Emmetropic,But Not Myopic Human Eyes Distinguish Positive Defocus From Calculated Blur

PurposeDefocus blur imposed by positive lenses can induce hyperopia, whereas blur imposed by diffusers induces deprivation myopia. It is unclear whether the retina can distinguish between both conditions when the magnitude of blur is matched.MethodsTen emmetropic (average 0.0 ± 0.3 diopters [D]) and 10 subjects with myopia (−2.7 ± 0.9 D; 24 ± 4 years) watched a movie on a large screen (65 inches at 2 meters (m) distance. The movie was presented either unfiltered (“control”), with calculated low-pass filtering equivalent to a defocus of 2.5 D, or with binocular real optical defocus of +2.5 D. Spatial filtering was done in real-time by software written in Visual C++. Axial length was followed with the Lenstar LS-900 with autopositioning system.ResultsWatching unfiltered movies (“control”) caused no changes in axial length. In emmetropes, watching movies with calculated defocus caused axial eye elongation (+9.8 ± 7.6 µm) while watching movies with real positive defocus caused shorter eyes (−8.8 ± 9.2 µm; difference between both P < 0.0001). In addition, in myopes, calculated defocus caused longer eyes (+8.4 ± 9.0 µm, P = 0.001). Strikingly, myopic eyes became also longer with positive defocus (+9.1 ± 11.2 µm, P = 0.02). The difference between emmetropic and myopic eyes was highly significant (−8.8 ± 9.2 µm vs. +9.1 ± 11.2 µm, respectively, P = 0.001).Conclusions(1) In emmetropic human subjects, the retina is able to distinguish between real positive defocus and calculated defocus even when the modulation transfer function was matched, (2) in myopic eyes, the retina no longer distinguishes between both conditions because the eyes became longer in both cases. Results suggest that the retina in a myopic eye has reduced ability to detect positive defocus.     

Peripheral Refraction With Toric Orthokeratology and Soft Toric Multifocal Contact Lenses in Myopic Astigmatic Eyes

PurposeThere has been little research on myopia management options for patients with astigmatism. This study quantified changes in peripheral refraction induced by toric orthokeratology (TOK) and soft toric multifocal (STM) contact lenses.MethodsThirty adults with refractive error of plano to −5.00 D (sphere) and −1.25 to −3.50 D (cylinder) were enrolled. Cycloplegic autorefraction was measured centrally, ±20 degrees, and ±30 degrees from the line of sight nasally (N) and temporally (T) on the retina. Measurements were made at baseline, after 10 ± 2 days of TOK wear (without lenses on eye), and after 10 ± 2 days of STM wear (with lenses on the eyes) and compared with repeated-measures analysis of variance.ResultsCompared to baseline, TOK induced a myopic shift in defocus (M) at all locations (all P < 0.01), but STM only induced a myopic shift at 20 T in both eyes and 30 N/T in the left eye (all P < 0.01). TOK resulted in more myopic defocus than STM at all locations (all P < 0.05) except 20 T in the left eye. TOK induced more J₀ astigmatism at all locations (all P < 0.02), except 20 N in the right eye; J₀ with STM was different than baseline at 20 N in both eyes and 30 N in the right eye (all P < 0.02). TOK induced more J₀ astigmatism than STM at all locations (all P < 0.01), except 20 T in the left eye. Differences in J₄₅ astigmatism, when significant, were clinically small.ConclusionsGreater amounts of peripheral myopic defocus and J₀ astigmatism were induced by TOK compared to STM, which may influence efficacy for myopia management.     

