The association between visual function and retinal structure in chronic central serous chorioretinopathy

Morphological and Functional Correlations in Acute Central Serous Chorioretinopathy

PURPOSE

We evaluate morphological and functional correlations in patients with acute central serous chorioretinopathy (CSC).

METHODS

A prospective study was conducted on 50 patients with an acute CSC episode lasting less than 3 months. At baseline, assessments included optical coherence tomography (OCT), best-corrected visual acuity (BCVA), contrast sensitivity (CS), microperimetry (MP), and multifocal electroretinography (mfERG). A correlation analysis between OCT morphological parameters (maximal subretinal fluid height (SRF), central retinal thickness (CRT), and macular volume (MV)) and functional parameters was conducted on the affected eye for each patient.

RESULTS

Among the morphological parameters, SRF showed the strongest correlations with functional parameters (r absolute value range = 0.10-0.70). Weak correlations were observed between BCVA and morphological parameters (r absolute value range = 0.14-0.26). Average retinal sensitivity (MP-A) was the functional parameter displaying the most robust negative correlation with morphological parameters (r absolute value range = 0.61-0.70). In contrast, average contrast sensitivity (CS-A) and mfERG average amplitude density in the first (mfERG-A1) and second (mfERG-A2) ring showed weak to moderate (r absolute value range = 0.35-0.56) yet statistically significantly nonzero correlations.

CONCLUSIONS

SRF and CRT could serve as the most representative morphological proxies for visual function deficit in acute CSC patients. Retinal sensitivity, as measured by MP, may be superior to BCVA in clinical research studies or when an in-depth visual function evaluation is needed.

Correlation between retinal sensitivity assessed by microperimetry and structural abnormalities on optical coherence tomography after successful epiretinal membrane surgery

BACKGROUND

To verify the correlation between retinal sensitivity (RS) assessed by the microperimetry (MP) and optical coherence tomography (OCT) parameters measured in eyes submitted to pars-plana vitrectomy (PPV) for idiopathic epiretinal membrane (ERM) treatment.

METHODS

43 patients underwent PPV. Best-corrected visual acuity (BCVA) and OCT imaging were acquired preoperatively and 6 months after surgery. The RS values were recorded 6 months after the surgery. Total macular thickness (TMT) measurements and OCT-evaluated structural findings were also analyzed. The MP examination tested 44 points, with direct topographic correspondence with the OCT-ETDRS map. Correlations between BCVA, RS, and OCT parameters were assessed.

RESULTS

TMT measurements in patients were significantly thicker preoperatively and reduced after surgery. All patients demonstrated BCVA improvements after surgery. The RS parameters after surgery were significantly lower in patients. For OCT structural analyses, patients with lower RS at the fovea correlated with the preexisting disorganization of retinal inner layers (DRIL). In addition, lower RS values were associated with DRIL, outer retinal changes (ORC), and intraretinal microcysts after surgery.

CONCLUSIONS

The RS values after surgery were significantly lower when compared to controls. The DRIL presence before and after surgery, and microcysts and ORC after surgery were related to worse visual outcomes.

Predicting retinal sensitivity using optical coherence tomography parameters in central serous chorioretinopathy

PURPOSE

To predict changes in retinal sensitivity using optical coherence tomography (OCT) in eyes with central serous chorioretinopathy (CSC).

METHODS

Twenty-three eyes in 23 patients with CSC were enrolled. Retinal sensitivity was measured twice using microperimetry in all the examined eyes. Spectral domain OCT measurements were simultaneously conducted. The relationship between retinal sensitivity and the thicknesses of (i) the retinal nerve fiber layer plus the ganglion cell layer (RNFL + GCL), (ii) the inner nuclear layer (INL), (iii) the outer nuclear layer (ONL), and (iv) the serous retinal detachment height (SRDH) were investigated in a point-wise manner. The associations between the change in retinal sensitivity and the OCT parameters at baseline were also investigated.

