The spectrum of iris angiography abnormalities 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.

The Blood-ocular Barriers and their Dysfunction: Anatomy, Physiology, Pathology

Complex barriers comprise the blood-aqueous (BAB) and the blood-retinal barrier (BRB), and separate anterior and posterior eye chambers, vitreous body, and sensory retina from the circulation. They prevent pathogens and toxins from entering the eye, control movement of fluid, proteins, and metabolites, and contribute to the maintenance of the ocular immune status. Morphological correlates of blood-ocular barriers are tight junctions between neighboring endothelial and epithelial cells, which function as gatekeepers of the paracellular transport of molecules, thereby limiting their uncontrolled access to ocular chambers and tissues. The BAB is composed of tight junctions between endothelial cells of the iris vasculature, endothelial cells of Schlemm's canal inner wall, and cells of the nonpigmented ciliary epithelium. The BRB consists of tight junctions between endothelial cells of the retinal vessels (inner BRB) and epithelial cells of the retinal pigment epithelium (outer BRB). These junctional complexes respond rapidly to pathophysiological changes, thus enabling vascular leakage of blood-derived molecules and inflammatory cells into ocular tissues and chambers. Blood-ocular barrier function, which can be clinically measured by laser flare photometry or fluorophotometry, is compromised in traumatic, inflammatory, or infectious processes, but also frequently contributes to the pathophysiology of chronic diseases of the anterior eye segment and the retina, as exemplified by diabetic retinopathy and age-related macular degeneration.

The Effect of Amniotic Membrane Transplantation on Trabeculectomy in Patients with Pseudoexfoliation Glaucoma

Purpose

The aim is to evaluate the effect of amniotic membrane transplantation (AMT) on trabeculectomy with mitomycin C in patients with pseudoexfoliation glaucoma (PXG).

Methods

This retrospective cohort study included 85 eyes of PXG who underwent trabeculectomy with or without AMT (52/33 eyes in the AMT/control group). Surgical success was defined by these criteria: (1) intraocular pressure (IOP) ≤18 mmHg and IOP reduction ≥20% and (2) IOP ≤15 mmHg and IOP reduction ≥25%. Criteria A and B defined complete success rates as patients who met these criteria without medication, respectively. Criteria C and D defined qualified success rates as patients who met these criteria with medication, respectively. Cumulative probabilities of success were compared using the Kaplan–Meier survival analysis. Cox proportional hazard models were used to evaluate the influence of AMT on surgical success accounting for confounding variables.

Results

For the AMT group, compared with the control group, the complete success rates at 12 months for criterion A were 86.5% and 63.6%, respectively (P = 0.017) and for criterion B, 86.4% and 63.6% (P = 0.005). The qualified success rates at 12 months for criterion C were 92.1% and 75.1%, respectively (P = 0.047) and for criterion D, 92.1% and 72.1% (P = 0.021). On multivariable Cox regression analyses, AMT was associated with a lower failure rate on criteria A, B, and D (all P ≤ 0.047). Incidence of avascular bleb was higher in the control group than in the AMT group (7 vs 0 eyes; P = 0.004).

Conclusions

In patients with PXG, trabeculectomy with AMT was associated with higher success rates and a lower incidence of avascular bleb compared with conventional trabeculectomy. Research Registration. This retrospective cohort study was registered at the Clinical Trial Registry of Korea (https://cris.nih.go.kr/cris/index/index.do, KCT0007228).

Automated iris volume analysis and trabecular meshwork length using anterior segment optical coherence tomography - Application in pseudoexfoliation and pseudoexfoliation glaucoma

Purpose:

The aim of this study was to evaluate differences in the iris and angle parameters in psuedoexfoliation syndrome (PXF) and pseudoexfoliation glaucoma (PXG) using anterior segment optical coherence tomography (ASOCT).

Methods:

Patients with PXF or PXG were compared using ASOCT with primary open-angle glaucoma POAG eyes as controls in this noninterventional comparative study conducted at a tertiary eye care center in East India. All angle parameters, TM length, and iris thickness were analyzed from the enhanced depth imaging (EDI) single scans obtained. Quadrant scans were used for the calculation of iris volume using a custom-built in-house software. In particular, the software performs multiple operations including edge detection, connected components, and thresholding to localize and segment the iris. Differences in the iris volume/thickness and TM length in PXF and PXG with POAG were analyzed.

Results:

A total of 225 eyes were included, which included 75 PXG and 98 PXF cases and 52 POAG with a mean age of 67 ± 9.7 years at presentation. The algorithm repeatability and reproducibility was also established with correlation coefficients more than 99% which was substantiated with Bland-Altman plots. The iris volume (calculated in 197 images of 225 eyes) did not differ significantly in PXF and PXG eyes, although both had significantly greater volume compared to POAG eyes. The iris volume or other angle parameters including TM length did not correlate with clinical variables such as IOP, age, or visual field indices.

Conclusion:

Iris parameters or TM length do not explain pathogenesis of glaucoma in pseudoexfoliation.

