Central Macula Research Articles

Combined Phacoemulsification and Intravitreal Dexamethasone Is an Effective Option for High-Risk Diabetic Macula Oedema Patients.

ObjectiveCataract surgery in diabetic patients carries an increased risk of post-operative macula oedema, particularly in those with a history of diabetic macula oedema (DMO) treatment or DMO at the time of surgery. We investigated whether simultaneous phacoemulsification with intravitreal Ozurdex® reduces the risk of developing new, or deteriorating current, DMO.MethodsWe conducted a retrospective review of 79 consecutive ‘high-risk’ diabetic patients who underwent phacoemulsification with intraocular lens insertion and intravitreal Ozurdex® implantation immediately subsequently. ‘High risk’ was defined as diabetic patients with prior treatment history for DMO or current DMO. Central macula thickness (CMT), best-corrected visual acuity and intraocular pressure were recorded pre-operatively, at two to four weeks and at three months post-operatively. A significant change in CMT was defined as a change of ≥0.1 LogOCT units.ResultsThe mean age was 72.6 years; 52% were males. The mean pre-operative CMT was 365um. Thirty-seven per cent (37%) patients had prior DMO history that had resolved; 63% had confirmed DMO in surgery. Two to four weeks post-operatively, 82% of patients had stable CMT and 18% showed improvement. No patients deteriorated. Three months post-operatively, 48% of patients had stable CMT relative to pre-operative measurements, 38% improved, and 14% deteriorated. Analysis of variance (ANOVA) indicated no significant differences in response with demographical or pathological factors, including diabetic retinopathy grade and treatment history.ConclusionPhacoemulsification surgery combined with Ozurdex® insertion at the end of the procedure is a highly effective strategy for protecting against the formation of new, or the deterioration of current DMO, in the highest risk diabetic patients undergoing cataract surgery.

AYURVEDIC APPROACH ON CYSTOID MACULAR OEDEMA - A CASE REPORT

Cystoid Macular Oedema or CME is a painless disorder that affects the central retina or macula. It refers to the accumulation of fluid in the outer plexiform and inner nuclear layer of the retina with the formation of a fluid-filled cyst. The primary symptom of macular oedema is blurry or wavy vision near or in the centre of your field of vision. Materials and Methods: A male patient of 48 yrs. presented in Shalakya OPD of GAMC Bengaluru with symp- toms of diminished vision in his right eye for one year. The patient was diagnosed with cystoid macular oedema in the right eye for which he was given photocoagulation therapy but did not find much relief. So, he approached our OPD. After thorough examination patient was started with Ayurvedic Medicines. Result: The subject showed marked improvement both subjectively and objectively. Discussion: Oedema which is the terminus of the pathology in this condition has to be understood as Ekanga Shopha. Though Kapha is the predominant dosha involved in forming Shopha here, the lakshanas manifesting are that of Vataja Timira. So, in this case study, Kapha Vata Hara followed by Shopha Hara line of treatment is adopted. Keywords: Cystoid macular oedema, Shopha, Vataja Timira, Nasya, Punarnavadi Kashaya.

Quantitative evaluation of damage to retinal capillaries caused by half-dose and half-time photodynamic therapy with optical coherent tomographic angiography

