Müller cells and choriocapillaris in the pathogenesis of geographic atrophy secondary to age-related macular degeneration.

PURPOSE: To better understand the pathophysiology of geographic atrophy (GA), secondary to age-related macular degeneration, eyes affected by unilateral GA (and CNV in the fellow eye; U-GA group) or by bilateral GA (B-GA group) were evaluated using an integrated morpho-functional approach and quantifying biomarker of retinal macroglial activity. METHODS: Patients with U-GA and B-GA and foveal-sparing were consecutively enrolled in a prospective study. All included eyes underwent fundus photography, fundus autofluorescence (FAF), foveal retinal and choroidal thicknesses (RT, CT), contrast sensitivity, best-corrected visual acuity (BCVA), low-luminance VA (LLVA) and low-luminance deficit (LLD), and mesopic and scotopic microperimetry and multifocal electroretinography (mfERG). Glial fibrillary acidic protein (GFAP), biomarker of Müller cell activation, was quantified in the aqueous humor (AH). RESULTS: Forty eyes of 40 patients (18 in the U-GA group and 22 in the B-GA group) were studied. RT, GA area, BCVA, contrast sensitivity, mfERG, and microperimetry (at both background luminances) were not different between groups. CT was significantly thinner in U-GA compared to B-GA group (p = 0.020). Both LLVA and LLD were significantly worse in the B-GA vs U-GA group (p = 0.033 and p = 0.048, respectively). GFAP intraocular concentration was significantly higher in the B-GA group (p = 0.01). CONCLUSIONS: Different pathophysiologic mechanisms may be responsible for GA in unilateral (with CNV in the fellow eye) compared to bilateral GA cases. In unilateral cases, a thinner choroid seems to play a key role. Whereas, in bilateral cases, Müller cells and their supported photoreceptors may be primarily involved.

Repeatability and Reproducibility of Foveal Avascular Zone Area Measurement on Normal Eyes by Different Optical Coherence Tomography Angiography Instruments.

PURPOSE: To compare the foveal avascular zone (FAZ) area measurements produced by different optical coherence tomography angiography (OCTA). METHODS: Healthy enrolled volunteers underwent OCTA using 2 different devices: Spectralis HRA+OCTA (Heidelberg Engineering, Heidelberg, Germany) and RS-3000 Advance (Nidek, Gamagori, Japan). Two graders measured FAZ in both superficial (SCP) and deep (DCP) retinal capillary plexuses. The SCP and DCP en face images were visualized automatically segmenting 2 separate slabs defined by the arbitrary segmentation lines created by the software of each OCT device. One grader repeated each measure twice. RESULTS: Fifty-nine eyes were included. The mean FAZ was 0.33 ± 0.09 mm2 at the SCP and 0.57 ± 0.17 mm2 at the DCP measured with RS-3000 versus 0.30 ± 0.08 and 0.35 ± 0.08 mm2, respectively, measured with Spectralis. The measurements of the 2 devices were significantly different (p < 0.0001). The intraoperator agreement was excellent at the SCP (intraclass correlation coefficient, ICC: 0.97 with Spectralis and 0.96 with RS-3000). At the DCP, it was good with Spectralis and fair with RS-3000 (ICC: 0.85 and 0.64, respectively). The interoperator agreement was excellent for Spectralis and good for RS-3000 at the SCP (ICC: 0.97 and 0.93, respectively). It was good at the DCP with both devices (ICC: 0.74 with RS-3000 and 0.81 with Spectralis). CONCLUSIONS: FAZ measurements obtained with different OCTA devices differ. These findings should be considered in follow-up studies of patients with retinal vascular diseases.

Long-term longitudinal modifications in mesopic microperimetry in early and intermediate age-related macular degeneration.

