What's new in laser treatment for glaucoma?

Argon Laser Synechiolysis for Irido-Corneal Adhesion

Purpose

To introduce a new method for treating irido-corneal adhesion (ICA) by using argon laser. Case Presentation. A 60-year-old woman with advanced glaucoma who is undergoing trabeculectomy. In follow-up visits, choroidal effusion and iridocorneal adhesion were seen in the examination. The massive choroidal effusion was treated with medical therapy. In further follow-up examination, ICA was repaired with argon laser.

Result

Early laser treatment prior to surgical management is suggested in postoperative synechia.

Conclusion

Early argon laser synechiolysis is a less-invasive procedure which prevents probable surgical complications such as local detachment of Descemet's membrane or bleeding in surgical synechiolysis.

Comparison of ultrasound cycloplasty and transscleral cyclophotocoagulation for refractory glaucoma in Chinese population

Background

To compare the efficacy and safety of focused ultrasound cycloplasty (UCP) and transscleral cyclophotocoagulation (TSCP) in the treatment of refractory glaucoma in a Chinese population.

Methods

We retrospectively compared twenty-eight eligible patients with refractory glaucoma, who were divided into the UCP group and TSCP group. Patients in these two groups underwent a corresponding procedure from June 2018 to February 2019. The intraocular pressure (IOP), visual acuity, the number of anti-glaucoma agents used and complications were reviewed and compared between groups. Proper statistical methods were selected according to comparison models under IBM SPSS 25 software.

Results

After the 12-months follow-up, postoperative IOP and number of anti-glaucoma agents used in the two groups were both reduced than the baseline level, and the differences were statistically significant (P < 0.05). There were no significant differences in IOP, number of anti-glaucoma agents and the best-corrected visual acuity between the two groups at each follow-up time point (P>0.05). In terms of complications, the pain at 1 day after surgery in the UCP group was significantly milder than that in the TSCP group (P < 0.05). And there were no significant differences in other complications between the two groups (P > 0.05).

Conclusions

Both UCP and TSCP are safe and effective methods for the treatment of refractory glaucoma. Nevertheless, pain is less severe after UCP.

Outcomes of micropulse transscleral cyclophotocoagulation in primary open-angle glaucoma, pseudoexfoliation glaucoma, and secondary glaucoma

PURPOSE

The aim of this study is to compare the outcomes of micropulse transscleral cyclophotocoagulation between primary open-angle glaucoma, pseudoexfoliation glaucoma, and other types of secondary glaucoma.

METHODS

Outcomes of 96 consecutive patients with refractory, end-stage glaucoma treated with micropulse transscleral cyclophotocoagulation were retrospectively reviewed. Follow-up examinations were performed on a regular basis until 12 months postoperatively. Surgical successes were defined as maintaining intraocular pressure ⩽18 mmHg and ⩾20% reduction in intraocular pressure (criteria A), ⩽15 mmHg intraocular pressure and ⩾25% reduction in intraocular pressure (criteria B), and ⩽12 mmHg intraocular pressure and ⩾30% reduction in intraocular pressure from baseline (criteria C).

RESULTS

Ninety-six eyes of 96 patients (50 (52%) females, 46 (48%) males) were included. Among all eyes, 32 were primary open-angle glaucoma, 30 were pseudoexfoliation glaucoma, and 34 were other types of secondary glaucoma. The mean age was 59.37 ± 11.45 (range: 20-91) years. The mean follow-up period was 14.2 ± 3.9 (range: 12-16) months. At 12 months, the success rates of primary open-angle glaucoma, pseudoexfoliation glaucoma, and secondary glaucoma group were 68.75%, 66.6%, and 64.7% (p = 0.185) for criteria A; 56.25%, 53.3%, and 50% (p = 0.153) for criteria B; and 43.75%, 43.3%, and 38.2% (p = 0.146) for criteria C. Four patients (12.5%) in primary open-angle glaucoma group, 5 patients (16.6%) in pseudoexfoliation glaucoma group, and 14 (41.2%) patients in other secondary glaucoma group required reoperation during the follow-up (p < 0.05).

CONCLUSION

Micropulse transscleral cyclophotocoagulation is an equally effective method of lowering intraocular pressure in patients with primary open-angle glaucoma, pseudoexfoliation glaucoma, and other types of secondary glaucoma. The rate of reoperation was higher in refractory secondary glaucoma patients.

Efficacy and safety of micropulse laser trabeculoplasty for primary open angle glaucoma

AIM

To evaluate the efficiency and safety of micropulse laser trabeculoplasty (MLT) for primary open angle glaucoma (POAG) patients.