Effects of Atropine Treatment on Choroidal Thickness in Myopic Children

PurposeTo examine the changes in choroidal thickness (ChT) after 6 months of 1% or 0.01% atropine treatment and the independent factors associated with eye elongation.MethodsA total of 207 myopic children aged 6 to 12 years were recruited and randomly assigned to groups A and B in a ratio of 1:1. Participants in group A received 1% atropine once a day for 1 week, and then once a week for 23 weeks. Participants in group B received 0.01% atropine once a day for 6 months. ChT and internal axial length (IAL) were measured at baseline, 1 week, 3 months, and 6 months.ResultsIn group A, the ChT significantly increased after a 1-week loading dose of 1% atropine (26 ± 14 µm; P < 0.001) and the magnitude of increase stabilized throughout the following weekly treatment. The internal axial length did not significantly change at the 6-month visit (−0.01 ± 0.11 mm; P = 0.74). In contrast, a decreased ChT (−5 ± 17 µm; P < 0.001) and pronounced eye elongation (0.19 ± 0.12 mm; P < 0.001) were observed in group B after 6 months. Multivariable regression analysis showed that less increase in ChT at the 1-week visit (P = 0.03), younger age (P < 0.001), and presence of peripapillary atrophy (P = 0.001) were significantly associated with greater internal axial length increase over 6 months in group A.ConclusionsOne percent atropine could increase the ChT, whereas 0.01% atropine caused a decrease in ChT after 6 months of treatment. For participants receiving 1% atropine, the short-term increase in ChT was negatively associated with long-term eye elongation. Younger age and the presence of peripapillary atrophy were found to be risk factors for greater eye elongation.     

Effects of Monocular Light Deprivation on the Diurnal Rhythms in Retinal and Choroidal Thickness

PurposeTo determine the effects of monocular light deprivation on diurnal rhythms in retinal and choroidal thickness.MethodsTwenty participants, ages 22 to 45 years, underwent spectral domain optical coherence tomography imaging every three hours, from 8 AM to 8 PM, on two consecutive days. Participants wore an eye patch over the left eye starting at bedtime of day 1 until the end of the last measurement on day 2. Choroidal, total retinal, photoreceptor outer segment + retinal pigment epithelium (RPE), and photoreceptor inner segment thicknesses were determined.ResultsFor both eyes, significant diurnal variations were observed in choroidal, total retinal, outer segment + RPE, and inner segment thickness (P < 0.001). For light-deprived eyes, choroid diurnal variation persisted, although the choroid was significantly thinner at 8 AM and 11 AM (P < 0.01) on day 2 compared to day 1. On the other hand, diurnal variations in retinal thickness were eliminated in the light-deprived eye on day 2 when the eye was patched (P > 0.05). Total retinal and inner segment thicknesses significantly decreased (P < 0.001) and outer segment + RPE thickness significantly increased (P < 0.05) on day 2 compared to day 1.ConclusionsBlocking light exposure in one eye abolished the rhythms in retinal thickness, but not in choroidal thickness, of the deprived eye. Findings suggest that the rhythms in retinal thickness are, at least in part, driven by light exposure, whereas the rhythm in choroidal thickness is not impacted by short-term light deprivation.     

Choroidal Changes in Eyes With Polypoidal Choroidal Vasculopathy After Anti-VEGF Therapy Imaged With Swept-Source OCT Angiography

PurposeSwept-source optical coherence tomography angiography was used to investigate choroidal changes and their association with pigment epithelial detachments (PEDs) in eyes with polypoidal choroidal vasculopathy (PCV) after treatment with vascular endothelial growth factor (VEGF) inhibitors.MethodsPatients with treatment-naïve PCV were included and underwent anti-VEGF therapy. Mean choroidal thickness (MCT), choroidal vascularity index (CVI), and PED volume measurements were obtained before and after treatment.ResultsThirty-four treatment-naïve PCV eyes from 33 patients were included. The PED volume decreased after treatment (P < 0.05). The MCT decreased from 223.0 ± 79.6 µm at baseline to 210.9 ± 76.2 µm after treatment (P < 0.001). The CVI at baseline was 0.599 ± 0.024, and the CVI after treatment was 0.602 ± 0.023 (P = 0.16). There was a correlation between the decreased PED volumes and the decreased MCT measurements (r = 0.47; P = 0.006). Also, there was a correlation between the decreased PED volumes and the increased CVI measurements (r = −0.63; P < 0.001).ConclusionsIn treatment-naïve eyes with PCV, the decreases in PED volumes were correlated with the decrease in MCT and the increase in CVI measurements. We propose that, at baseline, the PCV lesions serve as high-volume arteriovenous shunts between choroidal arterial and venous circulation, causing transudation into the choroidal stroma. We propose that, after treatment, the blood flow through the vascular shunt is reduced, the excess stromal transudation is resorbed, and the exudation from the neovascular lesion is reduced, resulting in thinning of the choroid, resolution of the PEDs, and an increase in the CVI due to the resorption of excess choroidal transudation.     

