Evaluation of Choroidal Thickness in Patients with Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma

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.

Optic Nerve Head, Peripapillary and Macular Microvascular Characteristics in Patients With Unilateral Pseudoexfoliation Glaucoma

PRCIS

In unilateral pseudoexfoliation glaucoma (PEXG), there may be decreased choroidal vascularity index (CVI), radial peripapillary capillary plexus' perfusion and flow. CVI may also be reduced in fellow eyes, suggesting that PEXG is bilateral disease.

PURPOSE

Evaluation of peripapillary and macular choroidal microvascularity and radial peripapillary capillary plexus in both eyes with unilateral PEXG and healthy eyes.

MATERIALS AND METHODS

Ninety-six eyes of 48 patients with unilateral PEXG [PEX (+): 48 eyes with PEXG; PEX (-): 48 eyes without PEX] and the right eyes of 45 age- and sex-matched healthy controls were included in the study. CVI was calculated on enhanced depth imaging optical coherence tomography scans. Radial peripapillary capillary vascular layer were evaluated by OCT-angiography.

RESULTS

Macular CVI (mCVI), temporal and nasal peripapillary CVI (pCVI) was significantly decreased in the PEX (+) compared with the PEX (-) and control group ( P <0.05 for all). Although there was a significant difference between PEX (-) and the control group in terms of mCVI and temporal pCVI, there was no significant difference between the 2 groups in terms of nasal pCVI ( P =0.008, P =0.036, and P =0.604, respectively). There was a significant difference in perfusion density (PD) and flux index (FI) between PEX (+) group, PEX (-) group and control group in all quadrants and average value ( P <0.05 for all). Although the PD and FI values in all quadrants and average values of the PEX (-) group were lower than the control group, this difference was not significant.

CONCLUSIONS

CVI in the macula and peripapillary region was significantly decreased in eyes with PEXG. Similarly, PD and FI were lower in eyes with PEXG. Low mCVI and temporal pCVI can also be seen in eyes without PEX.

Choroidal thickness measurements of subjects with pseudoexfoliative syndrome and pseudoexfoliative glaucoma: A contralateral eye study

AIM

In this study, we aimed to investigate the peripapillary choroidal thickness (PPCT) and macular choroidal thickness (MCT) in pseudoexfoliation (PEX) syndrome and compare the data of the contralateral eyes according to the presence of biomicroscopic eye involvement and glaucoma.

METHOD

In this cross-sectional case-control study, PPCT and MCT measurements were analyzed in 162 eyes of 81 subjects with PEX syndrome, diagnosed biomicroscopically with the detection of PEX material. The sample included 63 eyes with pseudoexfoliation glaucoma (PG), 49 eyes with visible PEX material alone without glaucoma (PM), 50 fellow eyes without biomicroscopically visible PEX material (F), and 48 eyes of 24 healthy individuals (controls) without any sign of PEX in the detailed ophthalmologic examination. The PEX syndrome group consisted of 25 PM-F, 25 PG-F, 19 PG-PG, and 12 PM-PM eye pairs. The PPCT and MCT values were compared between the eye-pairs of the subjects with the PEX syndrome.

RESULTS

The mean PPCT measurements were 183.3 ± 8.1 µm, 158.5 ± 5.4 µm, 167.8 ± 5.9 µm, and 149.9 ± 5.5 µm for the eyes in the control, F, PM, and PG groups, respectively. The eyes in the PG group had statistically significantly lower measurements than those in the control group (p < 0.01). In the contralateral eye comparison of the subjects with PEX syndrome, no significant difference was found in relation to the mean PPCT and MCT measurements between the PM-F, PG-F, and PG-PG eye pairs (p > 0.05 for all).

CONCLUSION

Although the eye groups with PEX syndrome had lower mean PPCT measurements than the controls, the contralateral eye analysis of the asymmetrically involved eye pairs showed no significant differences.

Genome-Wide RNA Sequencing of Human Trabecular Meshwork Cells Treated with TGF-β1: Relevance to Pseudoexfoliation Glaucoma

Pseudoexfoliation glaucoma (XFG) is an aggressive form of secondary open angle glaucoma, characterised by the production of exfoliation material and is estimated to affect 30 million people worldwide. Activation of the TGF-β pathway by TGF-β1 has been implicated in the pathogenesis of pseudoexfoliation glaucoma. To further investigate the role of TGF-β1 in glaucomatous changes in the trabecular meshwork (TM), we used RNA-Seq to determine TGF-β1 induced changes in the transcriptome of normal human trabecular meshwork (HTM) cells. The main purpose of this study was to perform a hypothesis-independent RNA sequencing analysis to investigate genome-wide alterations in the transcriptome of normal HTMs stimulated with TGF-β1 and investigate possible pathophysiological mechanisms driving XFG. Our results identified multiple differentially expressed genes including several genes known to be present in exfoliation material. Significantly altered pathways, biological processes and molecular functions included extracellular matrix remodelling, Hippo and Wnt pathways, the unfolded protein response, oxidative stress, and the antioxidant system. This cellular model of pseudoexfoliation glaucoma can provide insight into disease pathogenesis and support the development of novel therapeutic interventions.