PURPOSE: To evaluate functional changes (retinal sensitivity and fixation characteristics) determined by microperimetry in patients with early and intermediate AMD over 6 years. METHODS: Prospective, longitudinal follow-up (FU) study of 16 patients (29 eyes) with early and intermediate AMD (AREDS 2 and AREDS 3 classification). All eyes underwent: complete ophthalmic examination with best corrected visual acuity (BCVA) determination, color fundus photo (CFP), optical coherence tomography and microperimetry. All CFP were evaluated by two retinal specialists masked to functional data for changes in severity of clinical features over the course of FU. RESULTS: Of 17 eyes graded as AREDS 2 at baseline, 14 (82.35 %) remained stable, and 3 (18.75 %) progressed to AREDS 3. Of 12 eyes graded as AREDS 3 at baseline, 10 remained stable (83.33 %), and 2 (16.67 %) progressed to AREDS 4. Mean BCVA significantly deteriorated in both AREDS 2 (p = 0.006) and AREDS 3 (p = 0.016), with greater decrease in AREDS 3 (p = 0.01)6. Mean retinal sensitivity (RS) significantly decreased over time in both AREDS 2 (p < 0.0001) and AREDS 3 group (p = 0.002), with greater decrease in AREDS 3 (p = 0.006). The mean number of dense scotomas did not change in AREDS 2 (p = 0.3), but significantly increased in the AREDS 3 group (p = 0.035). Points with decreased RS were located in all but the central point (p < 0.0001 for all), without significant differences in number among rings. In the AREDS 2 group, fixation stability remained unchanged. In the AREDS 3 group, four eyes deteriorated from stable to unstable fixation at FU (p = 0.045). CONCLUSION: A significant deterioration in RS is reported in early and intermediate AMD eyes, whereas fixation stability changed only in intermediate AMD (AREDS 3) over long-term follow-up. Microperimetry examination can become a new functional biomarker in early and intermediate AMD patients.

Aging and corneal layers: an in vivo corneal confocal microscopy study.

PURPOSE: To describe age-related changes of different corneal layers using a quantitative analysis of in vivo corneal confocal microscopy. DESIGN: Descriptive observational cross-sectional study. METHODS: A total of 108 healthy corneas of 108 subjects, distributed in four age categories, underwent in vivo corneal confocal microscopy. The effect of aging on the main features of corneal epithelium, sub-basal nerve plexus, stroma, and endothelium was investigated. RESULTS: Mean diameter of superficial epithelial cells increases with age (0.05 µm per year; p < 0.0001). Mean cell density of basal epithelium does not change with age (p = 0.37). The sub-basal nerve plexus fiber number, density, and the number of beadings do not statistically change with age (p = 0.14, p = 0.10 and p = 0.17, respectively). Keratocyte density significantly reduces with age in each stromal layer (p < 0.0001). Endothelial cell count decreases by 10.92 cells/mm(2) per year (p < 0.0001). Endothelial polymegathism index and pleomorphism index do not change with age (p = 0.79 and p = 0.39, respectively). CONCLUSIONS: Corneal confocal microscopy allows a non-invasive examination of the living cornea, analyzing the microstructure of each corneal layer. Aging significantly influences the corneal confocal microscopy parameters of individual corneal layers, except sub-basal nerve plexus and basal epithelium.

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 µm (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.

RETINAL DYSTROPHY IN JEUNE SYNDROME: A MULTIMODAL IMAGING CHARACTERIZATION.

PURPOSE: To report multimodal imaging findings in a patient affected by Jeune syndrome-associated retinal dystrophy. METHODS: Observational case report. RESULTS: An 18-year-old girl affected by Jeune syndrome was referred to our low vision unit. She presented with bilateral high myopia, reduced visual acuity, exotropia, and nystagmus. Fundus examination detected posterior myopic staphyloma and diffuse retinal dystrophy confirmed using a full-field electroretinogram as a cone-rod dystrophy. Spectral domain optical coherence tomography detected a thick anomalous hyperreflective band located beneath an irregular and disrupted external limiting membrane, showing the primary involvement of the photoreceptors outer segment with relative sparing of the retinal pigment epithelium, as confirmed by fundus autofluorescence. CONCLUSION: This is a case of Jeune syndrome with retinal abnormalities studied with fundus autofluorescence and optical coherence tomography. Retinal noninvasive multimodal imaging could provide significant insight in the retinal involvement of patients affected by Jeune syndrome and should have an essential role in the multidisciplinary diagnostic approach and follow-up.