Retinal OFF-Pathway Overstimulation Leads to Greater Accommodation-Induced Choroidal Thinning

PurposeTo examine the interactions between accommodation and overstimulation of the retinal ON- and OFF-pathways, and their association with changes in choroidal thickness (ChT) and vascularity.MethodsOptical coherence tomography imaging of the choroid of twenty young adults (ages 25 ± 5 years) was performed before and after a series of 30-minute-long viewing tasks, including reading a bright text on dark background (ON-pathway overstimulation) and dark text on bright background (OFF-pathway overstimulation), and a control task of viewing a movie with unbiased ON-/OFF-pathway activation. The viewing tasks were performed with relaxed, and 5 diopter (D) accommodation (induced by soft contact lenses) demands. Both reading texts were matched for the mean luminance (35 cd/m²), luminance contrast (87%), and letter size (approximately 11.8 arc minutes). The change in ChT from baseline associated with contrast polarity and accommodation was examined using linear mixed model analysis.ResultsThe subfoveal ChT decreased significantly by −7 ± 1 µm with 5 D accommodation compared with relaxed accommodation (−3 ± 1 µm; P < 0.001), and by −9 ± 1 µm with OFF-pathway compared with ON-pathway overstimulation (−4 ± 1 µm; P = 0.002) and the control condition (−2 ± 1 µm; P < 0.001). Overstimulation of the OFF-pathway, but not the ON-pathway, resulted in a significantly greater choroidal thinning compared with the control condition, both at relaxed (−7 ± 1 µm; P = 0.003) and 5 D (−11 ± 1 µm; P = 0.005) accommodation levels. Similar changes were also observed for macular total, stromal, and luminal ChT.ConclusionsRetinal OFF-pathway stimulation enhanced the choroidal thinning associated with accommodation, thereby providing a potential mechanism that involves accommodation and the retinal OFF-signaling pathway, linking near work and myopia.     

Wide-Field Swept-Source Optical Coherence Tomography Analysis of Interocular Symmetry of Choroidal Thickness in Healthy Young Individuals

PurposeThe purpose of this paper was to study the bilateral choroidal thickness (CT) symmetry and differences in healthy individuals using wide-field swept-source optical coherence tomography (SS-OCT).MethodsAll participants underwent a wide-field 16-mm 1-line scan using SS-OCT. CTs were measured at the following 12 points: 3 points at 900 µm, 1800 µm, and 2700 µm away from the nasal optic disc margin (nasal peripapillary area), 1 point at the subfovea, 6 points at 900 µm, 1800 µm, and 2700 µm away from the subfovea to the nasal and temporal areas (macular area), and 2 peripheral points at 2700 and 5400 µm from temporal point 3 (peripheral area). Bilateral CTs were measured; their correlations and differences in the corresponding regions were analyzed.ResultsThere were no statistically significant differences in CTs between the right and left eyes in all corresponding areas (all P > 0.05); they all showed significant positive correlation coefficients (r) (all P < 0.001). However, the nasal peripapillary and peripheral areas had relatively low correlation coefficients, compared to the macular areas. In addition, the bilateral CT differences were 32.60 ± 25.80 µm in the macular area, 40.67 ± 30.58 µm in the nasal peripapillary area, and 56.03 ± 45.73 µm in the peripheral area (all P < 0.001).ConclusionsOverall, the CTs of each region were bilaterally symmetrical. However, the differences in CTs increased from the center to the periphery, which indicated that the anatomic variation of the nasal peripapillary and peripheral choroid was greater than that of the macula.     