Purpose: To determine and compare retinal capillaries damage in patients with chronic central serous chorioretinopathy (CSC) after half-dose and half-time photodynamic therapy (PDT) based on optical coherence tomographic angiography (OCTA). Methods: Thirty-three eyes of 33 patients and 32 eyes of 32 patients with active CSC were treated with half-dose PDT and half-time PDT respectively and followed up for 3 months. Fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were performed at baseline; best corrected visual acuity (BCVA) and OCTA were performed at baseline, 3-day, 7-day, 14-day, 1-month, and 3-month follow-up visits. Results: Twenty-eight patients in half-dose group and 27 patients in the half-time group finished the 3-month follow-up visits. BCVA was significantly improved at post-PDT 1 month and 3 months (both P < 0.05) and central macula thickness (CMT) was significantly decreased at all post-PDT time points (all P < 0.05) in both groups. 22 patients (78.57%) in the half-dose group and 21 patients (77.78%) in the half-time group had complete absorption of subretinal fluid (SRF) at post-PDT 3 months. There was no significant difference in the above-mentioned prognostic measurements between two groups. The mean vessel densities of superficial retina (VDSR) and inner retina (VDIR) layers were decreased at all post-PDT time points in both groups. However, the decrease of VDIR and VDSR at post-PDT 3 days and 3 months in the half-dose group was much severe than those in the half-time group (P < 0.05). Conclusions: Both half-dose and half-time modifications of PDT were similarly effective in improving the BCVA and decreasing the SRF for chronic CSC. However, the retinal capillaries damage in the half-time group was less severe than that in the half-dose group, so the half-time modification may be a more appropriate parameter for patients with chronic CSC.

MACULAR SENSITIVITY IN THE AREA OF INTERNAL LIMITING MEMBRANE PEELING IN EYES AFTER PARS PLANA VITRECTOMY WITH THE TEMPORAL INVERTED INTERNAL LIMITING MEMBRANE FLAP TECHNIQUE FOR A FULL-THICKNESS MACULAR HOLE.

To examine the relationship between retinal sensitivity and the area of internal limiting membrane (ILM) peeling during pars plana vitrectomy for a full-thickness macular hole. Twenty-four eyes a minimum of 6 months after temporal inverted flap pars plana vitrectomy for a full-thickness macular hole were included in the study. En face spectral-domain optical coherence tomography images were used to assess margins of the peeled ILM area. Microperimetry was performed to examine retinal sensitivity within the central 10°. Areas of peeled ILM in en face optical coherence tomography images were correlated with the average sensitivity threshold. Retinal sensitivities at the location of each measurement point were compared with structural abnormalities observed in en face spectral-domain optical coherence tomography images. The mean retinal sensitivity in the area of ILM removal was significantly lower compared with the area of preserved ILM (24.29 ± 3.96 dB vs. 26.19 ± 2.10 dB, P < 0.0001, respectively). The peeled ILM area showed a negative correlation with the average sensitivity threshold (r = -0.56, P < 0.01). A larger area of ILM peeling during temporal inverted flap pars plana vitrectomy for a full-thickness macular hole is related to lower retinal sensitivity in the central macula.

Clinical observation of macular choroidal thickness in primary chronic angle-closure glaucoma.

To comparatively analyze differences in macular choroidal thickness and volume in primary chronic angle-closure glaucoma (PACG) eyes. Thirty-one PACG patients were sequentially selected for this case-control study. Thirty-one eyes with PACG were included in group A, 31 fellow eyes were included in group B, and group C included 67 normal eyes. Enhanced-depth imaging optical coherence tomography (EDI-OCT) was used to measure choroidal thickness and volume. The choroidal thicknesses and volumes of the central subfield macula (CSM), nasal inner macula (NIM), temporal inner macula (TIM), inferior inner macula (IIM), temporal outer macula (TOM), inferior outer macula (IOM), and mean macula (MM) in group A were all higher than those in group C (P <0.05). The choroidal thicknesses and volumes of the NIM, superior inner macula (SIM), IIM, nasal outer macula (NOM), and MM in group B were all higher than those in group C (P <0.05). No statistically significant differences were found between groups A and B (P >0.05). The choroidal thicknesses of different macular regions in group A were not correlated with the mean defect (MD). Increased macular choroidal thickness may be a common anatomical characteristic of PACD eyes. Macular choroidal thickness is not a good marker for assessing PACG severity.