METHODS

Retrospective study. POAG patients undergoing MLT in Peking University Third Hospital from June 2016 to November 2017. Seventy-two eyes of 72 POAG patients were enrolled. Only one eye of each patient was treated by MLT. The intraocular pressure (IOP) before MLT and at 1d, 1, 4, 12 and 24wk and glaucoma medication before and after treatment were compared.

RESULTS

The IOP was 20.6±5.9 mm Hg before MLT and 20.8±6.8 mm Hg at 2h after MTL. The IOP at 1d, 1, 4, 12 and 24wk was 17.9±4.4, 18.0±4.3, 17.5±3.4, 17.0±2.7, and 16.5±2.9 mm Hg, respectively. The IOP before and after MLT demonstrated a statistically significant difference by ANOVA analyses (F=5.797, P<0.001). Least significant difference t-tests showed there was no statistically significant difference between pre-MLT IOP within 2h after MLT (P=0.207). The statistically significant difference was confirmed between the pre-MLT IOP at 1d, 1, 4, 12 and 24wk after MLT (P=0.006, 0.009, 0.001, <0.001, <0.001, respectively). The number of glaucoma medications before MLT was 1.7±1.4 and 1.5±1.4 24wk after MLT with a significantly statistical difference (t=2.219, P=0.031).

CONCLUSION

MLT is effective and safe for POAG patients. No patient experienced IOP spikes after MLT. The IOP 6mo after treatment decreased significantly with less glaucoma medication.

New approaches to selective laser trabeculoplasty

Selective laser trabeculoplasty (SLT) is the “golden standard” of laser glaucoma surgery. Its efficacy can be compared to pharmacological therapy, while in some cases its advantages may even lead to a more stable hypotensive effect. SLT may be used as a primary treatment for primary open-angle glaucoma patients and patients with ocular hypertension, while also considered safe and effective in cases when a repeat procedure is required. SLT may potentially decrease the demand for antiglaucoma drugs, improve patient’s response to treatment, make the treatment more comfortable and overall increase the patient’s quality of life. New modifications of standard laser treatment procedures have been emerging lately. This article summarizes scientific data on the efficacy and safety of the new generation of laser trabeculoplasty. It specifies the charateristics of micropulse laser trabeculoplasty (MLT), pattern-scanning trabeculoplasty (PLT) and titaniumsapphire laser trabeculoplasty (TSLT) and recounts the latest research dedicated to them.

Axenfeld-Rieger syndrome

Axenfeld-Rieger syndrome (ARS) is a clinically and genetically heterogeneous group of developmental disorders affecting primarily the anterior segment of the eye, often leading to secondary glaucoma. Patients with ARS may also present with systemic changes, including dental defects, mild craniofacial dysmorphism, and umbilical anomalies. ARS is inherited in an autosomal-dominant fashion; the underlying defect in 40% of patients is mutations in PITX2 or FOXC1. Here, an overview of the clinical spectrum of ARS is provided. As well, the known underlying genetic defects, clinical diagnostic possibilities, genetic counseling and treatments of ARS are discussed in detail.

Glaucoma: Biological Trabecular and Neuroretinal Pathology with Perspectives of Therapy Innovation and Preventive Diagnosis

Glaucoma is a common degenerative disease affecting retinal ganglion cells (RGC) and optic nerve axons, with progressive and chronic course. It is one of the most important reasons of social blindness in industrialized countries. Glaucoma can lead to the development of irreversible visual field loss, if not treated. Diagnosis may be difficult due to lack of symptoms in early stages of disease. In many cases, when patients arrive at clinical evaluation, a severe neuronal damage may have already occurred. In recent years, newer perspective in glaucoma treatment have emerged. The current research is focusing on finding newer drugs and associations or better delivery systems in order to improve the pharmacological treatment and patient compliance. Moreover, the application of various stem cell types with restorative and neuroprotective intent may be found appealing (intravitreal autologous cellular therapy). Advances are made also in terms of parasurgical treatment, characterized by various laser types and techniques. Moreover, recent research has led to the development of central and peripheral retinal rehabilitation (featuring residing cells reactivation and replacement of defective elements), as well as innovations in diagnosis through more specific and refined methods and inexpensive tests.