RESULTS

The mean age of the participants was 49.8 ± 10.7 years. The mean SRDH was significantly lower (p < 0.001), and the mean retinal sensitivity (p < 0.001) was significantly higher at the second examination, compared with the first; however, the logMAR visual acuity (VA) did not differ significantly between the two examinations (p = 0.063). The logMAR VA was associated with retinal sensitivity at both the first and second examinations (p < 0.001). The retinal sensitivity at the second examination was significantly correlated with the retinal sensitivity, RNFL + GCL, INL, ONL, and SRDH at the first examination and with the improvement in SRDH.

CONCLUSIONS

Retinal sensitivity was associated with the retinal structure in eyes with CSC; these parameters could be useful for predicting the change in visual function prior to treatment.

FUNCTIONAL AND STRUCTURAL OUTCOMES AFTER FOVEA-SPARING INTERNAL LIMITING MEMBRANE PEELING FOR MYOPIC MACULAR RETINOSCHISIS BY MICROPERIMETRY

PURPOSE

To determine the morphological and physiological outcomes and safety of vitrectomy with fovea-sparing internal limiting membrane peeling for myopic macular retinoschisis (MRS).

METHODS

Highly myopic eyes (refractive error greater than -8.0 diopters or an axial length longer than 26.5 mm) with MRS that underwent vitrectomy with fovea-sparing internal limiting membrane peeling were analyzed retrospectively. The best-corrected visual acuity, retinal morphology, and the central and paracentral retinal sensitivities at 2°/6° by microperimetry were evaluated before and after the surgery. Postoperative microscotomas were also determined.

RESULTS

Thirty-three eyes with MRS; 16 eyes with and 17 eyes without a foveal retinal detachment, were studied. All 33 eyes had an improvement of MRS and foveal retinal detachment partially or completely after surgery, and none developed a full thickness macular hole. The postoperative best-corrected visual acuity, the central retinal sensitivity, and the retinal sensitivity at 2° were significantly better than the preoperative values. Sixteen eyes developed postoperative microscotomas at paracentral 2° and/or 6°.

CONCLUSION

The results showed that vitrectomy with fovea-sparing internal limiting membrane peeling is an effective and safe method to treat an MRS regardless of the presence of a foveal retinal detachment. However, careful follow-up should be performed to detect postoperative microscotomas.

Clinical Perspectives and Trends: Microperimetry as a trial endpoint in retinal disease

Endpoint development trials are underway across the spectrum of retinal disease. New validated endpoints are urgently required for the assessment of emerging gene therapies and in preparation for the arrival of novel therapeutics targeting early stages of common sight-threatening conditions such as age-related macular degeneration. Visual function measures are likely to be key candidates in this search. Over the last two decades, microperimetry has been used extensively to characterize functional vision in a wide range of retinal conditions, detecting subtle defects in retinal sensitivity that precede visual acuity loss and tracking disease progression over relatively short periods. Given these appealing features, microperimetry has already been adopted as an endpoint in interventional studies, including multicenter trials, on a modest scale. A review of its use to date shows a concurrent lack of consensus in test strategy and a wealth of innovative disease and treatment-specific metrics which may show promise as clinical trial endpoints. There are practical issues to consider, but these have not held back its popularity and it remains a widely used psychophysical test in research. Endpoint development trials will undoubtedly be key in understanding the validity of microperimetry as a clinical trial endpoint, but existing signs are promising.

