A histopathologic study of zonular instability in pseudoexfoliation syndrome

Prevalence and prediction of intraoperative floppy iris syndrome in patients with pseudoexfoliation syndrome

OBJECTIVE

To investigate the incidence of intraoperative floppy iris syndrome (IFIS) in patients with pseudoexfoliation syndrome (PXF) and analyze preoperative ocular predicting factors.

DESIGN

A retrospective case-control study METHODS: The study included 224 eyes with PXF and 287 control eyes without PXF. One eye per patient, who underwent cataract surgery at the Wolfson Medical Center between January 2020 to December 2021, was included. Medical records of the patients were reviewed. Data collected included demographic characteristics, medical history, preoperative comprehensive ophthalmic examination, biometry, surgical procedure details, and IFIS occurrence. The association of IFIS with preoperative ocular parameters was analyzed through both univariant and multivariant analyses.

RESULTS

Patients with PXF were older and had a higher prevalence of glaucoma (77.6 ± 6.4 years vs 74.2±7.6 years; p < 0.001, and 20.1 % vs 9.8 %, p < 0.001, respectively). Prevalence of α-blockers treatment was similar in both groups. IFIS rate among the PXF group was 12.5% (n = 28) compared to 7.3% (n = 21) in the control group (p < 0.05). When omitting patients exposed to α-blockers, the PXF group exhibited a significantly higher IFIS rate (9.9% vs 4.8%; p < 0.05). Pupil dilation diameter was significantly lower among PXF patients (5.8 ± 1.1 mm vs 6.9 ± 0.99 mm; p < 0.001). Biometric evaluation revealed significant differences in anterior segment depth (ACD) and lens thickness (LT). Multivariate analysis indicated that PXF and decreased mydriatic pupil size remained significant predictors of IFIS.

CONCLUSION

This study establishes an association between PXF and an increased risk of IFIS during cataract surgery, independent of α-blockers treatment.

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.

Secondary glaucoma: Toward interventions based on molecular underpinnings

Glaucoma is a heterogeneous group of progressive diseases that leads to irreversible blindness. Secondary glaucoma refers to glaucoma caused by a known underlying condition. Pseudoexfoliation and pigment dispersion syndromes are common causes of secondary glaucoma. Their respective deposits may obstruct the trabecular meshwork, leading to aqueous humor outflow resistance, ocular hypertension, and optic neuropathy. There are no disease-specific interventions available for either. Pseudoexfoliation syndrome is characterized by fibrillar deposits (pseudoexfoliative material) on anterior segment structures. Over a decade of multiomics analyses taken together with the current knowledge on pseudoexfoliative glaucoma warrant a re-think of mechanistic possibilities. We propose that the presence of nucleation centers (e.g., vitamin D binding protein), crosslinking enzymes (e.g., transglutaminase 2), aberrant extracellular matrix, flawed endocytosis, and abnormal aqueous-blood barrier contribute to the formation of proteolytically resistant pseudoexfoliative material. Pigment dispersion syndrome is characterized by abnormal iridolenticular contact that disrupts iris pigment epithelium and liberates melanin granules. Iris melanogenesis is aberrant in this condition. Cytotoxic melanogenesis intermediates leak out of melanosomes and cause iris melanocyte and pigment epithelium cell death. Targeting melanogenesis can likely decrease the risk of pigmentary glaucoma. Skin and melanoma research provides insights into potential therapeutics. We propose that specific prostanoid agonists and fenofibrates may reduce melanogenesis by inhibiting cholesterol internalization and de novo synthesis. Additionally, melatonin is a potent melanogenesis suppressor, antioxidant, and hypotensive agent, rendering it a valuable agent for pigmentary glaucoma. In pseudoexfoliative glaucoma, where environmental insults drive pseudoexfoliative material formation, melatonin's antioxidant and hypotensive properties may offer adjunct therapeutic benefits. This article is categorized under: Neurological Diseases > Molecular and Cellular Physiology.

Prevalence of pseudoexfoliation in diabetic patients with senile cataract: A hospital-based study in Kashmir, India

Purpose

: To study the prevalence of pseudoexfoliation syndrome (PEX) in diabetics with senile cataracts and compare it to the prevalence in nondiabetic control group.

Methods

: Two hundred and fifty diabetics and 250 nondiabetics (age and sex matched) were evaluated for PEX deposition.

Results

: Chi-squared test was employed, and a P value < 0.05 was considered significant. In the PEX group, most patients belonged to the age group of 60-70 years (55.17%). Out of 18 patients with PEX, 11 (61.1%) showed bilaterality. There was a higher frequency of raised intraocular pressure (IOP; >20 mmHg) in PEX eyes (10.3%) than in the non-PEX eyes (5.9%). The PEX group had a higher number of eyes with cup-to-disc ratio (CDR) >0.6 (11.12%) than the non-PEX group (4.32%). Nuclear cataracts were more frequent in PEX eyes than non-PEX eyes, whereas PSC and mature cataracts were more prevalent in the non-PEX group. Most eyes had PEX deposition on the anterior lens capsule and pupillary margin. Of the 500 study eyes corresponding to the diabetic group, 418 had cataracts (rest pseudophakic), of which 28 had pseudoexfoliation, accounting for 6.7% of the total. In the nondiabetic control group comprising 500 eyes, 430 had senile cataracts (rest pseudophakic), of which 105 had PEX deposition, accounting for 24.4% of the total.

Conclusion

: According to our findings, diabetics have a lower prevalence of PEX than nondiabetics. Few such studies have been conducted so far, and none have been conducted in the Indian population.

Clinical profile and demographic distribution of pseudoexfoliation syndrome: An electronic medical record-driven big data analytics from an eye care network in India

Purpose

To describe the demographics and clinical profile of pseudoexfoliation syndrome (PXF or PES) in patients presenting to a multi-tier ophthalmology hospital network in India.

Methods

This cross-sectional hospital-based study included 3,082,727 new patients presenting between August 2010 and December 2021. Patients with a clinical diagnosis of PXF in at least one eye were included as cases. The data were collected using an electronic medical record system.

Results

Overall, 23,223 (0.75%) patients were diagnosed with PXF. The majority of the patients were male (67.08%) and had unilateral (60.96%) affliction. The most common age group at presentation was during the seventh decade of life with 9,495 (40.89%) patients. The overall prevalence was higher in patients from a lower socio-economic status (1.48%) presenting from the urban geography (0.84%) and in retired individuals (3.61%). The most common location of the PXF material was the pupillary margin (81.01%) followed by the iris (19.15%). The majority of the eyes had mild or no visual impairment (<20/70) in 12,962 (40.14%) eyes. PXF glaucoma was documented in 7,954 (24.63%) eyes. Krukenberg's spindle was found in 64 (0.20%) eyes, phacodonesis in 328 (1.02%) eyes, and lens subluxation in 299 (0.93%) eyes. Among the surgical interventions, cataract surgery was performed in 8,363 (25.9%) eyes, trabeculectomy was performed in 966 (2.99%) eyes, and a combined procedure in 822 (2.55%) eyes.

Conclusion

PXF more commonly affects males presenting during the seventh decade of life from lower socio-economic status and is predominantly unilateral. A quarter of the affected eyes are associated with glaucoma and the majority of the eyes have mild or no visual impairment.