Two novel compound heterozygous SAG mutations in an Italian patient with Oguchi disease: A genetic and multimodal retinal imaging study.

BACKGROUND: Oguchi disease is a rare autosomal recessive retinal dystrophy, characterized by congenital stationary blindness and caused by pathogenic variants in SAG and GRK1 genes. The present study aimed to report an Italian patient affected by Oguchi disease, evaluated by means of a multimodal retinal imaging study and harboring two novel heterozygous pathogenic variants in the SAG gene. MATERIALS AND METHODS: A 60-year-old female complaining congenital stationary night blindness was investigated through fundus photograph, optical coherence tomography (OCT), electroretinography (ERG), and genetic testing. RESULTS: Fundus examination showed a golden-grayish fundus aspect. The rod response of the scotopic ERG was undetectable and mixed rod-cone response was electronegative. Fundus photographs obtained in light and in prolonged dark-adapted conditions allowed to detect the Mizuo-Nakamura phenomenon. Light condition OCT over the abnormal retinal regions showed high-intensity areas in the outer photoreceptor segment layer, that reduced with prolonged dark adaption. Genetic testing identified two rare heterozygous sequence variants in the SAG gene: NM_000541.5:c.807delA p.(Glu270Lysfs*9) and NM_000541.5:c.1047-1G>C confirming the diagnosis of Oguchi disease. CONCLUSIONS: We identified the first Italian compound heterozygous patient harboring two novel alterations in the SAG gene (a frameshift deletion and a splicing variant). The involvement of the SAG gene in Oguchi disease is a common finding in Japanese population, but rarely identified in Caucasians. Clinical suspicion should prompt the molecular analysis of genes associated with this condition.

Early Microvascular and Oscillatory Potentials Changes in Human Diabetic Retina: Amacrine Cells and the Intraretinal Neurovascular Crosstalk.

To analyze the early microvascular retinal changes and oscillatory potentials alterations secondary to diabetic retinal damage, 44 eyes of 22 diabetic patients without and with mild diabetic retinopathy (DR) and 18 eyes of 9 healthy controls were examined. All subjects underwent spectral domain optical coherence tomography (SD-OCT), OCT angiography (OCTA), and electroretinography of oscillatory potentials (OPs). At OCTA, vessel area density (VAD), vessel length fraction (VLF), and fractal dimension (FD) were significantly reduced in the superficial vascular plexus (SVP), VLF and FD in the intermediate capillary plexus (ICP), and FD in the deep capillary plexus (DCP) in the diabetic group compared to the control group. The amplitude (A) of OP2, OP3, OP4 and the sum of OPs were significantly reduced in the diabetic group versus the controls, and the last two parameters were reduced also in patients without DR versus the controls. Moreover, in the diabetic group, a significant direct correlation was found between the A of OP1, OP2, OP3 and sOP and the VLF and FD in the SVP, while a statistically significant inverse correlation was found between the A of OP3 and OP4 and the VDI in the ICP and DCP. The reduced oscillatory potentials suggest a precocious involvement of amacrine cells in diabetic eyes, independently of DR presence, and their correlation with vascular parameters underlines the relevance of the crosstalk between these cells and vascular components in the pathophysiology of this chronic disease.

Early Retinal Changes by OCT Angiography and Multifocal Electroretinography in Diabetes.

