Elevated Transforming Growth Factor-β2 in the Aqueous Humor: A Possible Explanation for High Rate of Capsular Contraction Syndrome in High Myopia

Outcomes of Cataract Surgery in Eyes With Axial Length > 33 mm

PURPOSE

To evaluate the visual outcomes and perioperative complications for cataract surgery in eyes with axial length (AL) >33.0 mm.

DESIGN

Prospective clinical cohort study.

METHODS

One hundred twenty-two eyes with moderate high myopia (26.0 mm ≤ AL < 28.0 mm, control group), and 118 eyes with extreme high myopia (AL > 33.0 mm, EHM group) were followed up after cataract surgery (1 week and 1 year post-op). Myopic maculopathy grading according to ATN system, best-corrected visual acuity (BCVA), and complications were compared.

RESULTS

Postoperatively, BCVA in the EHM group improved significantly at both visits (both P < .001), despite being worse than that of the control group (both P < .05). The EHM group exhibited greater hyperopic refractive errors (P < .001), which were found to be associated with more severe T grade, longer AL, poorer second follow-up BCVA, and smaller anterior capsular opening (ACO) area. A higher incidence of retinal detachment and a more constricted ACO were observed in the EHM group (P = .030 and <.001, respectively), with the latter being significantly associated with longer AL and the absence of capsular tension ring (both P < .05). No difference in BCVA was found between the aphakic and pseudophakic eyes in the EHM group at both visits (both P > .05).

CONCLUSION

Cataract surgery improves vision of eyes with AL >33 mm, yet the increased risk of perioperative complications requires attention. Leaving these eyes aphakic might be effective and safe in the long term.

Complications of high myopia: An update from clinical manifestations to underlying mechanisms

Background

High myopia is one of the major causes of visual impairment and has an ever-increasing prevalence, especially in East Asia. It is characterized by excessive axial elongation, leading to various blinding complications that extend beyond mere refractive errors and persist immovably after refractive surgery, presenting substantial public health challenge.

Main text

High myopia-related complications include lens pathologies, atrophic and tractional maculopathy, choroidal neovascularization, peripheral retinal degenerations and retinal detachment, and glaucoma and heightened susceptibility to intraocular pressure (IOP) elevation. Pathological lens changes characteristic of high myopia include early cataractogenesis, overgrowth of lens, weakened zonules, and postoperative capsular contraction syndrome, possibly driven by inflammatory pathogenesis, etc. Dome-shaped macula and cilioretinal arteries are two newly identified protective factors for central vision of highly myopic patients. These patients also face risks of open-angle glaucoma and IOP spike following intraocular surgery. Morphologic alternations of optic nerve in high myopia can complicate early glaucoma detection, necessitating comprehensive examinations and close follow-up. Anatomically, thinner trabecular meshwork increases this risk; conversely lamina cribrosa defects may offer a fluid outlet, potentially mitigating the pressure. Notably, anxiety has emerged as the first recognized extra-ocular complication in high myopia, with an underlying inflammatory pathogenesis that connects visual stimulus, blood and brain.

Conclusions

High myopia induces multiple ocular and potential mental health complications, underscoring the need to develop more effective strategies to improve both physical and emotional well-being of these patients, among which anti-inflammation might possibly represent a promising new target.

Exploring anterion capsular contraction syndrome in cataract surgery: insights into pathogenesis, clinical course, influencing factors, and intervention approaches

Anterior capsular contraction syndrome (ACCS) is a challenging complication that can occur following phacoemulsification cataract surgery. Characterized by capsular bag wrinkling, intraocular lens (IOL) decentration and tilt, ACCS can have negative effects on visual outcomes and patient satisfaction. This review aims to investigate the pathogenesis, clinical course, influencing factors, and intervention approaches for ACCS after cataract surgery. By understanding the underlying mechanisms and identifying factors that contribute to ACCS, surgeons can enhance their ability to predict and manage this complication. Various intervention strategies are discussed, highlighting their importance in reducing complications and improving surgical outcomes. However, further research is needed to determine optimal prevention and management strategies through long-term follow-up and comparative analyses. Advancements in this field will ultimately lead to improved visual outcomes and optimized cataract surgery for patients.

Cataract surgery in myopic eyes

PURPOSE OF REVIEW

We discuss the preoperative, intraoperative, and postoperative considerations for cataract surgery in eyes with high myopia. We also reviewed the recent literature on refractive outcomes and complications of cataract surgery in myopic eyes.

