyes and 60 NTG eyes. The overall success was 53.15% with a mean IOP reduction of 19.81±15.93%. In univariate analysis, a thinner RNFL [coefficient=-0.027; odds ratio (OR)=0.95; P=0.017] was associated with success. In multivariate analysis, a lower day 1 IOP (coefficient=-0.29; OR=0.75; P=0.049) and using topical carbonic anhydrase inhibitors (CAI) (coefficient=2.92; OR=18.63; P=0.0020) were associated with success. In both univariate and multivariate analyses, a higher pre-SLT IOP significantly predicted success (coefficient=0.20/0.46; OR=1.23/1.58; P=0.0017/0.0011) and using 3 anti-glaucoma medications (coefficient=-1.08/-3.74; OR=0.3/0.024; P=0.037/P=0.0081) was associated with SLT failure.

CONCLUSION

The positive predictors of SLT success included: higher pre-SLT IOP, use of topical CAI, thinner RNFL, and lower day 1 IOP. Using 3 anti-glaucoma medications was associated with failure.

The outcome of 270-degree selective laser trabeculoplasty

Purpose. To evaluate the reduction of intraocular pressure (IOP) by a single-session 270° selective laser trabeculoplasty (SLT) in pseudoexfoliation glaucoma (PXFG) and primary open angle glaucoma (POAG) patients. Methods. A successful outcome was defined as an IOP reduction ≥20% from baseline with no further need for laser or incisional surgery. The preoperative pharmaceuticals were maintained unchanged throughout the course of the study. 70–80 nonoverlapping pulses were distributed around 270° in the trabecular band. Results. Sixty-six eyes of 42 patients with PXFG (30 eyes) or POAG (36 eyes) met the inclusion criteria. The mean ± standard deviation preoperative IOP was 23.7 ± 4.5 mmHg and at the end of the followup was 19.0 ± 4.5 mmHg with a pressure drop of 4.7 ± 3.1 mmHg (20%) (P < 0.001, 95% confidence interval 3.94–5.46). The cumulative probability of success was 39% (26 of 66 eyes) after 6 months of followup. Statistically significant differences in success rates were observed between the PXFG and POAG groups (27% versus 50%; P = 0.025). Postoperative inflammatory reaction was scanty. Conclusions. 270-degree SLT is useful in lowering IOP in PXFG and POAG, but the average reduction of IOP seems to be within the same range as reported with 180-degree SLT previously.

Micropulse diode laser trabeculoplasty -- 180-degree treatment

PURPOSE

To evaluate the outcome of 180° micropulse diode laser trabeculoplasty (MDLT) in patients with open-angle glaucoma.

METHODS

A retrospective review of 40 eyes of 29 MDLT-treated patients with a minimum follow-up time of 6 months. Successful outcome was defined as follows: (i) a ≥20% or (ii) a ≥3-mmHg decrease of intraocular pressure (IOP), no further need for laser- or incisional surgery and the number of glaucoma medication was the same or less than preoperative. These definitions will from now on be referred to as definition one and definition two.

RESULTS

Life-table analysis showed an overall success rate of 2.5% (1/40) and 7.5% (3/40) (according to definitions one and two, respectively) after up to 19 months of follow-up. The average time for failure was by definition one 2.9 months (standard deviation, SD ± 3.5, range 1-12 months) and by definition two 3.3 months (SD ± 3.9, range 1-16 months). There were no intra- or postoperative complications caused by MDLT. Postoperative inflammatory reaction, cells and flare, was scanty.

CONCLUSION

Our results suggest that 180° MDLT is a safe but ineffective treatment in patients with open-angle glaucoma.

Selective Laser Trabeculoplasty in Phakic and Pseudophakic Eyes

BACKGROUND AND OBJECTIVE

To evaluate the effect of pseudophakia on the success of selective laser trabeculoplasty in lowering intraocular pressure (IOP).

PATIENTS AND METHODS

In this retrospective, nonrandomized clinical trial, a chart review of all patients who underwent selective laser trabeculoplasty from September 2002 to June 2004 using a frequency-doubled Q-switched 532-nm Nd:YAG laser was performed. Changes in IOP and statistical significance were determined at each follow-up period. Average decrease in IOP and success rates for phakic and pseudophakic eyes were compared statistically at each time period.

RESULTS

In the phakic group, mean IOP decreased from 18.1 to 15.5 mm Hg (P < .0005) and mean glaucoma medication use decreased from 2.1 to 1.6 medications after 24 months of follow-up. In the pseudophakic group, mean IOP decreased from 18.3 to 15.2 mm Hg (P < .005) and mean glaucoma medication use decreased from 2.2 to 1.6 medications. Success rates ranged from 54% to 67% in the phakic group and 52% to 65% in the pseudophakic group. No statistically significant difference between phakic and pseudophakic eyes in decreased IOP or success rates was seen at any time point (P > .05). No significant complications occurred in either group.

