Enrica Convento

Microperimetry and fundus autofluorescence in patients with early age‐related macular degeneration

Background: Early age-related macular degeneration (AMD) has been correlated with different functional alterations, but the exact relationship between fundus lesions and overlying sensitivity is not well known. The aim of this study was to compare fundus-related sensitivity (microperimetry) and fundus autofluorescence (FAF) of the macular area with drusen and pigment abnormalities in early AMD. Methods: 13 consecutive patients with early AMD and visual acuity of 20/20 were studied by means of microperimetry, which automatically analyses macular light differential threshold and fixation patterns. Fundus colour photo and FAF of the macular area were recorded on the same day. Microperimetry was exactly (topographically) superimposed over FAF images. Results: Macular sensitivity significantly decreased over large drusen (11.2 ± 5.6 dB, p<0.0001) and over pigment abnormalities (13.1 ± 3.6 dB, p<0.0001). When both characteristics were present the reduction was greater if compared with its absence (9.6 ± 4.3 versus 15.0 ± 4.5 dB, p<0.0001). Sensitivitity reduction was significant in areas with altered FAF when compared with areas with normal FAF (p<0.0001). Conclusions: Increased FAF in early AMD has a functional correlate exactly quantified by microperimetry. In retinal areas affected by early AMD retinal sensitivity deteriorates, despite good visual acuity. Microperimetry may allow the early detection of functional impairment caused by these lesions. Both microperimetry and FAF may be useful to monitor AMD progression.

Fixation pattern and macular sensitivity in eyes with subfoveal choroidal neovascularization secondary to age-related macular degeneration. A microperimetry study

Purpose. To investigate the effects of subfoveal choroidal neovascularizzation (CNV) secondary to age-related macular degeneration (AMD) on macular functional parameters quantified with an automatic fundus perimeter. Methods. 118 eyes of 98 consecutive patients with subfoveal CNV secondary to AMD were evaluated. Best corrected visual acuity (ETDRS charts), fundus photography, and fluorescein angiography were performed. Microperimetry (fundus-related perimetry) was used to quantify macular sensitivity and fixation pattern (location and stability). Results. Of 118 eyes: 26 (21.9%) had central, 18 (15.1%) poor central and 74 (63.0%) eccentric fixation; 31 (26.0%) had stable, 42 (35.6%) relatively unstable and 45 (38.4%) unstable fixation. In 75 eyes (63.4%) a dense central scotoma was found. Angiographic classification of subfoveal CNV (occult versus classic) was not significantly related to fixation pattern (location: P = 0.274; stability: P = 0.385), and presence of dense scotoma (P = 0.41). Conclusion. Microperimetric quantification of macular sensitivity and fixation pattern in eyes with subfoveal CNV secondary to AMD offers new data about the impact of visual impairment in these eyes. Moreover, microperimetry improves the functional evaluation of subfoveal CNV in AMD.

Microperimetry And Fundus Autofluorescence In Diabetic Macular Edema: Subthreshold Micropulse Diode Laser Versus Modified Early Treatment Diabetic Retinopathy Study Laser Photocoagulation

Purpose:The purpose of this study was to evaluate and compare microperimetry and fundus autofluorescence (FAF) after subthreshold micropulse diode laser versus modified Early Treatment Diabetic Retinopathy Study photocoagulation for clinically significant diabetic macular edema. Methods:A prospective randomized clinical trial including 62 eyes (50 patients) with untreated, center-involving, clinically significant diabetic macular edema was performed. All patients underwent best-corrected visual acuity determination (logarithm of the minimum angle of resolution), slit-lamp biomicroscopy, FAF, optical coherence tomography, microperimetry (macular sensitivity), and fluorescein angiography before and after treatment. Best-corrected visual acuity, optical coherence tomography, microperimetry, and FAF were repeated at 1-, 3-, 6-, 9-, and 12-month follow-up examinations. Fluorescein angiography was performed at baseline and at 6 and 12 months. Results:Before treatment, demographic and macular parameters were not different between the two treatment groups. At 12 months, best-corrected visual acuity remained stable in both groups (P = 0.41 and P = 0.82), mean central retinal thickness decreased in both groups (P = 0.0002 and P < 0.0001), and mean central 4° and 12° retinal sensitivity increased in the micropulse diode laser group (P = 0.02 and P = 0.0075) and decreased in the Early Treatment Diabetic Retinopathy Study group (P = 0.2 and P = 0.0026). There was no significant difference in either best-corrected visual acuity or central retinal thickness between the 2 treatment groups (P = 0.48 and P = 0.29), whereas there was a significant difference in 4° and 12° retinal sensitivity (P = 0.04 and P < 0.0001). Fundus autofluorescence never changed in the micropulse diode laser group even after retreatment. In the Early Treatment Diabetic Retinopathy Study group, FAF increased up to 9 months and decreased in 6 eyes (20%) at 12 months. Discussion:Micropulse diode laser seems to be as effective as modified Early Treatment Diabetic Retinopathy Study laser photocoagulation in the treatment of clinically significant diabetic macular edema. Micropulse diode laser treatment does not determine any change on FAF showing (at least) nonclinically visible damage of the retinal pigment epithelium. Microperimetry data encourage the use of a new, less aggressive laser therapeutic approach in the treatment of clinically significant diabetic macular edema.