Long-Term Effects of Half-Time Photodynamic Therapy on Retinal Sensitivity in Eyes with Chronic Central Serous Chorioretinopathy

The purpose of this study was to evaluate the long-term effects of half-time photodynamic therapy (PDT) on the retinal sensitivity in eyes with chronic central serous chorioretinopathy (CSC). Twenty-two eyes of 22 patients with chronic CSC were studied. PDT was applied with full-dose verteporfin and half-time laser duration. The best-corrected visual acuity (BCVA) and retinal sensitivity in the central 2 and 10 degrees were evaluated at the baseline, and at 12 and 24 months after the half-time PDT. The retinal sensitivity was determined by Macular Integrity Assessment microperimetry (MAIA, Centervue, Padova, Italy). The results showed that the mean retinal sensitivities in the central 2 and 10 degrees were significantly improved at 12 months (25.6 ± 2.79 dB, median; 26.11 dB, 25.6 ± 2.25 dB, median; 25.65 dB, respectively; P < 0.001) and at 24 months (26.3 ± 2.62 dB, median; 27.38 dB, 26.6 ± 2.21 dB, median; 27.45 dB, respectively; P < 0.001) after the treatment compared to that at the baseline (19.2 ± 3.93 dB, median; 19.34 dB, 20.9 ± 2.92 dB, median; 20.9 dB, respectively). The BCVA was also significantly improved from 0.18 ± 0.19 median; 0.15 logarithm of the minimum angle of resolution (logMAR) units at the baseline to 0.07 ± 0.15 median; 0 logMAR units at 12 months (P < 0.001) and to 0.049 ± 0.16 median; -0.039 logMAR units at 24 months (P < 0.001). We conclude that half-time PDT results in a significant improvement of the mean central retinal sensitivity for at least 24 months in eyes with chronic CSC. Thus, half-time PDT is beneficial in resolving chronic CSC for a relatively long period.

High myopic patients with and without foveoschisis: morphological and functional characteristics

PURPOSE

Myopic foveoschisis (MF) is characterized by the splitting of the retinal layers in the fovea of patients with high myopia (HM). MF may progress into foveal detachment or macular hole formation with consequent loss of central vision. The aim of this study is to investigate morphological and functional changes of the macular region in myopic subjects with and without foveoschisis.

DESIGN

Observational, cross-sectional, comparative study.

METHODS

Forty-eight patients with HM and 24 healthy controls were evaluated by spectral domain-optical coherence tomography (SD-OCT), multifocal electroretinography (mfERG) and microperimetry (MP-1) tests to assess macular thickness, functionality and sensitivity values, respectively. The results of the diagnostic examinations were compared between three groups: HM patients with MF (N = 24), HM patients without MF (N = 24) and control group (CG) (N = 24). All statistical analyses were performed with STATA 14.0 (Collage Station, Texas, USA). One-way analysis of variance (ANOVA) followed by Tukey's post hoc test was used to analyze differences between groups unless specified; p values < 0.05 were considered as statistically significant. Gender distribution was compared by the Chi square test.

RESULTS

The statistical analysis with one-way ANOVA followed by Tukey's post hoc test showed a significant increase in macular thickness in HM patients with MF when compared to both HM patients without MF and CG. Morphological changes were associated with functional impairment as demonstrated by the significant decrease in amplitude of the P1 wave and MP-1 sensitivity (p < 0.05), according to the anatomical landmarks.

CONCLUSIONS

This study showed that the morphological changes observed in the central retina of HM patients with MF are associated with functional alterations. High-tech diagnostic tests such as SD-OCT, mfERG and MP-1 could be useful for management in complications of MF.

Association between visual function and the integrity of residual ellipsoid zone in resolved central serous chorioretinopathy

Central serous chorioretinopathy (CSC) usually resolves spontaneously; however, in some patients, it can be chronic and visual impairment remains even after resolution of the serous retinal detachment. The impaired photoreceptor cells often present with disrupted ellipsoid zone (EZ) on optical coherence tomography (OCT). In this study, the integrity of EZ was quantified by calculating the index of residual EZ, identified on binarized OCT images from 25 eyes of 23 patients with resolved CSC. To estimate residual EZ, integrity of residual EZ with the central horizontal line on the fovea (rEZc) and average integrity of residual EZ within 3 × 3-mm macular area (rEZave) were investigated. The interrater reliability of the method was assessed using the intraclass correlation coefficient (ICC). The relationship between LogMAR VA and age, central retinal thickness, central choroidal thickness, rEZc, and rEZave were evaluated using the linear mixed model. Retinal sensitivity was measured with the MP-3 microperimeter and similar analyses were iterated for mean retinal sensitivity (MS). ICC values were 0.938 with rEZc and 0.979 with rEZave. rEZc was significantly related to LogMAR VA (p = 0.039). rEZave was significantly related to MS (p < 0.001). These results suggested potential usefulness of residual EZ to predict visual function in resolved CSC.

