Disc In Eyes Research Articles

Establishment and assessment of a rat model of nonarteritic anterior ischemic optic neuropathy

Objective To establish and evaluate a rat model of nonarteritic anterior ischemic optic neuropathy (NAION). Methods The rats were randomly divided into control group (n=13), sham laser group (n=11) and NAION group (n=23). The right eye was set as the experimental eye. NAION model was induced by directly illuminating the optic nerve (ON) of the right eye with 532 nm green laser, after intravenous infusion with the photosensitizing agent Rose Bengal. Sham laser treatment consisted of illuminating the ON region with 532 nm laser without Rose Bengal injection. Rats in control group underwent no intervention. The appearance of optic disc was observed with funduscope at 12 hours, 1, 3, 7, 28 days post-illumination. The histologic changes in the retina and ON of the NAION model were evaluated qualitatively with hematoxylin and eosin (HE) staining and transmission electron microscopy. The retrograde-labeled retinal ganglion cells (RGC) were counted on photographs taken from retinal flat mounts in a masked fashion. Results The optic disc in NAION eyes were swollen 3 days after photodynamic treatment. HE-stained longitudinal ON sections of NAION revealed vacuolar degeneration on day 3 after induction. Besides, ultrastructural study showed axonal edema and collapsed sheaths in the ischemic optic nerve at the same time point after modeling. ON edema resolved 7 days after induction. The final results revealed optic disc atrophy, extensive axonal loss, severe glial scar, and RGC death in large numbers 4 weeks after modeling. There were no aforementioned manifestations in control and sham laser group. The RGC density of the right eyes was statistically significantly lower in NAION group than that in control group and in sham laser group (t=−14.142, −14.088; P=0.000, 0.000). The survival rate of RGC was statistically significantly lower in NAION group than in control group and in sham laser group (t=−17.048, −16.667; P=0.000, 0.000). There was no difference of RGC density and survival rate of RGC between control and sham laser group (t=0.050, 0.348; P=0.961, 0.731). Conclusion A rat model of NAION was established successfully by photodynamic treatments with Rose Bengal, which induce optic nerve damage and RGC death. Key words: Optic neuropathy, ischemic; Retinal ganglion cells; Disease models, animal

Microvasculature dropout detected by the optical coherence tomography angiography in nonarteritic anterior ischemic optic neuropathy.

To investigate microcirculation characteristics of peripapillary superficial retina and optic disc in eyes with nonarteritic anterior ischemic optic neuropathy (NAION) using optical coherence tomography angiography (OCTA). Forty-one eyes of 30 NAION patients and 30 eyes of 30 normal subjects were evaluated with OCTA (AngioVue, Optovue). The whole vessel density, inside disc vessel density, peripapillary vessel density, and vessel densities based on the sectorial division in the nerve head mode peripapillary superficial retina and RPC mode optic disc were measured respectively. In the NAION group, vessel densities in both the peripapillary superficial retina and optic disc were significant reduced (P < 0.01), as compared with the control group. The whole vessel density of the optic disc in chronic NAION group were significantly lower than that in acute NAION group (P < 0.01). The whole and temporal vessel density of the peripapillary superficial retina was significantly correlated with log MAR VA (r = -0.381 and r = -0.337, both P < 0.05). Vessel densities in both the peripapillary superficial retina and optic disc were reduced (P < 0.05) in unilateral involved eyes, as compared to the unaffected fellow eyes, except for the inside disc (P = 0.270) and SN (P = 0.054) vessel density in the optic disc, while there was no difference in the fellow eyes compared to the normal eyes. In NAION patients, a dropout of microvasculature in peripapillary superficial retina and optic disc could be detected by OCTA directly. OCTA might become a useful tool for detection and monitoring of NAION. Lasers Surg. Med. 50:194-201, 2018. © 2017 Wiley Periodicals, Inc.

Optic disc, rim and peripapillary chorioretinal atrophy in normal Japanese eyes: the Kumejima Study.