Fundus autofluorescence and microperimetry in progressing geographic atrophy secondary to age-related macular degeneration

Purpose To prospectively analyse microperimetry, standard short-wavelength fundus autofluorescent (SW-FAF) and near infrared-wavelength FAF (NIR-FAF) changes in eyes with geographic atrophy (GA) secondary to age-related macular degeneration. Methods Twenty consecutive eyes (14 patients) affected by GA were enrolled. Repeated microperimetric examinations and FAF images were obtained over a mean follow-up period of 12.3±4.5 months. Results GA area was always wider on NIR-FAF versus SW-FAF images (5.05±2.40 mm2 vs 4.45±2.41 mm2, p=0.005 baseline; 5.78±2.87 mm2 vs 5.21±2.77 mm2, p<0.0001 follow-up). Mean retinal sensitivity significantly decreased during follow-up from 7.68±3.92 dB to 6.71±4.37 dB (p=0.0013). 47.3% of the relative dense scotomas (≤5 dB) progressed to dense scotoma (0 dB). Retinal areas showing relative dense scotoma and characterised by hypo-SW-FAF or hyper-NIR-FAF at baseline had a higher risk of evolving to dense scotoma compared with normo-FAF and hyper-FAF on SW-FAF (OR=2.62 and 2.77, respectively), or normo-FAF at NIR-FAF (OR=2.96). Conclusions SW-FAF, compared with NIR-FAF, underestimates GA area at baseline and at follow-up. The enlargement rate of progression based on NIR-FAF is not greater than on SW-FAF. Different SW-FAF and NIR-FAF patterns show different relative risk of progression from relative to dense scotoma. Microperimetry, SW-FAF and NIR-FAF should be combined to obtain adequate morphological and functional prospective information.

Macular automatic fundus perimetry threshold versus standard perimetry threshold.

Purpose To evaluate if retinal sensitivity threshold obtained with an automatic fundus perimeter may be compared with a standard perimeter retinal threshold. Methods Automatic full-threshold fundus perimetry (microperimetry) of the macular area (10° grid, 37 stimulated points) was quantified with a new automatic fundus perimeter (MP1 microperimeter) in nine normal subjects (18 eyes). Retinal threshold was also quantified using an identical grid projected with a standard Octopus 101 perimeter. Results Mean threshold registered by MP1 microperimeter was 19.7±0.8 dB (range 16–20 dB; 4.38±0.96 asb, range 4–10 asb) versus 33.1±1.7 dB (range 27–38 dB; 0.53±0.22 asb, range 0.16–2 asb) obtained with Octopus perimeter. Mean SD of intraindividual variation was 0.74 dB in MP1 and 1.51 dB in Octopus. No statistically significant differences were documented between right and left eye with both instruments (p=0.64). No reliable mathematical relationship between retinal thresholds could be obtained with the two perimeters. Conclusions Fundus perimetry is a precise, functional fundus-related technique which allows threshold determination at selected retinal points even if fixation is unstable and visual acuity is low. This is beyond the possibility of any static standard perimetry. Normal threshold values obtained with MP1 automatic microperimeter cannot be currently compared with those obtained with standard Octopus perimeter. (Eur J Ophthalmol 2007; 17: 63–8)

Short wavelength fundus autofluorescence versus near-infrared fundus autofluorescence, with microperimetric correspondence, in patients with geographic atrophy due to age-related macular degeneration