Early Postnatal Oxygen Exposure Predicts Choroidal Thinning in Neonates

PurposeTo evaluate whether choroidal thickness (CT) using arm-mounted optical coherence tomography (OCT) in infants screened for retinopathy of prematurity (ROP) correlates with oxygen exposure in neonates.MethodsOCT images were obtained in infants screened for ROP in a single level IV neonatal intensive care unit. CT was measured at three different locations: the subfoveal center and 1.5 mm from the fovea center in each direction. Correlation and regression analyses were performed to determine the relationship between clinical factors and CT. Clinical factors included gestational age, birth weight, presence of bronchopulmonary dysplasia (BPD), and fraction of inspired oxygen (FiO₂) at defined time points: 30 weeks postmenstrual age (PMA), 36 weeks PMA, and on day of imaging.ResultsMean subfoveal, nasal, and temporal choroidal thicknesses CT (SFCT, NCT, and TCT, respectively) were 228.0 ± 51.4 µm, 179.7 ± 50.3 µm, and 186.4 ± 43.8 µm, respectively. SFCT was found to be significantly thicker than NCT and TCT (P < 0.0001 and P = 0.0002, respectively), but no significant difference was found between NCT and TCT (P = 0.547). Compared with infants without BPD, infants with BPD had thinner SFCT and NCT (P = 0.01 and P = 0.0008, respectively). Birth weight was positively correlated with SFCT (r = 0.39, P = 0.01) and NCT (r = 0.33, P = 0.045) but not TCT. Gestational age and ROP stage were not significantly associated with CT. SFCT was found to be significantly thinner with higher average FiO₂ supplementation levels at 30 weeks PMA (r = –0.51, P = 0.01) but not at 36 weeks PMA. Regression analysis revealed that FiO₂ at 30 weeks PMA was an independent predictor of SFCT in infants screened for ROP (P = 0.01).ConclusionsEarly postnatal exposure (<32 weeks PMA) to higher oxygen supplementation in premature neonates statistically predicts choroidal thinning.     

Ambient Light Regulates Retinal Dopamine Signaling and Myopia Susceptibility

PurposeExposure to high-intensity or outdoor lighting has been shown to decrease the severity of myopia in both human epidemiological studies and animal models. Currently, it is not fully understood how light interacts with visual signaling to impact myopia. Previous work performed in the mouse retina has demonstrated that functional rod photoreceptors are needed to develop experimentally-induced myopia, alluding to an essential role for rod signaling in refractive development.MethodsTo determine whether dim rod-dominated illuminance levels influence myopia susceptibility, we housed male C57BL/6J mice under 12:12 light/dark cycles with scotopic (1.6 × 10⁻³ candela/m²), mesopic (1.6 × 10¹ cd/m²), or photopic (4.7 × 10³ cd/m²) lighting from post-natal day 23 (P23) to P38. Half the mice received monocular exposure to −10 diopter (D) lens defocus from P28–38. Molecular assays to measure expression and content of DA-related genes and protein were conducted to determine how illuminance and lens defocus alter dopamine (DA) synthesis, storage, uptake, and degradation and affect myopia susceptibility in mice.ResultsWe found that mice exposed to either scotopic or photopic lighting developed significantly less severe myopic refractive shifts (lens treated eye minus contralateral eye; –1.62 ± 0.37D and −1.74 ± 0.44D, respectively) than mice exposed to mesopic lighting (–3.61 ± 0.50D; P < 0.005). The 3,4-dihydroxyphenylacetic acid /DA ratio, indicating DA activity, was highest under photopic light regardless of lens defocus treatment (controls: 0.09 ± 0.011 pg/mg, lens defocus: 0.08 ± 0.008 pg/mg).ConclusionsLens defocus interacted with ambient conditions to differentially alter myopia susceptibility and DA-related genes and proteins. Collectively, these results show that scotopic and photopic lighting protect against lens-induced myopia, potentially indicating that a broad range of light levels are important in refractive development.     

Evaluation of the Effect of a Novel β3-Adrenergic Agonist on Choroidal Vascularity

PurposeTo determine the effect of the new β₃-agonist (mirabegron), which is used for overactive bladder (OAB) treatment, on central retinal thickness (CRT) and choroidal vascularity.Material and MethodsThe 26 eyes of 26 cases using 50 mg tablet mirabegron once per day for OAB were included in this prospective case control study. The CRT, choroidal thickness (ChT), and choroidal vascularity were measured at baseline, week 1 (W1), month 1 (M1), month 2 (M2), and month 3 (M3). Subfoveal ChT measurement included the total subfoveal choroidal thickness (SFCT), and the small and large choroidal vessel layer (SCVL and LCVL) thickness. The total choroidal area (TCA), lumen area (LA), stromal area (SA), stroma/lumen ratio, and choroidal vascularity index (CVI) were measured with the Image-J software.ResultsThe largest SFCT increase compared to baseline was at M1 (26.8 ± 40.8 µm, P = 0.001). The subfoveal SCVL thickness showed a significant decrease at M2 and M3 (−6.0 ± 8.9 µm, P = 0.002; −7.8 ± 13.4 µm, P = 0.046, respectively). LCVL thickness showed a significant increase at W1, M1, and M2, with the largest at M1. CVI showed a significant increase at M1, M2, and M3 (P < 0.05 for all). The TCA, LA, and SA showed a significant increasing trend at all follow-up periods. LA/SA decreased at W1 because of stromal expansion but increased at M3 with more prominent vascular dilatation. CRT values showed no significant change.ConclusionsMirabegron had a significant effect on choroidal thickness. Choroidal vascular response is in the form of narrowing in the choriocapillaris and enlargement in the Haller''s layer.     