BACKGROUND: To evaluate the earliest retinal morphological and functional changes in diabetic eyes without or with early signs of diabetic retinopathy (DR). METHODS: Twenty-two eyes with no DR (noDR group), 22 eyes with mild DR (DR group), and 18 healthy nondiabetic eyes (controls) were enrolled. All eyes were studied by means of spectral domain optical coherence tomography (OCT), OCT angiography (OCTA), and multifocal electroretinogram (mfERG). RESULTS: A significantly higher number of OCT hyperreflective intraretinal foci (HRF) was found in both noDR and DR groups versus controls, but not between DR groups. The OCTA parameters of the superficial vascular plexus (SVP) were significantly reduced in the noDR group both versus controls and DR group (p < 0.05). The OCTA parameters of the intermediate capillary plexus (ICP) were significantly reduced in the DR group versus controls. An increased number of altered hexagons on mfERG was found in the noDR versus the DR group (p = 0.0192). CONCLUSIONS: Retinal vascular and functional parameters are differently involved in diabetic eyes; major vascular changes in the SVP and functional alterations of the mfERG are present in diabetic eyes with no clinical microvascular signs of DR, while ICP is mainly involved when early ophthalmoscopic signs of DR are present. The integrated use of mfERG and OCTA provides new significant insights into the pathogenesis of diabetic related retinal disease.

Final versus referral diagnosis of childhood visual impairment in an Italian tertiary low vision rehabilitation centre.

PURPOSE: To compare the final diagnosis of the causes of low vision in children attending a tertiary rehabilitation centre for visually impaired children versus referral diagnosis. METHODS: Retrospective review of clinical charts of all children referred to the Robert Hollman Foundation, a tertiary centre for visually impaired children, between January 2010 and June 2011. The following clinical data were analysed: entry diagnosis made by the referral ophthalmologist and final diagnosis made at Robert Hollman Foundation based on a complete ophthalmic evaluation. RESULTS: Ninety-two consecutive children (mean age = 2.37 ± 1.98 years, range = 0-9) were included. A referral diagnosis was retrieved in 76 cases (82.6%), including cerebral visual impairment (14.1%), retinopathy of prematurity (14.1%), hereditary retinal diseases (10.9%), nystagmus (8.7%) and other rarer diseases (34.8%). In the remaining 16 children (17.4%), a precise referral diagnosis was unavailable. Final clinical diagnosis made at Robert Hollman Foundation was normal visual function in 8.7%, cerebral visual impairment in 30.4%, retinopathy of prematurity in 10.9%, hereditary retinal disease in 9.8% and other in 40.2%. In 17 cases (18.5%), the diagnosis made at the Robert Hollman Foundation did not confirm the entry diagnosis. Among patients where measurement of visual acuity was possible (84), 66.7% were blind or seriously visual impaired, and the main causes were cerebral visual impairment (32.1%) and retinopathy of prematurity (16.1%). CONCLUSION: The most frequent diseases were cerebral visual impairment, retinopathy of prematurity and hereditary retinal diseases. Approximately one-third of referred children had not a correct diagnosis at baseline. The activity of an ophthalmic tertiary centre is essential to offer a precise diagnosis to visually impaired (sometimes with other deficits) children.

Early OCT angiography changes of type 1 CNV in exudative AMD treated with anti-VEGF.