RECENT FINDINGS

Several novel intraocular lens (IOL) power calculation formulas have recently been developed to optimize refractive outcomes. Haigis formula is the most accurate among the third-generation IOL formulas. Novel formulas such as Barrett Universal II, Kane, and modified Wang-Koch adjustment for Holladay I formula provide a better refractive prediction compared with old formulas. Intraoperatively, the chopping technique is preferred to minimize pressure on weak zonules and reduce the incidence of posterior capsule rupture. Anterior capsular polishing is recommended to reduce the risk of postoperative capsular contraction syndrome (CCS). Postoperatively, complications such as refractive surprises, intraocular pressure spikes, and CCS remain higher in myopic eyes. Only 63% of myopic patients with axial length more than 26 mm achieve a visual acuity at least 20/40 after cataract surgery, mainly because of coexisting ocular comorbidities.

SUMMARY

There are multiple preoperative, intraoperative, and postoperative considerations when performing cataract surgery in myopic eyes. Further research is needed to optimize the refractive outcomes in these eyes and determine the best IOL formula. Surgeons should be adept and knowledgeable with different techniques to manage intraoperative complications.

TGF-β2 levels in the aqueous humor are elevated in the second eye of high myopia within two weeks after sequential cataract surgery

Transforming growth factor-β (TGF-β) is the critical regulator of physiological and pathological conditions in lens. The TGF-β signaling pathway is closely associated with high myopia patients. Thirty eyes from fifteen patients with high myopia who received sequential cataract surgery were enrolled in this prospective study. Ten cataract patients with non-myopia were chosen as a control group. Aqueous humor (AH) samples were used to detect the levels of TGF-β1, TGF-β2, and TGF-β3 in both groups. Compared with the non-myopic cataracts patient group, the highly myopic cataracts group had a significantly higher TGF-β2 (P = 0.019). Besides, the level of TGF-β2 of the second eye was significantly higher than that in the first eye in high myopia cataract patients group (P = 0.037). And TGF-β1 showed significant differences with age and axial length of high myopia cataract patients. Therefore, TGF-β2 may contribute to the development of high myopia and cataract surgery increased the expression of TGF-β2.

Effect of capsular tension ring implantation on capsular stability after phacoemulsification in patients with weak zonules: a randomized controlled trial. CTR implantation in cataract patients with weak zonules

BACKGROUND

The use of capsular tension ring (CTR) implantation to treat cataract patients with weak zonules is still controversial. The aim of this study was to examine the effects of CTR implantation on capsular stability after phacoemulsification in patients with weak zonules, especially patients who have undergone pars plana vitrectomy (PPV) or those who suffer from severe myopia.

METHODS

A total of 42 patients who underwent phacoemulsification and received an intraocular lens (IOL) were randomized to undergo CTR implantation or not. The control and CTR groups were compared in terms of uncorrected distant visual acuity (UDVA), best corrected distant visual acuity (BCDVA), refractive prediction error, the area of anterior capsulorhexis, and IOL inclination angle. Follow-up visits were conducted postoperatively at 1 day, 1 week, 1 month and 3 months. Subgroup analyses were performed based on PPV and severe myopia.

RESULTS

Surgery significantly improved UDVA and BCDVA to similar extents in CTR and control patients, and refraction prediction error was similar between the two groups at all follow-up times. At 3 months after surgery, the area of anterior capsulorhexis was significantly larger in CTR patients than in controls (p = 0.0199). These differences were also significant between the subgroups of patients with severe myopia. Vertical IOL inclination was less within CTR groups at 3 months after surgery, especially in patients with severe myopia (p = 0.0286). At 1 week postoperatively, the proportion of individuals whose posterior lens capsule that had completely adhered to the posterior IOL surface was significantly higher among CTR patients (p = 0.023). No serious surgical complications were observed.

CONCLUSION

CTR implantation can benefit cataract patients with weak zonules by maintaining the shape of the capsular bag, reducing capsule shrinkage and stabilizing IOL inclination.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR-INR-17011217 , date of registration April 22, 2017, prospectively registered.