Long-Term Evaluation of Pseudoexfoliation Syndrome Post-Cataract Extraction

The study aimed to examine the effect of cataract extraction on ophthalmologists' ability to detect pseudoexfoliation (PXF) syndrome. A total of 31 patients admitted for elective cataract surgery were enrolled in this prospective comparative study. Prior to surgery, patients underwent slit-lamp examination and gonioscopy conducted by experienced glaucoma specialists. Subsequently, patients were re-examined by a different glaucoma specialist and comprehensive ophthalmologists. Pre-operatively, 12 patients were diagnosed with PXF on the basis of a Sampaolesi line (100%), anterior capsular deposits (83%), and pupillary ruff deposits (50%). The remaining 19 patients acted as controls. All patients were re-examined 10-46 months post-operatively. Of the 12 patients with PXF, 10 (83%) were correctly diagnosed post-operatively by glaucoma specialists and 8 (66%) by comprehensive ophthalmologists. There was no statistically significant difference in PXF diagnosis. However, detection of anterior capsular deposits (p = 0.02), Sampaolesi lines (p = 0.04), and pupillary ruff deposits (p = 0.01) were significantly lower post-operatively. Diagnosis of PXF is challenging in pseudophakic patients as the anterior capsule is removed during cataract extraction. Therefore, PXF diagnosis in pseudophakic patients relies mainly on the presence of deposits at other anatomical sites, and careful attention to these signs is required. Glaucoma specialists may be more likely than comprehensive ophthalmologists to detect PXF in pseudophakic patients.

Incidence and Risk Factors for Berger's Space Development after Uneventful Cataract Surgery: Evidence from Swept-Source Optical Coherence Tomography

Background: This study investigates the incidence and risk factors for the development of Berger’s space (BS) after uneventful phacoemulsification based on swept-source optical coherence tomography (SS-OCT). Methods: Cataractous eyes captured using qualified SS-OCT images before and after uneventful phacoemulsification cataract surgery were included. Six high-resolution cross-sectional anterior segment SS-OCT images at 30° intervals were used for BS data measurements. BS width was measured at three points on each scanned meridian line: the central point line aligned with the cornea vertex and two point lines at the pupil’s margins. Results: A total of 223 eyes that underwent uneventful cataract surgery were evaluated. Preoperatively, only two eyes (2/223, 0.9%) were observed to have consistent BS in all six scanning directions. BS was observed postoperatively in 44 eyes (44/223, 19.7%). A total of 13 eyes (13/223, 5.8%) with insufficient image quality, pupil dilation, or lack of preoperative image data were excluded from the study. A total of 31 postoperative eyes with BS and 31 matched eyes without BS were included in the final data analysis. The smallest postoperative BS width was in the upper quadrant of the vertical meridian line (90°), with a mean value of 280 μm. The largest BS width was observed in the opposite area of the main clear corneal incision, with a mean value >500 μm. Conclusions: Uneven-width BS is observable after uneventful phacoemulsification. Locations with a much wider BS (indirect manifestation of Wieger zonular detachment) are predominantly located in the opposite direction to the main corneal incisions.

Bilateral posterior capsule rupture and anterior vitreous prolapse from vigorous eye rubbing

Purpose

We present the case of a 71-year-old male who developed decreased visual acuity eleven years after uncomplicated bilateral cataract extraction and in-the-bag IOL implantation following recent bouts of vigorous eye rubbing.

Observations

On examination, the posterior capsules were ruptured centrally in both eyes, and there was anterior vitreous prolapse bilaterally. While both IOLs remained in the visual axis, there was mild bilateral decentration and resultant decreased vision.

Conclusion and importance

To the authors’ knowledge, this is the first reported case of bilateral simultaneous posterior capsule rupture with anterior vitreous prolapse due to eye rubbing. Contrasting to previous case reports, this scenario demonstrates that severe eye rubbing can have variable severity and complications. Frequent and vigorous eye rubbing can be a precipitating cause of late postoperative posterior capsule rupture and should be avoided in pseudophakic patients, especially those with older IOL models.

3D Modeling of the Crystalline Lens Complex under Pseudoexfoliation

Pseudoexfoliation, one of the most frequent crystalline lens complex disorders, is prevalent in up to 30% of individuals older than 60 years old. This disease can lead to severe conditions, such as subluxation or dislocation of the lens, due to the weakening of the zonules. The goal for the present study was to understand the relevant biomechanical features that can lead to the worsening of an individual’s visual capacity under pseudoexfoliation. To this end, finite element models based on a 62-year-old lens complex were developed, composed by the capsular bag, cortex, nucleus, anterior, equatorial, and posterior zonular fibers. Healthy and pseudoexfoliative conditions were simulated, varying the location of the zonulopathy (inferior/superior) and the degenerated layer. The accommodative capacity of the models with inferior dialysis of the zonular fibers was, on average, 4.7% greater than for the cases with superior dialysis. If the three sets of zonules were disrupted, this discrepancy increased to 14.9%. The present work provides relevant data to be further analyzed in clinical scenarios, as these models (and their future extension to a wider age range) can help in identifying the most influential regions for the reduction of the visual capacity of the lens.

Intraocular Pressure in Eyes with Intraocular Lens Dislocation and Pseudoexfoliation Syndrome

PURPOSE

To investigate intraocular pressure in eyes with intraocular lens subluxation and pseudoexfoliation syndrome.

METHODS

In this retrospective study conducted at one eye centre (tazz) in Zurich, Switzerland, we reviewed 85 eyes with intraocular lens subluxation and pseudoexfoliation syndrome. Intraocular lens exchange was carried out by two surgeons between 03/2016 and 12/2019 (45 months). Information on baseline characteristics and diagnosis of glaucoma was recorded. Intraocular pressure and best-corrected visual acuity were analysed preoperatively and at five time points up to 12 months after lens exchange. Data on antiglaucomatous medication was collected before surgery and at two different time points after surgery. Postoperative pressure lowering procedures and complications were further analysed.

RESULTS

This study includes 85 pseudoexfoliation eyes with intraocular lens subluxation. The mean interval between cataract surgery and lens exchange was 8.9 ± 5.2 years. Intraocular pressure elevation in the event of intraocular lens subluxation was found in 54% (46/85) of eyes. Mean intraocular pressure decreased from 22.9 ± 9.4 mmHg preoperatively to 15.2 ± 3.4 mmHg at follow-up 12 months after lens exchange (p < 0.001). Postoperative topical antiglaucomatous drug requirements were comparable to preoperative levels (p = 0.520). Less systemic acetazolamide was required 12 months postoperatively (p = 0.018). A pressure lowering procedure was required in seven (8%) eyes in the postoperative period due to persistence of high intraocular pressure. Intermittent increase or persistence of high intraocular pressure occurred in 13 (15%) eyes.

CONCLUSION

This study emphasises the connection between acute pressure elevation and intraocular lens subluxation in patients with pseudoexfoliation syndrome. Intraocular pressure decreases after lens exchange and decrease sustains for a postoperative period of 12 months. Postoperative pressure lowering procedures were not required in the majority of eyes. We therefore conclude that intraocular lens exchange is efficient in the management of lens subluxation and pressure elevation in patients with pseudoexfoliation syndrome.

RNA Sequencing of Lens Capsular Epithelium Implicates Novel Pathways in Pseudoexfoliation Syndrome

Purpose

Pseudoexfoliation syndrome (PEX) is a common systemic disease that results in severe and often irreversible vision loss. Despite considerable research effort, PEX remains incompletely understood. This study sought to perform the first RNAseq study in elucidate the pathophysiology of PEX, and contribute a publicly available transcriptomic data resource for future research.

Methods

Human ocular lens capsular epithelium samples were collected from 25 patients with PEX and 39 non-PEX controls undergoing cataract surgery. RNA extracted from these specimens was subjected to polyadenylated (mRNA) selection and deep bulk RNA sequencing. Differential expression analysis investigated protein-coding gene transcripts. Exploratory analyses used pathway analysis tools, and curated class- and disease-specific gene sets.

Results

Differential expression analysis demonstrated that 2882 genes were differentially expressed according to PEX status. Genes associated with viral gene expression pathways were among the most upregulated, alongside genes encoding ribosomal and mitochondrial respiratory transport chain proteins. Cell adhesion protein transcripts including type 4 collagen subunits were downregulated.