Retinal sensitivity in angioid streaks

PURPOSE

To investigate retinal sensitivity in eyes with angioid streaks (AS).

METHODS

This study was a retrospective observational case series. A total of 13 eyes from 9 patients with AS underwent ophthalmologic examination, including fundus autofluorescence (FAF), spectral domain optical tomography (SD-OCT), and microperimetry. Retinal pigment epithelium (RPE) atrophy was assessed using FAF. Outer retinal atrophy, more specifically, disruption of the ellipsoid zone, was evaluated using SD-OCT images. The association between retinal sensitivity, RPE atrophy or outer retinal atrophy, and patient demographic characteristics or ophthalmologic findings were investigated.

RESULTS

The mean area of outer retinal atrophy was 14.5 ± 12.9 mm², significantly larger than the mean area of RPE atrophy (9.0 ± 9.0 mm²; P = 0.0028). The average retinal sensitivity in the area of RPE atrophy was 2.4 ± 5.6 dB, that in the area of outer retinal atrophy outside RPE atrophy was 14.6 ± 7.5 dB, and that in the area without any atrophy was 25.6 ± 5.1 dB. Reticular pseudodrusen (RPD) was observed in 5 eyes. Eyes with RPD showed a greater extent of both outer retinal atrophy and RPE atrophy than those without RPD and a greater decrease in mean retinal sensitivity.

CONCLUSIONS

In eyes with AS, especially in those with RPD, large areas of outer retinal atrophy and RPE atrophy were observed, and the retinal sensitivity in the areas was correspondingly decreased.

Ozurdex for refractory macular edema secondary to diabetes, vein occlusion, uveitis and pseudophakia

OBJECTIVE

To analyze the functional and morphological effects of the intravitreal dexamethasone implant (Ozurdex, Allergan) on patients with macular edema secondary to retinal vein occlusion (RVO), diabetic retinopathy (DME), posterior noninfectious uveitis (NIU), or pseudophakic Irvine-Gass syndrome (IGS).

METHODS

144 charts were retrospectively reviewed; 100 eyes met inclusion criteria for analysis: at least one intravitreal dexamethasone implant injection, refractory to antivascular endothelial growth factor, and had ≥6 months of follow-up postinsertion. The primary outcome was the efficacy of the dexamethasone implant in reducing macular edema as measured by reduction in central retinal thickness (CRT). Secondary outcomes included visual acuity (VA), duration of treatment efficacy (measured by time to next treatment), and safety. The Wilcoxon signed-rank test was used to compare values from baseline, and Kaplan-Meier survival curves were used to analyze time to retreatment.

RESULTS

There were 28 patients with RVO, 30 with DME, 24 with posterior NIU, and 18 with IGS. VA improved from baseline to month 6 in all groups, but was not statistically significant. CRT improved in all 4 groups, and was statistically significant for DME (p = 0.008) and NIU (p = 0.05). At 3 months, 34 patients (41.5%) required retreatment; by month 6, 46 patients (56.1%) required retreatment. There was a large variation between the groups in number of patients requiring intraocular pressure (IOP)-lowering medications. Two patients needed IOP-lowering surgery. One patient developed endophthalmitis.

CONCLUSION

The use of intravitreal dexamethasone implants in patients with refractory retinal diseases is well tolerated and results in consistently improved anatomic outcomes, but the positive anatomic outcomes are not necessarily correlated to improvements in visual function. Patients who are treated earlier in the disease process will had better outcomes. This patient population were refractory to treatment and, therefore, have less-predictable functional outcomes.