Change in the ophthalmoscopical optic disc size and shape in a 10-year follow-up: the Beijing Eye Study 2001–2011

BackgroundTo assess prevalence and associated factors of changes in the ophthalmoscopic optic disc size and shape.MethodsThe case–control study included all highly myopic eyes (myopic refractive error ≤−6.0 diopters) and a randomly selected group of non-highly myopic eyes, examined in the population-based Beijing Eye Study 2001 and 2011.ResultsThe study included 89 highly myopic eyes (age:65.0±9.8 years) and 86 non-highly myopic eyes. Reduction in ophthalmoscopic disc size (prevalence, high myopia: 30 (33.7%) eyes; non-high myopia: 7 (8.1%) eyes) was associated with non-circular gamma zone enlargement (OR: 19.4; 95% CI: 6.7 to 56.6; p<0.001) and disc-fovea line elongation (OR: 2.80;95% CI: 1.12 to 6.98; p=0.03). Disc size reduction was correlated with a disc diameter shortening in direction of the widest gamma zone enlargement (correlation coefficient r=34; p=0.01). The perpendicular disc diameter remained mostly unchanged, resulting in an ovalisation of the ophthalmoscopic disc shape. Enlargement of the ophthalmoscopic disc size (prevalence, high myopia: 22 (24.7%) eyes; non-high myopia: 4 (4.7%) eyes) was associated with circular gamma zone enlargement (4.99; 95% CI: 1.95 to 12.8; p=0.001) and high myopia (OR: 4.29; 95% CI: 1.34 to 13.8; p=0.01).ConclusionsMyopic axial elongation may lead first to a Bruch’s membrane (BM) opening (BMO) shift into the foveal direction leading to BM overhanging into the nasal intrapapillary compartment, development and enlargement of gamma zone at the temporal disc side, reduction in the ophthalmoscopically visible disc area and ovalisation of the ophthalmoscopic disc shape. In a second step, an axial elongation-associated BMO enlargement may lead to a circular gamma zone increase and, due to the retraction of BM at the nasal disc border, to an enlargement of the ophthalmoscopically visible optic disc.

Morphological characteristics of ephyrae of Aurelia coerulea derived from planula strobilation

Ephyrae are produced through the strobilation of polyps in the general life cycle of Aurelia coerulea. However, it has been reported that planulae can also metamorphose directly into ephyrae, without passing through the polyp stage. There is a mixture of ephyrae developed from planulae (planula-strobilated ephyrae) and ephyrae developed from polyps (polyp-strobilated ephyrae) in the ephyra population. However, the effect of the planula-strobilated ephyrae on the ephyra population is yet to be determined, since their morphological characteristics have not yet been elucidated. This study aimed to determine the morphological characteristics to distinguish between planula-strobilated and polyp-strobilated ephyrae. The differences in body dimensions, such as total body diameter (TBD), central disc diameter (CDD), lappet stem length (LStL), rhopalial lappet length (RLL), and total marginal lappet length (TMLL) were compared between the two types of ephyra. Thus, we show that body proportions can be used to identify planula- and polyp-strobilated ephyrae. The ranges for identifying planula-strobilated ephyra were 35.0–38.3% for CDD/TBD, 56.7–64.9% for LStL/CDD, 84.7–99.5% for TMLL/CDD, and 31.0–37.5% for RLL/TMLL. This method could be an important basis for devising countermeasures for jellyfish blooms in areas where ephyrae deriving from planula strobilation occur.

Performance of gerbera varieties under naturally ventilated polyhouse

An experiment was conducted to evaluate ten varieties of gerbera under polyhouse conditions in Hyderabad. Vegetative, flowering and flower characters varied significantly among the cultivars and variations in different growth parameters were prominent. Mean performance of the cultivars revealed that cv. Helix recorded maximum plant height, flower diameter, flower stalk diameter and ray florets. The same cultivar Helix also produced maximum number of suckers per plant, number of flowers per plant, Fresh weight of flower, dry weight of flower and possessed longest field life which was at par with cv. Goliath. The cv. Goliath found superior with respect to maximum chlorophyll content, minimum days required for commence of first-flower and days taken for 50% flowering.Maximum disc diameter and number of leaves were produced by cv. balance. While cv. Savannah had significantly maximum leaf area and length of the flower stalk. However, the cv. ‘Montenegro recorded least mean value in terms of plant height, number of leaves per plant, leaf length, leaf breadth, leaf area, number of suckers, chlorophyll content, flower diameter, flower stalk diameter, ray florets, disc diameter, number of flowers per plant and took maximum days for first flower opening, 50 % flowering and which was late in inducing flowering had lesser duration of flowering. Cultivar Helix exerted best performance on various growth and flower characters along with the cultivars Goliath, Danaellen, Balance and Savannah.

