Evaluation of choroidal thickness using enhanced depth imaging by spectral-domain optical coherence tomography in patients with pseudoexfoliation syndrome

Subfoveal choroidal thickness changes in patients with pseudoexfoliation syndrome (PEX) compared to healthy controls: A systematic review and meta-analysis

PURPOSE

To investigate changes in choroidal thickness in patients diagnosed with pseudoexfoliation syndrome (PEX) compared to healthy controls, using optical coherence tomography (OCT).

METHODS

PubMed and Scopus databases were systematically searched for published articles comparing choroidal thickness between patients with PEX and healthy controls. Standardized Mean Difference (SMD) with 95 % confidence interval (CI) was computed to compare continuous variables. Revman 5.4 was used for the analysis. Subgroup analyses were performed according to OCT devices used.

RESULTS

12 studies were included in our analysis. Subfoveal choroidal thickness was decreased in patients with PEX compared to healthy controls. Subgroup analysis confirmed this finding in studies that used Heidelberg or Optovue OCT Devices.

CONCLUSION

Our meta-analysis showed that choroidal thickness was decreased in patients with PEX compared to controls. Increased heterogeneity and small case-control studies are the main limitations of the meta-analysis. Further studies are needed to evaluate the clinical significance of reduced subfoveal choroidal thickness in PEX.

Choroidal and central macular thickness before and after treatment in post fever retinitis

PURPOSE

To study the choroidal thickness (CT) and central macular thickness (CMT) in post-fever retinitis (PFR) and their correlation with visual acuity and treatment.

METHODS

A retrospective, observational study of patients presenting with PFR from 2013 to 2021 and with spectral domain optical coherence tomography (SD-OCT) (Heidelberg®, SpectralisTM, Heidelberg, Germany) images were included. The CT and CMT were measured at presentation and at the final visit. The CT was measured subfoveally and at points 2000 µm superior, inferior, medial, and lateral from the fovea using the caliper tool.

RESULTS

Seventy-nine eyes of 65 patients were included for this study. The mean age was 39.03 (±16.00) years with female preponderance of 53.84% (n = 35). Mean follow-up duration was 30 days. Mean CT at presentation and at follow-up was 254.12 µm and 241.51 µm, respectively. CT was decreased in majority of the eyes 67.1% (n = 53) from their baseline value. Mean CMTs at presentation and final visit were 454.8 µm and 223.7 µm, respectively. Best corrected visual acuity had a positive correlation with CMT (r = 0.340; P = 0.002) and negligible correlation with CT. A significant decrease in the mean CT was noted in patients who received doxycycline either alone or in combination with a steroid as compared to those who did not receive any treatment (P < 0.001). The significance of which is unknown presently.

CONCLUSION

CMT has a greater role in determining the final visual outcome than CT. CT can be reduced post-treatment with no effect on vision.

Comparison of Choroidal Vascularity Index in Patients with Pseudoexfoliation Glaucoma, Pseudoexfoliation Syndrome, and Healthy Controls

PURPOSE

To compare peripapillary choroidal vascularity index (CVI) parameters in pseudoexfoliation glaucoma (PEG), pseudoexfoliation (PEX) syndrome, and healthy controls.

METHODS

A total of 240 eyes of 240 patients were included in this cross-sectional prospective study, and the three groups consisted of (i) 80 eyes of 80 patients with PEG, (ii) 80 eyes of 80 patients with PEX syndrome, and (iii) 80 healthy control eyes. Peripapillary enhanced depth imaging optical coherence tomography images were binarized via standard protocols with the ImageJ software. CVI was analyzed in all sectors of the peripapillary region.

RESULTS

Peripapillary CVI was found to be significantly lower in the PEG group (61.6 ± 2.32) compared with the PEX group (64.7 ± 3.15) and the control group (67.5 ± 2.44) (p < .001), and patients with PEX also had significantly lower values compared to controls (p < .001). Peripapillary CVI values were significantly lower in the temporal, nasal, superotemporal, superonasal, inferotemporal and inferonasal sectors of the PEG group compared to both the PEX group and controls (p < .001). Peripapillary CVI was also found to be lower in all sectors in the PEX group compared to controls (p < .001). Global peripapillary choroidal thickness was significantly thinner in the PEG group than the PEX and control groups (133.37 ± 39.16, 154.36 ± 33.28 and 157.82 ± 36.77 μm, respectively, p < .001).

