MORPHOLOGY SCORE AS A MARKER OF RETINAL FUNCTION IN DRUSENOID PIGMENT EPITHELIAL DETACHMENT

Influence of drusenoid pigment epithelial detachments on the progression of age-related macular degeneration and visual acuity

OBJECTIVE

To analyze the presence and morphologic characteristics of drusenoid pigment epithelial detachments (DPEDs) in spectral-domain optical coherence tomography (SD-OCT) in Caucasian patients with early and intermediate age-related macular degeneration (AMD) as well as the influence of these characteristics on best-corrected visual acuity (BCVA) and disease progression.

DESIGN

Prospective observational cohort study.

PARTICIPANTS

89 eyes of 56 patients with early and intermediate AMD.

METHODS

Examinations consisted of BCVA, SD-OCT, and indocyanine green angiography. Evaluated parameters included drusen type, mean drusen height and -volume, the presence of DPED, DPED maximum height, -maximum diameter, -volume, topographic location, the rate of DPED collapse, and the development of macular neovascularization (MNV) or geographic atrophy (GA).

RESULTS

DPED maximum height (162.34 µm ± 75.70 μm, p = 0.019) was significantly associated with the development of GA and MNV. For each additional 100 μm in maximum height, the odds of developing any late AMD (GA or MNV) increased by 2.23 (95% CI = 1.14-4.35). The presence of DPED (44 eyes, p = 0.01), its volume (0.20 mm ± 0.20 mm, p = 0.01), maximum diameter (1860.87 μm ± 880.74 μm, p = 0.03), maximum height (p < 0.001) and topographical location in the central millimetre (p = 0.004) of the Early Treatment Diabetic Retinopathy Study (ETDRS)-Grid were significantly correlated with BCVA at the last follow-up (0.15logMAR ± 0.20logMAR; Snellen equivalent approximately 20/28). DPEDs occurred significantly less in the outer quadrants than in the central millimetre and inner quadrants of ETDRS-Grid (all p values < 0.001).

CONCLUSIONS

The height of drusen and DPEDs is a biomarker that is significantly associated with the development of late AMD and visual loss. DPEDs affect predominantly the center and inner quadrants of the ETDRS-Grid.

OPTICAL COHERENCE TOMOGRAPHY BIOMARKERS FOR REDUCTION OF DRUSENOID PIGMENT EPITHELIUM DETACHMENT

PURPOSE

To identify the optical coherence tomography biomarkers that can collectively predict the probability of collapse or reduction of drusenoid pigment epithelium detachment (PED).

METHODS

This consecutive observational case series reviewed the clinical data of 24 eyes with non-neovascular drusenoid PED. Among the study population, 17 eyes showed collapse or reduction of drusenoid PED. The mean follow-up duration was 44.8 ± 24.6 months. Optical coherence tomography-derived parameters were analyzed at baseline, at the last available visit before reduction of PED, at the first available visit after reduction of PED, and at the final visit.

RESULTS

The mean subfoveal choroidal thickness showed a significant decrease after PED reduction and at the most recent visit (P = 0.015). Migration of retinal pigment epithelium cells was detected in 15 (88.2%) after PED reduction; however, there was no significance in the frequency of migration of retinal pigment epithelium cells at each time point (P = 0.392). Non-neovascular subretinal fluid was detected in 7 (41.2%) before PED reduction, 2 (11.8%) after PED reduction, and 2 (11.8%) at the final visit. Interestingly, subretinal fluid appeared more frequently just before reduction of PED (P = 0.029).

CONCLUSION

We found evidence of non-neovascular subretinal fluid and choroidal thinning before reduction in PED. This finding might be useful for detection and prediction of the progression of drusenoid PED.

Long-term Choroidal Thickness Changes in Eyes With Drusenoid Pigment Epithelium Detachment

PURPOSE

To analyze the changes in visual acuity and subfoveal choroidal thickness in patients with non-neovascular age-related macular degeneration (AMD) and drusenoid pigment epithelium detachments (PED).

DESIGN

Consecutive observational case series.

METHODS

Observational retrospective review of eyes diagnosed with drusenoid PED in a single clinical setting. Demographic and clinical data included age, sex, laterality, best-corrected visual acuity (BCVA), and subfoveal choroidal thickness measured at baseline. before and after the collapse of the PED, and at the last available follow-up. The presence of geographic atrophy (GA) was also assessed.

RESULTS

Thirty-seven eyes of 25 patients (18 female) were included in the analysis. Mean age at baseline was 71 ± 8.4 years. During a mean follow-up period of 4.9 ±1.9 years, PED collapse was observed in 25 eyes (68%). Mean BCVA, mean maximum PED height, and mean subfoveal choroidal thickness significantly decreased from baseline to the last available follow-up (P < .001) in patients showing PED collapse. Choroidal thinning was faster during the PED collapse (speed rate of 35.9 μm/year). From those, 23 eyes (92%) developed GA. A significant correlation between the area of GA and the decrease in choroidal thickness was found (P = .010).