A comprehensive enhanced depth imaging spectral-domain optical coherence tomography analysis of pseudoexfoliation spectrum from non-glaucomatous to advanced stage glaucoma in the aspect of Bruch's membrane opening-minimum rim width

PURPOSE

To compare the correlations between lamina cribrosa (LC) and related structures with Bruch's membrane opening-minimum rim width (BMO-MRW) and retinal nerve fiber layer (RNFL) thickness in pseudoexfoliation syndrome (PXS) and different stages of pseudoexfoliation glaucoma (PXG).

METHODS

This prospective cross-sectional study included 32 PXS eyes of 24 patients and 94 PXG eyes (early-stage (n: 55) and advanced-stage glaucoma (n: 39) of 78 patients. Global and six sectors of RNFL thicknesses and BMO-MRW parameters were measured with enhanced depth imaging (EDI) mode of SD-OCT. Structural parameters; lamina cribrosa thickness (LCT), lamina cribrosa depth (LCD), prelaminar tissue thickness (PLTT), four quadrants of peripapillary choroidal thicknesses (PPCT), and subfoveal choroidal thickness (SFCT) were measured and statistical relationships between the structural parameters have been laid out. We apply the generalized estimating equations method to take into account dependency of right and left eyes.

RESULTS

From PXS to mild and advanced PXG groups LCT and PLTT decrease from 147.29 ± 33.10, 145.62 ± 30.64, 126.30 ± 29.14 and 260.93 ± 185.07, 247.27 ± 142.58, 159.89 ± 86.84, respectively, and LCD varies as 159.89 ± 86.84, 420.88 ± 117.80, and 505.64 ± 183.25. The correlations between LCD, LCT, and PLTT and the stage of the disease are significant. BMO-MRW shows slightly stronger correlations than the RNFL with LC related parameters. SFCT does not exhibit any significant relationship with the stage of the disease. However, PPCT in only the interior quadrant does. The significant correlations between LCD and all quadrants of PPCT is the sign of important anatomic relationship.

CONCLUSION

These findings show that the BMO-MRW parameter may be more sensitive than RNFL and can safely be used in the diagnosis and follow-up in PXS and PXG, but this result should be supported with longer and larger series.

Clinical Analysis of Macular Choroidal Thickness in Pseudoexfoliative Glaucoma and Primary Open-Angle Glaucoma

Purpose

To evaluate the differences in macular choroidal thickness and volume among patients with pseudoexfoliative glaucoma (PXG), patients with primary open-angle glaucoma (POAG), and controls.

Methods

A total of 50 PXG patients (50 eyes) and 56 POAG patients (56 eyes) were selected as the PXG group and the POAG group, respectively, in this case-control study. A total of 54 age-, gender-, IOP-, and axial length-matched healthy individuals (54 eyes) were selected as the control group. Enhanced-depth imaging-optical coherence tomography (EDI-OCT) was used to measure and analyze the choroidal thicknesses and volumes in 9 macular regions of all subjects.

Results

The choroidal thicknesses in the central subfield (CSM), temporal inner macula (TIM), inferior inner macula (IIM), and temporal outer macula (TOM) and the mean macular choroidal thickness were significantly thinner in the PXG group than in the control group (all P < 0.05). The choroidal volumes in the TIM, IIM, and TOM and the mean macular choroidal volume were significantly smaller in the PXG group than in the control group (all P < 0.05). The choroidal thicknesses in the CSM and IIM and the mean macular choroidal thickness were significantly thinner in the PXG group than in the POAG group (all P < 0.05). The choroidal volumes in the IIM and TOM and the mean macular choroidal volume were significantly smaller in the PXG group than in the POAG group (all P < 0.05). Multivariable linear regression analysis showed that the mean macular choroidal thickness was significantly thinner in association with older subjects and longer axial length eyes. There was no association between the macular choroidal thickness of various macular regions and visual field mean defect (MD) in groups PXG and POAG (all P > 0.05).