Quantitative analysis of radial peripapillary capillary plexuses in patients with clinically unilateral pseudoexfoliation syndrome

PURPOSE

The aim of this study was to image the radial peripapillary capillary vessel densities (RPCvds) of the affected eyes and fellow unaffected eyes of individuals with unilateral pseudoexfoliation syndrome (PES) using optical coherence tomography angiography (OCTA) and to compare the RPCvds with those of normal age-matched individuals.

METHODS

The eyes were divided into three groups: the pseudoexfoliative material (PXM)-positive eyes of patients with clinically unilateral PES (study eyes), the fellow eyes of the PXM-positive patients (fellow eyes), and the eyes of healthy patients (control eyes). Those patients with glaucomatous findings, including peripapillary hemorrhaging, cupping, notching, focal thinning of the neuroretinal rim, or intraocular pressure readings greater than 21 mmHg, were excluded from the study. The RPCvd (%), peripapillary retinal nerve fiber layer (RNFL) thickness (μm), cup/disc area ratio, rim area (mm²), disc area (mm²), and cup volume (mm³) were automatically calculated via OCTA.

RESULTS

This cross-sectional comparative prospective study included 128 eyes of 88 patients: 40 PXM-positive eyes, 40 fellow eyes, and 48 control eyes. The RPCvds and RNFL thicknesses in the peripapillary region were significantly lower in the study eyes than in the fellow eyes and the control eyes (p = 0.011 and p = 0.011, p = 0.009 and p = 0.004, respectively). There were no significant differences between the fellow eyes and the control eyes with regard to the RPCvd and RNFL values in any region (p > 0.05 for all).

CONCLUSION

Lower RPCvds could provoke capillary deficiency and deterioration of the perfusion of the optic nerve head in patients with PES.

Effect of Tropicamide on Laser Flare Meter Measurements in Patients with Pseudoexfoliation

PURPOSE

To investigate the effect of 1% tropicamide on anterior chamber aqueous flare (ACAF) measurements acquired with laser flare meter in patients with pseudoexfoliation.

METHODS

Thirty-three eyes of 33 patients with pseudoexfoliation were enrolled. Patients with the history of other ocular diseases, intraocular surgeries, and the presence of severe posterior synechia were excluded. Besides routine ophthalmological examination, ACAF levels were measured by laser flare meter device (Kowa FM 600) before and after instillation of 1% tropicamide.

RESULTS

The mean age of 33 patients was 67.3±7.1 (53-85) years. Patients had a mean best corrected visual acuity of 0.25±0.41 (1.80-0.00) logMAR, cup-to-disc ratio of 0.45±0.22 (0.2-1), and IOP of 15.33±2.82 (9-20) mmHg. Although the mean ACAF value increased from 14.68±8.40 (3.4-40.4) photon/ms predilation to 15.41±10.74 (3.8-46.8) photon/ms post-dilation, the difference was not statistically significant (p=0.835).

CONCLUSIONS

ACAF values in patients with pseudoexfoliation did not significantly differ after instillation of 1% tropicamide.

[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.

Choroidal Vessel Diameters in Pseudoexfoliation and Pseudoexfoliation Glaucoma Analyzed Using Spectral-Domain Optical Coherence Tomography

PURPOSE OF THE STUDY

The purpose of the study was to analyze choroidal vessel diameters in pseudoexfoliation (PXF) and pseudoexfoliation glaucoma (PXFG) using spectral-domain optical coherence tomography (SD-OCT).

MATERIALS AND METHODS

Fifty patients (100 eyes) with PXF and PXFG who underwent high-definition 1-line raster SD-OCT imaging at New England Eye Center, Boston, were retrospectively identified and divided into unilateral PXFG (26 patients, 52 eyes), unilateral PXF (4 patients, 8 eyes), bilateral PXFG (4 patients, 8 eyes), and bilateral PXF (16 patients, 32 eyes). Eyes with concomitant chorioretinal pathology, history of shunting/filtering for glaucoma, and significant anisometropia were excluded. SD-OCT scans were divided into subfoveal, central, and peripheral zones and choroidal vessel diameters were measured.

RESULTS

In patients with unilateral PXFG, mean choroidal vessel diameter was 12.9 μm smaller in the affected eyes when compared with their contralateral eyes (45.7 vs. 58.6 μm; P<0.0001) with the greatest reduction (16.6 μm) in the subfoveal zone (49.0 vs. 65.6 μm; P<0.0001). In patients with unilateral PXF, the mean choroidal vascular diameter was 13.3 μm smaller in the affected eyes when compared with their contralateral eyes (42.8 vs. 56.1 μm; P=0.02). As expected, no significant difference was observed between the 2 eyes of patients with bilateral PXFG (45.5 vs. 45.7 μm; P=0.95) and bilateral PXF (51.4 vs. 50.2 μm; P=0.52).

CONCLUSIONS

Choroidal vessel diameters are smaller in the affected eyes of patients with unilateral PXF and PXFG when compared with their contralateral unaffected eyes. These changes appear to be independent of the presence or absence of glaucoma. Future studies may identify the choroidal vascular changes and their relationship with the pathogenesis of these conditions.