Evaluation of Retinal Structure in Pediatric Subjects With Vitamin D Deficiency

To quantitatively evaluate the retinal structural parameters of pediatric patients who were determined to be deficient in vitamin D. Prospective, cross-sectional study. Retinal structural parameters, including the peripapillary retinal nerve fiber layer (RNFL), central macula, retinal layer, and choroidal thicknesses, central retinal artery equivalent (CRAE), and central retinal vein equivalent (CRVE), in pediatric subjects with vitamin D deficiency (group 1) and those without (group 2) were compared. Group 1 comprised 70 individuals, while group 2 comprised 80 individuals. The mean peripapillary RNFL (except for the nasal superior sector [P=.037]), central macula, and retinal layer thicknesses were also determined to be similar in both groups (P > .05 for both groups). The mean choroidal thickness was lower in the subfoveal (P=.006) and nasal 3000-µm-diameter areas (P=.004) in group 1. The mean CRAE was determined to be lower (P=.031) and the CRVE was higher in group 1 (P=.005); it was determined that there was a significant correlation between the vitamin D level and both the CRAE (r=0.447, P < .001) and CRVE (r=-0.320, P=.013). Choroidal thinning, a decrease in the CRAE, and increase in the CRVE were structural changes that occurred in the pediatric subjects who had vitamin D deficiency. The alterations in these parameters became more prominent in pediatric subjects who were determined to have lower vitamin D levels.

Impact of Neodymium-Doped Yttrium Aluminum Garnet (ND-YAG) Posterior Capsulotomy Laser Treatment on Central Macular Thickness: A Prospective, Observational Study From a Tertiary Care Center.

IntroductionOpacification of the posterior capsule is labeled as a secondary cataract. The objective of the current study was to assess central macular thickness (CMT) changes following neodymium-doped yttrium aluminum garnet (ND-YAG) posterior capsulotomy and to find out the correlation between CMT with the age, energy, and total shots utilized during the procedure.MethodologyIn this single-centered prospective observational study, 137 patients with a mean age of 57 ± 12.61 years, who had cataract surgery previously and were candidates for ND-YAG posterior capsulotomy were recruited through consecutive sampling. The study was conducted at Layton Rahmatulla Benevolent Trust (LRBT) Free Eye Hospital, Township, Lahore, Pakistan, between April 2020 to April 2021. The CMT, total energy, and sum total of shots used were recorded. The thickness of the central macula was measured preoperatively and postoperatively after two weeks. The paired sample t-test was used to find out any significant changes in CMT pre and two weeks postoperatively. The comparison of changes in CMT to age, energy, and the total number of shots was made through Pearson correlation. Means of CMT were compared using an independent sample t-test, at two weeks postoperatively among two energy groups.ResultsNo statistically significant differences were found between preoperative and two weeks postoperative values of the CMT (P-value= 0.209). No significant difference was found in CMT statistically among the two energy groups (p=0.11). The patient's age, sum total of laser shots, and aggregate of laser energy did not have any significant correlation with CMT changes. The time period between cataract surgery and ND-YAG surgery showed a moderately positive correlation with a p-value of 0.01.ConclusionThe current study revealed that ND-YAG capsulotomy does not affect the CMT significantly postoperatively. The patient's age, total energy applied, and the total number of laser shots used do not influence the macular thickness. However, the length of duration from the last cataract surgery to the current surgery was significantly associated with a change in the CMT.

Ocular Pharmacokinetics of Brimonidine Drug Delivery System in Monkeys and Translational Modeling for Selection of Dose and Frequency in Clinical Trials.

