Extent of diabetic macular edema by scanning laser ophthalmoscope in the retromode and its functional correlations.

BACKGROUND: To determine whether scanning laser ophthalmoscope in the retromode (RM-SLO) is useful to evaluate the extent of diabetic macular edema (DME) and its functional characteristics. METHODS: Comparative case series of 37 eyes (27 patients with diabetes). Inclusion criteria were: center involving DME determined by optical coherence tomography; RM-SLO, optical coherence tomography, fluorescein angiography (FA), and microperimetry performed on the same day; no significant media opacities. Two masked retinal specialists independently graded all images. The full extent of DME areas and two grades (small and large) DME areas were separately evaluated. The relationship between the DME extent obtained by RM-SLO and FA was assessed by Pearson correlation coefficient, intraclass correlation coefficient, and Bland-Altman plot. T-test was used to compare DME extent to central retinal thickness and macular sensitivity. RESULTS: The values of RM-SLO from the right and left prospective were highly correlated in the evaluation of the extent of DME (rho = 0.99, P < 0.0001). Mean DME area on RM-SLO was 5.7 + 5.6 mm (range, 0.3-18.2 mm); mean DME area on FA was 6.4 + 5.9 mm (range, 0.3-19.7 mm). The correlation between RM-SLO and FA in the evaluation of DME extent was highly significant (rho = 0.97, P < 0.0001), even when DME extent was divided in 2 major areas (intraclass correlation coefficient >0.8, P < 0.0001). The correlation between retinal sensitivity and DME area (RM-SLO) was significant (rho = -0.61, P = 0.0003). CONCLUSION: The extent has become an important parameter for monitoring DME, with or without treatment. The extent of DME well correlates with functional data, mainly retinal sensitivity. Retromode SLO can be reliably and easily used in the evaluation of DME extent, avoiding the use of invasive FA.

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.

In Vivo Detection of Choroidal Abnormalities Related to NF1: Feasibility and Comparison With Standard NIH Diagnostic Criteria in Pediatric Patients.

PURPOSE: To evaluate the feasibility of near-infrared (NIR) imaging acquisition in a large sample of consecutive pediatric patients with neurofibromatosis type 1 (NF1), to evaluate the diagnostic performance of NF1-related choroidal abnormalities as a diagnostic criterion of the disease, and to compare this criterion with other standard National Institutes of Health (NIH) diagnostic criteria. METHODS: A total of 140 consecutive pediatric patients (0-16 years old) affected by NF1 (at least two diagnostic criteria), 59 suspected (a single diagnostic criterion), and 42 healthy subjects (no diagnostic criterion) were consecutively included. Each patient underwent genetic, dermatologic, and ophthalmologic examination to evaluate the presence/absence of each NIH diagnostic criterion. The presence of NF1-related choroidal abnormalities was investigated using NIR confocal ophthalmoscopy. Two masked operators assessed Lisch nodules and NF1-related choroidal abnormalities. RESULTS: Neurofibromatosis type 1-related choroidal abnormalities were detected in 72 affected (60.5%) and 1 suspected (2.4%) child. No healthy subject had choroidal abnormalities. Feasibility rate of this sign was 82%. Sensitivity, specificity, and positive and negative predictive values of NF1-related choroidal abnormalities were 0.60, 0.97, 0.98, and 0.46, respectively. Compared with standard NIH criteria, the presence of NF1-related choroidal abnormalities was the third parameter for positive predictive value and the fourth for sensitivity, specificity, and negative predictive value. Compared with Lisch nodules, NF1-related choroidal abnormalities were characterized by higher specificity and positive predictive value. The interoperator agreement for Lisch nodules and NF1-related choroidal abnormalities was 0.67 (substantial) and 0.97 (almost perfect), respectively. The use of this sign moved one patient from the suspected to the affected group (0.5%). CONCLUSIONS: Neurofibromatosis type 1-related choroidal abnormalities represent a new diagnostic sign in NF1 children. The main advantage of this sign seems the theoretical possibility to anticipate NF1 diagnosis, whereas the main obstacle is the cooperation required by very young patients.

Long-term echographic surveillance of elevated choroidal nevi.