To report reference data for optic disc, neuroretinal rim and β-peripapillary atrophy (β-PPA) in normal Japanese. In the Kumejima study, all participants underwent disc stereo-photography; 2208 normal subjects had good-quality disc stereo and β-PPA photographs OU. The disc and rim area and the area and angular extent of β-PPA were evaluated by computer-assisted planimetry. The disc, rim, and β-PPA area and its angular extent OD (OS) averaged 2.54±0.50 (2.53±0.49), 1.67±0.29 (1.67±0.30), 0.47±0.66 (0.42±0.59)mm2, and 99±85 (92±82) degrees (mean±standard deviation) with bilateral Pearson's correlation coefficient of 0.890, 0.769, 0.679 and 0.632 (P<0.001), respectively, while the 95th percentiles of the absolute inter-eye differences were 0.48, 0.41, 0.96mm2, and 153°. The correlation coefficient between β-PPA area and its angular extent was 0.963 (P<0.001). Age showed negative correlation with the rim area and positive correlation with β-PPA area (P<0.001). Among ocular factors, disc area showed positive correlation and intraocular pressure negative correlation with the rim area (P≤0.001), axial length and disc area positive correlation with β-PPA area (P<0.001 and P=0.051). The averages and distribution of the optic disc and rim area, β-PPA area and its angular extent in normal Japanese are reported, which will facilitate screening of glaucoma in Japanese. In normal Japanese eyes, the disc size and intraocular pressure significantly correlated with the rim area, and the axial length with β-PPA area.

Morphometric parameters of the optic disc in normal and glaucomatous eyes based on time-domain optical coherence tomography image analysis

Background and objectiveAssessment of optic disc morphology is essential in diagnosis and management of visual impairment. The aim of this study was to evaluate associations between optic disc morphometric parameters, i.e., size and shape, and age, gender, and ocular axial length in normal and glaucomatous eyes based on time-domain optical coherence tomography image analysis. Materials and methodsIt was a case–control study of 998 normal and 394 eyes with primary open angle glaucoma that underwent an ophthalmological examination and time-domain optical coherence topography scanning. Areas and shapes of the disc, cup, and neuroretinal rim were analyzed. ResultsThe shape of the optic disc did not differ between the study groups, i.e., normal and glaucomatous case groups, but the disc area of the primary open angle glaucoma group was significantly larger. The shape of the small disc was significantly different, but the shape of the medium and the large disc did not differ between the study groups. The central area of the disc, i.e., cup area was significantly larger in the case group and its shape was significantly different between the study groups. No significant differences in the area of the cup and its shape, nerve fibers on the edge of the disc, i.e., neuroretinal rim area, were found between the study groups of the small discs. There were significant associations between age, gender, and ocular axial length and morphometric parameters of the optic disc. ConclusionsInformative results with regard to the size and shape due to various ocular characteristics between the healthy control group and patients suffering with primary open angle glaucoma were obtained. Both study groups were significant in size, which makes the findings interesting and important contribution in the field.

Optic Disc and Macular Imaging in Blind Eyes from Non-glaucomatous Optic Neuropathy: A Study with Spectral-domain Optical Coherence Tomography

ABSTRACTThe purpose of this study was to determine and compare the optic disc and macular thickness measurements using two spectral-domain optical coherence tomography (SD-OCT) instruments in long-standing blind eyes diagnosed with non-glaucomatous optic neuropathies (NGON). A prospective observational case-series design was used. Twelve eyes from 12 NGON patients with no light perception for at least 6 months underwent optic disc and macular imaging with Cirrus HD-OCT and Spectralis OCT. The correlation between the peripapillary retinal nerve fibre layer (PRNFL) and macular ganglion cell layer and inner plexiform layer (GCL+IPL) thicknesses, and between the duration of no light perception (NLP) and PRNFL/GCL+IPL thicknesses were determined using Spearman’s correlation analysis. The mean average PRNFL thickness was 55.9 ± 4.8 µm for Cirrus HD-OCT, which was significantly thicker than that measured by Spectralis OCT (31.9 ± 7.4 µm; p < 0.001). The mean central macular thickness on Cirrus HD-OCT was normal, but there was global thinning at the other macular areas. The mean average GCL+IPL thickness on Cirrus HD-OCT was 51.8 ± 5.8 µm. There was a good correlation between average PRNFL thickness and GCL+IPL thickness (r = 0.830, p = 0.002); however, there was no significant correlation between the duration of NLP to the average PRNFL thickness (on either instruments) or GCL+IPL thickness on Cirrus HD-OCT (p > 0.7). These results show that there was residual PRNFL thickness in NGON eyes with NLP, which varied significantly between SD-OCT instruments. The values of the residual PRNFL and GCL+IPL thicknesses in blind eyes (the “floor” effect) may be useful for prognostic purposes for patients with partial optic atrophy.