Comparisons of retinal vessel diameter and glaucomatous parameters between both eyes of subjects with clinically unilateral pseudoexfoliation syndrome

Purpose

Pseudoexfoliation syndrome (PEX), the most common identifiable cause of open-angle glaucoma, might affect the retinal hemodynamics. To test this, we compared retinal vessel diameter and glaucoma-related parameters between eyes with pseudoexfoliation material (PE+) and fellow unaffected (PE-) eyes of patients with clinically unilateral PEX.

Methods

The medical records of 30 consecutive Japanese subjects were reviewed retrospectively. The retinal vessel diameters were measured and expressed as the central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) using standardized software. During the chart review, we recorded glaucoma-related parameters including intraocular pressure (IOP), visual field mean deviation (MD) value, planimetrically measured vertical cup-to-disc (C/D) ratio, circumpapillary retinal nerve fiber layer thickness (cpRNFLT) and macular inner retinal thickness (mIRT) measured by spectral-domain optical coherence tomography, anterior chamber flare (ACF), corneal endothelial cell density (CECD), and number of antiglaucoma medications.

Results

Compared with PE- eyes, the CRAE, CRVE, MD, cpRNFLT and mIRT, and CECD were significantly lower in PE+ eyes; the IOP, vertical C/D ratio, number of antiglaucoma medications, and ACF were significantly higher in PE+ eyes (P<0.0001 for all comparisons). The CRAE, cpRNFLT, and MD were correlated positively with each other (ρ = 0.456–0.499, P<0.0001–0.0002) and negatively with the IOP (ρ = -0.562- —0.432, P<0.0001–0.0006). The vertical C/D ratio was correlated positively with the IOP (ρ = 0.483, P<0.0001) and negatively with the CRAE, cpRNFLT, and MD (ρ = -0.745–-0.479, P<0.0001–0.0001).

Conclusions

Deposition of PE can cause retinal vessel narrowing in arterioles and venules. The roles and mechanisms of retinal vessel narrowing in glaucoma pathogenesis need clarification.

Anterior chamber aqueous flare, pseudoexfoliation syndrome, and glaucoma

The purpose of this study is to evaluate anterior chamber aqueous flare (ACAF) in Tunisian patients with pseudoexfoliation (PEX) syndrome with or without associated glaucoma. This is a prospective, cross-sectional, comparative study including 53 patients (88 eyes) with PEX syndrome, 48 patients with PEX glaucoma (86 eyes), and 53 healthy sex-and age-matched control subjects (106 eyes). All patients underwent a complete ophthalmic examination and laser flare photometry. Mean ACAF was significantly higher in the PEX syndrome group in comparison with the control group (17.96 ± 10.05 vs 7.06 ± 2.95 ph/ms; p = 10(-4)), in patients with PEX glaucoma compared to PEX syndrome without associated glaucoma (27.99 ± 15.45 vs 17.96 ± 10.05 ph/ms; p = 10(-4)), in the PEX glaucoma group in comparison with control group (27.99 ± 15.45 vs 7.06 ± 2.95 ph/ms; p = 10(-4)), and in patients with unilateral PEX syndrome in comparison with contralateral-unaffected eyes (25.72 ± 14.88 vs 8.58 ± 3.45 ph/ms; p = 0.000). For patients with PEX syndrome, a high ACAF might be a predictor for the development of glaucoma. Further investigations are needed to clarify the role of laser flare photometry in predicting the risk of glaucoma in patients with PEX syndrome.

Pattern of pseudoexfoliation deposits on the lens and their clinical correlation--clinical study and review of literature

PURPOSE

To study the clinical correlates of pattern of deposits over the lens in patients with pseudoexfoliation syndrome (PXF) or pseudoexfoliation glaucoma.

METHODS

This retrospective observational study screened 346 patients with PXF seen in glaucoma clinic of a tertiary hospital from 2011-2013. Details like pattern of deposits, location on the lens surface and pupillary abnormalities in slit lamp photographs and their correlation with clinical and demographic variables, were analysed.

RESULTS

A total of 84 eyes of 42 patients with bilateral PXF were included for the study. Glaucoma was seen in 30 eyes with baseline IOP of 24+3.8 mm Hg. Comparing the type of deposits, namely classical (n = 39 eyes), radial pigmentary (RP) form (n = 39 eyes) and combined classical and radial pigmentary (CR) forms (n = 6 eyes) of deposits, pupillary ruff atrophy was common in all forms while poor dilatation was rare in the RP type (n = 5 vs n = 25 in classical forms, p < 0.001). Mean deviation (MD) was worse in the classical and CR form as compared to RP type with the latter presenting much earlier, 43 ± 3.2 years vs 48 ± 4.1 years in CR and 56 ± 5.7 years in classical form, p < 0.001. The baseline IOP in the RP group (18 ± 2.3 mm Hg) was significantly lower than the other two forms (CR 20 ± 3.2 mm Hg, classical 28 ± 2.3 mm Hg), p < 0.001, with only 2 eyes on anti-glaucoma drugs at presentation.

CONCLUSION

Pattern of exfoliation deposits may indicate the stage and severity of the disease process in evolution with the RP representing an earlier/less severe form of pseudoexfoliation syndrome.