A Case of Idiopathic Dense Vitreous Hemorrhage: Suspected Rupture of a Large Retinal Arterial Macroaneurysm on the Optic Disc

We report a novel case of vitreous hemorrhage associated with suspected rupture of 2-disc-diameter retinal arterial macroaneurysm on the optic disc. A 90-year-old woman presented with blurred vision (sudden onset) in her left eye. Examination of the fundus revealed acute onset vitreous hemorrhage of unknown origin without retinal detachment. She underwent vitrectomy, but after excision of the dense vitreous hemorrhage, a 2-disc-diameter hematoma appeared on the optic disc and was removed promptly. Because the bleeding at the base of the hematoma was of arterial origin and pulsating, the first vitrectomy could not achieve hemostasis. Five days after the first surgery, we performed a second vitrectomy. This revealed a subretinal hemorrhage along the superior and inferior arcade vessels and a macular hole, which was almost completely closed with an inverted internal limiting membrane flap. Unfortunately, the macular hole reopened 41 days after the second surgery. In patients presenting with only a large hematoma on the optic disc, it might be prudent to leave the hematoma. However, this large retinal arterial macroaneurysm was on a rare location on the optic disc, making it doubly difficult for the surgeons to diagnose and choose the best option intraoperatively. The differential diagnosis for dense vitreous hemorrhage of unknown origin should include a large retinal arterial macroaneurysm on the optic disc.

Optic disc morphometry using spectral domain optical coherence tomography in a Nigerian population

Purpose: To assess morphological optic disc dimensions using spectral-domain optical coherence tomography (OCT) in a Nigerian population. Materials and method: Good quality SD-OCT scans of the optic disc of 147 eyes of 88 participants were selected, enrolled, and retrospectively reviewed. All subjects had optic nerve head and retinal nerve fibre layer OCT imaging, as well as analysis, done using the Topcon 3D OCT-1 Maestro®. The age, sex, and some OCT-generated optic disc dimensions namely disc area (DA), vertical disc diameter (VDD), horizontal disc diameter (HDD) were retrieved from the database and analyzed. Results: The mean age of the study subjects was 52.6±20.9 years with a range of 8–90 years; male to female ratio was 1:1.3. The right eye and left eye accounted for 75 and 72 of the 147 scans respectively. The mean DA, VDD, and HDD were 2.54 ± 0.48 mm2, 1926.5 ± 189.6 μm and 1673.9 ± 173.9 μm, respectively. Males had significantly larger DA than females (2.56 ± 0.53 mm2 vs 2.51 ± 0.44 mm2, p = 0.043). The mean DA and VDD of eyes of subjects aged 21–40 years were significantly higher compared to subjects aged 60 years and more ( p = 0.008 and 0.001, respectively). Conclusion: The mean optic disc area and diameters are larger than those reported in similar studies involving blacks and other races. The mean disc area reduces with increasing age.

Removal of Sticky Silicone Oil Adhered to the Retinal Surface: Comparison of Methodological Safety and Effectiveness

Purpose: To compare safety and effectiveness among methods to remove sticky silicone oil bubbles adhered to the retinal surface. Methods: This retrospective nonrandomised case series included 14 eyes of 14 patients who had sticky silicone oil residue during silicone oil removal surgery. For small sticky silicone oil bubbles (<2-disc diameter), aspiration was performed with a 23-gauge vitreous cutter. Residual tiny oil bubbles were then removed with a silicone-tipped flute needle or internal limiting membrane (ILM) peeling. For large sticky silicone oil bubbles (≥2-disc diameter) that could not be removed with a 23-gauge vitreous cutter, we devised a more efficient active removal method involving a modified 22-gauge venous indwelling cannula device. Results: The mean preoperative best-corrected visual acuity (BCVA; logarithm of the minimum angle of resolution [logMAR]) significantly improved from 1.28±0.63 logMAR to 0.77±0.58 logMAR (p=0.014). The postoperative BCVA and improvement in BCVA were significantly better in the ILM peeling group than in the non-ILM peeling group (p=0.004 and p=0.045, respectively). Postoperative complications included residual sticky silicone oil bubbles in seven eyes without ILM peeling (50.0%), retinal neuroepithelial layer damage in two eyes (14.3%), and temporary hypotony in five eyes (35.7%). Conclusion: Various methods can safely and efficiently remove sticky silicone oil bubbles adhered to the retinal surface. A 22-gauge venous indwelling cannula enabled simple and safe removal of large sticky silicone oil bubbles, while small residual sticky silicone oil bubbles could be completely removed by ILM peeling.