Brimonidine, a selective α 2-adrenoceptor agonist, displays putative retinal cyto- and neuroprotective activity in vitro and in vivo. An intravitreal sustained-release brimonidine implant, Brimonidine Posterior Segment Drug Delivery System (brimonidine DDS), allowing targeted drug delivery to the retina has been developed for potential clinical application. This study evaluates the in vivo posterior segment pharmacokinetics of brimonidine DDS implant in the monkey eye and applies translational pharmacokinetic modeling to predict tissue exposure in the human eye. Anesthetized cynomolgus monkeys received a single intravitreal injection of brimonidine DDS 400 µg implant before removal of study eyes at days 7, 30, 60, 92, 120, and 150 postimplant (three to four animals per time point) for assay of brimonidine in aqueous humor, vitreous, and retina samples. Brimonidine concentrations in the human eye were modeled using a linear, three-compartment model assuming bidirectional distribution to/from the aqueous humor and retina and elimination from the aqueous humor. Monkey tissue volumes were scaled up to human values; intercompartmental and elimination rate constants were assumed to be identical in the two species. Modeling and simulations were performed using NONMEM v. 7.3, R 3.5.1. Brimonidine exposure was highest in the monkey vitreous and retina; concentrations in the central (macula) and peripheral retina were maintained at high levels (>100 ng/g) for 3 to 4 months. Simulated brimonidine concentration-time profiles in human macula indicated that brimonidine DDS 400 µg implant would deliver effective drug concentrations (20.7‒82.2 ng/g, based on animal pharmacology) for approximately 3 months. Accordingly, administration of the 400 µg implant at 3-month intervals is recommended. SIGNIFICANCE STATEMENT: Brimonidine, an α 2-adrenoceptor agonist, is cyto- and neuroprotective in animal models of retinal/optic nerve injury. Brimonidine Posterior Segment Drug Delivery System (brimonidine DDS) is an intravitreal sustained-release implant with potential ophthalmological applications. This study explores the pharmacokinetics of brimonidine DDS 400 µg implant in the monkey eye and uses compartmental modeling to predict human ocular tissue exposure. Targeted retinal brimonidine delivery from vitreous was demonstrated in monkeys. Simulated tissue concentration-time profiles indicated persistence of pharmacologically effective brimonidine concentrations for ≈3 months in human retina.

A Rare Case of Stargardt’s Disease

Abstract Objective To describe a clinical case of rare eye diseases – Stargardt’s disease. Material and methods: A detailed clinical examination, fundus autofluorescence, optical coherence tomography and electrophysiological studies were performed. The clinical diagnosis was also genetically confirmed. Results A classic Stargardt’s disease phenotype was found in a 10-year old boy with decreased visual acuity, atrophy of the photoreceptors and retinal pigment epithelium layers in the macula, plus hypoautofluorescence in the fovea. In full-field ERG there was no diffuse cone involvement. Multifocal ERG demonstrated a lower cone activity in the area of the central macula in both eyes, which is characteristic for hereditary maculopathies and differentiates them from cone-rod dystrophies, in which generalized damage of the photoreceptors in the retina may be observed. The genetic studies identified two missense mutations: c.3113C&gt; T (p.Ala1038Val) and c.1622T&gt; C (p.Leu541Pro) in a cis-position and a missense mutation c.2588G&gt; C (p.Gly863Ala) in the other allele of ABCA4 gene. The two pathogenic variants c.3113C&gt; T and c.1622T&gt; C formed a complex allele p. [A1038V; L541P], which was found in the genome of the asymptomatic mother. The other mutation c.2588G&gt; C affects a highly conserved amino acid from the ABCA4 protein (p.Gly863Ala) and was inherited from the patient’s clinically healthy father, who was a heterozygous carrier. Conclusion The comprehensive clinical, electrophysiological and genetic testing of patients with rare hereditary retinal dystrophies is essential for the correct diagnosis and the choice of therapeutic behavior.

