Accommodative Exercises to Lower Intraocular Pressure

Exploring the relationship between accommodation and intraocular pressure: a systematic literature review and meta-analysis

PURPOSE

To investigate the relationship between accommodation and intraocular pressure (IOP).

METHODS

Systematic literature search and meta-analysis following PRISMA guidelines was conducted on studies analyzing the relationship between accommodation and intraocular pressure. After removal of duplicates, title and abstract screening, full-text analysis was performed to select relevant articles and meta-analysis was then conducted as well.

RESULTS

Of the 1357 records identified, 17 met the selection criteria and were included. Overall, all studies showed that accommodation can influence IOP levels and meta-analysis indicated a significant IOP reduction of 1.10 mmHg (95%CI, -1.77; -0.42) following accommodative stimulus in healthy individuals, albeit with high heterogeneity among studies. Differences in IOP changes between emmetropic and progressing myopic individuals were not significant. Controversial results were obtained in patients with glaucoma with significantly lower IOP fluctuations being noted in eyes with previous trabeculectomy; however, the clinical heterogeneity of enrolled patients among studies made it not possible to combine results. Type of accommodative task, extraocular muscle contraction, head and body position all could potentially play a role in the measured IOP changes with, interestingly, near reading on a smartphone suggesting IOP increase.

CONCLUSION

Accommodation has an impact on IOP measurements and, overall, determines IOP decrease in healthy individuals. While such variations might not hold clinical significance for individuals in good health, their impact in patients with glaucoma should be considered. Further studies focused on specific components of such relationship are required to elucidate their individual impact and to define their potential role as non-pharmacological strategies to reduce IOP levels in selected patient categories.

Pharmaceutical In Situ Gel for Glaucoma: Recent Trends and Development with an Update on Research and Patents

Glaucoma is a progressive visual polyneuropathy characterized by retinal ganglion cell atrophy and optic nerve head changes. It's generally triggered due to increased intraocular pressure compared with the healthy eye. Glaucoma is treated with various medications in traditional eye drops, such as prostaglandins, carbonic anhydrase inhibitors, beta-blockers, and others. Such treatments are difficult to use and produce lachrymal leakage and inadequate corneal permeability, resulting in lower availability. Ophthalmic in situ gels, introduced in past decades with tremendous effort, are among the finest various choices to solve the drawbacks of eye drops. Employing different polymers with pH-triggered, temperature-triggered, and ion-activated processes have been used to generate ophthalmic in situ gelling treatments. Once those preparations are delivered into the eye, they change phase from sol to gel, allowing the medicine to stay in the eye for longer. These formulations are known as smart gels as they turn into gelling fluids when administered into the eyes. The different mechanisms of in situ gel formulations are used for the management of glaucoma and are discussed in this review article.

A Review of Intraocular Pressure (IOP) and Axial Myopia

The pathogenesis of myopia is driven by genetic and environmental risk factors. Accommodation not only alters the curvature and shape of the lens but also involves contraction of the ciliary and extraocular muscles, which influences intraocular pressure (IOP). Scleral matrix remodeling has been shown to contribute to the biomechanical susceptibility of the sclera to accommodation-induced IOP fluctuations, resulting in reduced scleral thickness, axial length (AL) elongation, and axial myopia. The rise in IOP can increase the burden of scleral stretching and cause axial lengthening. Although the accommodation and IOP hypotheses were proposed long ago, they have not been validated. This review provides a brief and updated overview on studies investigating the potential role of accommodation and IOP in myopia progression.

Comparison Between an Intraocular Lens With Extended Depth of Focus (Tecnis Symfony ZXR00) and a New Monofocal Intraocular Lens With Enhanced Intermediate Vision (Tecnis Eyhance ICB00)

PURPOSE

This study compared the extended depth of focus (EDOF) intraocular lens (IOL) (ZXR00; Tecnis Symfony, Johnson & Johnson Vision, Santa Ana, CA, US) to a novel, higher-order aspheric monofocal IOL (ICB00; Tecnis Eyhance, Johnson & Johnson Vision, Santa Ana, CA, US) which uses the same platform and material.

METHODS

Medical records of patients undergoing cataract surgery with ZXR00 or ICB00 implantation between March 2020 and January 2021 and with the data available for the 3-month visit were reviewed. The uncorrected near, intermediate, and distance visual acuity (VA); corrected distance VA; and optical quality parameters were the main outcome measures.

RESULTS

Among the 174 enrolled patients, 72 and 102 received the ZXR00 and ICB00, respectively. The average patient ages were 59.6 ± 10.6 (range: 49 to 70) and 65.2 ± 8.2 (range: 45 to 82) years in the ZXR00 and ICB00 groups, respectively, with significantly older patients in the ICB00 group. The other baseline parameters were not different for the 2 groups. Compared to the ICB00 group, the ZXR00 group showed markedly superior near VA (P < 0.05) at 3 months postoperatively. In terms of optical quality, ICB00 was, statistically, significantly superior to ZXR00.

CONCLUSIONS

The ZXR00 showed remarkable near vision and defocus curve smoothness, while the ICB00 achieved better optical quality. The 2 IOLs had comparable distance and intermediate vision.

Dynamic changes of scleral spur length in different accommodation stimuli states

This study aimed to evaluate the scleral spur length (SSL) in response to different accommodation stimuli states, as well as the correlation with Schlemm’s canal (SC) and trabecular meshwork (TM). 74 children were recruited for this study. The 0D, − 4D, and − 8.0 D accommodation stimuli state was achieved by looking at a variable distance optotype. The ciliary muscle (CM), scleral spur (SS), SC, and TM were imaged by swept-source optical coherence tomography. The SSL (Method III) increased significantly from 221.56 ± 30.74 μm at base state to 234.99 ± 30.11 μm at − 4D accommodation stimuli state (p = 0.028) and increased to 250.09 ± 29.87 μm at − 8D accommodation stimuli state (p = 0.011). Method III had the largest areas under receiver operating characteristic (ROC) curves (0.798, 95% CI 0.721–0.875). Moreover, CM 1, SC, and trabecular meshwork length (TML) were significantly correlated with SSL (Method III) (p < 0.05). These findings suggest that the contractile ability and compliance of the SS play an important role in maintaining the morphology of the SC. Moreover, the force of accommodation regulates the SC size by increasing the length of SS.