Conclusions

This comparative transcriptomic dataset highlights novel and previously recognized pathogenic pathways in PEX and provides the first comprehensive transcriptomic resource, adding an additional layer to build further understanding of PEX pathophysiology.

Outcomes of flanged IOL fixation combined with microhook trabeculotomy

PURPOSE

To evaluate the outcomes of flanged intraocular lens fixation combined with microhook trabeculotomy.

PATIENTS AND METHODS

This study was a retrospective case series and included nine eyes of nine exfoliation glaucoma patients with subluxated lens or intraocular lens who underwent flanged intraocular lens fixation combined with microhook trabeculotomy between May 2019 and February 2020 at the Kochi University Hospital. The mean best-corrected visual acuity, intraocular pressure, and number of antiglaucoma medications were compared before and after surgery.

RESULTS

The mean follow-up period was 5.67 ± 2.50 months. The mean best-corrected visual acuity improved significantly from 0.83 ± 0.72 preoperatively to 0.22 ± 0.34 at the last visit (p = 0.015). The mean intraocular pressure had significantly reduced from 27.1 ± 8.12 mmHg preoperatively to 13.2 ± 3.73 at the last visit (p = 0.008). The mean number of antiglaucoma medications decreased significantly from 4.56 ± 1.88 to 2.0 ± 1.0 at the last visit (p = 0.008). Postoperative intraocular pressure control to 21 mmHg or lower was achieved or maintained in all patients. Postoperative vitreous hemorrhage was observed in six eyes (66.7%), two of which needed reoperation.

CONCLUSIONS

This study showed that flanged intraocular lens fixation combined with microhook trabeculotomy might be effective for exfoliation glaucoma with subluxated lens or intraocular lens.

Exfoliation syndrome: association with systemic diseases-the Maccabi glaucoma study

PURPOSE

To investigate the relationship between exfoliation syndrome (XFS) and systemic diseases.

METHODS

A population-based, retrospective study with control group was conducted using the electronic medical database of Maccabi Health Services, the second largest Health Maintenance Organization (HMO) in Israel. Study population included Maccabi members from January 2003 to April 2016. Cases consisted of patients diagnosed with XFS regardless of glaucoma. The control group included Maccabi members without XFS, matched on age, sex, and ancestry, that were examined by an ophthalmologist within the last year.

MAIN OUTCOME MEASURES

Associations between XFS and systemic diseases.

RESULTS

We identified 16,388 patients with XFS, in whom 40.3% (n = 6613) had glaucoma. The control group included 14,015 patients. Mean age was 78.3 ± 8.9 years and 76.2 ± 8.5 years for the XFS and control group, respectively. In unconditional logistic regression analyses, after adjusting for age, sex, and ancestry, XFS was significantly associated with risk of cardiovascular diseases including hypertension (OR 1.07, 95% CI 1.01-1.13, p = 0.02), myocardial infarction (OR 1.21, 95% CI 1.17-1.31, p < 0.0001), and congestive heart failure (OR 1.70, 95% CI 1.55-1.88, p < 0.0001) as well as higher risk for high creatinine (OR 1.28, 95% CI 1.2-1.37, p < 0.0001). Diabetes mellitus and body mass index were inversely associated with XFS (OR 0.70, 95% CI 0.67-0.73, p < 0.0001 and OR 0.88, 95% CI 0.84-0.93, p < 0.0001, respectively). Overall cancer diagnoses were more common in the XFS group (OR 1.05, 95% CI 1.0-1.1, p = 0.05). XFS was associated with more hospitalizations (mean 5 ± 5.3 hospitalizations in the XFS group and 3.3 ± 4.0 in the controls, p < 0.0001).

CONCLUSION

XFS is significantly associated with cardiovascular systemic diseases (in a population living in Israel and predominantly born in Russia).

Complications and visual outcomes of cataract surgery in patients with pseudoexfoliation

PURPOSE

To compare outcomes of cataract surgery performed by ophthalmic trainees and consultants in patients associated with pseudoexfoliation (PXF) METHODS: Retrospective review of medical records of all patients with PXF who had undergone cataract surgery from January 2016 to December 2018 at L V Prasad Eye Institute, Hyderabad, India, were analysed RESULTS: A total of 914 eyes were included in the study; surgeries on 501 (54.8%) eyes with PXF were performed by trainees, while 413 (45.2%) were performed by consultants. Posterior capsule rupture (PCR) with vitreous loss (VL) occurred in significantly fewer eyes operated on by consultants (n = 8, 1.9%) than those operated on by trainees (n = 23, 4.5%) (p = 0.002). Eyes that underwent small incision cataract surgery (n = 100, 21.2%) had a significantly greater number of complications than those that underwent phacoemulsification (n = 31, 7.1%) (p = 0.00001). Multivariate logistic regression analysis shows that chances of a complication are higher when operated on by a trainee (OR = 1.59, 95% CI: 1.09-2.34, p = 0.02).The mean logMAR corrected distance visual acuity of patients one month post-surgery was significantly higher for patients in the consultant group (0.15 ± 0.3) than for those in the trainee group (0.2 ± 0.4) (p = 0.003).

CONCLUSION

Patients with PXF operated on by trainees for cataract had a relatively higher risk of developing PCR with VL and had poorer visual outcomes than those operated on by consultants.

Evaluation of serum and aqueous humor klotho levels in pseudoexfoliation syndrome, pseudoexfoliation and primary open-angle glaucoma

PURPOSE

The aim of our study was to compare klotho in the serum and aqueous humor of patients with primary open-angle glaucoma (POAG), pseudoexfoliation glaucoma (PEXG) and pseudoexfoliation syndrome (PEX).

MATERIALS AND METHODS

18 POAG, 20 PEXG, 19 PEX and 20 control patients were included in our study. Aqueous humor and serum samples were collected at the time of cataract surgery. Samples were collected using enzyme-linked immunosorbent assay to evaluate the levels of Klotho protein.

RESULTS

Klotho levels in the serum and aqueous humor of PEXG patients (34.45 ± 3.59, 0.20 ± 0.15 ng/ml), PEX (35.85 ± 4.26, 0.23 ± 0.20 ng/ml) patients and POAG patients (35.99 ± 3.73, 0.25 ± 0.20 ng/ml) were significantly lower than control group (40.14 ± 3.85, 0.53 ± 0.39 ng/ml) (PEXG, P < 0.001, P < 0.001; PEX, P = 0.002, P = 0.003; POAG, P = 0.006, P = 0.003, respectively). Both serum and aqueous levels of klotho in the PEXG and PEX patients were lower than POAG patients, but the difference did not reach statistical significance (PEXG & POAG P = 0.149, P = 0.696), (PEX & POAG P = 0.845, P = 0.775).

CONCLUSION

Klotho levels in the serum and aqueous humor decreased in PEX, PEXG and POAG groups compared to control group, but the reduction was most significant in PEXG group.

Long-term myofibroblast persistence in the capsular bag contributes to the late spontaneous in-the-bag intraocular lens dislocation

Late spontaneous in-the-bag intraocular lens (IOL) dislocation is a complication presenting 6 months or later after cataract surgery. We aimed to characterize the cells in the lens capsules (LCs) of 18 patients with spontaneous late in-the-bag IOL dislocation. Patients' average age was 82.6 ± 1.5 years (range 72-98), and most of them had pseudoexfoliation syndrome (PEX). Cells from the LCs were positive for myofibroblast (αSMA), proliferation (Ki-67, PCNA), early lens development/lens progenitor (SOX2, PAX6), chemokine receptor (CXCR4), and transmembrane (N-cadherin) markers, while negative for epithelial (E-cadherin) marker. Moreover, the cells produced abundant fibronectin, type I and type V collagen in the nearby extracellular matrix (ECM). During ex vivo cultivation of dislocated IOL-LCs in toto, the cells proliferated and likely migrated onto the IOL's anterior side. EdU proliferation assay confirmed the proliferation potential of the myofibroblasts (MFBs) in dislocated IOL-LCs. Primary cultured lens epithelial cells/MFBs isolated from the LC of dislocated IOLs could induce collagen matrix contraction and continuously proliferated, migrated, and induced ECM remodeling. Taken together, this indicates that long-lived MFBs of dislocated IOLs might contribute to the pathogenic mechanisms in late in-the-bag IOL dislocation.

