Associations of pre- and postnatal exposures with optic nerve status in young adults.

PURPOSE: We aimed to explore the effect of multiple pre- and postnatal exposures on optic nerve status in young adults due to this critical period for development. METHODS: We analysed peripapillary retinal nerve fibre layer (RNFL) status and macular thickness at age 18 years in the Copenhagen Prospective Studies on Asthma in Childhood 2000 (COPSAC2000 ) cohort in relation to several exposures. RESULTS: Of the 269 participants (median (IQR) age, 17.6 (0.6) years; 124 boys), 60 participants whose mothers had smoked during pregnancy had a thinner RNFL: adjusted mean difference -4.6 µm (95% CI -7.7; -1.5 µm, p = 0.004) compared with participants whose mothers had not smoked during pregnancy. A total of 30 participants who were exposed to tobacco smoke both during foetal life and childhood had thinner RNFL: -9.6 µm (-13.4; -5.8 µm, p < 0.001). Smoking during pregnancy was also associated with a macular thickness deficit: -4.7 µm (-9.0; -0.4 µm, p = 0.03). Higher indoor concentrations of particulate matter 2.5 (PM2.5) was associated with thinner RNFL: -3.6 µm (-5.6; -1.6 µm, p < 0.001) and a macular deficit: -2.7 µm (-5.3; -0.1 µm, p = 0.04) in the crude analyses, but not in the adjusted analyses. No difference was found among participants who smoked at age 18 years compared with non-smokers on RNFL or macular thickness. CONCLUSIONS: We found that exposure to smoking during early life was associated with a thinner RNFL and macula at age 18 years. The absence of an association between active smoking at 18 years suggests that the vulnerability of the optic nerve is highest during prenatal life and early childhood.

Peripapillary Hyperreflective Ovoid Mass-like Structures (PHOMS) in Children: The Copenhagen Child Cohort 2000 Eye Study.

PURPOSE: To determine the prevalence of peripapillary hyperreflective ovoid mass-like structures (PHOMS) in a population-based child cohort and to study their association with other optic nerve head features and myopia. DESIGN: Observational, population-based cohort study of 1407 children aged 11-12 years. METHODS: Optical coherence tomography scans of optic nerve heads were graded for PHOMS, disc tilt, prelaminar hyperreflective lines, and scleral canal diameter and investigated for associated prenatal and ocular parameters. Children with optic disc drusen or optic disc edema were excluded. RESULTS: PHOMS were found in 8.9% of children. The location of PHOMS was predominantly in the superonasal section of the optic disc. Myopia and optic nerve head tilt were more common in children with PHOMS than in children without PHOMS (P < .001 and P < .001, respectively). Prelaminar hyperreflective lines were found in 17.9% of children with PHOMS compared to 7.3% of children without PHOMS (P < .001). Prelaminar hyperreflective lines with and without PHOMS were associated with a shorter axial length of the eye (P < .001). There were no prenatal factors associated with PHOMS. Prelaminar hyperreflective lines were associated with higher birth weight and continued maternal smoking during pregnancy (P = .01 and P = .02, respectively). CONCLUSIONS: PHOMS had a prevalence of 8.9% in healthy children without optic disc drusen or optic disc edema and was associated with increasing myopic refraction and the presence of a tilted optic nerve head and prelaminar hyperreflective lines. Given the high prevalence of PHOMS, they should not unreservedly be taken as evidence of optic neuropathy.

Heritability and Risk Factors of Incident Small and Large Drusen in the Copenhagen Twin Cohort Eye Study: A 20-Year Follow-Up.