CONCLUSIONS

In the current study, it was shown that the presence of PEX caused a decrease in CVI value and this decrease was highest in patients with PEG. CVI may be a useful parameter to show vascular dysfunction in PEG and PEX syndrome.

Does Pseudoexfoliation Syndrome Affect the Choroidal Response After Uneventful Phacoemulsification

Purpose

To examine subfoveal and peripapillary choroidal thickness changes after successful phacoemulsification in cataract cases with nonglaucomatous pseudoexfoliation syndrome (PXS).

Materials and Methods

Nineteen cataract patients with PXS and 19 without PXS were included in this prospective and interventional controlled study. Subfoveal and peripapillary choroidal thicknesses were measured before surgery and on the postoperative first day (D1), first week (W1), first month (M1), second month (M2), and third month (M3). Subfoveal choroidal thickness measurement included total subfoveal choroidal thickness (tSFCT), the small choroidal vessel layer (SF-SCVL) thickness, and the large choroidal vessel layer (SF-LCVL) thickness.

Results

The greatest increase in mean tSFCT compared to baseline was observed between W1 and M1 with values of 23.33 ± 2.96 µm and 31.84 ± 2.88 µm, respectively, for the PXS and non-PXS groups (P = 0.014). The greatest increase in SF-SCVL thickness compared with baseline occurred at M1 with values of 6.66 ± 1.97 µm and 26.52 ± 1.92 µm, respectively, for the PXS and non-PXS groups (P < 0.001). The peripapillary choroidal thickness only showed a significant difference between the groups at the inferior measurement point with values of 117.94 ± 14.15 µm and 137.52 ± 34.53 µm, respectively, for the PXS and non-PXS groups (P = 0.032).

Conclusions

Cataract cases with PXS exhibited a different choroidal thickness response compared to non-PXS eyes after successful phacoemulsification. The increased choroidal thickness was particularly observed in Haller's layer in the eyes with PXS and in the choriocapillaris and Sattler's layer in the eyes without PXS.

Peripapillary and Macular Vessel Density Measurement With Optical Coherence Tomography Angiography in Exfoliation Syndrome

PRECIS

Although peripapillary retinal nerve fiber layer thickness (RNFLTs) and vessel density (VD) values were similar to healthy group, eyes with exfoliation syndrome had significantly lower superficial macular VDs and minimum ganglion cell analysis values.

PURPOSE

To compare peripapillary and macular perfused capillary densities with optical coherence tomography angiography (OCT-A) between patients with eyes having exfoliation syndrome (XFS) and normal age-matched healthy controls.

PATIENTS AND METHODS

This cross-sectional study included patients diagnosed with XFS from December 2017 to January 2020 at the Glaucoma Department. Peripapillary and parafoveal superficial VDs were obtained using OCT-A. The RNFLTs and ganglion cell analysis values were compared.

RESULTS

Thirty-nine eyes of 39 XFS patients (26 women; mean age, 69.0±8.1 y) and 39 eyes of 39 healthy patients (25 women; mean age, 68.0±8.6 y) were enrolled. There were no statistically significant differences in sex or age distribution, central corneal thickness measurements, refractive errors, or intraocular pressures between both groups (all P>0.05). There were no statistically significant differences in the peripapillary VD or peripapillary RNFLT between XFS eyes and healthy eyes (P>0.05 for all). In the macular region, most superficial VD parameters were significantly reduced in the XFS group (P=0.02 for parafoveal VD, P=0.04 for both hemifields). While the average ganglion cell and internal plexiform layer (GCL+IPL) values were similar between groups (P=0.19), the minimum GCL+IPL value was lower in the XFS group than in the healthy group (P=0.03).

CONCLUSION

Although structural test results, especially peripapillary RNFLT and mean GCL+IPL, were similar between the healthy and XFS groups, macular VD values were lower in XFS eyes. Our findings implicate microvascular damage can be the mechanism underlying XFS-related changes and indicate that it precedes significant structural damage.

Peripapillary and macular choroidal vascularity index in patients with clinically unilateral pseudoexfoliation syndrome

PURPOSE

To investigate choroidal vascular changes using an image binarization tool in patients with clinically unilateral pseudoexfoliation syndrome (XFS).

METHODS

This cross-sectional study included 150 eyes of 100 patients. The eyes were divided into three groups: (1) 50 affected eyes of patients with clinically unilateral XFS; (2) 50 unaffected fellow eyes; and (3) 50 healthy control eyes. Enhanced depth imaging optical coherence tomography scans of the macula and peripapillary regions were acquired. Images were binarized using ImageJ software (National Institutes of Health, Bethesda, MD, USA). The choroidal vascularity index (CVI) was defined as proportion of the luminal area to the total circumscribed choroidal area.

