Laser peripheral iridotomy changes anterior chamber architecture

Efficacy of Selective Laser Trabeculoplasty in Primary Angle-closure Glaucoma after Peripheral Iridotomy

Aim

To evaluate the efficacy of selective laser trabeculoplasty (SLT) in Southeast Asian eyes with primary open-angle glaucoma (POAG) vs primary angle-closure glaucoma after peripheral iridotomy (PACG-PI).

Materials and methods

Records of glaucoma patients who underwent SLT and had a 24-month follow-up were reviewed. Pre- and post-treatment intraocular pressure (IOP), percentage of IOP reduction in POAG, and PACG-PI groups, and probability of failure were analyzed. SLT failure was defined as any eye that did not have IOP lower than 20% compared to the baseline or had an IOP higher than the baseline on two consecutive visits. Adding medication, repeating SLT, or surgical intervention to control IOP was also considered a failure.

Results

Sixty-three POAG and 12 PACG-PI eyes were eligible. The mean (standard deviation [SD]) age was 62.9 (10.2) years in POAG and 60.3 (6.2) years in PACG-PI. Mean (SD) prelaser IOP in POAG was 19.0 (4.4) mm Hg and 20.7 (4.7) mm Hg in PACG-PI. At 24 months post-SLT, mean (SD) IOP was 14.1 (4.7) mm Hg and 13.6 (2.0) mm Hg in POAG and PACG-PI, respectively. There was no significant difference in percentage of IOP reduction (22.8 ± 23.0% for POAG and 30.7 ± 19.5% for PACG-PI, p = 0.96), or failure probability (p = 0.10) between both groups.

Conclusion

The efficacy of SLT at 24 months was comparable between POAG and PACG-PI.

Clinical significance

Selective laser trabeculoplasty may be an option to further lower IOP in eyes with angle closure with visible trabecular meshwork (TM) after iridotomy, especially in highly pigmented eyes of Southeast Asians.

How to cite this article

Wongwuticomjon T, Chansangpetch S, Inobhas A, et al. Efficacy of Selective Laser Trabeculoplasty in Primary Angle-closure Glaucoma after Peripheral Iridotomy. J Curr Glaucoma Pract 2022;16(2):124-127.

Rate of central corneal thickness changes in primary angle closure eyes: long-term follow-up results

Background

Central corneal thickness (CCT) and its association with intraocular pressure, which is a pivotal parameter in glaucoma management, has previously been reported. In this study, we intended to investigate the long-term change of CCT in terms of rate in eyes with primary angle-closure (PAC). Additionally, we aimed to analyze events that could affect CCT.

Methods

In this retrospective study, 26 patients with PAC who had a follow-up period of more than 5 years were analyzed. The rate of CCT changes from baseline was evaluated from the serial CCT measurements over the average follow-up period. The pattern of CCT change rate according to modes of treatment and history of angle-closure attack was analyzed using the repeated linear mixed model analysis.

Results

A total of 52 eyes were enrolled. The CCT reduction rate of the entire study population was − 0.72 ± 0.22 μm/yr (P = 0.001) with statistical significance. The CCT thinning rate of the laser peripheral iridotomy (PI) group was − 0.53 ± 0.25 μm/yr (P = 0.034) and that of the surgical trabeculectomy group was − 1.32 ± 0.43 μm/yr (P = 0.002), and it was not statistically significant (P = 0.112). The rate of CCT thinning in patients with a history of acute angle-closure attack was − 0.81 ± 0.31 μm/yr (P = 0.009) and that in patients without an attack was − 0.63 ± 0.30 μm/yr (P = 0.001), and it was not statistically significant (P = 0.680). Baseline CCT appeared to be the only significant factor affecting the rate of CCT changes (P < 0.001).

Conclusions

We found a significant reduction in CCT over a long observation period in PAC eyes. We also found that the rates of CCT reduction were not affected by different treatment modalities or acute angle-closure attacks. The analysis of long-term CCT changes in conjunction with baseline CCT would also be helpful in the clinical evaluation of the PAC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-01908-4.

Changes in anterior chamber volume after implantation of posterior chamber phakic intraocular lens in high myopia

Background

The present study aimed to assess changes in, and the factors that influence, anterior chamber volume (ACV) after implantable contact lens (ICL) implantation in high myopia eyes using a Pentacam.

Methods

The study sampled 26 high myopia patients (45 eyes) who were treated with ICL implantation. These patients were followed for an average of 4.28 months postoperatively. ACV was measured with a Pentacam preoperatively and at 3 months postoperatively. The data were analyzed by paired samples Wilcoxon signed-rank test. Generalized estimating equation (GEE) model adjusting within-patient intereye correlations in addition to Pearson’s and Spearman’s correlation tests were performed to determine associations.

Results

The mean ACV was 198.33 ± 33.08 mm³ before surgery and 118.65 ± 17.70 mm³ after surgery. A significant decrease of 79.68 mm³ (40.18%) (Z = 5.841, P <  0.001) was detected. Positive correlations were found between ACV changes and ICL central vault (r = 0.528, P <  0.001) and preoperative anterior chamber depth (ACD) (r = 0.665, P <  0.001). There were positive correlations between postoperative ACV and postoperative anterior chamber angle (ACA) at 3:00 o’clock (r = 0.448, P = 0.002) and at 9:00 o’clock (r = 0.405, P = 0.006). GEE regression model showed that postoperative ACV significantly positively correlated with preoperative ACV (P = 0.002), ACD (P = 0.002) and horizontal ACA (P = 0.005) and negatively correlated with ICL central vault (P <  0.001).

Conclusion

Complementary to vault and ACD, ACV is a sensitive parameter with certain value of preoperative assessment and postoperative monitoring in ICL implantation.

[Role of the aging visual system in glaucoma]

BACKGROUND

Glaucoma is the second leading cause of blindness worldwide and is usually diagnosed in higher age groups. The goal was to survey how patient age influences the development of glaucoma.

MATERIALS AND METHODS

A web-based search on aging of the visual system and its influence on glaucoma was performed and the most important results are summarized.

RESULTS

The prevalence of glaucoma rises with age. Aging processes of the trabecular meshwork and the uveoscleral outflow pathway lead to a rise in the intraocular pressure. Chronically elevated intraocular pressure leads to remodelling of the lamina cribrosa and narrowing of its pores through which ganglion cell axons leave the eye. Age-dependent glia cell, mitochondria and immune system alterations are discussed to influence glaucoma. Patient age and further age-related nonophthalmological systemic diseases also influence adherence and persistence to the prescribed therapy.

CONCLUSIONS

Aging is an important risk factor for developing glaucoma and is a main factor which influences therapy and course of the disease. At this point in time it remains unclear to which extent additional factors determine the development of glaucoma.