INTRODUCTION: The transition from a normal fundus to one with early drusen (≥20 small hard drusen) to age-related macular degeneration (AMD) in the form of drusen ≥63 µm in diameter is of interest, because small hard drusen may be precursors of large drusen. Study of AMD precursor lesions may provide valuable insight into factors that initiate AMD. Here, the progression of drusen was studied over an interval of 20 years in a population-based twin cohort. METHODS: Single-center, 20-year follow-up of 138 twins include biometry, fundus optical coherence tomography, and fundus photography. Macular characteristics were hierarchically classified as (per eye) (1) <20 small hard drusen, (2) ≥20 small hard drusen, (3) drusen ≥63 µm, or (4) ≥20 small hard drusen combined with drusen ≥63 µm. Additive and dominant genetic effects as well as shared and nonshared environmental effects were analyzed in a bivariate biprobit model with a classic liability-threshold approach and polygenic modeling with random effects. RESULTS: Median participant age was 59 (range 41-66) years. Of 25 (18%) cases of incident macular drusen, 7 had ≥20 small hard drusen, and 18 had drusen ≥63 µm at follow-up, whereas no participant had developed both traits simultaneously. Smoking was associated with incident ≥20 small hard drusen (p = 0.04) and incident drusen ≥63 µm (p = 0.003). Having ≥20 small hard drusen at baseline was associated with incident drusen ≥63 µm at follow-up (p = 0.02). Development of drusen ≥63 µm was attributable to 49% genetic effects and 51% environmental effects. CONCLUSION: The risk of progressing from 0 to 19 small hard macular drusen per eye to having ≥20 small hard drusen or drusen ≥63 µm at follow-up was associated with smoking and genetic predisposition. Having ≥20 small hard drusen in the absence of drusen ≥63 µm at baseline was associated with incident drusen ≥63 µm when examined 20 years later. The study confirms that small hard macular drusen is a forewarning of AMD and that progression to AMD may be hindered by avoidance of smoking.

Cone photoreceptor density in the Copenhagen Child Cohort at age 16-17 years.

PURPOSE: To examine cone density in relation to gestational and morphological parameters in the Copenhagen Child Cohort (CCC2000). METHODS: The macula was imaged using adaptive optics in 1,296 adolescents aged 16-17 years. Axial length and distance visual acuity were determined. Absolute and angular cone photoreceptor density were analysed for an 80 × 80-pixel area, 2 degrees temporal to the fovea. Association with axial length was analysed with linear regression. Correlation with visual acuity was described with a Pearson correlation coefficient. Associations of cone density with gestational parameters, maternal smoking, sex and age were analysed using multiple regression adjusted for axial length. RESULTS: Mean absolute cone density was 30,007 cones/mm2 (SD ± 3,802) and mean angular cone density was 2,383 cones/deg2 (SD ± 231). Peri- and postnatal parameters, sex and age had no statistically significant effect on cone density (p > 0.05). Absolute cone density decreased with longer axial length (-2,855 cones/mm2 per mm or -9.7% per mm, p < 0.0001). For angular density, which included a correction for the geometrical enlargement of the eye with axial length, a decrease with axial length was detectable, but it was small (-20 cones/deg2 per mm or -0.84% per mm, p = 0.009). CONCLUSIONS: The decrease in cone density per unit solid angle with increasing axial length was small, less than 1 percent per mm, indicating that expansion of the posterior pole during the development of refraction takes place without a clinically significant loss of cones. Perinatal parameters, within the spectrum presented by the study population, had no detectable effect on cone density.

Incidence of cilioretinal arteries in 11- to 12-year-old children and association with maternal smoking during pregnancy: the Copenhagen Child Cohort 2000 Eye Study.

PURPOSE: To estimate the incidence of cilioretinal arteries in a Danish child cohort and associations with birth parameters. METHODS: The population-based Copenhagen Child Cohort 2000 Eye Study examined 1406 children aged 11-12 years. Colour fundus images of both eyes were graded for cilioretinal arteries in the three categories large temporal (defined as supplying the central macula), small temporal and nasal. Data on maternal smoking during pregnancy, gestational ageand birth weight were obtained from the Danish Medical Birth Registry. RESULTS: A total of 463/1338 (35%) children were found to have one or more cilioretinal arteries per child. Large temporal cilioretinal arteries were present in 280/1338 (21%) of children and were associated with tobacco smoking during pregnancy, being present in 70/246 (28%) of children with mothers who were smoking during pregnancy, but only in 191/990 (19%) of children whose mothers did not smoke during pregnancy (p = 0.0022). After adjustments for potential confounders, the odds ratio of having one or more large temporal cilioretinal arteries was 1.72 (CI95% 1.19-2.47; p = 0.0035) in the smoking versus none smoking category. No other associations with birth parameters were found. CONCLUSION: Cilioretinal arteries were present in more than one third of 11- to 12-year-old Danish children. Large temporal cilioretinal arteries were found in one fifth of children and were associated with maternal smoking during pregnancy. This finding suggests that the intrauterine environment may have an impact on the development of retinal vessels during foetal life.