Physics-based modeling of Age-related Macular Degeneration—A theoretical approach to quantify retinal and choroidal contributions to macular oxygenation

We developed a mathematical model to characterize how macular oxygenation may be affected by abnormalities in the retinal and choroidal oxygen supplies. The macular region is modeled as a layered structure including: ganglion cell and nerve fiber layers, inner plexiform layer, inner nuclear layer, outer plexiform layer, outer nuclear layer, inner segment of photoreceptors layer and retinal pigmented epithelium. Each layer is characterized by specific levels of oxygen consumption. The vitreous and the choroid are located at the macula boundary and provide oxygen via boundary conditions of Dirichlet type. The three capillary plexi (superficial, intermediate, and deep) of the retinal circulation pierce the macular layers and provide oxygen via a volumetric source that depends on the retinal blood flow. Oxygen profiles through the macular tissue are calculated by simulating the balance among oxygen supply, consumption and diffusion in: (a) physiological baseline conditions; (b) retinal blood flow reduced by 10%, 30% and 50% with respect to baseline; (c) choroidal oxygen level diminished by 10%, 30% and 50% with respect to baseline. Model simulations predict that: (1) the oxygenation of the foveal avascular zone is not affected by reduction in retinal blood flow; (2) a reduction in choroidal oxygen supply significantly affects the outer layers, especially the photoreceptors and outer nuclear layers; (3) the impact of reduction in choroidal oxygen supply is larger in the region more proximal to the macular center; (4) the impact of reduction in retinal blood flow is larger in the region more proximal to the macular periphery. The proposed mathematical model suggests that changes in retinal and choroidal oxygen supplies impact the oxygenation of the macular tissue differentially. These results may help better understand the pathogenesis of macular degeneration.

Correlation between electroretinography, foveal anatomy and visual acuity in aniridia due to PAX6 mutations.

Aniridia patients have poor visual acuity and iris malformation. The fovea in these patients is underdeveloped, but the relationship between structure and electrophysiologic function remains incompletely understood. This study correlates electrophysiology, visual acuity and optical coherence tomography (OCT) in patients with aniridia secondary to mutations in the PAX6 gene and compares with age-similar controls. Patients were recruited from clinical practice. The mfERG protocol was a 4-min 103-hexagon protocol covering approximately 40° in diameter of central retina. Diagnosys full-field ERG (ffERG) and VERIS multifocal ERG (mfERG) were obtained using standard International Society for Clinical Electrophysiology of Vision protocols. OCT central thickness was recorded, and an OCT foveal score was calculated. Nonparametric permutation testing was utilized to determine the statistical significance. A total of 6 aniridia patients and 25 control patients were recruited. On mfERG, aniridia patients had significantly lower amplitudes in rings 1-3 (p = 0.0006, 0.0013, 0.0132), shorter latencies in ring 1 (p = 0.0312) and longer latencies in rings 5 and 6 (p = 0.0026, p = 0.0042) than controls. There was a significantly positive relationship in aniridia patients between logMAR visual acuity and mfERG amplitude in ring 4 (p = 0.0392) and ring 5 (p = 0.0489). On ffERG, there was no difference in amplitudes, though photopic 3.0 a- and b-wave latency, 30Hz flicker latency and scotopic 0.01 b-wave latency were significantly longer in aniridia patients versus control (p = 0.0018, 0.0.0005, 1.00 x [Formula: see text], 0.0198). Thicker central macula on OCT correlated with lower mfERG amplitudes in rings 4-6 (p = 0.0369, 0.0292, 0.0255). There was no correlation between visual acuity and central macular thickness or foveal hypoplasia score as determined by OCT. Higher amplitude on mfERG correlated with poorer visual acuity in rings 4 and 5 in patients with PAX6 mutations. The slope of the change in amplitude from central to peripheral rings on the mfERG is significantly different in aniridia patients compared to controls, with a slower drop-off of amplitude from center to periphery. Additionally, mfERG in aniridia showed lower amplitudes than controls in rings 1-3. These changes along with the lack of correlation between visual acuity and central macular thickness/OCT score suggest that changes in electrical topography may be important to visual deficits in patients with PAX6 gene mutations.

Real Life Data of Treat and Extend Intravitreal Ranibizumab and Aflibercept Therapy in Wet Age-related Macular Degeneration Patients: 3-Year Results.

