Incidence of defects in the pigmented pupillary ruff in eyes with and without fibrillopathia epitheliocapsularis (so-called senile exfoliation or pseudoexfoliation of the anterior lens capsule)

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.

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.

The depigmentation degree of iris pigment epithelium in pseudoexfoliation syndrome

BACKGROUND

To compare the optical density of iris pigment epithelium (OD_IPE) and iris stromal thickness (IST) measurements in patients having pseudoexfoliation syndrome (PXS) and age-gender matched participants.

METHODS

This is a cross-sectional study. Patients with PXS were enrolled in the study group. Age and gender-matched healthy subjects with no evidence of PXS were recruited as controls. After a comprehensive ophthalmological evaluation, the anterior segment images were acquired using anterior segment spectral-domain optical coherence tomography (AS SD-OCT). The acquired pictures were further analyzed using the ImageJ program. Two investigators measured the OD_IPE and the IST of the subjects, and the repeatability and reproducibility were checked. SPSS program was used for statistical analysis.

RESULTS

The PXS group was comprised of twenty-two eyes (n = 22 patients), and the control group contained twenty-six eyes of 26 age and gender-matched healthy subjects. The mean temporal OD_IPE of the study group was found to be decreased significantly in comparison to the mean temporal OD_IPE of the control eye (p = 0.018). Both the mean nasal (N) and temporal (T) ISTs of the PEX eyes were thinner than the control eyes (p = 0.006 and p = 0.002, respectively). The mean baseline IOP was found to significantly negatively correlate with the OD_IPE in the PEX group at both N and T sides (r = -0.531, p = 0.011 and r = -0.685, p < 0.001, respectively).

CONCLUSION

The pupillary margin IPE was found more depigmented, and the mean N and T IST were significantly thinner in the PEX group by comparison with the age-gender matched healthy controls. The mean baseline IOP was negatively correlated with the pupillary margin's IPE pigmentation degree in patients with PXS.

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.

Novel grading system for pupillary ruff changes and associated features

BACKGROUND

  To evaluate the reproducibility of a new system for grading pupil ruff changes and associated findings.

DESIGN

  Observational comparative study.

PARTICIPANTS

  Forty-seven photograph sets including iris, pupil edge and ruff, and inferior anterior chamber drainage angle.

METHODS

  A novel system for recording pupillary ruff changes was developed, along with reference iris, pupil and gonioscopy images. A prospective masked agreement study was undertaken using two observers who graded the photograph sets using this new system. Parameters included pupillary ruff absence and abnormality, pupil edge pigment, trabecular meshwork pigment, Sampaolesi line pigment, iris root pigment, and pigment 'lumps' and 'piles'.

MAIN OUTCOME MEASURES

  Intraobserver and interobserver agreement for the parameters of the grading system, assessed with the intraclass correlation coefficient and Bland-Altman plots.

RESULTS

  Photographs of 47 eyes of 47 glaucoma suspects and glaucoma patients were evaluated. Agreement percentages of ≥95% (average 96%) and ≥60% (average 70%) were obtained for intraobserver and interobserver agreement, respectively. The average interobserver single-measure intraclass correlation coefficient and repeat-measures intraclass correlation coefficient were 0.75 (range 0.54-0.88) and 0.85 (range 0.70-0.94), respectively. There was a non-significant trend towards interobserver systematic bias on one of the nine parameters (iris stroma pigment at the pupil edge).

CONCLUSION

  This grading system provides a reliable and reproducible system for encoding of clinical signs of pupil ruff atrophy for clinical research.

Delayed intraocular pressure elevation after pupillary dilation in exfoliation syndrome

PURPOSE

To determine the effect of pupillary dilation on intraocular pressure (IOP) in normotensive patients with exfoliation syndrome (XFS).

METHODS

Patients with XFS were enrolled in this prospective trial. All eyes were untreated, had no previous laser or operative surgery and were normotensive with full visual fields and open angles. IOP was measured before dilation and hourly for four consecutive hours after dilation with tropicamide 1% and phenylephrine 2.5% eyedrops.