Axial length change and its relationship with baseline choroidal thickness - a five-year longitudinal study in Danish adolescents: the CCC2000 eye study.

BACKGROUND: Myopic eyes are longer than nonmyopic eyes and have thinner choroids. The purpose of present study was to investigate whether a thinner subfoveal choroid at 11 years of age predicted axial eye elongation and myopia during adolescence. METHODS: Longitudinal, population-based observational study. Axial length was measured using an interferometric device and choroidal thickness was measured by spectral-domain optical coherence tomography. Myopia was defined as non-cycloplegic subjective spherical equivalent refraction ≤ - 0.50 diopters. RESULTS: Right eyes of 714 children (317 boys) were examined at age (median (IQR)) 11.5 (0.6) years and 16.6 (0.3) years during which axial length (median (IQR)) increased by 243 (202) µm in eyes without myopia (n = 630) at baseline compared with 454 (549) µm in eyes with myopia (n = 84) at baseline, p < 0.0001. A thicker baseline subfoveal choroid was associated with increased five-year axial elongation after adjustment for baseline axial length in nonmyopic eyes (ß = 27 µm/100 µm, 95%CI 6 to 48, p = 0.011) but not in myopic eyes (p = 0.34). Subfoveal choroidal thickness at 11 years of age did not predict incident myopia at 16 years of age (p = 0.11). Longer baseline axial length was associated with greater five-year axial elongation in both myopic (ß = 196 µm/mm, 95%CI 127 to 265, p < 0.0001) and nonmyopic eyes (ß = 28 µm/mm, 95%CI 7 to 49, p = 0.0085) and the odds for incident myopia increased with 1.57 (95%CI 1.18 to 2.09, p = 0.0020) per mm longer axial length at baseline. CONCLUSION: A thin subfoveal choroid at age 11 years did not predict axial eye elongation and incident myopia from age 11 to 16 years. A longer eye at age 11 years was associated with greater subsequent axial eye elongation and with increased risk of incident myopia at age 16 years.

Migration of an outer retinal element in a healthy child followed by longitudinal multimodal imaging.

PURPOSE: To describe the migration of an outer retinal element using longitudinal multimodal imaging. OBSERVATIONS: In the retina of a healthy 7-year-old girl, movement of a hyperreflective element of 15 µm extent was seen using optical coherence tomography (OCT), confocal scanning laser ophthalmoscopy (cSLO), and adaptive optics fundus photography (AO). On the OCT B-scan, the element initially appeared at the level of the outer limiting membrane with an umbra reaching the retinal pigment epithelium from where it gradually diminished and disappeared over 33 days. A corresponding disruption of the photoreceptor pattern on AO diminished over 52 days. CONCLUSIONS AND IMPORTANCE: This non-invasive observation of an isolated, cell-sized, migrating element in the human retina was made in vivo in the absence of confounding retinal disease or similar nearby elements. Based on prior preclinical observations we hypothesize that such a migrating element could be a macrophage. The case provides information about the time-scale and resolution needed for the monitoring of infiltrative processes in the retina.

Real-world 10-year experiences with intravitreal treatment with ranibizumab and aflibercept for neovascular age-related macular degeneration.