Predicting zonular strength based on maximum pupillary mydriasis in patients with pseudoexfoliation syndrome

Pseudoexfoliation Syndrome (PXFS) is considered a systemic disorder with significant ocular manifestations ranging from corneal decompensation, non-dilating pupil, zonular weakness, subluxated lens, and glaucoma. PXFS may lead to increased complications during routine cataract surgery. Zonular dialysis is a common complication during or after cataract surgery in such patients. However, not all patients with pseudoexfoliation are at a higher risk. We hypothesize that there is an inverse correlation between the maximum pupillary dilation and the degree of zonular disintegration. Available evidence supporting the hypothesis is discussed. We propose a new clinical classification for predicting the zonular strength based on the maximum pupillary dilation so that it can serve as a guide to identify PXFS patients who are at high risk of complications during or after cataract surgery.

Effect of capsular tension ring on refractive results in cases with pseudoexfoliation syndrome

PURPOSE

To investigate the effect of capsular tension rings (CTRs) on postoperative refractive results in patients with pseudoexfoliation (PSX) syndrome.

MATERIALS AND METHODS

Sixty-nine patients with PSX syndrome who had uncomplicated cataract surgery between March 2016 and February 2019 were reviewed retrospectively. The patients were divided into two groups. The 35 patients in Group 1 received CTRs prior to intraocular lens implantation during cataract surgery, and the 34 patients in Group 2 had cataract surgery without CTRs. Significant zonular weakness, uncontrolled glaucoma, and ocular pathologies causing low visual acuity were excluded. The preoperative and postoperative keratometry and autorefraction measurements, preoperative expected refractive values, and absolute refractive error were recorded.

RESULTS

The mean ages of patients were 73.54 ± 9.78 years in Group 1 and 72.23 ± 6.72 years in Group 2 (p = 0.521). There was no statistically significant difference between Group 1 and Group 2 in terms of expected preoperative refraction values (-0.52 ± 0.12,-0.56 ± 0.08, respectively, p = 0.118). There was a statistically significant difference in postoperative spherical equivalent values between Group 1 and Group 2 (-0.05 ± 0.97 and -0.92 ± 0.57, respectively, p < 0.01). A statistically significant difference was found between the two groups in terms of absolute refractive error (0.46 ± 0.74 in Group 1 and -0.34 ± 0.59 in Group 2 p < 0.01).

CONCLUSION

CTR implantation causes hyperopic shift, which should be taken into consideration when calculating the lens power of intraocular lens in patients with PSX syndrome.

Zinn's zonule

The Zonule of Zinn, or ciliary zonule, is the elaborate system of extracellular fibers that centers the lens in the eye. In humans, the fibers transmit forces that flatten the lens during the process of disaccommodation, thereby bringing distant objects into focus. Zonular fibers are composed almost entirely of 10-12 nm-wide microfibrils, of which polymerized fibrillin is the most abundant component. The thickest fibers have a fascicular organization, where hundreds or thousands of microfibrils are gathered into micrometer-wide bundles. Many such bundles are aggregated to form a fiber. Dozens of proteins comprise the zonule. Most are derived from cells of the non-pigmented ciliary epithelium in the pars plana region, although some are probably contributed by the lens and perhaps other tissues of the anterior segment. Zonular fibers are viscoelastic cables but their component microfibrils are rather stiff structures. Thus, the elastic properties of the fibers likely stem from lateral interactions between microfibrils. Rupture of zonular fibers and subsequent lens dislocation (ectopia lentis) can result from blunt force trauma or be a sequela of other eye diseases, notably exfoliation syndrome. Ectopia lentis is also a feature of syndromic conditions caused typically by mutations in microfibril-associated genes. The resulting ocular phenotypes raise the possibility that the zonule regulates lens size and shape, globe size, and even corneal topology, in addition to its well-recognized role in accommodation.

Comparison of phacoemulsification parameters in eyes with and without exfoliation syndrome

OBJECTIVE

To evaluate and to compare the phacoemulsification machine parameters in eyes with and without XFS, requiring cataract surgery.

METHODS

Patients who underwent phacoemulsification and in-the-bag IOL implantation for cataract were included in this retrospective study. All surgeries were performed by the same experienced surgeon using the stop & chop technique with the same phacoemulsification device (Infiniti Vision System, Alcon Laboratories, Inc., USA). Patients were divided into two groups according to the presence of exfoliation material (XFM). Each group consisted of consecutive patients. Their characteristics and intraoperative phacoemulsification parameters were compared.

RESULTS

Sixty-eight eyes of 68 patients [29 in the exfoliation syndrome (XFS) (-) group, 39 in XFS (+)] were enrolled. There were no statistical differences regarding preoperative patient characteristics. There was a statistically significant difference in total U/S time, phaco time, aspiration time and estimated fluid used between the XFS (+) and XFS (-) groups (P=0.021, P=0.017, P=0.009 and P=0.002, respectively). Considering that the use of a CTR (capsule tension ring) might be an important factor potentially affecting surgical parameters, the data were analyzed accordingly. Aspiration time and estimated fluid used remained statistically significant (P=0.046 and P=0.017, respectively); however, although the U/S total and phaco time were found to be longer in XFS (+) group compared to XFS (-) group, the difference did not show statistical significance (P=0.061 and P=0.059, respectively). There were no differences between groups regarding endothelial cell loss or any other postoperative complications.

CONCLUSIONS

The presence of XFS results in longer total U/S time, phaco and aspiration time and more estimated fluid used in phacoemulsification, but this prolongation does not result in additional complications.

Corneal endothelial cell loss following cataract surgery in patients with pseudoexfoliation syndrome: a 2-year prospective comparative study

PURPOSE

To compare the corneal endothelial cell density (ECD) before and after cataract surgery in patients with and without pseudoexfoliation syndrome (PEX).

METHODS

In this prospective study, we compared the ECD in 62 PEX patients with 62 patients without PEX (controls). The mean age was 78.3 ± 6.2 years and 77.2 ± 5.9 years, respectively. Patients were examined before and at 6 months, 1 year and 2 years after cataract surgery. The corneal endothelium was examined with confocal microscopy, and the ECD was counted both automatically and semi-manually. Nine patients in the PEX group (15%) and 11 patients in the control group (18%) were lost to follow-up in the 2-year period. Within the PEX and the control groups, we also compared the ECD between patients with and without glaucoma.

RESULTS

Before surgery, the ECD (semi-manual counting) was 2258 ± 342 cells/mm² in the PEX group and 2322 ± 321 cells/mm² in the control group (p = 0.29). There were no significant differences in postoperative ECD between these groups at any visit. After 2 years, the ECD had changed by -679 ± 337 cells/mm² and -704 ± 484 cells/mm² , respectively (p = 0.78). The preoperative ECD was lower in eyes with glaucoma compared to eyes without glaucoma, both within the PEX group (p = 0.05) and the control group (p = 0.03). After surgery, there were no differences between eyes with or without glaucoma.

CONCLUSION

The ECD was not significantly different in PEX eyes compared with control eyes, neither before nor after cataract surgery. However, there seemed to be a lower ECD in eyes with glaucoma before surgery.

Phacoemulsification And Zonular Weakness: Contribution Of The Capsular Tension Ring With A Thread

Purpose

Cataract surgery in patients suffering from zonular weakness can be difficult and lead to severe complications. The insertion of capsular tension rings to stabilize the capsular bag along all steps of the phacoemulsification is an option, although can be difficult to remove intra- or post-operatively. A capsular tension ring with a thread is a safe alternative, which allows its easy removal at the end of the surgery.