AIMS: To investigate, with optical coherence tomography angiography (OCTA), short-term changes of type 1 choroidal neovascularisation (CNV), secondary to exudative age-related macular degeneration, after anti-vascular endothelial growth factor (VEGF) treatment. METHODS: Patients affected by type 1 CNV treated with intravitreal anti-VEGF were consecutively enrolled. All patients underwent OCTA examination before and 48 hours after anti-VEGF treatment. Quantitative and qualitative vascular and morphological macular changes were evaluated. RESULTS: Sixteen eyes were included (11 treated with aflibercept and 5 with ranibizumab). Both CNV mean area and pigment epithelium detachment significantly reduced (p=0.0004 and p=0.0007, respectively) after treatment. Cystoid macular oedema (four eyes) decreased in all cases. Neuroretinal detachment (13 eyes) decreased in 85% of cases (11 eyes). Fine CNV vessels density decreased in 75% (12 eyes), whereas larger CNV vessels density remained stable in 66.7% (10 eyes), choroidal flow void signal (7 eyes at baseline) increased in 42.9% (3 eyes) of them and remained stable in 57.1% (4 eyes). Interoperator reproducibility for OCT examination was good for all measurements (intraclass correlation coefficient>0.65). CONCLUSION: Early remodelling of type 1 CNV network after treatment may be non-invasively and reproducibly analysed by means of OCTA. Choroidal perfusion impairment, choroidal flow void signal, surrounding CNV may change during treatment.

Early retinal and choroidal OCT and OCT angiography signs of inflammation after uncomplicated cataract surgery.

PURPOSE: To evaluate, by means of optical coherence tomography (OCT) and OCT angiography (OCTA), early retinal, choroidal and macular perfusion changes induced by a local inflammatory reaction secondary to uncomplicated cataract surgery. METHODS: Selected eyes undergoing cataract surgery were enrolled in a prospective study. OCT and OCTA were performed before cataract surgery (T0) and at day: 1 (T1), 7 (T7), 30 (T30) and 90 (T90). Inner (IR) and outer retinal (OR) volumes, choroidal volume, hyper-reflective retinal spots (HRS) in IR and OR changes were measured at OCT. Macular perfusion was analysed in superficial (SCP), intermediate (ICP) and deep retinal capillary plexuses (DCP). RESULTS: Nine eyes of nine selected patients were consecutively enrolled. Mean IR volume changed after surgery (p=0.0001), increasing progressively from 4.391±0.231 mm³ at T0 to 4.573±0.241 mm³ at T30, p=0.0002. Both mean OR and choroidal volume increased, mainly at T30, but not significantly (p=0.4360 and p=0.2300, respectively). Mean HRS changed during follow-up, increasing at first in IR and later in OR (at T1 and T7, respectively, both p<0.0001). Macular ICP and DCP perfusion increased at T1, whereas macular SCP perfusion did not change. At T90, all OCT and OCTA parameters had almost reached baseline levels. CONCLUSIONS: The increase of HRS at first in IR and later in OR seems to confirm their inflammatory nature. Early OCTA changes (underline) underscore a selective susceptibility of DCP and ICP to a localised inflammatory reaction induced by cataract surgery.

Microperimetry Features of Geographic Atrophy Identified With En Face Optical Coherence Tomography.