PurposeTo compare functional and anatomic outcome of intravitreal ranibizumab (IVR) and intravitreal aflibercept (IVA) treatments in neovascular age-related macular degeneration by using the treat and extend (TE) protocol.MethodsIn this retrospective chart study, treatment naïve 74 eyes of 74 age-related macular degeneration patients treated with IVR and IVA (38 eyes in IVR and 36 eyes in IVA group) with TE protocol were included. Following three consecutive monthly intravitreal injections, TE protocol was applied to each group. Patients were followed up for at least 36 months. Mean change in best-corrected visual acuity (BCVA), central macula thickness (CMT) and injection numbers over 3 years were compared.ResultsAmong 36 months period, the mean number of injections was 17 ± 4 for both groups (p > 0.05). In terms of CMT, there was no statistically significant difference between groups at 36 months compared to baseline. A decrease of 72.55 ± 39.37 μm in CMT was detected in IVR group, whereas the decrease was 70.58 ± 33.96 μm in IVA group (p > 0.05). There was a significant increase in BCVA at 36 months of measurements. In addition, BCVA demonstrated an increase of 4.1 ± 0.44 letters in IVR group and 4.36 ± 0.67 letters in IVA group after 36 months compared to the baseline (p > 0.05).ConclusionsBoth IVR and IVA injections provided significant improvements and stability in BCVA and CMT, however there was no significant difference between IVR and IVA injections with TE protocol of 36 months.

Pattern and distribution of neovascularization in proliferative diabetic retinopathy on fundus fluorescein angiography: A growing paradigm

BackgroundThe objective of this study was to evaluate pattern and distribution of neovascularization of optic disc (NVD) and elsewhere (NVE) in proliferative diabetic retinopathy (PDR). MethodsA cross-sectional study was conducted among freshly detected cases of PDR. Fundus fluorescein angiographic images of 61 eyes were assessed. Parameters studied for NVD were their number and location and for NVE were their number, location, type of leak, and distance from center of optic disc. ResultsOf 61 eyes, 29 eyes (47.5%) had NVD with a total of 49 leaks. Of these 49 NVD leaks, the maximum was concentrated in the superotemporal quadrant with 21 leaks (42.9%; 95%CI 28.8–57.8%). Of 61 eyes, 50 eyes (82%) had NVE with 97 leaks. Of 97 NVE leaks, 41 were found in the superotemporal quadrant (42.3%; 95%CI 32.3–52.7%). Maximum NVE was found within the circle of radius 3–6 mm centered on optic disc (p value = 0.001) with no leaks in central macula. Of 29 eyes with NVD, only 7 eyes had >1/3 area of disc involvement. Also, of 18 eyes with concurrent NVD and NVE, only 2 eyes had >1/3 area of disc involvement which is a high-risk characteristic of PDR. ConclusionNeovascular lesions have a predilection for superotemporal part for both NVD and NVE. NVE leaks were almost double the number of NVD leaks. Maximum NVE leaks were found at posterior pole with no central macular involvement. This study provides comprehensive data and further adds to knowledge of neovascularization for early diagnosis and management of PDR.

Neuroretinal Biomarkers for Schizophrenia Spectrum Disorders.