Clinical manifestations and visual outcomes associated with ocular toxoplasmosis in a Brazilian population

Ocular toxoplasmosis is the leading cause of posterior uveitis worldwide. We conducted an observational study of 262 consecutive individuals (n = 344 eyes) with ocular toxoplasmosis who were followed over a 34-month period. Most subjects were T. gondii IgG + /IgM- (n = 242; 92.4%; 317 eyes), and 140 eyes (40.7%) had active lesions. For eyes in which retinal lesions were active at recruitment and best-corrected visual acuity (BCVA) could be measured (n = 133), 21.0% (n = 28) remained blind (BCVA below 20/400) after inflammation resolved. In these eyes, atypical ocular toxoplasmosis (OR 4.99; 95% CI 1.14–22.85; p = 0.0330), macular lesion (OR 9.95; 95% CI 2.45–47.15; p = 0.0019) and any complication (OR 10.26; 95% CI 3.82–30.67; p < 0.0001) were associated with BCVA below 20/200. For eyes with only inactive lesions at recruitment and BCVA measured (n = 178), 28.1% (n = 50) were blind. In these eyes, having at least one lesion larger than one disc-diameter (OR 6.30; 95% CI 2.28–22.46; p = 0.0013) and macular lesion (OR 5.69; 95% CI 2.53–13.54; p < 0.0001) were associated with BCVA below 20/200. Older age (OR 1.02; 95% CI 1.00–1.05; p = 0.0493) and active disease at presentation (OR 4.74; 95% CI 1.95–12.91; p = 0.0011) were associated with recurrences. Additional clinical attention should be directed towards patients with risk factors for poor visual outcome.

Violations of the Clausius–Duhem inequality in Couette flows of granular media

Spontaneous violations of the Clausius–Duhem (CD) inequality in Couette-type collisional flows of model granular media are studied. Planar systems of monosized circular discs (with disc numbers from 10 to 204, and disc diameters from 0.001 m to 1 m) with frictional-Hookean contacts are simulated under periodic boundary conditions by a molecular dynamics. The scale-dependent homogenization of micropolar media is used to determine the energy balances and mechanical entropy production. The dissipation function exhibits spontaneous negative entropy increments described by the fluctuation theorem. The boundary between violations and non-violations of the CD inequality is mapped in the parameter space, where the probability of such events diminishes with the disc diameter, the disc number and the area fraction increasing. The dissipation function is a random process, tending to Gaussian as the number of discs increases, and possessing non-trivial fractal and anti-persistent Hurst properties.

Association between morphological characteristics of the optic disc and other anatomical features of the fundus in highly myopic eyes

Purpose: To investigate associated factors with optic disc characteristics in high myopia patients. Methods: According to the meta-analysis of pathologic myopia study, patients were divided into groups from categories 1 (C1) to C4. The diameters, tilt ratio, and rotation degree of optic disc, and the diameters of parapapillary atrophy were measured among other morphometric variables. Results: Totally 147 eyes (84 patients) were included. Longer horizontal optic disc diameter was associated with smaller tilt ratio ( p < 0.001, unstandardized regression coefficient B: −0.59), greater rotation degree ( p < 0.001, B: 0.01), and longer horizontal delta zone diameter ( p < 0.001, B: 0.09). Longer vertical optic disc diameter was associated with smaller rotation degree ( p < 0.001, B: 0.01), longer vertical delta zone diameter ( p < 0.001, B: 0.16), and longer disc–fovea distance (DFD; p < 0.024, B: 0.14). Generally, the horizontal optic disc diameter of C3 and C4 groups was smaller than C1 and C2, while vertical diameter and tilt ratio was greater than in C1 and C2. After setting axial length (AL) as an independent variable, horizontal diameters and tilt ratio still showed significant differences, while vertical diameters did not show significant differences. Conclusion: Axial elongation was associated with an increase of vertical optic disc diameter that was correlated with an reduction of optic disc rotation degree. By contrast, horizontal optic disc diameter elongation was correlated with an reduction of optic disc tilt ratio and an increase of optic disc rotation degree, which was independent of axial elongation.