Evaluation of macular ganglion cell complex and peripheral retinal nerve fiber layer structural damage in early primary glaucomous eyes by 3D-OCT

Background In previous study, peripheral retinal nerve fiber layer (RNFL) thickness is considered to be the earliest structural changes which can be detected.3D-OCT can measure the thickness of macular ganglion cell complex (mGCC), which makes the detection of primary glaucoma possible in the early stage. Objective This study was to measure the thickness of mGCC and disc-peripheral RNFL in early stage of primary glaucomous eyes by 3D-OCT and assess the anatomic basis of glaucoma-induced optical nerve damage. Methods 3D-OCT images from 10 patients with advanced stage primary glaucoma in one lateral eye and early stage glaucoma in fellow eye from December 2010 to December 2012 were prospectively analyzed in China-Japan Friendship Hospital.The patients were diagnosed based on the recommended standard of National glaucoma group (1987 version) and received routine eye examination.3D-OCT scanning was performed using 3D-macular mode, 3D-macular Wide mode and 3D-disc mode with TOPCON 3D-OCT 2000 system, and the images at macular 6 mm×6 mm area were analyzed.The posterior pole area was divided into 5 concentric rings from fovea toward periphery and equally subdivided into 100 small checks, with the area of 0.6 mm×0.6 mm for each.The probable values in each check were calculated as the ratio of each figure and corresponding normal value.The probable values were expressed as red color (P<1%), yellow color (P<5%) and gray color (P≥5%). Then the disc-periphery RNFL thickness and disc cup were evaluated. Results No evident abnormality was found in the thicknesses of photoreceptors layer and bipolar cell layer in both advanced glaucomous eyes and the early stage of glaucomous eyes in the 10 patients.Serious damage of visual field was seen in the advanced glaucomous eyes and presented with red color in the parapapillary RNFL area, mGCC area and macular RNFL area, showing an evidently attenuation of the thicknesses of parapapillary RNFL, mGCC and RNFL.However, the visual field was close normal in the early stage glaucomous eyes, and mGCC and macular RNFL showed yellow color, while green or yellow color was exhibited in the parapapillary RNFL area, indicating mGCC and macular RNFL thickness was reduced, but parapapillar RNFL thickness was near normal. Conclusions The change of mGCC thickness is earlier than that of peripheral RNFL at optic disc in primary glaucomaous eyes, which may imply that the disappear of macular ganglion cell body is earlier than that of the axon. Key words: Glaucoma, primary; Optical coherence tomography; Biometry; Retinal nerve fiber; Retinal ganglion cells; Retinal ganglion cell complex

Minification of fundus optical coherence tomographic images in gas-filled eye.

BackgroundOptical coherence tomography (OCT) is being used increasingly to evaluate and manage a variety of retinal diseases, but not much is known about the minification of the OCT images in gas-filled eyes. The purpose of this study was to investigate the effect of gas-filled eyes on the size of the OCT images.MethodsThis was retrospective case series of 81 consecutive eyes of 79 patients who had macular hole surgery between April 2012 and September 2014. Images of the optic disc were taken with a spectral domain-OCT instrument 2 days after surgery in gas-filled, pseudophakic eyes and from the same eyes but fluid-filled one month after the surgery. The vertical length, horizontal width, and the area of the optic disc were measured in the OCT images.ResultsClear images were obtained from 50 eyes of 49 patients (mean age 66.4 ± 5.9 years). The mean vertical length and mean horizontal width of the optic disc in the gas-filled eyes were about 25 % shorter than that of fluid-filled eyes (vertical, 1213.8 ± 170.5 and 1650.6 ± 195.9 μm, P < 0.01; horizontal, 1169.4 ± 143.1 and 1526.4 ± 219.9 μm, P < 0.01). The mean area of the optic disc was 1.12 ± 0.34 mm2 in gas-filled eyes which was significantly smaller than that in fluid-filled eyes (1.88 ± 0.37 mm2) by 40.4 %.ConclusionsThe fundus images of gas-filled eyes are significantly smaller than that in the same fluid-filled eyes. The minification of the OCT images should be considered when analyzing images obtained from gas-filled eyes.Trial registrationTrial registration number: UMIN000007517. Date of registration: 3/21/2012.Electronic supplementary materialThe online version of this article (doi:10.1186/s12886-016-0306-1) contains supplementary material, which is available to authorized users.