PurposeWe evaluated the patient-control differences and predictive value of the retina as potential biomarkers for schizophrenia.MethodsThe institutional study included both eyes of 58 schizophrenia spectrum disorder (SSD) patients (age 37.2 ± 12.3 years) and 35 controls (age 41.1 ± 15.2 years). Retinal nerve fiber layer (RNFL), ganglion cell–inner plexiform layer, outer retinal photoreceptor complex, and total macula thicknesses were measured by optical coherence tomography (OCT). Anterior segment parameters including central corneal thickness, anterior chamber depth, and axial length were measured to rule out confounds on the retinal measures.ResultsThe peripapillary RNFL was overall significantly thinner in SSD relative to controls (F = 3.97, P = 0.049), most pronounced in the temporal (5.2 µm difference, F = 6.95, P = 0.010) and inferior quadrants (12.1 µm difference, F = 7.32, P = 0.009). There were no significant group differences in thickness for the macular RNFL, ganglion, or photoreceptor cell related measures (P > 0.05). Peripapillary RNFL, central macula, and outer photoreceptor complex thicknesses were together able to classify SSD patients with 80% sensitivity and 71% specificity; area under the curve = 0.82 (95% confidence interval, 0.75–0.88).ConclusionsSSD patients exhibited significant RNFL thinning relative to controls. Notably, retinal thickness measures including both peripapillary and macular data exhibited improved diagnostic accuracy for SSD as compared to these regions alone.Translational RelevanceThis is the first study to evaluate the predictive value of both the inner and outer retina in SSD. OCT retinal thickness measures including peripapillary data in conjunction with macular data may provide an informative, noninvasive in vivo ocular biomarker for schizophrenia.

Segmentation of retinal vessels by fusing contour information and conditional generative adversarial

The existing retinal vessels segmentation algorithms have various problems that the end of main vessels are easy to break, and the central macula and the optic disc boundary are likely to be mistakenly segmented. To solve the above problems, a novel retinal vessels segmentation algorithm is proposed in this paper. The algorithm merged together vessels contour information and conditional generative adversarial nets. Firstly, non-uniform light removal and principal component analysis were used to process the fundus images. Therefore, it enhanced the contrast between the blood vessels and the background, and obtained the single-scale gray images with rich feature information. Secondly, the dense blocks integrated with the deep separable convolution with offset and squeeze-and-exception (SE) block were applied to the encoder and decoder to alleviate the gradient disappearance or explosion. Simultaneously, the network focused on the feature information of the learning target. Thirdly, the contour loss function was added to improve the identification ability of the blood vessels information and contour information of the network. Finally, experiments were carried out on the DRIVE and STARE datasets respectively. The value of area under the receiver operating characteristic reached 0.982 5 and 0.987 4, respectively, and the accuracy reached 0.967 7 and 0.975 6, respectively. Experimental results show that the algorithm can accurately distinguish contours and blood vessels, and reduce blood vessel rupture. The algorithm has certain application value in the diagnosis of clinical ophthalmic diseases.

Can the Macula be Attached if View Is Obscured by a Bullous Retinal Detachment? A Mathematical Consideration

PurposeThe purpose of this study was to determine if it is possible for the macula to remain attached if a bullous retinal detachment blocks the examiner's view to the macula.MethodsA mathematical analysis compared the arc length of the attached retina versus the length of a detached retina necessary to obscure the macula (hang over the visual axis). The shape (oblate ellipsoid) and dimensions of the retina were based on a published study. The complete path of the hanging retina was calculated as a static catenary so as to depict the lowest possible position (“worst case scenario”).ResultsThe measured and calculated angle between the fovea and ora serrata was 105 degrees. When considering a catenary shape of the hanging retina, the macula could, mathematically, still be attached despite the retina hanging down 1.03 mm below the visual axis for an emmetropic eye. The maximal distance calculated was 1.095 mm for a −12 diopter (D) myopic eye.ConclusionsIf the macular center cannot be viewed due to a bullous superior retinal detachment hanging into the examiner's view, it is unlikely but possible that the macula remains attached. If the view is obscured by at least 1 mm below the fovea, it is not mathematically possible for the fovea to be attached.Translational RelevanceThe status of the macula being detached is subject to mathematical constraints, which, explored herein, offer a higher certainty of clinical decision making that could inform management for better clinical results.