RESULTS

Twenty-five eyes of 19 White patients (nine male, 10 female) with XFS were enrolled. Twelve eyes (48%) had a rise in IOP of ≥ 4 mmHg above the pre-dilation baseline IOP and four (16%) had a rise of ≥ 9 mmHg (9-28 mmHg). Post-dilation gonioscopy confirmed the presence of an open anterior chamber angle in all eyes. The maximum IOP was reached 3 hr post-dilation in three eyes and after 2 hr in the remaining eyes. The four eyes with marked IOP rise exhibited an elevation of between 1 and 7 mmHg at 1 hr. Extensive pigment release was noticed in all eyes that had a rise in IOP.

CONCLUSION

Patients with XFS are at risk of developing delayed post-dilation IOP rises. Awareness of this phenomenon is particularly important in patients with advanced cupping and/or severe visual field loss who may not be able to tolerate a marked elevation of IOP. An early, mild rise in IOP at 1 hr may serve as a warning sign for a more severe, delayed response. Eyes with XFS should be monitored carefully after dilation, especially those with marked pigment release.

Exfoliation syndrome prevalence in the glaucoma population of South Louisiana

A prospective study was performed to determine the prevalence of exfoliation syndrome in a glaucoma population of South Louisiana. Five hundred consecutive open angle glaucoma patients over 50 years of age (median age 70.6 years) from both indigent clinic and private referral sources were examined for the presence of exfoliation material on the lens capsule. The prevalence in caucasian patients was 2.7%, blacks 0.4%, combined 1.4%. This compares with a reported prevalence of exfoliation syndrome among patients with open angle glaucoma in the United States of 3% to 28%, Denmark of 26%, Ireland of 66%, and Sweden of 75%. This low prevalence may be a reflection of the ethnic origin of the population, but other explanations are considered.

Iris transluminance in type 2 diabetes

PURPOSE

Cross-sectional analysis of iris transluminance in type 2 diabetic patients compared with control subjects, all followed in a cohort study.

METHODS

A cohort consisting of a well-characterized group of 82 type 2 diabetic patients were followed for 10 years after diagnosis, as were 125 control subjects. The prevalence of iris transluminance was determined by transscleral transillumination and by grading of black-and-white positive prints at the 10-year examination. The frequency of diabetic retinopathy was prospectively determined by grading of fundus photographs at baseline and after five and 10 years.

RESULTS

Iris transluminance was found in 27% of diabetic patients and 8.0% of control subjects (P = 0.001). The diabetic patients with more severe and short-term retinopathy more commonly had abnormal iris transluminance than those with no or only mild retinopathy (P < 0.05). Iris transluminance was not associated with intraocular pressure or glycemic control.

CONCLUSIONS

In type 2 diabetic patients, abnormal iris transluminance tended to associate with more severe and short-term retinopathy. Therefore we assume that hypoxia is responsible for the defects in the pigment layer of the iris. Thus, abnormal iris transluminance may serve as a marker for rapidly progressive retinopathy.

Exfoliation syndrome: clinical and genetic features

We have ascertained a large number of individuals and families with exfoliation syndrome in order to clarify the disorder's mode of inheritance. Patients with exfoliation syndrome and their relatives were recruited from the practices of a group of ophthalmologists in Maritime Canada. The degree to which the subjects were affected was graded according to a standardized 1-4-point clinical scheme. Pedigrees were constructed from information supplied by family members and from genealogical sources. A total of 782 patients and relatives participated, of whom 467 were definitely affected. The mean age of affected males and females did not differ significantly, but females appeared to be more severely affected at ascertainment than males. More than half of the affected subjects had definite exfoliation in only one eye. Approximately 30 multiplex families were discovered, including one containing 23 affected members among a total of 137 examined individuals that constitutes the largest exfoliative pedigree thus far described. We observed well-documented paternal transmission of the trait, a finding that has not to our knowledge been previously reported. Clustering of cases in the families provides evidence for the involvement of genetic factors. The possibility of homozygosity is suggested in a few patients by the earlier or more frequent presentation of the disorder in the offspring of two affected parents or consanguineous pairings. Although a multifactorial mode of inheritance cannot be excluded, exfoliation syndrome appears to be inherited as an autosomal dominant trait whose late onset and incomplete penetrance poses a significant but not insuperable obstacle to pedigree construction.