Microvascular Density in Glaucomatous Eyes With Hemifield Visual Field Defects: An Optical Coherence Tomography Angiography Study

To investigate microcirculation of peripapillary retina and optic disc in eyes with primary open-angle glaucoma (POAG) and hemifield visual field (VF) defects. Prospective observational case series with normal comparison group. Sixty eyes with POAG (41 with superior and 19 with inferior hemifield VF defects) and 21 normal eyes were included in this study. Optical coherence tomography (OCT) angiography was used to acquire 3× 3-mm optic disc cubes, and circumpapillary retinal nerve fiber layer thickness was also measured using OCT. Vessel densities in the peripapillary superficial retina and whole-signal-mode optic discwere individually analyzed based on the sectorial division. The peripapillary vessel densities were significantly reduced at the corresponding location of the VF defects in both non-highly myopic (P < .001, P= .006) and highly myopic glaucomatous eyes (P < .001, P= .005) compared with the normal eyes. Vessel densities of the optic discs were significantly reduced at locations corresponding to the VF defects in eyes without high myopia but with inferior hemifield VF defects (P= .006), but not in the other eyes. The vessel densities in the peripapillary retina were significantly associated with visual field total deviation values at their corresponding sides. The choroidal microvascular reduction in the peripapillary area extended to the α-peripapillary atrophy (PPA) as well as β-PPA zones. Microvascular reduction was associated with VF defects in a region-specific manner: significantly and partially in the peripapillary retina and optic disc, respectively.

Study of Retinal Nerve Fibre Layer Thickness in Patients with Diabetes Mellitus Using Fourier Domain Optical Coherence Tomography.

Diabetic retina undergoes degenerative changes in retinal nerve fiber layer (RNFL) in addition to vascular changes. Loss of RNFL with changes in inner retina and their association with metabolic control have been studied with varied results in diabetic patients. To compare the RNFL thickness between diabetic patients and age matched healthy controls and to correlate the thickness to metabolic control. One hundred and sixty five patients were enrolled in the study out of which 50 served as controls, 58 patients were diabetic without retinopathy and 57 patients had diabetic retinopathy. Both eyes of all patients underwent optical coherence tomography scans for RNFL and ganglion cell complex. Foveal and parafoveal thickness were also measured. All the parameters were compared to patient's metabolic control. RNFL thinning was observed in superotemporal (p-value = 0.001) and upper nasal sectors (p-value = 0.031) around the optic disc in eyes with diabetic retinopathy. Ganglion cell complex also showed statistically significant thinning in diabetic patients. Creatinine levels showed a weak negative correlation to the RNFL. This study positively concluded that neurodegeneration in an early component of diabetic retinopathy.

Correlation between radiation dose and damage to optic disc and macula in eyes treated with ruthenium brachytherapy

PurposePoor visual acuity and blindness due to retinal damage are challenging side effects to 106Ru‐plaque treatments of malignant melanomas. In this study, we evaluated the dose to fovea and to the optic nerve and investigated the link between dose and the occurrence of macular and optic nerve damage.MethodsThe study included 54 patients treated in 2005 and 2006 in Copenhagen University Hospital, Denmark. Six patients were excluded due to missing information on ocular outcome. Using dedicated commercial software, the tumour was retrospectively contoured on pre‐treatment fundus images. The position of the plaque was determined from the radiation scar in post‐treatment fundus images and enabled to recreate the dose distribution. The presence of ocular damage was determined from the same post‐treatment fundus images. The dose to the fovea and optic nerve were reported and compared to the presence of ocular damage.ResultsThe estimated dose to the macula for patients with macular damage (median: 64 Gy, range: 7–668 Gy) was significantly larger than for patients with no macular damage (me‐ dian: 7, range: 0‐31 Gy) (p = 1.8·10−7). Optic nerve doses for patients with optic nerve damage (median: 87 Gy, range: 38–257 Gy) similarly differed significantly from those for patients without damage (median: 17 Gy, range: 0–122 Gy) (p = 1.7·10−4).ConclusionsAfter 106Ru‐plaque treatment, patients where ocular damage was identified had received a significantly higher dose to the macula and optic nerve compared to patients with no signs of ocular damage.