PURPOSE: To report the outcomes of choroidal nevi monitoring and to compare the detection of ultrasonographic hollowness, a risk factor of malignant transformation, from a B-scan with results from an A-scan examination. DESIGN: Retrospective cohort study. METHODS: Standardized A- and B-scan echography and ophthalmoscopy in 358 consecutive patients with median age 69 years and baseline choroidal nevus higher or lower than 1.5 mm in 51 (14%) and 307 (86%) eyes, respectively. RESULTS: No growth or change in echographic or ophthalmoscopic features were found in 307 nevi with a median elevation of 0.9 mm (range, 0.7 to 1.5 mm) and a median follow-up of 6 years (range, 4 to 9 years). After 2 to 6 years, decreased internal reflectivity on standardized A-scan and ultrasonographic hollowness on B-scan were detected in 7 (18%) of 38 initially highly reflective choroidal nevi (thickness, 1.98 ± 0.37 mm); 2 (5%) nevi grew into melanoma 15 years after the first observation. Of 13 choroidal nevi (thickness, 2.75 ± 0.66 mm), with initial atypical medium to high reflectivity on standardized A-scan (100%) and hollowness on B-scan (85%), 6 (46%) were plaqued 6 to 15 months later because of the presence of multiple risk factors. CONCLUSIONS: No changes in thickness or echographic features of choroidal nevi elevated up to 1.5 mm were recorded during the follow-up period. In initially typical choroidal nevi higher than 1.5 mm, strong agreement was detected between decreased reflectivity on standardized A-scan and ultrasonographic hollowness on B-scan found after up to 15 years of stability. The vast majority of choroidal nevi with initial atypical standardized A-scan features showed ultrasonographic hollowness.

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.

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.

Optical coherence tomography in the diagnosis of optic pathway gliomas.

PURPOSE: To compare visual function assessment, optic disc evaluation by indirect ophthalmoscopy, and retinal nerve fiber layer analysis by optical coherence tomography (OCT) for the screening of optic pathway gliomas in pediatric patients (2-15 years old) affected by neurofibromatosis type 1. METHODS: Fifty-seven consecutive patients with neurofibromatosis type 1 with recent (<6 months) orbital/brain magnetic resonance images (MRI) were included. Patients underwent visual function assessment (Hyvarinen symbols chart and/or Snellen charts) and optic disc evaluation by indirect ophthalmoscopy performed by experienced, masked pediatric ophthalmologists. Spectral domain OCT was performed to assess retinal nerve fiber layer. RESULTS: Fifteen of 57 enrolled patients (26%) were affected by MRI-proven optic pathway gliomas. Visual function assessment, optic disc evaluation, and retinal nerve fiber layer analysis by OCT were feasible in 84%, 95%, and 88% of patients, respectively. Visual function assessment, retinal nerve fiber layer analysis, and optic disc evaluation results correlated with the presence of optic pathway gliomas (P = 0.007, P < 0.0001, and P = 0.03, respectively). Specificity and negative predictive value of each test were statistically significant in detecting optic pathway glioma (P < 0.0001), whereas only retinal nerve fiber layers analysis reached statistically significant sensitivity and positive predictive value (P = 0.0386). CONCLUSIONS: Retinal nerve fiber layer analysis assessment using spectral domain OCT is superior to visual function assessment and optic disc evaluation as a clinical screening tool for optic pathway gliomas.

Reduced endothelial progenitor cells and brachial artery flow-mediated dilation as evidence of endothelial dysfunction in ocular hypertension and primary open-angle glaucoma.

PURPOSE: This study aimed to assess vascular endothelial function in patients with ocular hypertension (OHT) or primary open-angle glaucoma (POAG) by measuring: (a) endothelium-dependent flow-mediated vasodilation (FMD) of the brachial artery, and (b) circulating endothelial progenitor cells, which are believed to support the integrity of the vascular endothelium. METHODS: We enrolled 25 patients with OHT, 23 with POAG and 26 control subjects, all of whom were aged < 65 years and had no medical history of cardiovascular disease or cardiovascular risk factors. All subjects underwent a complete ophthalmological examination, biochemistry study, assessment of cardiovascular parameters, brachial artery ultrasound assessment of endothelium-dependent FMD, generic circulating progenitor cell (CPC) and circulating endothelial progenitor cell (EPC) count with the use of flow cytometry. RESULTS: Flow-mediated vasodilation values differed significantly in OHT (4.5 +/- 1.1%; p = 0.021) and POAG (4.0 +/- 0.9%; p = 0.003) patients compared with controls (7.7 +/- 0.8%). The CD34(+) KDR(+) EPC count was markedly lower in OHT (28.0 +/- 5.0; p < 0.001) and POAG (24.3 +/- 3.4; p < 0.001) patients compared with controls (73.1 +/- 8.1). Neither FMD not EPCs differed significantly between OHT and POAG patients. No significant differences in CPC count or cardiovascular parameters were found among OHT or POAG patients and controls. The levels of CD34(+) KDR(+) EPCs were directly correlated (p = 0.043) with FMD, and inversely correlated (p = 0.032) with baseline intraocular pressure in OHT and POAG patients. CONCLUSIONS: Both OHT and POAG patients without cardiovascular risk factors have previously unreported severely reduced circulating EPCs and reduced FMD, both of which are indicators of endothelial dysfunction and increased risk of cardiovascular events.