Patients and methods

Retrospective study of regular practice on 14 patients with zonular weakness who underwent phacoemulsification. Among them, 12 suffered from pseudo-exfoliative syndrome and 2 suffered from a post-traumatic cataract. All benefited from the use of a capsular tension ring with a thread during their surgery.

Results

All surgeries were successful. Capsular tension ring with a thread was all removed at the end of surgery without any complication.

Conclusion

The addition of a thread to the capsular tension ring is a simple modification that enhances its use by facilitating its intraoperative removal if necessary or at the end of surgery.

Long-Term Outcomes after Surgery for Late In-The-Bag Intraocular Lens Dislocation: A Randomized Clinical Trial

PURPOSE

To compare the long-term efficacy and safety of 2 operation methods for late in-the-bag intraocular lens (IOL) dislocation.

DESIGN

Prospective, randomized, parallel group surgical clinical trial.

METHODS

During a 3-year period, 104 patients (104 eyes) were assigned one group for IOL repositioning by scleral suturing (n = 54) or one group for IOL exchange by retropupillary fixation of an iris claw IOL (n = 50). A single surgeon performed all operations using an anterior approach. Patients were examined before surgery and at 6 months and 1 and 2 years after surgery. The present study included the 66 patients (63%) who completed the 2-year follow-up, and the main outcaome measurement was corrected distance visual acuity (CDVA) 2 years after surgery.

RESULTS

After 2 years, the mean CDVA was 0.20 ± 0.29 logarithm of the minimum angle of resolution (logMAR) units (range, -0.18 to 1.10) in the repositioning group and 0.22 ± 0.30 logMAR (range, -0.10 to 1.22) in the exchange group (P = .69). A CDVA of 20/40 or better was achieved by 76% of all patients. Four eyes (12%) had cystoid macular edema in the repositioning group compared with 5 eyes (15%) in the exchange group. Two eyes underwent redislocation (1 in each group). There were no cases of endophthalmitis or retinal detachment.

CONCLUSIONS

There were no significant differences between the visual acuity using IOL repositioning and that using IOL exchange 2 years after surgery. The two methods were equally efficient and safe from a long-term perspective and are both considered acceptable treatments.

Histopathology of Exfoliation Syndrome

Exfoliation syndrome (XFS) is characterized by light and electron microscopy by age-dependent gradual accumulation of whitish material of largely unknown composition and origin along both the anterior and posterior chambers and widely within the iris stroma. These deposits can be fairly specifically labeled with selected antibodies and lectins. Immunohistochemistry shows that intraocular exfoliation deposits share antigens with the microfibrillar elastic fiber system and several basement membrane components, including carbohydrate epitopes on glycosaminoglycans, proteoglycans, and cell adhesion molecules. The earliest histopathologic manifestation of XFS seems to be the deposition of characteristic fibers in various extraocular and anterior segment tissues, as observed by electron microscopy, and perivascular deposition of material within the iris stroma, which is antigenically typical of that found in classic intraocular exfoliation deposits. These findings precede the clinical diagnosis of XFS and likewise can be detected in the seemingly uninvolved fellow eyes of patients with clinically unilateral XFS. Indeed, histopathologic examination of capsulotomy, iridectomy, and trabeculectomy specimens can lead to a clinically unexpected diagnosis of XFS. Exfoliation fibers are additionally found widely distributed in extraocular connective tissues and visceral organs, but the matrix of these fibers seems to differ from that of intraocular deposits. In addition to this histopathologic discrepancy, both the frequent occurrence of clinically unilateral, histopathologically highly asymmetric exfoliation deposits, and the relationship between the early iris vasculopathy that not infrequently may be observed histopathologically for years before classic widespread exfoliation deposits appear along the anterior and posterior chambers remain to be resolved.

Repressed Wnt Signaling Accelerates the Aging Process in Mouse Eyes

PURPOSE

Ocular aging is a natural process of functional decline in vision. When the process reaches a point that compromised vision affects normal daily activity, it manifests as age-related ocular diseases, such as age-related macular degeneration, cataracts, glaucoma, and pseudoexfoliation syndrome. We previously reported that repressed Wnt signaling accelerated the maturation of corneal epithelium during tissue development. Here, we explore the hypothesis that repressed Wnt signaling is associated with accelerated aging in mouse eyes.

METHODS

Wnt ligand antagonist secreted frizzled-related protein 1 (sFRP1) was expressed in the corneal stroma by a tissue-specific, inducible, bitransgenic system. Tissue structure was analyzed for signs of aging. Signal transduction analysis was performed to determine the cellular response to sFRP1.

RESULTS

Mouse eyes with sFRP1 expression showed signs of accelerated aging, resembling those found in pseudoexfoliation (PEX) syndrome, a known age-related disease. Specific findings include granular deposition on the surface of the anterior lens capsule, pigment loss from the anterior surface of the iris, the presence of fibrillary material in the anterior chamber, and changes in cell size (polymegethism) and shape (pleomorphism) of the corneal endothelial cells. In vitro studies demonstrated that sFRP1 did not inhibit Wnt5a function and that cells responded to sFRP1 and Wnt5a in a very similar manner.

CONCLUSION

The expression of sFRP1 accelerates the aging process in mouse eyes and future studies are warranted to elucidate the underlying mechanisms.

Exfoliation Fibrils within the Basement Membrane of Anterior Lens Capsule: A Transmission Electron Microscopy Study

Purpose: The aim of the present study was to demonstrate novel findings recognized within the basement membrane of the anterior lens capsules (ALCs) in exfoliation syndrome, in a transmission electron microscopy (TEM) study. Materials and methods: Twenty-one patients with age-related cataract were included in the study. Eleven out of them suffered from exfoliation syndrome (XFS). Anterior lens capsules were obtained from patients during phacoemulsification, applying continuous curvilinear capsulorhexis and then were examined by transmission electron microscope. Results: Six out of 11 examined basement membranes with XFS had a granular appearance with dotted deposits of electron-dense material. Fibrils were clearly detected, longitudinally, within the basement membrane, usually located in the outer quarter of the basement membrane, towards the anterior chamber. Conclusion: New data about the exfoliation material and its location within the basement membrane of the anterior lens capsules of XFS patients are presented. These findings constitute new evidence for XFS's histopathogenesis and might help clarify the lenticular exfoliation material's (XFM) mechanisms of origin.

SPECIFIC CHARACTERISTICS OF OCULAR BIOMETRIC FACTORS IN GLAUCOMATOUS PATIENTS WITH PSEUDOEXFOLIATIVE SYNDROME AS MEASURED BY OPTICAL LOW-COHERENCE REFLECTOMETRY

The aim of the study was to assess biometric factor aberrations and differences among groups of eyes with cataract and pseudoexfoliative syndrome, cataract and pseudoexfoliative glaucoma, and cataract and primary open-angle glaucoma (POAG), and to determine biometric factors of the eye specific for the group of glaucomatous patients with pseudoexfoliative syndrome by use of optical low-coherence reflectometry. This retrospective study included 72 patients, and the study sample of 102 eyes was divided into the following three groups according to diagnosis: 29 eyes with pseudoexfoliative syndrome and cataract; 36 eyes with POAG and cataract; and 37 eyes with pseudoexfoliative glaucoma and cataract. Data on biometric measurements (central corneal thickness, pupillary diameter, anterior chamber depth, lens thickness, axial length, retinal thickness, astigmatism and white-to-white) obtained by use of optical low-coherence reflectometry on a Lenstar LS 900® (Haag-Streit International) were collected and analyzed by thorough survey of medical documentation of patients scheduled for cataract surgery at Department of Ophthalmology, Sveti Duh University Hospital in Zagreb, Croatia. Comparative analysis of the groups yielded statistically significant differences in central corneal thickness (F2/99=7.066; p=0.001) and lens thickness (F2/96=5.133; p=0.008). The group of eyes diagnosed with pseudoexfoliative glaucoma and cataract had a significantly thinner cornea as compared with the other two groups and a significantly thicker lens as compared with the group of eyes with POAG and cataract. In conclusion, optical low-coherence reflectometry revealed differences in biometric factors among the three groups of eyes, with a statistically significantly thinner cornea and thicker lens in the group of glaucomatous patients with pseudoexfoliative syndrome.