Intraocular Pressure-Lowering Potential of Subthreshold Selective Laser Trabeculoplasty in Patients with Primary Open-Angle Glaucoma

Purpose. To compare the efficacy of subthreshold and conventional selective laser trabeculoplasty (SLT) in lowering intraocular pressure (IOP) in the patients with primary open-angle glaucoma (POAG). Methods. Fifty-two eyes from fifty-two POAG patients were randomized into two groups, one group treated with subthreshold SLT using two-thirds of the conventional energy and the other one treated with the conventional energy. IOP was measured with the Goldmann tonometer and the anterior chamber inflammation was determined using laser flare meter. Results. The initial energy dosage used in subthreshold SLT group was significantly lower than the amount of the energy used in conventional SLT group (0.4 ± 0.1 mJ versus 0.6 ± 0.1 mJ, P = 0.030). The total energy dosage was also significantly lower in subthreshold SLT group compared to the other group (37.6 ± 3.3 mJ versus 51.8 ± 5.7 mJ, P = 0.036). However, the level of inflammation in aqueous humor, amount of reduction in IOP, and the success rate in controlling IOP was the same in both groups. Conclusion. The efficacy of subthreshold SLT group in reducing IOP in POAG patients is comparable to the efficacy of conventional SLT group.

Current and Future of Laser Therapy in the Management of Glaucoma

There has been tremendous progress in the past decades in the utilization of lasers for treating patients with glaucoma. This article reviews the use of lasers in different areas of glaucoma, including the shift from argon laser trabeculoplasty (ALT) to selective laser trabeculoplasty (SLT), laser trabeculoplasty as an initial treatment for glaucoma, new laser trabeculoplasty procedures under investigation, and other recent laser treatment modalities such as endoscopic cyclophotocoagulation and laser-assisted deep sclerectomy.

Selective laser trabeculoplasty versus argon laser trabeculoplasty in patients with open-angle glaucoma: a systematic review and meta-analysis

Objective

To examine possible differences in clinical outcomes between selective laser trabeculoplasty (SLT) and argon laser trabeculoplasty (ALT) in open-angle glaucoma at different times post-treatment.

Methods

Randomized controlled trials (RCTs) comparing SLT versus ALT were searched through August 2013. The main outcome measure was IOP, and secondary outcomes included the number of glaucoma medications, the success rate, and adverse events.

Results

Six RCTs, involving 482 eyes treated with laser trabeculoplasty, were included in the meta-analysis. For all patients (including first and previous laser trabeculoplasy), no significant difference in IOP lowering was observed between SLT and ALT at one hour (P = 0.40), one week (P = 0.72), one month (P = 0.37), six months (P = 0.08), one year (P = 0.34), two years (P = 0.58), three years (P = 0.34), four years (P = 0.47), and five years (P = 0.50). A statistically significant difference in favor of SLT was found when comparing the IOP reduction at three months after intervention (weighted mean difference (WMD): 1.19 mmHg [0.41; 1.97]; I²=0%; P = 0.003). For patients who were naive to laser, there was no significant difference of reduction in IOP comparing SLT with ALT at any time point. In patients’ previous LT, no statistically significant difference in IOP reduction was found at six months (WMD: 1.92 mmHg [-0.91; 4.74]; I² = 77.3%; P = 0.18). There was no significant difference in the reduction in the number of glaucoma medications, the success rate, or adverse event rates between the two treatments.

Conclusions

SLT has equivalent efficacy to ALT with a similar constellation of side effects. In the case of retreatment, SLT appears to be similar to ALT in IOP lowering at six months.

Early results of selective laser trabeculoplasty in patients resistant to deep sclerectomy

PURPOSE

In this study, we aimed to determine the early results of selective laser trabeculoplasty to trabeculo-Descemet membrane in patients resistant to deep sclerectomy (DS) surgery.

METHODS

Twelve eyes of 12 patients that had undergone DS for primary open-angle glaucoma were enrolled. Preoperative and postoperative intraocular pressures (IOP) were measured by Goldmann applanation tonometer. Time to failure after DS was noted. Failure is described as IOP higher than 20 mm Hg. All patients underwent selective laser trabeculoplasty (SLT) after failure. Eight to 10 applications of SLT were applied over the trabeculo-Descemet membrane. Laser was applied to the surgical site only. The IOPs before SLT, at postoperative first week, first month, and third month were measured.

RESULTS

Mean follow-up time was 23.5 ± 9.5 months. Mean preoperative IOP was 34.2 ± 6.7 mm Hg; mean postoperative IOP at first week was 12.7 ± 3.2 mm Hg. Mean time to failure after DS procedure was 21.6 ± 7.6 months. Mean IOP was 20.6 ± 1.9 mm Hg just before SLT procedure. Mean IOP measurements after SLT at first week, first month, and third month were 10.5 ± 2.2 mm Hg, 10.5 ± 1.9 mm Hg, and 10.9 ± 2.1 mm Hg, respectively.

CONCLUSIONS

Selective laser trabeculoplasty after DS is an effective and noninvasive procedure that can be done on an outpatient basis. Our results suggest that SLT applied to the surgical site is an effective intervention in the short term but long-term results are required to assess the efficacy.