Morphology of the Trabecular Meshwork and Schlemm's Canal in Posner-Schlossman Syndrome

PurposeThe purpose of this study was to investigate trabecular meshwork (TM) and Schlemm''s canal (SC) morphology in Posner-Schlossman syndrome (PSS).MethodsForty-five patients with PSS were recruited. TM thickness and length as well as SC area and diameter of both affected and fellow eyes were assessed using swept-source optical coherence tomography.ResultsTM thickness (108.24 ± 28.29 µm vs. 89.36 ± 25.82 µm, P = 0.014), SC area (6010.90 ± 1287.54 µm² vs. 5445.69 ± 1368.89 µm², P = 0.003), and SC diameter (239.38 ± 60.17 µm vs. 217.76 ± 60.79 µm, P = 0.010) were significantly greater in the affected eyes. Furthermore, TM thickness (113.32 ± 30.03 µm vs. 89.00 ± 26.99 µm, P = 0.046), SC area (6216.32 ± 1267.87 µm² vs. 5476.40 ± 1390.15 µm², P = 0.001), and SC diameter (246.82 ± 64.12 vs. 212.53 ± 64.29 µm, P = 0.001) were significantly greater in the affected eyes than in the fellow eyes in the ocular hypertension (OHT) subgroup (affected eye with intraocular pressure [IOP] > 21 mm Hg). However, those differences were not noted in the ocular normal tension (ONT) subgroup (affected eye with IOP ≤ 21 mm Hg, all P > 0.05).ConclusionsTM edema might play a role in the IOP elevation in PSS. The edematous TM could make controlling IOP of the affected eyes difficult. When TM edema is relieved, IOP of the affected eyes can reduce to normal spontaneously or with IOP-lowing medications.     

Collateral Vessel Development in Central and Branch Retinal Vein Occlusions Are Associated With Worse Visual and Anatomic Outcomes

PurposeThe purpose of this study was to investigate the effects of the extension of collateral vessels on the outcomes of eyes affected by central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO).MethodsThe study was designed as a cross-sectional case series. Patients affected by CRVO and BRVO were progressively recruited, along with an age- and sex-matched control group of healthy subjects. Structural optical coherence tomography (OCT) and OCT angiography (OCTA; 4.5 × 4.5 mm and 9.0 × 9.0 mm acquisitions) were performed on all participants in order to assess the relationship between the presence of collateral vessels and final anatomical outcomes – central macular thickness (CMT), foveal avascular zone – and functional outcomes – best corrected visual acuity (BCVA).ResultsFifty-six eyes affected by CRVO and 47 eyes affected by BRVO were included. Baseline LogMAR BCVA was 0.41 ± 0.33 LogMAR in CRVO, and 0.39 ± 0.25 LogMAR in BRVO (P < 0.01), improving to 0.20 ± 0.26 LogMAR in CRVO (P < 0.01), and 0.19 ± 0.22 LogMAR in BRVO (P < 0.01). Baseline CMT was 511 ± 214 µm in CRVO and 482 ± 178 µm in BRVO (P > 0.05), decreasing to 328 ± 105 µm (P < 0.01) and 321 ± 78 µm in CRVO and BRVO, respectively (P < 0.01). Collateral vessels were detected in 16 of 56 eyes (29%) in CRVO and in 47 of 47 eyes (100%) in BRVO. Their extension was correlated with worse anatomic and visual outcomes. Remarkably, no correlation was found with peripheral capillary nonperfusion and vessel density impairment.ConclusionsThe present study demonstrates that collateral vessel extension is associated with worse anatomic and functional outcomes in patients affected by CRVO and BRVO.     

Association of choroidal thickness with eye growth: a cross-sectional study of individuals between 4 and 23 years

Background and aims

We aimed to evaluate the association of subfoveal choroidal thickness (SFCT) with age and to determine its relationship with axial length (AL) and ocular biometric parameters, in children and young adults during growth period.