PURPOSE: To report 10-year, real-world experiences with intravitreal therapy (IVT) using vascular endothelial growth factor inhibitors for neovascular age-related macular degeneration (nAMD). METHODS: Retrospective single-centre review of IVT-log 2007-2019 with a treatment-as-needed regimen and ETDRS visual acuity charts. RESULTS: The 4,678 treatment-naïve eyes of 3,668 patients received a mean of 5.4 IVT in the first year and 4.0-4.3 IVT yearly thereafter. Baseline mean best corrected visual acuity (BCVA) was 57.9 (±16.4) letters (6/18) that improved a mean +2.1 (±0.2) letters at the first follow-up visit and gradually declined to -5.0 (±2.2) letters after 10 years. At baseline, there were 29% with BCVA ≥6/12. This proportion increased to 31-37% until year 9. There were 8% with BCVA loss of ≥3 lines at the first follow-up visit increasing to 34% after 10 years. Poorer baseline BCVA was associated with larger increase in BCVA (p < 0.0001, multiple linear regression). The 2,566 (55%) discontinued eyes had a mean baseline BCVA of 56.9 (±16.4) letters compared with 61.5 (±15.9) letters for eyes remaining in treatment. In year 0-7, the discontinued eyes lost an additional mean 2-4 letters (last observation carried forward) but were similar thereafter. There were 12.6% (74 of 585 eligible eyes) that were still in treatment after 10 years. At baseline, 10% had bilateral nAMD. Of patients with unilateral presentation, 17% had received fellow-eye IVT after 5 years. CONCLUSION: A treatment-as-needed regimen stabilized BCVA in active nAMD up to 10 years in most eyes. Baseline BCVA was the most important prognostic factor.

Spectral-domain optical coherence tomography of retinal vessels in Waldenström's macroglobulinemia.

PURPOSE: To image retinal blood vessels in patients with Waldenström's macroglobulinemia using optical coherence tomography (OCT). METHODS: Retrospective case series examining fundus photographs and OCT scans of 16 eyes in eight patients with Waldenström's macroglobulinemia. Analyses included intravascular OCT reflectivity profiles and vessel diameters, and their relation to total immunoglobulin M (IgM) levels. RESULTS: In six out of eight patients, cross-sectional OCT scans of larger retinal vessels (diameter > 100 µm) showed normal intravascular reflectivity and retrovascular shadowing. In two patients with the highest total IgM > 60 g/l, altered intravascular reflectivity, distinct anterior and posterior vessel wall reflexes, and retrovascular hyposhadowing were seen. Normalization of the OCT reflectivity in these patients occurred after reduction of total IgM to < 17 g/l and was accompanied by decreasing venous tortuosity and disappearance of retinal haemorrhages and cotton wool spots. CONCLUSION: This study found that Waldenström's macroglobulinemia and total IgM > 60 g/l were associated with abnormal intravascular reflectivity and retrovascular shadowing on OCT. Awareness of these signs of hyperviscosity could potentially enable earlier detection of critical conditions in patients with Waldenström's macroglobulinemia and improve the assessment of severity and treatment effect.

Low physical activity and higher use of screen devices are associated with myopia at the age of 16-17 years in the CCC2000 Eye Study.

PURPOSE: To determine the myopia prevalence in a Danish cohort aged 16-17 years and its relation to physical activity and use of screen-based electronic devices. METHODS: The Copenhagen Child Cohort 2000 Eye Study is a prospective, population-based, observational study. Information about use of screen devices and physical activity was obtained using questionnaires. Myopia was defined as non-cycloplegic subjective spherical equivalent refraction ≤-0.50 D in right eye. RESULTS: We included 1443 participants (45% boys) with a median age (±IQR) of 16.6 years (±0.3). The prevalence of myopia was 25% (CI95% 23-28, n = 360) with no differences between sexes (p = 0.10). The odds ratio (OR) for myopia was 0.57 (CI95% 0.42-0.76, p = 0.0002) in participants physically active 3-6 hr/week (n = 502) and 0.56 (CI95% 0.42-0.76, p = 0.0002) if active >6 hr/week (n = 506), both compared with participants physically active <3 hr/week (n = 396). The use of screen devices >6 hr/day was associated with increased OR for myopia compared with screen device use <2 hr/day in both weekdays (OR = 1.95, CI95% 1.16-3.30, p = 0.012) and weekends (OR = 2.10, CI95% 1.17-3.77, p = 0.013). CONCLUSION: In this cohort of healthy 16-17-year olds, lower physical activity and more use of screen devices contributed significantly to the observed 25% prevalence of myopia with a roughly doubled risk of having myopia if physically active <3 hr/week or if using screen devices >6 hr/day. Our results support physical activity being a protective factor and near work a risk factor for myopia in adolescents.