Transmission electron microscopy study of undescribed material at the anterior lens capsule in exfoliation syndrome

PURPOSE

In the present study, we aimed to examine the anterior lens capsule using transmission electron microscopy (TEM) and compare the findings in patients with and without exfoliation syndrome (XFS).

METHODS

Eighteen patients with senile cataract, including 10 with XFS, were included. Anterior capsule specimens were obtained from patients during phacoemulsification through continuous curvilinear capsulorrhexis, and were examined via TEM.

RESULTS

In the XFS group, in addition to the typical fibrillar material above the basement membrane of the lens capsule, another unknown, microgranular, electron-dense, unbound material was observed beneath the lens epithelium. Larger formations appeared to detach from the surface of the epithelial cells, and oval or crescent-shaped structures of an electron-denser material were less commonly observed on the apical side of the epithelium. Membranous structures were occasionally attached to epithelial cells that often exhibited thicker or ruptured cell membranes on their apical-free side, along with deposits of electron-dense material. Degenerative lesions of various severities were observed at the epithelium in both groups.

CONCLUSION

The anterior lens capsule epithelium in patients with XFS exhibits a highly irregular and rough margin on its free side, with unbound material over its membrane, which probably contributes to loose contact with the underlying lens and leads to different clinical behaviors in XFS eyes during cataract surgery.

Exfoliation Syndrome: A Disease of Autophagy and LOXL1 Proteopathy

Exfoliation syndrome (XFS) is an age-related disease involving the deposition of aggregated fibrillar material (exfoliation material) at extracellular matrices in tissues that synthesize elastic fibers. Its main morbidity is in the eye, where exfoliation material accumulations form on the surface of the ciliary body, iris, and lens. Exfoliation glaucoma (XFG) occurs in a high proportion of persons with XFS and can be a rapidly progressing disease. Worldwide, XFG accounts for about 25% of open-angle glaucoma cases. XFS and XFG show a sharp age-dependence, similarly to the many age-related diseases classified as aggregopathies. Progress in understanding the cellular bases for XFS/XFG has been slowed by a lack of experimental models. Working with primary human tenon fibroblasts (TF) derived from trabeculectomies of XFG patients and age-matched primary open-glaucoma controls, we found that TF from XFG cells display many of the functional features observed in cells from other protein aggregate diseases, such as Parkinson, Alzheimer, Huntington, and age-related macular degeneration. We have documented defects in lysosomal positioning, microtubule organization, autophagy processing rate, and mitochondrial health. In regard to failure of lysosomal and autophagosome positioning in XFG cells, we have found that XFG TF are unable to establish the transnuclear microtubule organizing center that is required for efficient centripetal vesicular locomotion along microtubules. In regard to potential sources of the autophagy malfunction, we have directed our attention to a potential role of the lysyl oxidase-like 1 protein (LOXL1), the elastic fiber catalyst that displays variant-dependent association with risk for XFG. Our experiments show that (a) in XFG cells, a substantial fraction of LOXL1 is processed for degradation by the autophagic system; (b) most of the LOXL1 N-terminus domain exists in a highly disordered state, a condition known to greatly increase the frequency of polypeptide misfolding; (c) that maximum misfolding occurs at amino acid position 153, the location of the high risk variant G153D; and (d) that replacement of glycine (G) by aspartate (D) there results in a substantial decrease in disorder within the 20 amino acid surrounding domain. Finally, we show that clusterin, a protein that can be induced by the presence of intracellular, or extracellular aggregates, is uniformly overexpressed in XFG TF. The implications of our results for a theory relating XFG to cellular aggregopathy are discussed.

[Pseudoexfoliation syndrome and pseudoexfoliation glaucoma]

Pseudoexfoliation syndrome is an age-related systemic disease that mainly affects the anterior structures of the eye. Despite a worldwide distribution, reported incidence and prevalence of this syndrome vary widely between ethnicities and geographical areas. The exfoliative material is composed mainly of abnormal cross-linked fibrils that accumulate progressively in some organs such as the heart, blood vessels, lungs or meninges, and particularly in the anterior structures of the eye. The exact pathophysiological process still remains unclear but the association of genetic and environmental factors are thought to play a role in the development and progressive extracellular accumulation of exfoliative material. Hence, LOXL1 gene polymorphisms, responsible for metabolism of some components of elastic fibers and extracellular matrix, and increased natural exposure to ambient ultraviolet or caffeine consumption have been associated with pseudoexfoliation syndrome. Ophthalmological manifestations are commonly bilateral with an asymmetric presentation and can lead to severe visual impairment and blindness more frequently than in the general population, mainly related to glaucoma and cataract. Pseudoexfoliation glaucoma is a major complication of pseudoexfoliation syndrome and represents the main cause of identifiable glaucoma worldwide. Visual field progression is more rapid than that observed in primary open angle glaucoma, and filtering surgery is more frequently required. Nuclear cataract is more frequent and occurs earlier than in the general population. Owing to poorer pupil dilation and increased zonular instability, cataract surgery with pseudoexfoliation is associated with a 5- to 10-fold increase in surgical complications compared to cataract surgery without pseudoexfoliation. Some specific treatments targeting production, formation or accumulation of exfoliative material could improve the prognosis of this syndrome.

Short-term fluctuation of lens corneal distance and clinical correlation with phacodonesis

BACKGROUND

To analyze the role of short-term lens-corneal distance (LCD) fluctuation in quantifying preoperative phacodonesis and predicting intraoperative zonular weakness.

METHODS

Patients were divided into control (lens without clinical phacodonesis) and study (lens with suspicious and clinical phacodonesis) groups for evaluation. Slit-lamp examination followed by IOLMaster (Carl Zeiss) for LCD assessment was performed. Five readings were taken at five time points (0 s, 15 s, 30 s, 45 s & 60 s) continuously over a minute (short term) for the LCD fluctuation calculation.

RESULTS

A total of 135 eyes (82 controls and 53 study) were assessed. Study group included 32 (60.3%) suspicious and 21 (39.6%) moderate to severe phacodonesis. There was difference between the control and study eyes (p = 0.000) in short-term LCD fluctuation. Twenty-one study eyes (39.6%) showed LCD difference > 1 mm, including 11 eyes (52.3%) with > 2 mm. There was a difference in LCD with respect to severity of phacodonesis (p = 0.000). In the study eyes, 13 eyes underwent glued IOL implantation (clinical phacodonesis - ten, suspicious phacodonesis - three), and two eyes (suspicious phacodonesis) had glued capsular hook. Thirteen eyes (clinical phacodonesis - ten, suspicious phacodonesis - three) required intraoperative vitrectomy due to vitreous ingress. Intraoperative zonular weakness in 62.5% of eyes with suspicious donesis and association (Chi-square = 0.000) of weakness with preoperative LCD fluctuation was noted.

CONCLUSIONS

Short-term lens-corneal distance fluctuation can be used as a parameter for quantifying lens stability and as an aid in assessing the intraoperative risk.

Proteomic Analysis of the Bovine and Human Ciliary Zonule

Purpose

The zonule of Zinn (ciliary zonule) is a system of fibers that centers the crystalline lens on the optical axis of the eye. Mutations in zonule components underlie syndromic conditions associated with a broad range of ocular pathologies, including microspherophakia and ectopia lentis. Here, we used HPLC-mass spectrometry to determine the molecular composition of the zonule.