Exfoliation syndrome

Exfoliation syndrome (XFS) is an age-related disease in which abnormal fibrillar extracellular material is produced and accumulates in many ocular tissues. Its ocular manifestations involve all of the structures of the anterior segment, as well as conjunctiva and orbital structures. Glaucoma occurs more commonly in eyes with XFS than in those without it; in fact, XFS has recently been recognized as the most common identifiable cause of glaucoma. Patients with XFS are also predisposed to develop angle-closure glaucoma, and glaucoma in XFS has a more serious clinical course and worse prognosis than primary open-angle glaucoma. There is increasing evidence for an etiological association of XFS with cataract formation, and possibly with retinal vein occlusion. XFS is now suspected to be a systemic disorder and has been associated preliminarily with transient ischemic attacks, stroke, systemic hypertension, and myocardial infarction. Further ramifications await discovery. Deposits of white material on the anterior lens surface are the most consistent and important diagnostic feature of XFS. The classic pattern consists of three distinct zones that become visible when the pupil is fully dilated. Whereas the classic picture of manifest XFS has been often described, the early stages of beginning exfoliation have not been well defined. Next to the lens, exfoliation material is most prominent at the pupillary border. Pigment loss from the iris sphincter region and its deposition on anterior chamber structures is a hallmark of XFS. Despite extensive research, the exact chemical composition of exfoliation material (XFM) remains unknown. An overproduction and abnormal metabolism of glycosaminoglycans have been suggested as one of the key changes in XFS. The protein components of XFM include both noncollagenous basement membrane components and epitopes of the elastic fiber system such as fibrillium. Regardless of etiology, typical exfoliation fibers have been demonstrated electron microscopically in close association with the pre-equatorial lens epithelium, the nonpigmented ciliary epithelium, the iris pigment epithelium, the corneal endothelium, the trabecular endothelium, and with almost all cell types of the iris stroma, such as fibrocytes, melanocytes, vascular endothelial cells, pericytes, and smooth muscle cells. The presence of XFS should alert the physician to the increased risks of intraocular surgery, most commonly zonular dehiscence, capsular rupture, and vitreous loss during cataract extraction. Heightened awareness of this condition and its associated clinical signs are important in the detection and management of glaucoma, and preoperative determination of those patients at increased risk for surgical complications.

Phacoemulsification in eyes with pseudoexfoliation

PURPOSE

To compare intraoperative and postoperative complications in eyes with and without pseudoexfoliation having cataract surgery by phacoemulsification.

SETTING

Department of Ophthalmology, National Hospital, Oslo, Norway.

METHODS

Of 1152 consecutive phacoemulsification procedures, 164 cases with pseudoexfoliation (Group 1) and 916 cases without (Group 2) were followed for 4 months after cataract surgery in a prospective study. Of all cataract operations performed during that time, 96.2% were phacoemulsification procedures; 90.4 and 97.4% in eyes with and without pseudoexfoliation, respectively (P < .0005).

RESULTS

The frequency of capsular/zonular tear or vitreous loss was 9.6 and 3.7% in Groups 1 and 2, respectively (P = .0002). A visual acuity of 0.5 or better was achieved in 86.5% of eyes in Group 1 and 92.4% in Group 2 (P = .02). There were no statistically significant between-group differences in the frequency of a postoperative inflammatory response 1 day (6.7 versus 4.4%), 1 week (2.4 versus 1.6%), or 4 months (1.8 versus 0.9%) postoperatively.

CONCLUSION

Phacoemulsification was safe in most eyes with pseudoexfoliation even though significantly more complications occurred intraoperatively in these eyes. The low frequency of an inflammatory response indicates that the presence of pseudoexfoliation does not significantly increase the risk of inflammation.