Comparison between Heidelberg retinal tomography-II and Heidelberg optical coherence tomography in diagnosis of pre-perimetric glaucoma

Objective To compare the clinical value of Heidelberg retinal tomography (HRT-Ⅱ) and Heidelberg optical coherence tomography (HRA-OCT) in discriminating healthy eyes and pre-perimetric glaucoma eyes. Methods A total of 33 patients with pre-perimetric glaucoma and 37 healthy subjects were included in this study. All individuals underwent imaging tests with HRT-Ⅱ and HRA-OCT within 1-month period. ANOVA and Kruskal-Wallis test were used to compare all of the parameters from HRT-Ⅱ and HRA-OCT between pre-perimetric glaucoma eyes and normal eyes. Receiver operating characteristic curves (ROC) were calculated for all of the parameters to seek the best discriminant point of each instrument between pre-perimetric glaucoma and healthy eyes. Results Statistically significant differences were found in most of the HRT-Ⅱ parameters except for disc area and height variation contour between pre-perimetric glaucomatous eyes and normal eyes (all P 0.05). Conclusions Both HRT-Ⅱ and HRA-OCT can well reflect the damage of optic disc and retinal nerve fiber layer in eyes with pre-perimetric glaucoma. HRT-Ⅱ and HRA-OCT have higher accuracy and similar sensitivity and specificity for the diagnosis of pre-perimetric glaucoma. Key words: Retina; Visual fields; Glaucoma

Application on the thickness of nerve fiber layer of the optic disc in pathologic myopia eyes by OCT

Application on the thickness of nerve fiber layer of the optic disc in pathologic myopia eyes by OCT

Heidelberg retina tomography II parameters in evaluating high- and normal-pressure glaucoma progression

Heidelberg retina tomography II (HRT II) haves been employed to quantitatively assess the topography of optic discs in eyes with high-pressure glaucoma (HPG) and normal-pressure glaucoma (NPG), in order to determine which of global and segmental optic disc parameters will prove to be most suitable for monitoring the progression of these two conditions. The results of 73 eyes of 73 patients with HPG and NPG were analyzed in relation to age, refractive error, quality of HRT images and stereometric parameters. A statistically significant difference (p < 0.05) between the global baseline and follow-up results was found in: rim volume, maximum cup depth and cup shape measure (in the HPG group), and C/D ratio, cup volume, rim volume and cup shape measure (in the NPG group). The baseline and follow-up results of the retinal nerve fiber layer in the temporal and inferotemporal sectors show a significant difference in both groups. Several HRT stereometric parameters are useful for monitoring the progression of changes of the optic disc and local retina in eyes with HPG and NPG. Both segmental and global scanning is of importance in glaucoma progression analysis.

Morphology of Optic Disc Through Heidelberg Retina Tomograph in Retinal Vein Occlusions Alone or in Combination with Primary Open Angle Glaucoma§

Purpose:To evaluate the morphology of optic discs in eyes suffering from retinal vein occlusion (RVO) alone or in combination with primary open-angle glaucoma (POAG).Methods:Prospective, observational study. 48 consecutive patients were enrolled, 30 with unilateral RVO diagnosis, 18 with unilateral retinal vein occlusion (RVO) associated with POAG. We divided RVOs on the basis of occlusion site: arterio-venous crossing (AV-RVO), optic cup (OC-RVO), optic nerve (ON-RVO) with head nerve swelling (ONHS-RVO) or without it (NONHS-RVO). A control group of 25 patients who were sex and age matched was selected.Results:Comparing the fellow eyes of the patients with RVO and control healthy eyes, no differences emerged in cup/disc ratio but they came out for the HRT values in Rim Area, cup shape measure and height variation contour (p<0.05).The most frequent occlusion site was at the level of an arteriovenous crossing in patients not suffering from POAG (36.7%) and at the level of the optic cup in patients with RVO and POAG (50%). In the RVO group without POAG, the OC-RVO subgroup has shown an higher cup area (0.366±0.094) and cup/disc area ratio (0.184±0.063), a lower rim volume (0.374±0.021) and a different cup shape measure (-0.221±0.066) (p<0.05) compared with the AV and NONHS sites. Compared with NONHS group differences emerged also for the fibres parameters and in the height variation contour (0.346±0.081). Also in the RVO group with POAG significant differences (p<0.05) have been surveyed between OC-RVO and other occlusion sites in cup area (0.119±0.029), cup/disc area ratio (0.532±0.09), rim volume (0.374±0.07), cup/shape measure (-0.079±0.013).Conclusions:Classification of the analyzed parameters on the basis of the occlusion site provides a basis for which clinical decisions and research on causal factors in future studies can be based on.