Methods

Tryptic digests of human and bovine zonular samples were analyzed by HPLC-mass spectrometry. The distribution of selected components was confirmed by immunofluorescence confocal microscopy. In bovine samples, the composition of the equatorial zonule was compared to that of the hyaloid zonule and vitreous humor.

Results

The 52 proteins common to the zonules of both species accounted for >95% of the zonular protein. Glycoproteins constituted the main structural components, with two proteins, FBN1 and LTBP2, constituting 70%-80% of the protein. Other abundant components were MFAP2, EMILIN-1, and ADAMTSL-6. Lysyl oxidase-like 1, a crosslinking enzyme implicated in collagen and elastin biogenesis, was detected at significant levels. The equatorial and hyaloid zonular samples were compositionally similar to each other, although the hyaloid sample was relatively enriched in the proteoglycan opticin and the fibrillar collagens COL2A1, COL11A1, COL5A2, and COL5A3.

Conclusions

The zonular proteome was surprisingly complex. In addition to structural components, it contained signaling proteins, protease inhibitors, and crosslinking enzymes. The equatorial and hyaloid zonules were similar in composition, but the latter may form part of a composite structure, the hyaloid membrane, that stabilizes the vitreous face.

Spontaneous Late Intraocular Lens and Capsule Tension Ring Dislocation

In this report, three cases with pseudoexfoliation (PEX) and advanced age with spontaneous intraocular lens (IOL) and capsule tension ring (CTR) dislocation were presented. All of our cases experienced progressive vision loss without an episode of strenuous physical activity, trauma, or any other ocular disease. Spontaneous dislocation was observed 2.5 to 8 years after uneventful phacosurgery. Each patient underwent complete IOL and CTR removal combined with anterior chamber IOL implantation. No complications were noticed during follow-up. As a result, capsule tension ring does not prevent late IOL dislocation after uncomplicated phacosurgery in the presence of PEX. Therefore, close follow-up is essential for patients with PEX.

Outcome of phacoemulsification and intraocular lens implantion in eyes with pseudoexfoliation and weak zonules

PURPOSE

To evaluate the results of phacoemulsification and intraocular lens (IOL) implantation in eyes with pseudoexfoliation (PEX) and zonular weakness.

METHODS

Two hundred and ninety-five patients (295 eyes) were recruited. This study is a retrospective case review of 143 PEX eyes with preoperative (Group 1) and intraoperative (Group 2) signs of zonular weakness, 76 PEX eyes (Group 3) and 76 non-PEX eyes without zonular weakness (Group 4) undergoing phacoemulsification and IOL implantation performed by single surgeon from year 1988 to 2010. Outcome measures included frequency of postoperative pseudophakodonesis, anterior capsule contraction and IOL decentration/dislocation. Postoperative vision, intraocular pressure (IOP) and glaucoma medication requirements were also assessed. A subanalysis on identical postoperative outcomes of capsular tension ring (CTR) implantation was performed. Comparisons were made for 52 PEX eyes with zonular weakness receiving nonsutured CTR implantation (Group A), 91 PEX eyes with zonular weakness not receiving CTR implantation (Group B) and 142 PEX eyes without zonular weakness (Group C).

RESULTS

Mean follow-up was 4.08 ± 0.48 years and maximum was 8.3 years. Both Groups 1 and 2 showed higher incidence of complications than Groups 3 and 4 (p < 0.01). Vision, IOP and glaucoma medication requirements were similar postoperatively for all four groups. Groups A and B had a significantly higher proportion of postoperative complications than Group C (p < 0.01). There was no significant difference in risk of developing these complications between Groups A and B (p = 0.64).

CONCLUSION

Postoperative complication rates are higher in PEX eyes with preoperative and/or intraoperative signs of zonular weakness undergoing phacoemulsification. Nonsutured CTR implantation does not prevent IOL and capsular complications postoperatively.

Central cortical cleanup and zonular deficiency

BACKGROUND

Complete removal of the cortex has been advocated to prevent posterior capsular opacification but carries the risk of zonular dehiscence, hence there is a need for a safe maximal cortical cleanup technique in eyes with severe diffuse zonulopathy in subjects above age 90.

METHODS

We used bimanual central cortical cleaning by elevating central fibers and aspirating them toward the periphery. Peripheral cortical fibers were removed passively only when they became loose due to copious irrigation. A one-piece foldable implant was inserted without a capsular tension ring. Postoperative corticosteroid drops were used.

RESULTS

This technique was safely performed in a dozen eyes with severe pseudo-exfoliation or brunescent cataract with weak zonules. Posterior capsular rupture, iritis, vitreous loss, and lens subluxation were not observed. Moderate capsular phimosis occurred but with maintained central vision.

CONCLUSION

The dogma of "complete cortical cleanup" in severe zonulopathy needs to be revisited in favor of a clear visual axis with maximal preservation of the damaged zonules. This technique is ideal in patients above age 90 where posterior capsular opacification and late dislocation of intraocular lens-capsule bag complex are unlikely to occur until several years postoperatively.

Exfoliation syndrome: assembling the puzzle pieces

PURPOSE

To summarize various topics and the cutting edge approaches to refine XFS pathogenesis that were discussed at the 21st annual Glaucoma Foundation Think Tank meeting in New York City, Sept. 19-20, 2014.

METHODS

The highlights of three categories of talks on cutting edge research in the field were summarized.

RESULTS

Exfoliation syndrome (XFS) is a systemic disorder with a substantial ocular burden, including high rates of cataract, cataract surgery complications, glaucoma and retinal vein occlusion. New information about XFS is akin to puzzle pieces that do not quite join together to reveal a clear picture regarding how exfoliation material (XFM) forms.

CONCLUSION

Meeting participants concluded that it is unclear how the mild homocysteinemia seen in XFS might contribute to the disarrayed extracellular aggregates characteristic of this syndrome. Lysyl oxidase-like 1 (LOXL1) variants are unequivocally genetic risk factors for XFS but exactly how these variants contribute to the assembly of exfoliation material (XFM) remains unclear. Variants in a new genomic region, CACNA1A associated with XFS, may alter calcium concentrations at the cell surface and facilitate XFM formation but much more work is needed before we can place this new finding in proper context. It is hoped that various animal model and ex vivo systems will emerge that will allow for proper assembly of the puzzle pieces into a coherent picture of XFS pathogenesis. A clear understanding of XFS pathogenesis may lead to 'upstream solutions' to reduce the ocular morbidity produced by XFS.

Autophagy and Mitochondrial Dysfunction in Tenon Fibroblasts from Exfoliation Glaucoma Patients

Purpose

To test the hypothesis that autophagy dysfunction is involved in exfoliation syndrome (XFS), a systemic disorder of extracellular elastic matrices that causes a distinct form of human glaucoma.

Methods

Fibroblasts derived from tenon tissue discards (TFs) from filtration surgery to relieve intraocular pressure in XFS patients were compared against age-matched TFs derived from surgery in primary open-angle glaucoma (POAG) patients or from strabismus surgery. Differential interference contrast light, and electron microscopy were used to examine structural cell features. Immunocytochemistry was used to visualize LOXL1 and Fibulin-5, lysosomes, endosomes, Golgi, and microtubules. Light scatter, Cyto-ID^TM and JC1 flow cytometry were used to measure relative cell size, autophagic flux rate and mitochondrial membrane potential (MMPT), respectively. Enhanced autophagy was induced by serum withdrawal.