Five-Year Change in Choroidal Thickness in Relation to Body Development and Axial Eye Elongation: The CCC2000 Eye Study.

Purpose: We describe changes in choroidal thickness from age 11 to 16 years and its association with ocular biometrics and body development. Method: In this longitudinal, population-based observational study, choroidal thickness was measured subfoveally and 1- and 3-mm temporal thereof using enhanced depth imaging spectral domain optical coherence tomography. Analyses were stratified by sex and adjusted for age and the time of day that the scan was performed. Results: The study included 687 participants (304 boys). Median (interquartile range [IQR]) age was 11.5 (0.6) years at baseline and 16.6 (0.3) years at follow-up. Mean increase in choroidal thickness was 33, 27, and 11 µm at the three respective locations. The subfoveal choroid thickened less in eyes whose axial length increased more (boys, ß = -85 µm/mm; 95% confidence interval [CI], -104 to -66, P < 0.0001; girls, ß = -105 µm/mm; 95% CI, -121 to -89, P < 0.0001) and in eyes with a more negative refractive development (boys, 11 µm/diopters [D]; 95% CI, 4.0 to 18, P = 0.0022; girls, 22 µm/D; 95% CI, 16 to 27, P < 0.0001). Subfoveal choroidal thickness increased less in girls who underwent early puberty (Tanner stage 4 vs. 1; -39 µm' 95% CI, -72 to -5.9, P = 0.021) and who had a longer baseline axial length (ß = -8.6 µm/mm; 95% CI, -15 to -2.7, P = 0.0043), and more in girls who grew taller (ß = 0.9 µm/cm; 95% CI, 0.1 to 1.7, P = 0.026). Conclusions: The choroid increased in thickness from age 11 to 16 years. The increase was greater in girls with later sexual maturation and smaller in eyes that added more axial length and had a relatively negative refractive development.

Small Hard Macular Drusen and Associations in 11- to 12-Year-Old Children in the Copenhagen Child Cohort 2000 Eye Study.

Purpose: To assess the prevalence and associations of small hard drusen in a child cohort. Methods: Cross-sectional study of 11- to 12-year-old Danish children from the population-based Copenhagen Child Cohort 2000 Eye Study. Fovea-centered, 45° color images of both eyes were graded for macular drusen (within one optic-disc-rim-to-fovea distance of the foveal center) and for extramacular drusen. Analyses tested for associations between drusen and anthropometric measures including choroidal thickness. Results: Gradable fundus images from both eyes were available for 1333 children (640 boys, 693 girls) with a mean (SD) age of 11.7 (0.40) years. One or more small hard macular drusen (diameter <63 µm) were present in 82 (6.2%) right eyes and 82 (6.2%) left eyes and in 147 (11.0%) subjects. Four children (0.30%) had 20 or more small hard macular drusen in one or both eyes. Extramacular small hard drusen were present in 10.7% of children, and 19% of children had such drusen anywhere. The odds for having one or more small hard macular drusen increased with subfoveal choroidal thickness with an odds ratio of 1.15 (95% confidence interval, 1.03-1.28; P = 0.013) per 50-µm thicker choroid, adjusted for age and sex. The association with choroidal thickness was also present for extramacular drusen. Conclusions: Having one or more small hard macular drusen was common in 11- to 12-year old children and it was associated with a thicker subfoveal choroid. Few children had many small hard drusen. There is no apparent clinical impact of small hard drusen in childhood.