A histopathologic study of iris changes in pseudoexfoliation syndrome

PURPOSE

To investigate the histopathologic causes for the most prominent clinical observations of the iris of patients with pseudoexfoliation syndrome (PXS), particularly poor mydriasis but also atrophy of the iris pigment epithelium with anterior chamber melanin dispersion, stromal atrophy, and vascular changes.

METHODS

Thirty-three iris specimens from patients with PXS with and without glaucoma were investigated by transmission electron microscopy with special regard to sphincter and dilator muscle tissues.

RESULTS

Pseudoexfoliation fibers were observed consistently in association with fibroblasts and melanocytes in the iris stroma, endothelial cells and pericytes of vessels, both anterior and posterior pigment epithelial cells, and muscle cells of sphincter and dilator muscles. The various cell types showed uniformly surface cell membrane excavations with PXS fibers, indicating local PXS production. Focal disintegration of the pigment epithelial layers was associated with unusual PXS material aggregations along the apical aspects of epithelial cells. Compared with age-matched control specimens, the muscle cells showed, in addition to PXS production, remarkable degenerative and atrophic changes in PXS eyes.

CONCLUSION

The authors suggest that abnormal extracellular matrix production and/or vascular abnormalities leading to tissue hypoxia cause degenerative tissue changes and that atrophy of muscle cells might potentiate the reduction of dilating properties of the iris.

Pseudoexfoliation syndrome and extracapsular cataract extraction

Extracapsular cataract extraction (ECCE) in 139 eyes with pseudoexfoliation syndrome was compared to 762 eyes without pseudoexfoliation syndrome in a consecutive study. Preoperative findings, operative procedure and problems were registered, stored and analyzed in a computer program package. Of the patients with pseudoexfoliation syndrome 88.5% were 70 years or older, compared to 67.2% of the patients without pseudoexfoliation syndrome (p < 0.001). Glaucoma occurred in 48.9% of eyes with pseudoexfoliation syndrome and in 6.8% of eyes without pseudoexfoliation syndrome, respectively. Poorly dilated pupil was demonstrated in 46.8% and in 5.8% of eyes with and without pseudoexfoliation syndrome, respectively. Capsule/zonulae tears (without vitreous loss) occurred in 4.3% of the pseudoexfoliation syndrome eyes, compared to 1.3% in eyes without pseudoexfoliation syndrome (p < 0.05). The incidence of vitreous loss was similar in both groups. We found no correlation between the pupil size and capsule/zonulae tears or vitreous loss in either group. In conclusion, when appropriate care is undertaken, ECCE with posterior chamber IOL implantation is a safe procedure in pseudoexfoliation syndrome eyes.

Exfoliation syndrome and the effect of phenylephrine and pilocarpine on pupil size

The horizontal diameter of the pupil was measured on 20 eyes with exfoliation syndrome and 20 control eyes before and after the instillation of 10% phenylephrine and 4% pilocarpine eye drops. Pupil dilation induced by topical application of the alpha 1 adrenoceptor agonist phenylephrine was significantly smaller in eyes with exfoliation syndrome compared to controls. The cholinergic agonist pilocarpine decreased pupil diameter and this effect was significantly less in cases with exfoliation syndrome. We conclude from these data that the pharmacological response to both adrenergic and cholinergic stimulation is weaker in eyes with exfoliation syndrome compared to controls.

Pseudoexfoliation glaucoma in Greece

Pseudoexfoliation glaucoma is commonly seen in Greece, however there is little data concerning the prevalence and characteristics of this disorder. Patients undergoing trabeculectomy for open angle glaucoma were investigated both by the appraisal of the case notes and by re-examination. The prevalence of pseudoexfoliation glaucoma in this population was found to be 87.8%. The characteristics of this disease process in the population studied are discussed. These findings indicate that pseudoexfoliation is a major contributor to severe glaucoma in the population of Northern Greece.