Conclusions

The macular choroidal thicknesses and volumes (inferior and temporal) in PXG patients were thinner and smaller than those in POAG patients and healthy individuals. The role of choroidal thickness changes in the course of PXG remains unclear. A future prospective study is needed to better define these changes in PXG patients.

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.

Comparison of Macular Choroidal Thickness and Volume between Pseudoexfoliative Glaucoma and Pseudoexfoliative Syndrome

Purpose

To evaluate the difference in macular choroidal thickness and volume between patients with pseudoexfoliative glaucoma (PXG), patients with pseudoexfoliative syndrome (PEX), and normal controls.

Methods

This case-control study included 49 PXG patients (group A), 33 PEX patients (group B), and 42 sex-, age-, and axial length-matched healthy volunteer eyes (group C). The macular choroidal thickness and volume of all subjects studied were measured by enhanced depth imaging optical coherence tomography.

Results

The average macular (AM) choroidal thickness was 170.79 ± 50.18 μm, 184.65 ± 57.54 μm, and 206.46 ± 48.90 μm, and the average volume was 0.52 ± 0.15 μm³, 0.56 ± 0.17 μm³, and 0.63 ± 0.15 μm³ in groups A, B, and C, respectively. The macular choroidal thickness, the volumes of various macular regions, and the average choroidal thickness and volume in group A were lower than those in group C (all P < 0.05). There were no significant differences in the macular choroidal thickness, volumes of various macular regions, or average choroidal thickness or volume between group A and B (all P > 0.05). The macular choroidal thickness and volume of the TIM and SOM in group B were lower than those in group C (P < 0.05). There was no association between the macular choroidal thickness of various macular regions and visual field mean defect (MD) in group A (all P > 0.05).

Conclusion

The macular choroidal thickness in patients with PXG or PEX (TIM and SOM) is thinner than that in normal subjects. The macular choroidal thickness in patients with PXG is not significantly different from that in patients with PEX. The role of macular choroidal thickness changes in the glaucomatous damage of patients with PXG is still unclear.

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.

Analysis of Peripapillary and Macular Choroidal Thickness in Eyes with Pseudoexfoliative Glaucoma and Fellow Eyes

Purpose

To compare differences in peripapillary and macular choroidal thickness in pseudoexfoliative glaucoma (PXG) eyes, nonexfoliative fellow eyes, and normal eyes.

Methods

This case-control study included 37 PXG patients (group A: 37 PXG eyes; group B: 37 nonexfoliative fellow eyes) and 37 sex-, age-, and axial length-matched healthy volunteer eyes (group C). Peripapillary and macular choroidal thickness and volume were measured in all subjects via enhanced-depth imaging-optical coherence tomography.

Results

The average peripapillary (AP) choroidal thickness was (130.10 ± 46.14) μm, (131.43 ± 46.00) μm, and (147.89 ± 53.32) μm; average macular (AM) choroidal thickness was (191.72 ± 68.07) μm, (204.62 ± 69.54) μm, and (215.10 ± 45.40) μm; and average volume was (0.59 ± 0.21) μm³, (0.63 ± 0.21) μm³, and (0.65 ± 0.14) μm³ in groups A, B, and C, respectively. NIP choroidal thickness was significantly lower in groups A and B than in group C (P < 0.05). TIM and TOM choroidal thickness and volume were significantly lower in group A than in group C (P < 0.05). NIM, SIM, NOM, IOM, AM choroidal thickness and volume, and CSM choroidal thickness were significantly lower in group A than in group B (P < 0.05). CSM, TIM, and TOM in group A and TIM, TOM choroidal thickness, and volume in group B were significantly lower than in group C (P < 0.05).

Conclusions

NIP choroidal thickness in PXG eyes and nonexfoliative fellow eyes and temporal macular choroidal thickness in PXG eyes were significantly lower than in normal eyes. Macular choroidal thickness (except in temporal regions) was significantly lower in PXG eyes than in nonexfoliative fellow eyes. Changes in peripapillary and macula choroidal thickness further elucidate the choroid's role in PXG development and progression.

EDI-OCT choroidal thickness in Posner-Schlossman syndrome

PURPOSE

To compare the choroidal thickness (CT) of the affected eyes with the contralateral eyes in the active period and in the remission period in Posner-Schlossman syndrome (PSS) using EDI-OCT.