Methods

One hundred and sixty patients (80 male, 80 female) aged between 4 and 23 years were included. Patients were classified into five groups according to their ages as group 1 (4–7 years of age), group 2 (8–11 years), group 3 (12–15 years), group 4 (16–19 years), and group 5 (20–23 years). SFCT was assessed using spectral-domain optical coherence tomography (3D OCT-2000). The measurements were taken at the same daytime (1000–1200 hours) to avoid diurnal fluctuation. Ocular AL and anterior segment parameters were measured using optical biometry (Lenstar LS900)).

Results

The average SFCT was 308.1±47.6 μm, ranging from 206 to 410 μm. The mean SFCT values in group 1 to 5 were measured as 306.8±42.0, 297.8±48.1, 283.2±38.9, 326.9±57.4, and 325.8±35.9 μm, respectively. The mean CT of group 3 was significantly thinner than group 4 and 5 (P<0.05 for two groups), however, there was no statistical significance compared with group 1 (P=0.227) and group 2 (P=0.693). On stepwise regression analysis, age exhibited a positive association with SFCT (B=2.8, P<0.001) and AL exhibited a negative association with choroidal thickness (B=−16.7, P<0.001).

Conclusions

We found that SFCT shows no age-related difference until age of 15, whereas 16–23-year old participants had thicker SFCT compared with the younger ones. In that aspect, a thicker choroid associated with age in certain age groups suggests an age period of SFCT increase to a plateau in young adulthood. Larger studies are warranted to elucidate the age-related changes in SFCT in childhood, as improved evaluation of normal choroidal thicknesses during eye growth should assist in the diagnosis of choroidal abnormalities associated with eye disease.     

Assessment of Choroidal Vascularity and Choriocapillaris Blood Perfusion in Anisomyopic Adults by SS-OCT/OCTA

PurposeTo explore the association of choroidal vascularity and choriocapillaris blood perfusion with myopic severity in anisomyopes.MethodsRefractive error, axial length (AL), and other biometric parameters were measured in 34 anisomyopic young adults. Macular choroidal thickness (ChT) and choroidal vascularity, including total choroidal area (TCA), luminal area (LA), stromal area (SA), and choroidal vascularity index (CVI), were determined from swept-source optical coherence tomography (SS-OCT) vertical and horizontal B-scans. The percentage of choriocapillaris flow voids (FV%) was obtained from en face SS-OCT-angiography.ResultsThe spherical equivalent refraction (SER) was –3.35 ± 1.25 diopters in the more myopic eyes and –1.25 ± 1.17 diopters in the less myopic eyes (P < 0.001). The interocular difference in SER was highly correlated with that in AL (P < 0.001). The macular ChT, TCA, LA, and SA were smaller in the more myopic eyes than in the less myopic eyes in both vertical and horizontal scans (all P < 0.001). Importantly, the CVIs in vertical and horizontal scans were smaller and the FV% was greater in the more myopic eyes (P < 0.05). In vertical scans, the interocular difference in CVIs was correlated with that in the SER, AL, and ChT (all P < 0.05). The interocular difference in FV% was correlated with that in SER, AL, and vertical and horizontal ChTs (all P < 0.05).ConclusionsChoroidal vascularity and choriocapillaris blood perfusion were lower in the more myopic eyes of anisomyopic adults. These changes were correlated with the severity of myopia and choroidal thinning, indicating that choroidal blood flow is disturbed in human myopia.     

Smoking and choroidal thickness in patients over 65 with early-atrophic age-related macular degeneration and normals

Objective

To compare macular choroidal thickness between cigarette smokers, those with a history of smoking, and nonsmokers in patients over 65 years of age with early-atrophic age-related macular degeneration (AMD) and normals.

Methods

Prospective, consecutive, observational case series. Enhanced depth imaging spectral domain optical coherence tomography 12-line radial scans were performed and choroidal thickness manually quantified at 84 points in the central 3 mm of the macula. Data of normals, soft drusen alone, and soft drusen with additional features of early AMD were compared. A multivariate analysis of variance (MANOVA) model, controlling for age, was constructed to evaluate the effect of smoking history and AMD features on choroidal thickness.