RESULTS

Horizontal and vertical scans revealed that the macular CVI values of the affected eyes (60.08 ± 2.06 and 62.21 ± 2.10, respectively) were lower compared with control eyes (67.31 ± 2.24; p = 0.001 and 68.11 ± 2.36; p < 0.001, respectively). Conversely, no significant difference in the macular CVI was found between unaffected fellow and control eyes (p = 0.094 and p = 0.120, respectively). The mean peripapillary CVI values of the temporal (58.73 ± 3.15), superior (59.84 ± 3.09), and inferior (56.94 ± 2.47) sectors were significantly lower in affected eyes compared to control eyes (63.21 ± 3.00, 62.07 ± 3.05, and 60.78 ± 2.88, respectively; p < 0.05 for all). In addition, the unaffected fellow eyes had significantly lower CVI values in the temporal (61.42 ± 3.07) and inferior (57.61 ± 2.56) peripapillary sectors compared with the control eyes (p = 0.007 and p = 0.005, respectively).

CONCLUSIONS

These findings suggest that XFS is associated with decreased macular and peripapillary choroidal vascularity. Furthermore, the unaffected eyes of patients with unilateral XFS may show vascularity changes in the peripapillary choroid.

Retinal and Choroidal Vascular Changes in Eyes with Pseudoexfoliation Syndrome: A Comparative Study Using Optical Coherence Tomography Angiography

Background:

Optical coherence tomography angiography allows a detailed evaluation of retinal and choroidal microvascular structures without the need for a contrast agent. Pseudoexfoliation syndrome is a condition that leads to anatomical and functional losses due to accumulation of degraded abnormal fibrillar material in the intraocular and extraocular tissues. Histopathological studies have shown that the accumulation of Pseudoexfoliation syndrome material in the vascular structures may play a role in different ocular pathologies such as retinal vein occlusion, iris hypoperfusion, anterior segment hypoxia, retinal arterial occlusion, and neovascular glaucoma.

Aims:

To evaluate and compare flow and vascular density in the retina and choroid in eyes with Pseudoexfoliation syndrome, fellow eyes without Pseudoexfoliation syndrome, and healthy eyes using optical coherence tomography angiography.

Study Design:

Case control study.

Methods:

The study included 35 eyes with Pseudoexfoliation syndrome of 35 Pseudoexfoliation syndrome patients, 32 fellow eyes without Pseudoexfoliation syndrome of 32 unilateral Pseudoexfoliation syndrome patients, and 35 eyes of healthy control subjects. Flow area and vascular density in the superficial capillary plexus and deep capillary plexus were measured by optical coherence tomography angiography as three separate parameters: total, parafoveal, and foveal. Choroidal thickness and foveal avascular zone area were measured for each patient.

Results:

There were significant differences between the Pseudoexfoliation syndrome eyes and control eyes in total, parafoveal, and foveal flow and vascular density in the superficial capillary plexus (p<0.05 for all), while there were no significant differences between these groups in any of the flow or vascular density values in the deep capillary plexus (p>0.05). None of the superficial capillary plexus and deep capillary plexus flow and vascular density values showed significant differences between Pseudoexfoliation syndrome eyes and non-Pseudoexfoliation syndrome fellow eyes or between the non-Pseudoexfoliation syndrome fellow eyes and control eyes (p>0.05). Choroidal thickness was significantly lower in Pseudoexfoliation syndrome eyes compared to control eyes. Foveal avascular zone area was significantly enlarged in Pseudoexfoliation syndrome eyes compared to control eyes in both the superficial and deep layers (p<0.05).

Conclusion:

Pseudoexfoliation syndrome eyes exhibit significant damage to the retinal and choroidal vascular structures.

Lamina Cribrosa and Choroid Features and Their Relationship to Stage of Pseudoexfoliation Glaucoma

Purpose

To better understand the relationship of lamina cribrosa (LC) and choroid features to the severity of pseudoexfoliation glaucoma (PXG).