Quantitative evaluation of hard exudates in diabetic macular edema by multicolor imaging and their associations with serum lipid levels

To quantify hard exudates (HEs) by multicolor imaging (MCI) and traditional color fundus photography (CFP) in diabetic macular edema (DME), and study their associations with serum lipid levels. Observational study. DME patients with HEs were recruited. The HE area and location both by MCI and CFP were measured by ImageJ software. Multivariate regression models were used to analyze the associations of serum lipid levels with the total HE area and HE location. Sixty-two patients (74 eyes) were enrolled to quantify HEs in DME. The total HE area by MCI was larger than that by CFP (P = 0.004), and the distance between the fovea and the nearest HE by MCI was shorter than that by CFP (P = 0.003). The percentage of patients with HEs involving the central macula by MCI was significantly higher than that by CFP (P < 0.001). Furthermore, 62 eyes of 62 patients were included to analyze the associations of HE parameters with serum lipid levels. In both MCI and CFP, the HE areas were positively associated with triglyceride level (P = 0.016, P = 0.022, respectively). HEs involving the central macula were positively associated with triglyceride and low-density cholesterol levels in MCI (P = 0.028, P = 0.046, respectively), while no significant association was found between serum lipid levels and HE location in CFP. MCI is superior to traditional CFP for the detection of HEs and the analysis of associations between HEs and serum lipid levels in DME.

Imaging the pediatric retina: An overview.

Recent decade has seen a shift in the causes of childhood blinding diseases from anterior segment to retinal disease in both developed and developing countries. The common retinal disorders are retinopathy of prematurity and vitreoretinal infections in neonates, congenital anomalies in infants, and vascular retinopathies including type 1 diabetes, tumors, and inherited retinal diseases in children (up to 12 years). Retinal imaging helps in diagnosis, management, follow up and prognostication in all these disorders. These imaging modalities include fundus photography, fluorescein angiography, ultrasonography, retinal vascular and structural studies, and electrodiagnosis. Over the decades there has been tremendous advances both in design (compact, multifunctional, tele-consult capable) and technology (wide- and ultra-wide field and noninvasive retinal angiography). These new advances have application in most of the pediatric retinal diseases though at most times the designs of new devices have remained confined to use in adults. Poor patient cooperation and insufficient attention span in children demand careful crafting of the devices. The newer attempts of hand-held retinal diagnostic devices are welcome additions in this direction. While much has been done, there is still much to do in the coming years. One of the compelling and immediate needs is the pediatric version of optical coherence tomography angiography. These needs and demands would increase many folds in future. A sound policy could be the simultaneous development of adult and pediatric version of all ophthalmic diagnostic devices, coupled with capacity building of trained medical personnel.

Macular Thickness Profile and Its Association With Best-Corrected Visual Acuity in Healthy Young Adults.

PurposeTo describe the thickness profiles of the full retinal and outer retinal layers (ORL) at the macula in healthy young adults, and associations with best-corrected visual acuity (BCVA).MethodsIn total, 1604 participants (19–30 years) underwent an eye examination that included measurements of their BCVA, axial length, and autorefraction. The retinal thickness at the foveal pit and at the nine Early Treatment of Diabetic Retinopathy Study macular regions (0.5-mm radius around the fovea, and superior, inferior, temporal, and nasal quadrants of the inner and outer rings of the macula) were obtained using spectral-domain optical coherence tomography imaging. A custom program was used to correct for transverse magnification effects because of different axial lengths.ResultsThe median full retinal and ORL thicknesses at the central macula were 285 µm and 92 µm. The full retina was thinnest centrally and thickest at the inner macula ring, whereas the ORL was thickest centrally and gradually decreased in thickness with increasing eccentricity. There was no association between axial length and the full retinal or ORL thickness. Increased thicknesses of the full retina at the central macula was associated with better BCVA; however, the effect size was small and not clinically significant.ConclusionsThis article mapped the full retinal and ORL thickness profile in a population-based sample of young healthy adults.Translational RelevanceThickness values presented in this article could be used as a normative reference for future studies on young adults and in clinical practice.

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.

To estimate the incidence of cilioretinal arteries in a Danish child cohort and associations with birth parameters. The population-based Copenhagen Child Cohort 2000 Eye Study examined 1406 children aged 11-12years. 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. 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. 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.