Results

A history of smoking was significantly associated with a thinner choroid across all patients via logistic regression (P=0.004; O.R.=12.4). Mean macular choroidal thickness was thinner for smokers (148±63 μm) than for nonsmokers (181±65 μm) among all diagnosis categories (P=0.003). Subgroup analysis of patients with AMD features revealed a similar decreased choroidal thickness in smokers (121±41 μm) compared with nonsmokers (146±46 μm, P=0.006). Bivariate analysis revealed an association between increased pack-years of smoking and a thin choroid across all patients (P<0.001) and among patients with features of early AMD (P<0.001). Both the presence of features of macular degeneration (P<0.001) and a history of smoking (P=0.024) were associated with decreased choroidal thickness in a MANOVA model.

Conclusion

Chronic cigarette smoke exposure may be associated with decreased choroidal thickness. There may be an anatomic sequelae to chronic tobacco smoke exposure that underlies previously reported AMD risk.     

Green tea—a new perspective of glaucoma prevention

AIMTo determine how green tea and catechins can affect intraocular pressure (IOP) changes.METHODSTotally 43 young volunteers were included in the study. The experiment was held between noon and 2 p.m. Two extracts—green tea and epigallocatechin gallate (EGCG, 400 mg capsules) and placebo (400 mg capsules) were used in the study. Participants were divided into three groups. Green tea extract group (GT group) had 17 subjects, EGCG extract group 17 subjects, control (placebo) group 9 subjects. IOP was measured with the Icare tonometer before and 30min, 1, 1.5, 2h after the consumption of each extract and placebo. Results were analyzed using the IBM SPSS program. Statistical confidence level P<0.05.RESULTSThe most significant reduction of IOP from the beginning of the experiment was measured after 2h in GT group (left 2.18±3.19 mm Hg, P=0.012; right 2.59±1.97 mm Hg, P<0.000) and after 1h in EGCG extract group (left 2.41±2.98 mm Hg, P<0.004; right 1.94±1.98 mm Hg, P<0.001). In control group no significant changes were measured.CONCLUSIONPeople who have increased IOP or risk factors for glaucoma development, could benefit from drinking green tea or its concentrated extracts in moderate doses.     

Choroidal and retinal thickness variations in ocular albinism

Purpose:To study the retinal and choroidal thickness variations on enhanced depth imaging optical coherence tomography scans in ocular albinism (OA) and compare with age-matched healthy subjects.Methods: This retrospective observational study had 48 eyes of 24 patients diagnosed clinically as OA and age, sex, and axial length-matched control healthy subjects. All patients underwent detailed ophthalmic examination and a single-line horizontal-raster enhanced depth imaging – optical coherence tomography scan (Spectralis, Heidelberg Engineering). Retinal and choroidal thickness was measured, compared, and analyzed between the two groups. Mann–Whitney U test was used for analysis between the two groups. P < 0.05 was considered significant.Results: The mean age was 28.3 ± 11.6 and 29.9 ± 10.6 years in the OA group and control group, respectively. Spherical equivalents ranged from −8.5D to +10.5D in the OA group and from −8.0D to +10.0D in the control group. The mean axial length between the two groups (P = 0.652) were comparable. The average retinal thickness (272 ± 34.3 vs. 213 ± 13.8 mm; P < 0.001) was greater in the OA group as compared to controls. The mean choroidal thickness (184 ± 78.4 vs. 287 ± 46.4 mm; P < 0.001) was significantly thinner in the OA group.Conclusion: Acquisition of OCT scans in OA can be challenging. This study showed that the subfoveal retinal thickness and choroidal thickness measured across the scans were significantly different in the OA group compared to controls. In the future, more studies are required to evaluate the role of the choroid and its relationship to emmetropization in albinism.     

Evaluation of choroidal thickness using enhanced depth imaging by spectral-domain optical coherence tomography in patients with pseudoexfoliation syndrome

Purpose

To investigate the choroidal thickness using optical coherence tomography in the eyes of patients with unilateral and bilateral pseudoexfoliation syndrome and to compare them with healthy controls.

Methods

We studied four groups: (1) affected eyes from 30 patients with unilateral PEX syndrome affecting the right eye of 17 patients and the left eye of 13 patients; (2) clinically unaffected eyes of 30 patients with unilateral PEX syndrome; (3) the eyes of 30 patients with bilateral PEX syndrome; and (4) the eyes of 30 normal healthy subjects. Choroidal thickness was evaluated using high-speed, high-resolution enhanced depth imaging by spectral-domain optical coherence tomography. Optical coherence tomography features were compared in all groups using the statistical package SPSS v 15.0.