Proteomic analysis of Exosomes derived from the Aqueous Humor of Myopia Patients

Objectives: Myopia is the most common refractive vision disorder. In recent years, several studies have suggested that the alteration of the exosomal protein levels in the aqueous humor (AH) is associated with the development of several eye diseases. Therefore, we aimed to explore the exosomal protein profile of the AH from myopia patients. Methods: Exosomes were isolated from the AH. The quality, concentration, and size distribution of exosomes for each patient were measured using nanoparticle tracking analysis system. Then, the exosomal proteins were purified and digested by trypsin for liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Results: There was no significant difference observed between the myopia and control when comparing the concentration and size distribution of exosomes in the AH for each sample. Based on LC-MS/MS analysis, myopia patients had higher and more complex exosomal peptide content. We found two proteins that were common in AH exosomes and eight proteins that were highly expressed in the myopia group. Conclusions: Our results provide pioneering findings for the exploration of the exosomal protein profile in myopia development. Further studies may provide significant information for the diagnosis, clinical treatment, and prognosis of myopia.

Expression Profiles of Inflammatory Cytokines in the Aqueous Humor of Children after Congenital Cataract Extraction

Purpose

To investigate the change in cytokine microenvironment of the aqueous humor (AH) after surgery in children with congenital or developmental cataracts.

Methods

AH samples were obtained from 59 eyes diagnosed with a congenital or developmental cataract. Thirty-three of these eyes were aphakic following previous cataract surgery and were scheduled for secondary intraocular lens (IOL) implantation. Additionally, AH samples from 26 eyes that had not undergone surgery were taken. AH samples were then analyzed for 16 different inflammatory immune mediators using multiplex bead immunoassays and enzyme-linked immunosorbent assay (ELISA).

Results

The mean interval between secondary IOL implantation and original cataract surgery was 24.85 months (range, 9–60 months). Levels of IL-6, IP-10 (CXCL10), MCP-1 (CCL2), and IL-2 were significantly elevated in the AH of eyes after surgery compared to eyes that did not undergo surgery (P < 0.001, P = 0.047, P = 0.006, P = 0.012, respectively). There was significant correlation between the levels of TGF-β2 and intraocular pressure (IOP) in postsurgical and nonsurgical eyes (r = 0.532, P = 0.006; r = 0.57, P = 0.001). Postsurgical outcomes, such as iris adhesions, capsular fibrosis, and capsular contraction, were found not to be significantly associated with cytokine levels in the AH after surgery; however, IL-6 levels in capsular exposure eyes were significantly higher than those in cortical closure eyes (P = 0.023).

Conclusions

To our knowledge, this is the first study to report significantly increased proinflammatory cytokine levels in the AH after congenital cataract extraction in children. Our study also suggests that this proinflammatory state may be maintained for a prolonged period of time. Overall, these results give us insight into the relationship between the inflammatory cytokine microenvironment of the aqueous humor and potential long-term complications following congenital cataract surgery.

Translational Relevance

The inflammatory cytokine microenvironment of the aqueous humor might help explain potential long-term complications after surgery in patients with congenital or developmental cataracts.

Decentration and tilt of plate-haptic multifocal intraocular lenses in myopic eyes

Background

To investigate the decentration and tilt of plate-haptic multifocal intraocular lenses (MfIOLs) in myopic eyes.

Methods

Myopic (axial length [AXL] > 24.5 mm) and non-myopic (21.0 mm < AXL ≤ 24.5 mm) cataract eyes were enrolled in this prospective study and randomly assigned to receive implantation of Zeiss AT LISA tri 839MP lenses (Group A) or Tecnis ZMB00 lenses (Group B). In total, 122 eyes of 122 patients were available for analysis. Decentration and tilt of MfIOLs, high-order aberrations (HOAs), and modulation transfer functions (MTFs) were evaluated using the OPD-Scan III aberrometer 3 months postoperatively. Subjective symptoms were assessed with a Quality of Vision questionnaire.

Results

Near and distance visual acuities, tilt and horizontal decentration did not differ between the two groups, postoperatively. However, myopic eyes of Group B showed greater vertical decentration than those of Group A (− 0.17 ± 0.14 mm vs. -0.03 ± 0.09 mm, respectively), particularly when the MfIOLs were placed horizontally or obliquely. Overall decentration of myopic eyes was greater in Group B than in Group A (0.41 ± 0.15 mm vs. 0.16 ± 0.10 mm, respectively). In Group B, AXL was negatively correlated with vertical decentration and positively correlated with overall decentration. No such correlations were found in Group A. Intraocular total HOAs, coma, trefoil and spherical aberrations were lower in Group A than in Group B for a 6.0 mm pupil among myopic eyes. Generally, Group A had better MTFs and fewer subjective symptoms than Group B among myopic eyes.