The Danish Rural Eye Study: prevalence of strabismus among 3785 Danish adults - a population-based cross-sectional study.

PURPOSE: To determine the prevalence of strabismus among Danish adults and to find the frequency of history of strabismus and strabismus surgery. Furthermore, to evaluate the prevalence of strabismus-associated amblyopia among participants with strabismus and to relate the results to the current national vision screening programme. METHODS: In total, 3785 adults in the Danish Rural Eye Study underwent an interview regarding eye health, visual acuity measurement, Hirschberg test and retinal photography. Participants were categorized into groups based on their birth date in relation to the introduction of the national vision screening programme. RESULTS: In total, the prevalence of strabismus was 1.1% (41/3785; 95% CI: 0.8-1.5); no differences were found in relation to gender or screening status. The prevalence of exotropia (XT) was 0.3% (12/3785; 95% CI: 0.2-0.6) and of esotropia (ET) 0.8% (29/3785; 95% CI: 0.5-1.1), resulting in an XT:ET ratio of 1:2.7. A history of strabismus was present in 4.6% (174/3785; 95% CI: 4.0-5.3), and a history of strabismus surgery was present in 0.8% (32/3785; 95% CI: 0.6-1.2) of the participants. Among participants with manifest strabismus, 24% had strabismus-associated amblyopia. CONCLUSION: In this first European population-based study of strabismus prevalence in adults, the prevalence was similar to three out of five previous studies using cover test. The use of Hirschberg test may have led to an underestimation of the true prevalence. The prevalence was neither related to screening status nor gender. Our results are the first to display a predominance of ET among Caucasian Scandinavian adults.

RELATION BETWEEN FLUORESCEIN ANGIOGRAPHIC AND SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY FINDINGS OF BLOOD FLOW TURBULENCE AT ARTERIOVENOUS CROSSINGS IN THE RETINA.

PURPOSE: To examine retinal blood flow at arteriovenous crossings using spectral-domain optical coherence tomography (SD-OCT). METHODS: Retrospective observational case series of 11 arteriovenous crossings in 10 eyes examined by SD-OCT and fluorescein angiography on suspicion of manifest or imminent branch retinal vein occlusion. RESULTS: Fluorescein angiographic evidence of turbulence was seen at 5 of 11 arteriovenous crossings, whereas laminar angiographic flow was intact at the crossing and downstream thereof at the remaining 6 crossings. On SD-OCT, chaotic reflectivity patterns were seen at the point of crossing and downstream thereof in all 5 cases with angiographic turbulence, whereas an intravascular trilayer SD-OCT pattern consistent with laminar flow was seen throughout the examined course of the vein in the eyes with laminar angiographic flow. CONCLUSION: We examined retinal blood flow at and near arteriovenous crossings and found that SD-OCT may rival fluorescein angiography in the ability to demonstrate turbulent venous blood flow.

Visual acuity and amblyopia prevalence in 11- to 12-year-old Danish children from the Copenhagen Child Cohort 2000.

PURPOSE: To evaluate the prevalence of amblyopia and associated biometric factors in Danish children. METHODS: Determination of best-corrected visual acuity (BCVA) using ETDRS charts, non-cycloplegic subjective refractioning guided by automated refractometry, axial length and corneal curvature, fundus photography and optical coherence tomography (OCT) in 1335 children from the population-based Copenhagen Child Cohort 2000 (CCC2000) Eye Study. Birth data were obtained from the Danish Medical Birth Registry. RESULTS: The mean (±SD) age of children was 11.7 (±0.4) years, and 47% were boys. Amblyopia prevalence was 1.5 (95% CL 0.8-2.2) %. Unilateral amblyopic eyes [BCVA < 80 ETDRS letters (0.8 snellen) and ≥2 lines difference between the eyes] was 0.6 (95% CL 0.3-1.0) mm shorter, 1.34 (95% CL 0.30-2.37) D more hyperopic and had 0.79 (95% CL 0.14-1.44) D more astigmatism compared with fellow eyes. Compared with the right eyes of the non-amblyopic children, unilateral amblyopic eyes were 1.0 (95% CL 0.5-1.6) mm shorter, 2.48 (95% CL 1.11-3.86) D more hyperopic, 1.09 (95% CL 0.43-1.75) D more astigmatic and had a 47 (95% CL 13-81) µm thicker subfoveal choroid. CONCLUSION: Amblyopia was found in 1.5% of Danish children born 22 years after the inception of the nationwide preschool visual screening programme. Amblyopia was associated with anisometropia, astigmatism, a thicker subfoveal choroid and a history of childhood strabismus.