PATIENTS AND METHODS

This prospective longitudinal study included 15 patients with PSS and 15 age- and sex-matched healthy subjects. All subjects underwent complete ophthalmologic examinations, and EDI-OCT was conducted to measure macular CT (mCT) at the subfoveal locations and at 0.5, 1.0 and 2.0 mm superior, inferior, nasal and temporal to the fovea. The mean measurements at each location were used for analysis. Linear regression analysis was performed to analyse the correlation between the choroidal thickness and IOP, and the correlation between the choroidal thickness and episode time.

RESULTS

The mean mCT was significantly thinner in affected eyes than in contralateral eyes in the acute phase (p = 0.010) but were not different in the remission phase (p = 0.404). The mean mCT was significantly increased in the remission phase compared to that in the acute phase in the affected eyes (p = 0.000). The mCT of healthy subjects was significantly thicker than in the affected eyes (p = 0.020) and similar to the fellow eyes of PSS patients (p = 0.357) in the acute phase. Linear regression analyses show negative correlations between the mCT changes and IOP changes in the affected eyes compared to those in the fellow eyes in the acute period (R² = 0.396, p = 0.033) and between the mCT changes and IOP changes from the acute period to the remission period in the affected eyes (R² = 0.372, p = 0.027). Linear regression analyses show positive correlations (age- and sex-matched) between the CT changes and episode time from the affected eyes to the fellow eyes in the acute period (R² = 0.492, p = 0.012).

CONCLUSIONS

The mCT values of the PSS-affected eyes were significantly thinner than those of the fellow eyes in the acute phase and in the remission phase, and this change was correlated with IOP reduction and episode time.

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.

Comparison of peripapillary and macular choroidal thickness and ganglion cell complex thickness in glaucomatous and healthy eyes

AIM

To assess choroidal thickness (CT) and its association with ganglion cell-inner plexiform layer thickness (GCIPLT) and retinal nerve fiber layer thickness (RNFLT) in open angle glaucoma (OAG) comparing with preperimetric glaucoma (PPG) and normal eyes.

METHODS

Totally 55 eyes of OAG, 40 eyes of PPG, and 40 eyes of age-matched normal eyes were studied. Peripapillary CT (PCT), macular CT (MCT), RNFLT, and GCIPLT were evaluated. Relationship between the CT with RNFLT and GCIPLT were studied. The correlation between CT and confounding variables as gender, age, intraocular pressure, and visual field mean deviation were analyzed.

RESULTS

Mean PCT were 113.6±39.1 µm in OAG, 116.3±42.7 µm in PPG, and 148.9±41.7 µm in normal eyes. PCT and MCT was thinner in OAG compared to healthy eyes. There was a significant correlation for PCT and mean RNFLT in 1, 2, 6, and 7 clock hours of OAG eyes. The difference in PCT remained after adjusting for axial length, age, and disc area (P=0.003). No significant correlation was shown between MCT and mean GCIPLT in all eyes.

CONCLUSION

PCT is thinner in OAG and PPG compared with healthy eyes. The correlation of RNFLT and PCT found in OAG and PPG is not revealed in normal eyes.

SD-OCT Choroidal Thickness in Advanced Primary Open-Angle Glaucoma

PURPOSE

To assess the choroidal thickness in advanced primary open-angle glaucoma (POAG) comparing patients affected by advanced glaucoma and normal subject using spectral domain optical coherence tomography (SD-OCT).

METHODS

In total, 35 eyes of 35 patients affected by POAG with advanced perimetric defect (mean deviation worse than -12 dB) were prospectively enrolled and underwent a complete ophthalmologic examination, including enhanced depth imaging SD-OCT. One eye of 35 healthy subjects served as control group. Choroidal thickness was measured at the subfoveal location, at 0.5, 1.0, and 2.0 mm nasal and temporal to the fovea. Primary outcome measure was the identification of different choroidal thickness between advanced glaucoma patients and normal subjects.

RESULTS

Glaucoma and control group were homogenous for age, sex, and axial length (P>0.05 in all cases). A significant difference was found in the subfoveal choroidal thickness (SFCT) adjusted for age and axial length between glaucoma and control eyes (P=0.042); in glaucoma patients the mean adjusted SFCT was 209.90 μm compared with 234.78 μm in control subjects. Both temporal and nasal choroidal thickness measurements followed the same SFCT trend, even if only temporal ones were statistically significant. We also found that SFCT decreased with age and increased axial length (P=0.007 and 0.001, respectively). Sex and intraocular pressure did not significantly influence the choroidal thickness (P=0.87 and 0.35, respectively).

CONCLUSIONS

Patients affected by advanced POAG damage have a thinner choroidal thickness compared with normal subjects, using SD-OCT. We also confirmed that age and axial length were the main factors affecting choroidal thickness in these patients.

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.