Methods

In this cross-sectional study, 137 eyes of 122 subjects (47 eyes with moderate/advanced PXG [mean deviation (MD), -15.0 ± 7.7 dB], 34 eyes with mild PXG [MD, -2.7 ± 1.5 dB], 32 aged-matched pseudoexfoliation syndrome [PXS] eyes, and 24 aged-matched control eyes) were investigated. Optic discs, LC thickness, and anterior LC depth (ALD; midsuperior, center, and midinferior) as well as peripapillary choroidal thickness were determined. Linear mixed modeling was used to adjust for age, sex, and axial length.

Results

A progressive decrease in LC thickness was found when comparing controls (271.9 ± 61.3 μm), PXS (212.6 ± 51.5 μm), mild PXG (180.8 ± 24.6 μm), and moderate/advance PXG (138.9 ± 37.5 μm) (P < 0.001). ALD was greater (P < 0.001) in moderate/advance glaucoma (306.7 ± 105.3 μm) and mild PXG (209.5 ± 79.7 μm) compared with PXS (155 ± 86.7 μm) and healthy controls (149.2 ± 103 μm). Although eyes with moderate/advance PXG had the thinnest choroid (117.2 ± 36.6 μm), choroidal thickness was comparable in mild PXG, PXS, and controls (150.0 ± 46.1, 159.7 ± 65.5, and 157.5 ± 51.1 μm, respectively; P = 0.002). Worse MD was the only factor associated with thinner LC (β = 2.344, P < 0.001) and choroid (β = 1.717, P = 0.009 μm) in PXG eyes. Higher IOP (β = 4.305, P = 0.013) and worse MD (β = -6.390, P < 0.001) were associated with deeper ALD in PXG.

Conclusions

In pseudoexfoliation, LC thinning is an early sign, and there is progressive thinning with advancing glaucoma. Choroidal thinning is observable only with moderate/advanced glaucoma. In PXG eyes, LC thickness, depth, and peripapillary choroidal thickness are associated with glaucoma severity.

Assessment of Outer Retinal Remodeling in the Hibernating 13-Lined Ground Squirrel

Purpose

We examined outer retinal remodeling of the euthermic and torpid cone-dominant 13-lined ground squirrel (13-LGS) retina using optical coherence tomography (OCT) imaging and histology.

Methods

Retinas and corneas of living 13-LGSs were imaged during euthermic and torpid physiological states using OCT. Retinal layer thickness was measured at the visual streak from registered and averaged vertical B-scans. Following OCT, some retinas were collected immediately for postmortem histologic comparison using light microscopy, immunofluorescence, or transmission electron microscopy.

Results

Compared to OCT images from euthermic retinae, OCT images of torpid retinae revealed significantly thicker inner and outer nuclear layers, as well as increases in the distances between outer retinal reflectivity bands 1 and 2, and bands 3 and 4. A significant decrease in the distance between bands 2 and 3 also was seen, alongside significant thinning of the choriocapillaris and choroid. OCT image quality was reduced in torpid eyes, partly due to significant thickening of the corneal stroma during this state.

Conclusions

The torpid retina of the hibernating 13-LGS undergoes structural changes that can be detected by OCT imaging. Comparisons between in vivo OCT and ex vivo histomorphometry may offer insight to the origin of hyperreflective OCT bands within the outer retina of the cone-dominant 13-LGS.

Comparison of macular choroidal thickness in patients with pseudoexfoliation syndrome to normal control subjects with enhanced depth SD-OCT imaging

Purpose

To test the hypothesis that macular choroidal thickness is lower in patients with pseudoexfoliation syndrome (PXS) as compared to healthy control subjects.

Methods

In this cross-sectional, observational study, 38 non-glaucomatous PXS subjects and 37 healthy volunteers were enrolled in a tertiary care Glaucoma Clinic. The macular region was scanned with the enhanced depth imaging (EDI) protocol of a spectral domain optical coherence tomography (SD-OCT) device (Spectralis OCT, Heidelberg Engineering, Heidelberg, Germany). Macular choroidal thickness and volumes were compared in nine sectors of the Early Treatment Diabetic Retinopathy Study (ETDRS) layout profile across the central 3.45 mm zone after manual segmentation of the choroidal thickness. Linear mixed modeling was used to adjust for confounding variables.