Results

The mean subfoveal choroidal thicknesses were 237.35±58.01 μm in group 1; 330.75±47.84 μm in group 2; 206.3±86.75 μm in group 3; and 311.8±51.42 μm in group 4. Significant differences in the mean subfoveal choroidal thickness were found between groups 1 and 2 (P<0.001), groups 1 and 4 (P=0.004), groups 2 and 3 (P<0.001), and groups 3 and 4 (P<0.001).

Conclusion

In this study, it was observed that clinically affected eyes of patients with PEX syndrome have significantly thinner choroids compared with the clinically unaffected eyes of patients with unilateral PEX syndrome and eyes of healthy controls.     

Distribution of Pigment Particles in Aqueous Drainage Structures in a DBA/2J Mouse Model of Pigmentary Glaucoma

PurposeTo characterize the distribution of pigment particles in aqueous drainage structures of DBA/2J mice with different intraocular pressure (IOP) levels.MethodsDBA/2J mice were monitored from 9 to 44 weeks of age. IOP measurements were performed periodically. At 12, 20, 28, and 36 weeks, three mice were randomly selected for each time point and divided into three IOP groups. The morphology, size, and quantity of pigment particles in aqueous drainage structures were determined via transmission electron microscopy combined with ImageJ-based analysis. Between-group differences were evaluated with a one-way analysis of variance and Fisher''s least significant difference test.ResultsIn the anterior chamber, 74.2% (187/252) of pigment particles were round (diameter range, 0.20–0.73 µm), and 25.8% (65/252) were oval (length range, 0.35–1.20 µm ). In the high-IOP group (IOP≥15 mmHg), pigment particles in the trabecular meshwork (TM) were more abundant and larger in size than those in the normal-IOP group (P<0.001). All separate pigment particles in the TM of the high-IOP group were >0.4  µm in size. The diameters of round (IOP≤10 mmHg, 0.44±0.13 µm; IOP between 10 and 15 mmHg, 0.57±0.13 µm; IOP≥15 mmHg, 0.61±0.12 µm) and the lengths of oval (0.65±0.14 µm vs. 0.77±0.12 µm vs. 0.88±0.15 µm, respectively) pigment particles in the TM differed among groups (F=27.258 and F=27.295, respectively; both P<0.001). No such differences were discovered in the iris and around Schlemm''s canal (P>0.05).ConclusionsIn DBA/2J mice, large and medium pigment particles (>0.4 µm) seem to play an important role in causing aqueous outflow obstruction and IOP elevation.     

Clinical profile and long term outcomes of eyes with choroidal detachment following trabeculectomy

Purpose:To assess the long-term outcomes of choroidal detachments (CDs) in eyes following trabeculectomy.Methods:Retrospective comparative case series. Data of patients with CDs following trabeculectomy (5-year period) with or without cataract surgery with a minimum of 3 months of follow-up were included.Results:In total, 45 patients with CDs following trabeculectomy were included. The mean age was 63.27 ± 8.68 years, (M:F = 2:1); 29 of 45 eyes (64.4%) had a baseline IOP of >24 mm Hg. Patients had a median follow-up of 22.2 (IQR: 16.2–30.5) months. Further, 10 of 45 eyes (22.2%) had CDs following suture lysis. The median onset of choroidal detachment from the time of surgery was 16.0 (IQR: 11–36) days. The mean BCVA improved from 0.62 ± 0.28 to 0.24 ± 0.27 (P < 0.001) and mean IOP increased from 4.07 ± 2.66 to 11.20 ± 5.31 (P < 0.001) at last visit. The cumulative success rates were 76.4% (95% CI: 48.4–90.5) in POAG eyes and 79.3% (95% CI: 62.8–89.1) in PACG eyes (P = 0.547). Medical management was the mainstay in all patients. Four of 45 (8.88%) patients underwent subsequent choroidal drainage.Conclusion:Choroidal detachment following modern-day trabeculectomy has favorable long-term visual acuity and IOP outcomes. There was no difference in the long-term surgical success of trabeculectomy with choroidal detachments in primary angle-closure and open-angle glaucoma eyes. Long-term follow-up is essential to prevent chronic hypotony and trabeculectomy failure.