Clinical signs of the pseudoexfoliation syndrome

Pseudoexfoliation syndrome (PXS) is a common cause of glaucoma throughout the world. It is most commonly diagnosed after the observation of pseudoexfoliation material (PXM) on the anterior lens surface. However, there are numerous clinical signs of PXS that should alert the examiner to search carefully for PXM on the anterior lens surface. These include pupillary ruff defects, iris sphincter transillumination, a characteristic whorl-like pattern of particulate pigment deposition on the iris sphincter, particulate pigment deposition on the peripheral iris and trabecular meshwork, and exfoliation material on the zonules and ciliary body. Accuracy of diagnosis is important for purposes of treatment, prognosis, and basic research in he mechanisms of glaucoma, particularly tissue culture.

Anterior chamber angle in the exfoliation syndrome

The gonioscopic findings of 76 patients with the exfoliation syndrome were reviewed. A high frequency of narrowness of the anterior chamber (AC) angle was found (32%). 18% had angles considered occludable, and 14% had obvious angle-closure glaucoma as shown by the presence of peripheral anterior synechias (PAS). Increased pigmentation of the posterior trabecular meshwork (PTM) was noted in all cases. When this pigmentation was markedly asymmetrical, unilateral exfoliation with glaucoma was common in the more pigmented eye. In addition heavy angle pigmentation in the absence of exfoliation was noted in the fellow eye of patients with characteristic exfoliated material in the other eye. Increased pigmentation of the PTM may be the earliest detectable sign of the exfoliation syndrome (ES). The clinical significance of our estimating PTM pigmentation at the 12 o'clock position is discussed. In view of the accelerated optic nerve damage associated with the development of glaucoma secondary to ES, routine estimation of the pigmentation of the PTM at 12 o'clock is recommended in the hope of early detection of cases of otherwise inapparent ES.

Cataract extraction complicated by capsular glaucoma

Synechiae involving the iris pigment epithelium and the peripheral anterior lens capsule occur in capsular glaucoma. During cataract extraction they may bring about traction on the capsule threatening its rupture. The ultrastructural basis of these adhesions is a bonding of pigment cells to capsular surface by pseudoexfoliative material.

The cyclopentolate provocative test in suspected or untreated open-angle glaucoma. III. The significane of pigment for the result of the cyclopentolate provocative test in suspected or untreated open-angle glaucoma

Significant elevations of IOP, i. e. responses, occurred in eyes with suspected or untreated open-angle glaucoma during the mydriasis test with 1% cyclopentolate (CPT). The possible role of pigment in the IOP elevations seen in the responders was studied. Pigment was liberated in the aqueous, sometimes very profusely, in 88 (31.9%) of 276 eyes during CPT. The maximal IOP elevations, ad 20 mmHg, were seen in just these eyes. They were eyes with capsular or pigmentary glaucoma or eyes in which exceptionally heavy pigment was demonstrated in the chamber angle for other reasons. There was a statistically significant correlation between pigment liberation and IOP elevation during CPT. Evidently profuse pigment liberation may have caused transient blocking of the trabecular meshwork, obstruction of aqueous outflow and elevation of IOP. Liberation of pigment in the aqueous during CPT was statistically highly significantly more profuse in eyes with pseudoexfoliation than in eyes without pseudoexfoliation. An equally significant correlation with demonstrated between the grade of chamber angle pigmentation and the degree of pigment liberation during CPT. The significance of pigment for IOP elevation was seen also in the statistically highly significantly more profuse pigmentation of the chamber angle in the responder than in the non-responder eyes.

The essentials of data sources in eye epidemiology

The extensive literature on eye epidemiology was selectively reviewed to provide a concise and comprehensive summary on the current status of available data sources. The topics being covered were epidemiologic data evaluation, data handling, card registration, computer analysis, geographic factors, socio-economic conditions, personal attributes, genetic backgrounds, twin analysis and laboratory procedures for host defense factors including humoral and cellular immunity. Also, the scope of this article encompassed such major practical issues as glaucoma, cataract and other blinding diseases as well as traffic and occupational hazards. Epidemiologic information thus obtainable through data searching may prove tobe instrumental in the identification of any potential preventive measures in ophthalmology and public health.