Aim To compare standard short-wavelength fundus autofluorescence (SW-FAF) and near infrared-wavelength fundus autofluorescence (NIR-FAF) in detecting geographic atrophy (GA) secondary to age-related macular degeneration, and its retinal sensitivity impairment. Methods Twenty-five consecutive patients (36 eyes) affected by GA were studied by means of fundus autofluorescence imaging, using both SW-FAF (excitation: 488 nm, emission >500 nm) and NIR-FAF (excitation: 787 nm, emission >800 nm). All patients underwent microperimetry to assess fixation characteristics and retinal sensitivity. Results In the extrafoveal region, the total hypoautofluorescent (hypo-FAF) area was significantly wider with NIR-FAF than with SW-FAF (8.03±6.68 mm2 vs 7.37±6.34 mm2 respectively; p=0.005). In the foveal area, the total hypo-FAF area was smaller with NIR-FAF than with SW-FAF (0.19±0.03 mm2 versus 0.42±0.12 mm2 respectively; p=0.008). Foveal sparing was larger at NIR-FAF compared with SW-FAF (p=0.021). In nine cases (25%) the site of fixation was hypoautofluorescent on SW-FAF, but normal on NIR-FAF with preserved retinal sensitivity. Conclusions Standard SW-FAF may overestimate GA in the foveal area, correctly detected by NIR-FAF. In the extrafoveal area, SW-FAF may underestimate GA. Standard SW-FAF should be integrated with NIR FAF when detecting and following GA to avoid inconsistent results and misinterpretation, from both a morphological and functional perspective. Microperimetry helps to quantify retinal sensitivity in GA.

SUBTHRESHOLD MICROPULSE YELLOW LASER VERSUS SUBTHRESHOLD MICROPULSE INFRARED LASER IN CENTER-INVOLVING DIABETIC MACULAR EDEMA: Morphologic and Functional Safety.

Background: To evaluate and compare in vivo retinal and choroidal morphologic changes and macular function in patients treated with yellow (Y-MPL) or infrared (IR-MPL) subthreshold micropulse laser in center-involving diabetic macular edema. Methods: Prospective, randomized, single institution, comparative 6-month pilot study of 53 eyes (53 patients with diabetes). Inclusion criteria were previously untreated center-involving diabetic macular edema with central retinal thickness ⩽400 &mgr;m (mild diabetic macular edema). Y-MPL or IR-MPL treatment was performed in a standardized pattern, using in both cases the lowest duty cycle (5%). Morphologic outcomes were the visibility of laser spots (on color fundus photographs [COL], fundus autofluorescence, fluorescein angiography, and spectral domain optical coherence tomography), retinal thickness and volume changes, foveal choroidal thickness changes, and integrity and reflectivity of the outer retinal layers. Visual function outcomes were variation in mean 4° and 12° retinal sensitivity and best-corrected visual acuity. Results: Twenty-six eyes were treated with Y-MPL and 27 eyes with IR-MPL. No visible laser spots on the retina were found on COL, fundus autofluorescence, and fluorescein angiography in both treatment groups at 3 months and 6 months of follow-up. Central retinal thickness, macular volume, foveal choroidal thickness, and best-corrected visual acuity were not significantly different at any follow-up visit between the two treatment groups. There were no changes in the integrity of the external limiting membrane or inner segment/outer segment junction in both treatment groups. Mean central 4° retinal sensitivity increased in both treatment groups at 6 months (P = 0.01 and P = 0.04, respectively). Mean central 12° retinal sensitivity increased in the Y-MPL group only (P = 0.047). But, there was no significant difference in mean 4° and 12° retinal sensitivity between the 2 treatment groups at any follow-up visit. Conclusion: No clinically visible or invisible scars in the macula were found after Y-MPL or IR-MPL treatment. Both Y-MPL and IR-MPL with the lowest duty cycle (5%) and fixed power parameters seem to be safe from the morphologic and visual function points of view in mild center-involving diabetic macular edema.

Microperimetry, fundus autofluorescence, and retinal layer changes in progressing geographic atrophy