Conclusions

Plate-haptic design of MfIOLs may be a suggested option for myopic cataract eyes due to the less inferior decentration and better visual quality postoperatively.

Measurement of crystalline lens tilt in high myopic eyes before cataract surgery using swept-source optical coherence tomography

Background

To measure the crystalline lens tilt in eyes with various degrees of myopia before cataract surgery using swept-source optical coherence tomography (SS-OCT).

Methods

We used SS-OCT (IOLMaster 700) to scan 131 emmetropic eyes (axial length < 24.5 mm), 25 mild/moderate myopic eyes (axial length 24.5-26 mm), and 123 high myopic eyes (52, 29, and 42 eyes with axial lengths of 26-28, 28-30, and > 30 mm, respectively) as part of the routine preoperative examination before cataract surgery. SS-OCT involved B-scans along six meridians. The data were analyzed to assess the magnitude and orientation of the lens tilt and their correlation with other optical biometric parameters.

Result

The mean tilt was 3.36 ± 0.98° in emmetropic eyes, 3.07 ± 1.04° in mild/medium myopic eyes, and 2.35 ± 1.01° in high myopic eyes. Tilt correlated significantly and inversely with axial length (Pearson's r = - 0.427, P < 0.001). The crystalline lens tilt predominantly faced the upper outer quadrant relative to the visual axis, symmetrically in both eyes, with mean angles of 24.32° and 147.36° in the right and left eyes, respectively. The variability in the lens tilt direction increased with increasing axial length (χ² test, P < 0.001).

Conclusion

The magnitude of crystalline lens tilt decreased with increasing axial length. The direction of tilt was predominantly towards the upper outer quadrant in both eyes. The variability in the tilt orientation increased with increasing axial length.

Trial registration

NIH (clinicaltrial.gov), NCT03062085. Registered 23 February 2017.

Profiling and Bioinformatic Analysis of Differentially Expressed Cytokines in Aqueous Humor of High Myopic Eyes - Clues for Anti-VEGF Injections

Purpose: To investigate the aqueous humor growth factor profile in high myopic eyes and analyze the interaction of differentially expressed cytokines.Methods: A case-control study including aqueous humor samples from 36 high myopic patients and 32 controls was conducted. Quantibody® Human Growth Factor Array was used to screen the presence of 40 growth factors in aqueous humor. Expressions of differential growth factors were validated by Bio-Plex Pro^TM multiplex bead-based immunoassay. Protein-protein interaction (PPI) and gene ontology (GO) analyses were performed.Results: Growth differentiation factor 15 (GDF-15), hepatocyte growth factor (HGF), and platelet-derived growth factor (PDGF)-AA were found to be significantly higher and vascular endothelial growth factor (VEGF) was detected to be lower in high myopic eyes (all P = .03). Multi-plex bead-based assay further validated the differential expressions of four growth factors and all of them were significantly correlated with axial length (P < .001). Twenty-six proteins were mapped into PPI network and positive regulation of cell migration, cellular component movement, and cell motility were the most enriched biological processes based on GO analysis.Conclusions: Differential expressed cytokines that indicates a distinctive intraocular microenvironment in high myopic eyes might provide clues for pathological changes within high myopic eyes after anti-VEGF injections.

Cataracts

An estimated 95 million people worldwide are affected by cataract. Cataract still remains the leading cause of blindness in middle-income and low-income countries. With the advancement of surgical technology and techniques, cataract surgery has evolved to small-incisional surgery with rapid visual recovery, good visual outcomes, and minimal complications in most patients. With the development of advanced technology in intraocular lenses, the combined treatment of cataract and astigmatism or presbyopia, or both, is possible. Paediatric cataracts have a different pathogenesis, surgical concerns, and postoperative clinical course from those of age-related cataracts, and the visual outcome is multifactorial and dependent on postoperative visual rehabilitation. New developments in cataract surgery will continue to improve the visual, anatomical, and patient-reported outcomes. Future work should focus on promoting the accessibility and quality of cataract surgery in developing countries.