Results

Six PXS eyes and 8 control eyes were excluded due to poor image quality leaving 32 PXS and 29 control eyes for final analyses. The average age and axial length of the PXS and control groups were 67.94 ± 7.30 vs 64.86 ± 7.04 and 22.91 ± 0.77 vs 23.24 ± 0.66 mm, respectively, (P = 0.10 and 0.20). There was no significant difference in retinal nerve fiber layer (RNFL) thickness between the two groups (P = 0.24). The choroidal thickness was significantly lower in the central subfield subfoveal area (P = 0.02) and in the inner superior (P = 0.03) and inner nasal quadrants (P = 0.03) in the PXS group compared to the control group, as was the choroidal volume (P = 0.02). No significant difference was found in macular choroidal thickness after adjusting for age, gender, and axial length. While there was a significant negative association between age and central subfield choroidal thickness in the control group (r = -0.48, P = 0.01), this association was not significant in the PXS group (r = -0.08, P = 0.68).

Conclusions

Our findings demonstrate that the choroid does not seem to be significantly altered in PXS eyes. Choroidal thickness changes need to be explored in PXS eyes with glaucoma.

Genetics, Diagnosis, and Monitoring of Pseudoexfoliation Glaucoma

Recent studies have shed new light on the genetic factors underlying pseudoexfoliation syndrome, growing our understanding of the role of the lysyl oxidase-like 1 (LOXL1) gene and its various polymorphisms as well as identifying new genetic associations. Recent years have brought new insight on how these genetic factors interact with other factors, including environmental, to confer risk to individuals and populations worldwide. All of these findings may hold importance to the screening, diagnosis, and monitoring of pseudoexfoliation and may also help lead to the identification of novel therapeutic targets. This review serves as an update on the recent trends and findings in pseudoexfoliation syndrome.

Corneal Alterations Associated with Pseudoexfoliation Syndrome and Glaucoma: A Literature Review

A systematic literature review was performed evaluating articles examining the effects of pseudoexfoliation syndrome (PEX) and glaucoma (PEXG) on the cornea with a focus on the corneal endothelium. We searched for articles relevant to pseudoexfoliation syndrome, pseudoexfoliation glaucoma and corneal endothelial cell counts using Pubmed, Google Scholar Database, Web of Science and Cochrane Library databases published prior to September of 2016. We then screened the references of these retrieved papers and performed a Web of Science cited reference search. Corneal characteristics analyzed included central corneal thickness (CCT), corneal nerve density, endothelial cell density (ECD), polymegathism, and pleomorphism. These parameters were compared in the following populations: control, PEX, PEXG, and primary open angle glaucoma (POAG). Over 30 observational studies were reviewed. Most studies showed a statistically significant lower ECD in PEX and PEXG populations compared to controls. Overall, PEX eyes had a non-statistically significant trend of lower ECDs compared to PEXG eyes. No consistent trends were found when analyzing differences in CCT amongst control, PEX and PEXG groups. For the few studies that looked at corneal nerve characteristics, the control groups were found to have statistically significantly greater nerve densities than PEX eyes, which had significantly greater densities than PEXG eyes. ECD and corneal nerve densities may be potential metrics for risk-stratifying patients with PEX and PEXG. Our literature review provided further evidence of the significant negative influence PEX has on the cornea, worsening as patients convert to PEXG.

Evaluation of choroidal thickness in patients with scleroderma

PURPOSE

To investigate the choroidal thickness in patients with scleroderma and to compare them with healthy control subjects.

METHODS

Forty-six patients with scleroderma (3 male and 43 female) and 31 healthy controls (6 male and 25 female) were included in the study. Twenty-five patients had limited-type and 21 patients had diffuse-type scleroderma. Only left eyes of the patients and control subjects were used in the analysis. Demographic features of all the patients and control subjects were recorded. Each subject underwent ophthalmological examinations including refraction, visual acuity, intraocular pressure, axial length (AXL) measurement, slit-lamp biomicroscopy, and fundus examination. Body mass index (BMI) was estimated for all participants.

RESULTS

There were no significant differences between the patients with scleroderma and the control subjects in terms of age, gender, BMI, mean AXL, and mean spherical equivalent refractive error (SE) (P=0.1, P=0.086, P=0.37, P=0.55, and P=0.072 respectively). The patients with scleroderma had significantly thinner nasal, temporal, and subfoveal choroid than the healthy control subjects (P1=0.012, P2=0.046, and P3<0.001, respectively). There were no significant differences between the patients with limited-type and diffuse-type scleroderma in terms of age, gender, BMI, mean AXL, mean SE, nasal, temporal, and subfoveal choroidal thicknesses (all P>0.05).

CONCLUSIONS

Choroidal thickness in patients with scleroderma was significantly less than healthy control subjects. Vasculopathy in scleroderma is characterized by obliteration of arterioles and reduced capillary density may cause atrophy of choroid in patients with scleroderma.