CONCLUSIONS

Choroidal thickness significantly decreased in eyes showing drusenoid PED collapse, but not in eyes in which the PED persisted. A significant correlation with resultant GA area following PED collapse and the magnitude of choroidal thinning was found. Further studies are warranted to better understand the mechanisms involved in the occurrence of choroidal changes during the life cycle of drusenoid PEDs.

Correlation between retinal function and microstructural foveal changes in intermediate age related macular degeneration

PURPOSE

To assess foveal microstructural changes influencing retinal sensitivity (RS) and fixation stability using microperimeter MP-1 in intermediate age-related macular degeneration (AMD).

METHODS

In this cross-sectional study, 22 eyes of 22 patients (mean age: 75 ± 9.02 years) with intermediate AMD were enrolled. Retinal sensitivity and bivariate contour ellipse area (BCEA) were obtained by microperimetry MP-1 (Humphrey 10-2 68-loci grid) under mesopic conditions. Drusen type, drusenoid pigment epithelial detachment, hyperreflective foci (HF), integrity of external limiting membrane (ELM), inner ellipsoid zone (ISel), RPE/Bruch's membrane complex (RPE/B) and subfoveal choroidal thickness were analyzed in the foveal region and compared with RS and BCEA. Spearman's rank correlation coefficient was used to evaluate the relationship between variables. Logistic regression analysis was also used to assess morphological predictor influencing RS or BCEA.

RESULTS

RS was strongly and inversely related with the presence of HF (r = -0.66, P = 0.001), integrity of ELM (r = -0.70, P < 0.001), ellipsoid zone (r = -0.45, P = 0.03). Instead, BCEA is positively related to the ellipsoid zone integrity (r = 0.45, P = 0.03). Logistic regression analysis confirmed that disruption of ISel influenced fixation stability (ExpB: 9.69, P = 0.04) but not RS. Instead, the presence of HF and disruption of ELM predicted RS reduction (ExpB: 0.55, P = 0.02 and ExpB: 0.29, P = 0.04, respectively).

CONCLUSIONS

The integrity of ELM and the presence of HF are both predictors of RS. The ELM status may be considered a new biomarker of retinal function together with HF. Instead, the integrity of ISel band seems to be a more selective predictor of BCEA than RS.

Histologic and Optical Coherence Tomographic Correlates in Drusenoid Pigment Epithelium Detachment in Age-Related Macular Degeneration

PURPOSE

Drusenoid pigment epithelium detachment (DPED) is a known precursor to geographic atrophy in age-related macular degeneration (AMD). We sought histologic correlates for spectral-domain (SD) optical coherence tomography (OCT) signatures in DPED and determined the frequency and origin of these OCT signatures in a clinical cohort of DPED eyes.

DESIGN

Laboratory imaging and histologic comparison, and retrospective, observational cohort study.

PARTICIPANTS

Four donor eyes with histopathologic diagnosis of AMD (2 with nonneovascular DPED and 2 with neovascular pigment epithelium detachment [PED]) and 49 eyes of 33 clinic patients with nonneovascular DPED more than 2 mm in diameter.

METHODS

Donor eyes underwent multimodal ex vivo imaging, including SD OCT, then processing for high-resolution histologic analysis. All clinic patients underwent SD OCT, near-infrared reflectance, and color photography.

MAIN OUTCOME MEASURES

Histologic correlates for SD OCT signatures in DPED, estimate of coverage by different retinal pigment epithelium (RPE) phenotypes in the DPED surface; frequency and origin of histologically verified SD OCT signatures in a clinical cohort of DPED eyes, and comparisons of histologic features between neovascular PED and DPED resulting from AMD.

RESULTS

Intraretinal and subretinal hyperreflective foci as seen on SD OCT correlated to RPE cells on histologic examination. Hypertransmission of light below the RPE-basal lamina band correlated with dissociated RPE. Subretinal hyperreflective material resulting from acquired vitelliform lesions corresponded to regions of apically expelled RPE organelles. In the clinical cohort, all histologically verified reflectivity signatures were visible and quantifiable. The appearance of intraretinal hyperreflective foci was preceded by thickening of the RPE-basal lamina band. Compared with PEDs associated with neovascular AMD, DPEDs had different crystallization patterns, no lipid-filled cells, and thinner basal laminar deposits.

CONCLUSIONS

Multiple RPE fates in AMD, including intraretinal cells that are highly prognostic for progression, can be followed and quantified reliably using eye-tracked serial SD OCT. This information may be particularly useful for obtaining an accurate timeline of incipient geographic atrophy in clinic populations and for quantifying anatomic end points and response to therapy in AMD clinical trials.