CONCLUSIONS

Selective laser trabeculoplasty is effective in lowering IOP in both phakic and pseudophakic patients.

Projected cost comparison of selective laser trabeculoplasty versus glaucoma medication in the Ontario Health Insurance Plan

BACKGROUND

The projected 6-year cost comparison of primary selective laser trabeculoplasty (SLT) versus primary medical therapy in the treatment of open-angle glaucoma for Ontario patients aged 65 years or more is presented. Costs are taken from the perspective of the Ontario Health Insurance Plan at a per-patient level.

METHODS

The cost of each medication was obtained from the 2003 Ontario Drug Benefits formulary. The average annual cost of medications was determined by estimating the provincial prescription rate of glaucoma medications, with reference to both a volume-per-bottle study of these drugs and a study of pharmacy claims reports. A representative provincial prescription rate was calculated by reviewing 707 patient charts selected randomly from 5 ophthalmologic practices across Ontario. Medication therapies were categorized into mono-, bi-, and tri-drug therapy groups. The cost of SLT was analyzed under the following 2 scenarios. SLT rep 2y assumed a duration of 2 years before repeat SLT was necessary. SLT rep 3y assumed a duration of 3 years before repeat SLT was necessary. Bilateral 180 degrees SLT treatment and repeatability of SLT was assumed. The cost of surgery for patients who fail SLT or medical therapy was not accounted for in this study nor was the cost of patients who required medical therapy in conjunction with SLT.

RESULTS

In the SLT rep 2y scenario, the use of primary SLT over mono-, bi-, and tri-drug therapy produced a 6-year cumulative cost savings of 206.54 dollars, 1668.64 dollars, and 2992.67 dollars per patient, respectively. In the SLT rep 3y scenario, the use of primary SLT over mono-, bi-, and tri-drug therapy produced a 6-year cumulative cost savings of 580.52 dollars, 2042.82 dollars, and 3366.65 dollars per patient, respectively.

INTERPRETATION

Our findings suggest that SLT as primary therapy, at a per-patient level, offers a modest potential cost saving over primary medical therapy in the management of open-angle glaucoma for Ontario patients aged 65 years or more.

Baseline IOP predicts selective laser trabeculoplasty success at 1 year post-treatment: results from a randomised clinical trial

BACKGROUND/AIMS

The efficacy and safety of selective laser trabeculoplasty (SLT) has been found to be equivalent to argon laser trabeculoplasty (ALT). Since SLT produces significantly less disturbance to the trabecular meshwork and is theoretically more repeatable than ALT, it has potential to replace ALT as the standard procedure to treat medically uncontrolled open angle glaucoma. This study's objective is to determine factors that predict successful SLT at 1 year post-treatment.

METHODS

As part of a randomised clinical trial comparing the efficacy and safety of SLT to ALT, data on 72 SLT patients were collected, and successful SLT defined as having an SLT induced intraocular pressure (IOP) reduction of >or=20% at 1 year post-treatment follow up.

RESULTS

43 out of the 72 patients who had completed their 1 year follow up visit had an IOP reduction of >or=20% from baseline. No glaucoma risk factors studied predicted successful SLT. The amount of trabecular meshwork pigmentation was not a significant predictor. However, it was discovered that baseline IOP strongly predicted SLT success (odds ratio=1.16; p=0.0001).

CONCLUSION

SLT success was significantly predicted by baseline IOP but not by age, sex, other glaucoma risk factors, type of open angle glaucoma, or by degree of trabecular meshwork pigmentation.

High Failure Rate Associated With 180?? Selective Laser Trabeculoplasty

PURPOSE

To determine the efficacy of selective laser trabeculoplasty (SLT) in a tertiary care referral center.

PATIENTS AND METHODS

In this retrospective study of selective laser trabeculoplasty performed by five physicians, 94 eyes from 94 patients were included. A majority (83/92, 90%) underwent 180 degrees selective laser trabeculoplasty. Selective laser trabeculoplasty failure was defined in two ways: (1) IOP decrease <3 mm Hg (definition one), or (2) IOP decrease <20% (definition two), on two successive visits > or =4 weeks after SLT.

RESULTS

Overall failure rates were 68% (64/94) and 75% (70/94) (by definitions one and two, respectively). By survival/life-table analysis, mean time to failure was 6 months and 5.5 months, by definitions one and two, respectively. By the end of the study (14.5 months), the failure rates were 86% and 92% by definitions one and two, respectively. By each definition, in both univariable and multivariable analysis, only lower baseline IOP was a significant predictor of failure.

CONCLUSIONS

Selective laser trabeculoplasty had an overall low success rate in our tertiary clinic population, with overall failure rates of 68% to 74% in those who underwent 180 degrees selective laser trabeculoplasty.