Macular perfusion velocities in the ocular ischaemic syndrome.

PURPOSE: To assess retinal perfusion in eyes with unilateral ocular ischaemic syndrome (OIS) and to compare with control subjects. METHODS: Retrospective case series. Linear blood flow velocities in macular vessels were estimated using motion-contrast fundus photography in eight patients with unilateral OIS (eight OIS eyes, seven fellow eyes) and 12 control subjects. The diagnosis of OIS was supported by carotid artery Doppler ultrasonography and pneumoplethysmographic measurement of ocular systolic perfusion pressure. RESULTS: Macular arterial blood flow velocity (median, range) was 1.8 (1.4-2.7) mm/s in OIS eyes, 4.0 (2.9-5.3) mm/s in fellow eyes (p = 0.016) and 3.8 (2.3-5.1) mm/s in control eyes (p = 0.0004 and p = 0.67 versus OIS and fellow eyes, respectively). Macular venous blood flow velocity was 1.5 (1.0-2.1) mm/s in OIS eyes, 2.6 (2.0-2.9) mm/s in fellow eyes (p = 0.016) and 2.7 (1.8-3.5) mm/s in control eyes (p = 0.0007 and p = 0.64). Arterial velocities were below or equal to the lowest value observed in control subjects (≤2.3 mm/s) in seven of eight eyes with OIS. Visual acuity 0.7 or worse was found in two OIS eyes with arterial velocities below 1.7 mm/s and venous velocities below 1.3 mm/s and together with neovascular glaucoma or polycythemia vera (one eye each). CONCLUSION: Motion-contrast imaging revealed markedly reduced macular perfusion velocities in OIS eyes compared with unaffected fellow eyes and healthy control eyes. The method appears to provide a clinically meaningful quantitative measure of macular hypoperfusion.

Multimodal imaging of small hard retinal drusen in young healthy adults.

BACKGROUND: Small hard macular drusen can be observed in the retina of adults as young as 18 years of age. Here, we seek to describe the in vivo topography and geometry of these drusen. METHODS: Retinal images were acquired in young, healthy adults using colour fundus photography, spectral domain optic coherence tomography (SD-OCT), reflectance flood-illuminated adaptive optic ophthalmoscopy (AO flood) and reflectance adaptive optic scanning light ophthalmoscopy (AOSLO) in both confocal and non-confocal split-detection modalities. Small bright yellow hard drusen within a 10 degree radius from the foveal centre were characterised. RESULTS: Small hard drusen were seen on colour photographs in 21 out of 97 participants and 26 drusen in 12 eyes in 11 participants were imaged using the full protocol. Drusen were easily identifiable in all modalities, except a few very small ones, which were not visible on SD-OCT. On AOSLO images, these drusen appeared as round, oval or lobular areas (up to three lobules) of diameter 22-61 µm where cone photoreceptor reflectivity and density was decreased (p=0.049). This was usually associated with discrete thickening of the retinal pigment epithelium (RPE) complex. CONCLUSION: High lateral resolution imaging of small lobular hard retinal drusen suggests formation through the confluence of two or more smaller round lesions. The outline and size of these smaller lesions corresponds to 1-4 RPE cells. Prospective longitudinal studies are needed to determine the ultimate fate of small hard drusen and their potential relation to age-related macular degeneration.