Experimental study on the mechanical strain of corneal collagen

Currently, investigations of biomechanical properties of the fibrous tunic are becoming even more topical, especially for diagnosis of corneal ectatic disease, as well as correct interpretation of intraocular pressure (IOP) parameters, particularly in patients with prior surgery on cornea. The study principle is based on the ability of substances to change optical anisotropy depending on mechanical strain applied to them. An experimental set-up was constructed which allows assessment of polarization degree of light which is emitted during luminescence of strained collagen. The study was performed on 18 corneoscleral discs of chinchilla rabbit eyes at 15 and 50mm Hg pressure, among them in 6 cases before and after making radial incisions, and in 6 cases before and after conducting the mechanical cornea abrasions that were asymmetrical by depth until reaching the local zone of iatrogenic keratectasia. Corneal collagen mechanical strain mappings were formed on 3 experimental models (intact cornea, cornea post radial keratotomy and keratectasia) under intra-chamber pressure of 15 and 50mm Hg. Corneal collagen mechanical strain is evenly allocated in the intact cornea. After radial keratotomy the main mechanical loading was concentrated over the middle part of corneal periphery, particularly in the bottom of keratotomic incisions. The increased intra-chamber pressure made the strain rise in those models. Upon cornea abrasion the main straining is distributed within the thinning zone, and the increase of intra-chamber pressure only increases the load over residual stroma. A new principle of corneal biomechanical properties investigation based on assessment of degree of light polarization emitted during luminescence of strained collagen, has been proposed and experimentally tested.

Aqueous Vascular Endothelial Growth Factor and Endothelin-1 Levels in Branch Retinal Vein Occlusion Associated With Normal Tension Glaucoma

To evaluate aqueous levels of vascular endothelial growth factor (VEGF) and endothelin-1 (ET-1) in patients with branch retinal vein occlusion (BRVO) with and without normal tension glaucoma (NTG), and to assess the therapeutic efficacy of intravitreal bevacizumab (IVB) in these patients. Sixteen eyes with NTG of 48 age and sex-matched eyes without NTG that had previously received IVB for BRVO were followed for 6 months. Aqueous VEGF and ET-1 levels were measured by enzyme-linked immunosorbent assay at the time of baseline IVB. Logarithm of the minimum angle of resolution best corrected visual acuity (BCVA) and central macular thickness (CMT) were measured at baseline and then at 1, 3, and 6 months postinjection. The obstruction site of BRVO was closer to the optic disk in eyes with NTG compared with controls (P=0.001). Baseline BCVA, CMT, and VEGF levels were similar between the 2 groups. Baseline ET-1 levels were significantly higher in eyes with NTG than those without NTG (P=0.009). After IVB, there was a significant improvement in both BCVA and CMT at 6 months, irrespective of the presence of NTG. However, BCVA in the presence of NTG was significantly worse at 6 months compared with eyes without NTG even though CMT was similarly reduced in both groups (P=0.04). Aqueous VEGF levels are similar in patients with BRVO with or without NTG, whereas aqueous ET-1 levels are elevated in the presence of NTG. Although IVB may be effective in the treatment of BRVO, the presence of NTG may limit visual recovery despite anatomic recovery of CMT.

The Glaucoma Guidelines of the Swedish Ophthalmological Society

The Glaucoma Guidelines of the Swedish Ophthalmological Society

Acquired Optic Nerve and Peripapillary Pits in Pathologic Myopia

To examine the incidence and characteristics of pit-like structures around the optic disc and myopic conus in eyes with high myopia. Prospective, observational case series. We evaluated 198 eyes of 119 patients with pathologic myopia (spherical equivalent >-8 diopters [D]). We also evaluated 32 eyes of 32 subjects with emmetropia (refractive error ≤±3 D) as controls. The papillary and peripapillary areas were examined with a prototype swept-source optical coherence tomography (OCT) system with a center wavelength of 1050 nm. We studied the structural characteristics of pit-like changes. The incidence and characteristics of the optic nerve (ON) pits in eyes with high myopia. Pit-like clefts were found at the outer border of the ON or within the adjacent scleral crescent in 32 of 198 highly myopic eyes (16.2%) but in none of the emmetropic eyes. The eyes with these pits were more myopic, had significantly longer axial lengths, and had significantly larger optic discs than the highly myopic eyes without pits. The pits were located in the optic disc area (optic disc pits) in 11 of 32 eyes and in the area of the conus outside the optic disc (conus pits) in 22 of 32 eyes. One eye had both optic disc pits and conus pits. The optic disc pits existed in the superior or inferior border of the optic disc. All but 1 eye with conus pits had a type IX staphyloma, and the location of the conus pits were present nasal to the scleral ridge or outside the ridge temporal to the nerve. The optic disc pits were associated with discontinuities of the lamina cribrosa, whereas the conus pits appeared to develop from a scleral stretch-associated schisis or to emissary openings for the short posterior ciliary arteries in the sclera. The nerve fiber tissue overlying the pits was discontinuous at the site of the pits. Optic nerve pits are common in highly myopic eyes. The ON pits are barely visible ophthalmoscopically but can be demonstrated by using swept-source OCT.