OBJECTIVE To analyze correlation among microperimetry, inner and outer retinal layers, and fundus autofluorescence (FAF) changes in eyes with progressing geographic atrophy (GA) secondary to age-related macular degeneration. METHODS Microperimetry, spectral-domain optical coherence tomography (SD-OCT), standard short-wavelength FAF (SW-FAF), and near-infrared-wavelength FAF (NIR-FAF) were performed for all patients at both baseline and follow-up visits. FAF pattern, integrity of photoreceptor inner segment/outer segment (IS/OS) junction, total retinal thickness (RT), inner retinal layers (IRL), and outer retinal layers (ORL) thickness changes of every microperimetry extrafoveal tested point were analyzed. RESULTS A total of 366 microperimetry tested points were analyzed (6 patients, 7 eyes). Mean retinal sensitivity significantly decreased (p = 0.0149), and the percentage of dense scotomas significantly increased (p = 0.0125). Mean RT and mean ORL thickness significantly decreased (both p < 0.0001). Mean IRL thickness significantly increased (p = 0.0001). The decrease of ORL thickness was inversely correlated to the IRL thinning (rho = -0.710). FAF pattern at baseline was correlated to RT and ORL thickness (both p < 0.0001) and was significantly correlated to the risk to evolve to dense scotoma during follow-up (p = 0.0001 at SW-FAF, p < 0.0001 at NIR-FAF). Tested points showing at baseline the loss of photoreceptor IS/OS junction had a greater risk for evolving to dense scotoma compared with those with intact photoreceptor IS/OS junction (odds ratio 3.56, 95% CI 2.41-5.27). CONCLUSIONS Retinal sensitivity changes are correlated to IRL and ORL thickness changes, and to photoreceptor IS/OS junction integrity. FAF patterns remain a relevant factor in predicting GA evolution. Microperimetry, SW-FAF and NIR-FAF, and SD-OCT should be combined to obtain adequate morphologic and functional prospective information.

Static and dynamic retinal fixation stability in microperimetry

OBJECTIVE To compare static (during a pure fixation task) versus dynamic (during microperimetry) quantification of fixation stability using microperimetry in normal and pathologic eyes, by means of 2 available (clinical and bivariate contour ellipse area [BCEA]) classification methods. DESIGN Prospective comparative observational study. PARTICIPANTS One hundred and forty-nine eyes (110 patients) with different macular diseases and 171 normal eyes (109 subjects). METHODS In all eyes studied, fixation stability was acquired during an isolated fixation task (static fixation) and during microperimetry (dynamic fixation). All fixation data were analyzed and compared by means of a clinical classification and by means of BCEA quantification. RESULTS Pathologic eyes were classified as follows: 41 eyes with diabetic macular edema (DME group), 13 eyes with vitreoretinal interface disease, 60 eyes with age-related macular degeneration (AMD group), and 35 eyes with primary open-angle glaucoma. Fixation stability was not uniform among groups according to clinical classification in both static and dynamic modalities (p < 0.0001). AMD group showed larger BCEA areas compared with all other groups (p < 0.0001). All pathologic groups showed more unstable fixation in dynamic fashion according to both clinical and BCEA methods (p < 0.0001). The variation of fixation stability of control group in dynamic task was highlighted only by BCEA analysis (p < 0.0001). A deterioration of retinal fixation according to clinical method matches a significant increase in BCEA areas (p < 0.0001). CONCLUSIONS The detection of clinical fixation stability changes improves when acquired in the dynamic modality. BCEA analysis provides more accurate evaluation of fixation stability and may detect minimal quantitative changes of the fixation area. However, a standard clinical classification can also detect changes in fixation stability in pathologic eyes. Both methods are useful tools in the evaluation of fixation stability.

Retinal function in patients with serpiginous choroiditis: a microperimetry study.

PurposeTo investigate fixation pattern and retinal sensitivity in patients with serpiginous choroiditis (SC).MethodsTwenty-eight eyes (14 patients) with SC were evaluated. Best-corrected visual acuity, color fundus photography, fundus autofluorescence, and fluorescein and indocyanine green angiography were performed. Microperimetry was used to assess fixation pattern and retinal sensitivity.ResultsOf 28 eyes, 16 (57%) had central, one (4%) poor central, and 11 (39%) eccentric fixation; and 18 (64%) had stable, four (14%) relatively unstable, and six (21%) unstable fixation. In patients with posterior pole symmetrically involved in both eyes, the better eye had stable and central fixation in all cases. Atrophic lesions were characterized by a dense scotoma in all cases, with a relative scotoma at their margins in ten eyes (38%). In two cases of active disease, a dense scotoma correlated to an active lesion could be detected. A relative scotoma was documented in areas not involved by the disease at the posterior pole in eight eyes (28%), and in the peripapillary area in 11 eyes (39%).ConclusionsQuantification of retinal sensitivity and fixation pattern by microperimetry offers new data about the impact of visual impairment in patients with SC. A reduction of retinal sensitivity in an apparently healthy area suggests a wider functional involvement of the retina, undetectable by morphologic evaluation alone.