Results

In culture, XFS-TFs were 1.38-fold larger (by light scatter ratio, p = 0.05), proliferated 42% slower (p = 0.026), and were morphologically distinct in 2D and 3D culture compared to their POAG counterparts. In extended 3D cultures, XFS-TFs accumulated 8–10 times more Fibulin-5 than the POAG-TFs, and upon serum withdrawal, there were marked deficiencies in relocation of endosomes and lysosomes to the perinuclear area. Correspondingly, the XFS-TFs displayed significant accumulation of the autophagasome marker LC3 II (3.9 fold increase compared to POAG levels, p = 0.0001) and autophagic flux rate as measured by Cyto-ID dye was 53% lower in XFS-TFs than in POAG-TFs (p = 0.01), indicating reduced clearance of autophagasomes. Finally the percent of cells with diminished MMPT was 3–8 times larger in the XFS-TFs than in POAG-TFs (p = 0.02).

Conclusions

Our results provide for the first time a link between XFS pathology to autophagy dysfunction, a major contributor to multiple age related diseases systemically throughout the body, in the brain and in the retina. A diminished capacity for degradation of denatured protein and aging cellular organelles may underpin the development of extracellular protein aggregates in XFS.

Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma: A Review of the Literature with Updates on Surgical Management

Pseudoexfoliation syndrome (PES) is a systemic disorder caused by progressive accumulation of extracellular material over various tissues. PES usually determines increased intraocular pressure, changes in the anatomical aspects of the optic nerve, and visual field alterations leading to the diagnosis of pseudoexfoliation glaucoma (PEG). Use of topical medical treatment usually leads to poor results in terms of long-term follow-up but many surgical techniques, such as Argon Laser or Selective Laser Trabeculoplasty, have been proposed for the management of PEG affected patients. The present paper is a review on the pseudoexfoliation syndrome and pseudoexfoliation glaucoma with an update on surgical management.

Characteristics of the Anterior Segment Biometry and Corneal Endothelium in Eyes with Pseudoexfoliation Syndrome and Senile Cataract

Objectives:

To evaluate the anterior segment biometric features and corneal endothelial changes in eyes with pseudoexfoliation (PEX) syndrome and senile cataract.

Materials and Methods:

The central corneal thickness, anterior chamber depth (ACD), pupil diameter, lens thickness, endothelial cell density (ECD), and percentages of polymegathism and pleomorphism of 52 subjects with PEX and cataract were compared with 51 age- and gender-matched control subjects with cataract using optical low-coherence reflectometry (OLCR, Lenstar LS 900; Haag Streit AG, Switzerland) and in-vivo confocal microscopy (Confo Scan 4, Nidek Co. Ltd, Osaka, Japan). Nineteen subjects with PEX syndrome had glaucoma and were using anti-glaucoma medications. Only one eye of the subjects was used in statistical analysis and a p value less than 0.05 was considered statistically significant.

Results:

None of the OLCR parameters reached statistically significant differences among the 3 groups (ANOVA p>0.05). The percentage of eyes with ACD <2.5 mm was 13.7% in the control group, 24.2% in PEX eyes without glaucoma and 21.1% in PEX eyes with glaucoma, with no statistically significant differences (p=0.45). There was a significant difference in mean ECD among the 3 groups (ANOVA p=0.02), whereas no differences could be found in respect to polymegathism and pleomorphism (p>0.05). Mean ECD was significantly lower in the PEX glaucoma group (2,199.5±176.8 cells/mm2) than the control group (2,363±229.3 cells/mm2) (p=0.02), whereas no difference was found in mean ECD of PEX eyes without glaucoma and the control group (p=0.42). ECD was less than 2,000 cells/mm2 in 15.8% of PEX subjects with glaucoma, 9.8% of control subjects and 6.1% of PEX eyes without glaucoma, with no statistically significant difference (p=0.52).

Conclusion:

As eyes with both PEX glaucoma and cataract seem to be associated with decreased endothelial cell number, specular or confocal microscopy screening should be done for the patients scheduled for intraocular surgery.

Cataract surgery in pseudoexfoliation syndrome

Pseudoexfoliation (PXF) syndrome is characterized by the deposition of distinctive fibrillar material in the anterior segment of the eye. It is an age-related process that is associated with open and narrow angle glaucomas and the formation of cataracts. Not only is PXF associated with the formation of dense nuclear cataracts, it is also well known that those presenting with PXF are at a higher risk of developing complications during, and even after, cataract surgery. Complications associated with cataract surgery in PXF can occur from poor pupillary dilation, zonular weakness leading to intraoperative or postoperative lens dislocation and vitreous loss, postoperative intraocular pressure (IOP) spikes potentiating glaucomatous damage, capsular phimosis, prolonged inflammation, and postoperative corneal decompensation. The surgeon should be prepared to encounter the various potential intraoperative and postoperative complications in eyes with pseudoexfoliation syndrome during cataract surgery. In this way, the surgeon can plan his/her surgical technique to help avoid surprises during cataract surgery and be prepared to manage the potential postoperative complications that can occur in pseudoexfoliation eyes.

Exfoliation syndrome: a disease with an environmental component

PURPOSE OF REVIEW

Exfoliation syndrome (XFS), the most common cause of secondary open angle glaucoma, is associated with significant ocular morbidity. Recent studies have pointed toward environmental components that may alter the risk of XFS development. This review focuses on the recent studies elucidating the role of environmental factors that play a role in the development of exfoliation syndrome.

RECENT FINDINGS

In XFS, aberrant microfibril formation emanating from the cell-extracellular matrix interface admixes with other macromolecules and is cross-linked by lysyl oxidase like 1 (LOXL1) activity. A common gene variant in the LOXL1 enzyme, an enzyme critical for enhancing the tensile strength of collagen and elastin in extracellular matrices, has been found in approximately 90% of XFS cases. However, approximately 80% of controls also have disease-associated LOXL1 gene variants. These findings point toward other nongenetic factors influencing the development of XFS. Increasing latitude, solar radiation, climatic variables and dietary factors such as high coffee consumption and low dietary folate intake are among the nongenetic factors associated with increased risk of XFS.

SUMMARY

A greater understanding of the environmental components associated with XFS may lead to lifestyle preventive strategies to ameliorate disease burden.

Intraoperative and Immediate Postoperative Outcomes of Cataract Surgery using Phacoemulsification in Eyes with and without Pseudoexfoliation Syndrome

BACKGROUND

To compare the intraoperative and immediate postoperative behavior and complications in eyes with pseudoexfoliation (PEX) syndrome with eyes having senile cataract without PEX during cataract surgery using phacoemulsification (PKE).

MATERIALS AND METHODS

In this prospective study, 68 eyes of 68 patients were divided into two groups: Group 1 (test) comprised 34 eyes with immature senile cataract with PEX and Group 2 (control) included 34 eyes with immature senile cataract without PEX and any coexisting ocular pathology. Phacoemulsification (modern cataract surgery) was performed on both groups through stop and chop technique and comparative analysis of the incidence of intraoperative and immediate postoperative complications was made.

RESULTS

There was no significant difference in rates of intraoperative complications between PEX (2.9%) and Control (0%) group. The mean pupil diameter was significantly smaller in Group 1 (p<0.001). No eye in either group had phacodonesis. 58.8% of eyes in Group 1 and 29.4% in Group 2 had a harder cataract (nuclear sclerosis) ≥ grade 3 (p=0.017). PKE was performed in all eyes with cataract in both groups. Intraoperative complication (zonular dialysis (dehiscence) was encountered in only 2.9% (1 case) of eyes with PEX. PC (posterior capsule) tear (rent) with vitreous loss was seen in 2.9% eyes of Group 1 and none in Group 2. Postoperatively, IOP (intraocular pressure) and aqueous flare response were comparable between the groups. Significantly higher inflammatory cell response was observed in Group 1 (p=0.014). BCVA (best corrected visual acuity) using Snellen chart with pinhole on postoperative day1 was significantly better in the control group compared to the group with PEX (p=0.027).

CONCLUSION

Phacoemulsification can be safely performed by experienced hands in cataractous eyes with PEX. The incidence of intraoperative and immediate post-operative complications in eyes with PEX was not significantly different compared to eyes without PEX in our study. Further studies among a larger population are required.