IMPORTANCE: Progressive geographic atrophy (GA) of the retinal pigment epithelium leads to loss of central vision. To identify GA in age-related macular degeneration and assess treatment, correlation of function observed on microperimetry with structure observed on optical coherence tomographic (OCT) images may be of value. OBJECTIVE: To characterize the microperimetric function of GA as identified from en face OCT imaging. DESIGN, SETTING, AND PARTICIPANTS: In a case-series study, 20 patients (22 eyes) entered the study at the University of Padova according to preplanned conditions. From March 1 to July 30, 2014, en face OCT images were obtained at the outer retinal layer and choroidal layer levels. The microperimetry sensitivity map was superimposed on the en face OCT images, which had been used to measure GA areas. Relative and dense scotoma rates were calculated in the GA areas. After data collection, the study eyes were divided into 3 groups according to the macular residual mean sensitivity. MAIN OUTCOMES AND MEASURES: Retinal sensitivity measured by microperimetry within areas of GA identified by en face OCT images. RESULTS: Twenty patients (5 men and 15 women) were included in the study, with a mean (SD) age of 79.5 (7.0) years (range, 69-98 years). Macular residual mean retinal sensitivity was less than 5 dB in 7 eyes (group 1), 5 to 10 dB in 9 eyes (group 2), and greater than 10 dB in 6 eyes (group 3). Mean (SD) GA area differed among the groups at the outer retinal (13.13 [5.03] mm2 [range, 5.75-21.04 mm2] in group 1; 7.80 [3.25] mm2 [range, 3.31-13.52 mm2] in group 2; and 3.94 [2.35] mm2 [range, 1.46-7.90 mm2] in group 3; P = .001) and choroidal (11.83 [5.55] mm2 [range, 4.55-22.14 mm2] in group 1; 7.00 [4.29] mm2 [range, 0.90-13.83 mm2] in group 2; and 3.27 [2.29] mm2 [range, 0.91-7.23 mm2] in group 3; P = .007) layer levels. Mean (SD) GA area imaged at the outer retinal layer level was significantly larger than that imaged at the choroidal level in group 3 (difference, 0.67 mm2; 95% CI, 0.31-1.03 mm2; P = .005), but not in groups 1 or 2. Mean (SD) rate of relative scotoma was significantly higher in the GA area imaged at the outer retinal layer level than at the choroidal level in group 3 (47.70% [31.30%] [range, 13.60%-100%] vs 34.00% [37.30%] [range, 0%-100%]; difference, 13.74%; 95% CI, 3.84%-23.63%; P = .02), but not in groups 1 or 2. CONCLUSIONS AND RELEVANCE: In the early stage of GA, when retinal sensitivity is relatively good, these data suggest that the GA area imaged on en face OCT at the outer retinal level correctly detects the wide functional degenerative involvement of the photoreceptors. These findings provide novel data that correlate function and structure, which may be of value when assessing treatments that might prevent or reduce the rate of growth of GA.

Rod function in diabetic patients without and with early diabetic retinopathy.

PURPOSE: To compare rod function among diabetic patients without and with mild nonproliferative diabetic retinopathy (DR) and healthy controls by means of scotopic microperimetry and dark-adapted electroretinography. METHODS: Sixty-one diabetic patients and 30 age-matched controls (control group) underwent complete ophthalmic examination, scotopic microperimetry, and dark-adapted 0.01 electroretinography (DA-ERG). RESULTS: In 32 eyes, DR was absent (no-DR group); in 29 eyes, only microaneurysms were observed (DR group). No statistically significant differences in fixation stability, fixation location, or scotopic sensitivity among the 3 groups were observed. Implicit time and amplitude of the DA-ERG b-wave of no-DR and DR groups were not different from controls. Scotopic microperimetry showed a dense scotoma centered onto the fovea in all subjects, consistent with the rod-free zone. Greater scotopic sensitivity was found in a ring located 8° from the fovea (9.33 ± 1.33 dB). CONCLUSIONS: Diabetic patients without DR and with mild nonproliferative DR did not show alterations in rod-based function, as examined by microperimetry and confirmed by DA-ERG. Scotopic microperimetry measures rod-based function and offers additional information in the evaluation of the aspects of involvement of retinal cells in diabetes.

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.

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.

Subthreshold laser therapy for diabetic macular edema: metabolic and safety issues.

PURPOSE: To review the most important metabolic effects and clinical safety data of subthreshold micropulse diode laser (D-MPL) in diabetic macular edema (DME). METHODS: Review of the literature about the mechanisms of action and role of D-MPL in DME. RESULTS: The MPL treatment does not damage the retina and is selectively absorbed by the retinal pigment epithelium (RPE). MPL stimulates secretion of different protective cytokines by the RPE. No visible laser spots on the retina were noted on any fundus image modality in different studies, and there were no changes of the outer retina integrity. Mean central retinal sensitivity (RS) increased in subthreshold micropulse diode laser group compared to standard ETDRS photocoagulation group. CONCLUSIONS: MPL is a new, promising treatment option in DME, with both infrared and yellow wavelengths using the less aggressive duty cycle (5%) and fixed power parameters. It appears to be safe from morphologic and functional point of view in mild center involving DME.