Optic disc appearance and retinal temporal vessel arcade geometry in high myopia, as based on follow‐up data over 38 years

To discuss (i) optic disc appearance and (ii) the retinal course of the temporal vessel arcade in a longitudinal series of high myopia patients followed between the ages of 16 and 54. Thirty-nine individuals from a 1948 Copenhagen birth cohort (n=9243) who had myopia of -6 to -15 D when aged 14 years were invited for current follow-up exams with 7-10-year intervals. Fundus photos were available from up to five occasions over 38 years, and single eye photo collages were studied with respect to posterior pole changes over time. Fifty-two eyes with high myopia were available. (i) Contrary to the expected predominance of large flat optic discs in long eyes, more than half the eyes in the sample had neurodiscs that were perceived to be small; many were also oval/kinked/tilted and with minimum or absent physiological cups. Among the fellow eyes with unilateral high myopia only one out of the 10 discs appeared as small/tilted. (ii) By age, a more acute angle between upper and lower temporal retinal vessel trunks was found in 12/20 eyes with adult myopia progression (change over time 5-23 degrees ) and in 6/24 eyes with stable myopia. In the myopia-progression subgroup, peaking of the angle was correlated with myopia degree, myopia increase and axial elongation. Contrary to clinical expectation, we found neurodiscs that appeared to be small and dense in eyes with high myopia. We further discussed the eventual peaking of the angle between the temporal vessel arcades that is sometimes observed in high myopia. Occasionally, literature on myopia reports the presence of small and tilted discs whereas no mention was found of the issue of temporal vessel arcade peaking.

The changes of tortuosity and bifurcation angle of retinal vessels at the posterior pole in the eyes with high myopia

Objective To observe the changes of tortuosity and bifurcation angle of retinal arteries and veins in each quadrant of the posterior pole in eyes with high myopia. Methods The tortuosity and bifurcation angle of retinal vessels in each quadrant of the posterior pole in 32 patients (52 eyes) with high myopia and 22 healthy people (30 eyes) were observed and compared. The outcomes were analyzed by multivariate analysis of variance. Results The tortuosity of macular vessels and the artery from optic disc in eyes with high myopia was (1.29±1.10)×10-4 and (5.39±1.93)×10-5 respectively, and in the normal eyes was (4.15±2.38)×10-4 and (9.75±4.99)×10-5 respectively; there was significant difference between the two groups (t=1.99, 2.00; P<0.05). The bifurcation angle of superior nasal and inferior nasal retinal arteries in eyes with high myopia was(66.17±14.04)° and (61.20±11.02)° respectively, and in the normal eyes was (77.66±14.12)° and (85.86±16.45)° respectively; there was significant difference between the two groups (F=0.77, 0.83; P<0.05). The bifurcation angle of superior temporal and inferior temporal retinal veins in eyes with high myopia was (92.39±20. 36)° and (83.56±23.50)° respectively, and in the normal eyes was (79.45±15.94)° and (70.59±17.27)°; there was significant difference between the two groups (F=2.34, 1.83; P<0.05). Conclusions The vessel tortuosity of retinal arteries and the vessels extending from the optic disc to macula is smaller in eyes with high myopia, while the venous tortuosity has no change. The bifurcation angle of retinal arteries in the superior nasal and inferior nasal field was smaller in eyes with high myopia, while the venous tortuosity has no change. The bifurcation angle of retinal veins in the superior temporal and inferior temporal field was larger in eyes with high myopia. Key words: Myopia; degenerative/pathophysiology; Retinal vessels/pathophysiology; Fluorescein angiography