Optic Layer Research Articles

Dissociated optic nerve fiber layer-like appearance indicating an internal limiting membrane defect associated with an epiretinal membrane: two case reports

BackgroundWe report for the first time a way to predict the 2-dimensional extension of an internal limiting membrane (ILM) defect by detecting the area with dissociated optic nerve fiber layer (DONFL)-like spots in the preoperative optical coherence tomography (OCT) en-face images.Case presentationsCase 1 was a 67-year-old man with metamorphopsia and decreased vision in his right eye. His best-corrected visual acuity (BCVA) was 20/100, with a pterygium, a moderate nuclear cataract, and an epiretinal membrane (ERM). Case 2 was a 73-year-old man with metamorphopsia and decreased vision in his left eye. His BCVA was 20/25, with a moderate nuclear cataract and an ERM. Both patients underwent simultaneous cataract surgery and pars plana vitrectomy with ERM and ILM peeling. Brilliant Blue G staining, performed before ERM and ILM peeling, revealed an unstained area. A careful evaluation of the area showed that it was not covered by either the ERM or ILM. A postoperative evaluation of the preoperative OCT images obtained from these cases showed DONFL-like low-brightness spots in the ILM defect area on the OCT en-face images.ConclusionsOCT en-face images may indicate the area of the ILM defect. To avoid iatrogenic damage to the retinal nerve fiber layer by touching/pinching it with forceps, detecting areas with DONFL-like spots in the preoperative OCT en-face images may be useful to predict an ILM defect.

Peripapillary Nerve Fiber Layer Thickness and Optic Nerve Head Parameters in Patients Recovered from COVID-19: A Longitudinal Study.

Purpose To quantify the longitudinal changes of the optic nerve head (ONH) parameters and peripapillary retinal nerve fiber layer (pRNFL) thickness in patients recovered from coronavirus disease 2019 (COVID-19) using spectral-domain optical coherence tomography (OCT) analysis. Materials and Methods In an observational longitudinal study, in patients recovered from COVID-19, ONH OCT images were recorded at least two weeks after recovery from the systemic disease as the baseline and after one and three-month follow-up. Ganglion cell complex (GCC) analysis, ONH parameters, and pRNFL thickness changes were measured. Results A total of 36 eyes from 18 recovered COVID-19 patients including eleven (61.2%) females were studied. The average age was 35.5 ± 7.5 years. The pRNFL thickness in the nasal lower sector significantly decreased from 77 ± 18 μm in the first post-COVID-19 month to 74 ± 10 μm in the third month (P=0.8). The average, superior, and inferior pRNFL thickness remained unchanged. The average cup volume significantly decreased from 0.27 ± 0.15 mm3 at baseline to 0.19 ± 0.15 mm3 in the third post-COVID-19 visit (P=0.028). In terms of ONH morphologies including rim, disc and cup to disc area, and the vertical and horizontal ratio, the changes were not significant over the 3-month study period. Focal loss volume and global loss volume values were not changed significantly. Conclusion Localized defect in the nasal lower sector of pRNFL is observed in 3-month post-recovery from COVID-19. Larger studies with longer follow-ups are required to reveal the exact changes in ONH parameters.

Temporal contrast adaptation in the analysis of visual function in primary open-angle glaucoma

PurposeTo explore the utility of the recovery time (RT) after temporal contrast adaptation in primary open-angle glaucoma (POAG) visual function analysis, especially in severe and end-stage glaucoma, by the Erlanger Flicker Test (EFT).MethodsThis study included 80 POAG eyes (45 subjects) and 20 normal eyes (20 subjects). POAG eyes were divided into 5 groups. The diagnostic efficacy of the EFT was assessed, and the RT of POAG eyes at different stages was compared. The EFT results were compared with glaucomatous structure and function test results. A nomogram was developed to predict disease progression by the RT and structural indicators.ResultsIn the normal eyes, as the test contrast increased, the RT gradually decreased. The EFT test–retest reproducibility was good, with intraclass correlation coefficient values of 0.6 (P < 0.05) for each test contrast. At 12%, 25%, and 35% contrast, the RT in the severe and end-stage glaucoma eyes was significantly prolonged compared with the control group (P < 0.05). The RT at different contrasts was significantly correlated with visual acuity, mean defect, mean sensitivity, and general and individual quadrant optic nerve fiber layer thickness (P ≤ 0.001). The receiver operating curve indicated that RT12% showed the best overall area under the curve (0.863). We included RT25% and average optic nerve fiber layer thickness in constructing the nomogram. POAG eyes were further divided into 8 stages. According to the probability distribution, this model showed good performance for visual function analysis in advanced glaucoma.ConclusionsCombined with traditional glaucomatous structural and functional parameters, the EFT can be used in the diagnosis and visual function analysis of POAG, especially for severe and end-stage glaucoma. It could be a potential test for disease staging in severe and end-stage glaucoma.

An effective model of clinical examination and monitoring of glaucoma patients

Open-angle glaucoma is a chronic progressive optic neuropathy characterized by morphological changes in the optic nerve head and retinal nerve fibers layer in the absence of other eye diseases.Regular medical check-ups are necessary to assess the progression of glaucoma, to correct the treatment regimen or prescribe surgical interventions, to control the stabilization of the glaucoma process and to preserve visual functions for longer period. When planning the number of monitoring visits, it is necessary to carefully study the prognostic risk factors, since they are statistically associated with the development and progression of glaucoma. Closer observation of patients with glaucoma reduces the risk of irreversible changes in the organ of vision.Patient compliance is of particular importance in the progression of glaucoma. The adherence rate in the treatment of glaucoma is relatively lower compared to other chronic diseases that require lifelong treatment.Currently, there is no effective model of regular checkups for glaucoma patients, therefore this direction requires improvement and development, both in the standards and timing of patient examination, and in the use of remote methods of glaucoma control. The disadvantage of the current medical check-ups routine is the lack of individual approach to patients, lack of equipment in the offices of regional ophthalmologists, and lack of specialized glaucoma offices.The tense epidemiological situation during the Covid-19 pandemic, gave understanding that while in-person consultations and remote consultations (telemedicine) cannot replace each other, a combination of these methods is cost-effective, can reduce the uneven distribution of ophthalmic resources, reduce the burden on the doctor and the rate of misdiagnosis. The situation was aggravated by the closure of ophthalmological hospitals and an increase in the waiting time for consultation in higher specialized medical institutions, which probably entails an increase in patients with progression of the glaucomatous process and the economic burden on both the state and the patients themselves.Telemedicine should be gradually introduced into everyday practice, for which it is advisable to create a single database of glaucoma patients to track the glaucomatous process.

Effect of acupuncture on retinal and choroidal thickness in patients with optic atrophy

To observe the effect of acupuncture on visual acuity, intraocular pressure, visual field, retinal and choroidal thickness on optic disc and macular area in patients with optic atrophy. A total of 33 patients with optic atrophy were treated with acupuncture. Acupuncture was given at Chengqi (ST 1), Shangjingming (Extra), Qiuhou (EX-HN 7) and Fengchi (GB 20) etc., 30 min each time, once a day, for 14 days. The visual acuity, intraocular pressure, visual field indexes (mean deviation [MD], pattern standard deviation [PSD] and visual field index [VFI]), optic disc retinal nerve fiber layer thickness, macular retinal thickness and choroidal thickness of optic disc and sub-foveal were compared before and after treatment. Compared before treatment, the visual acuity was increased (P<0.05), the MD value was decreased (P<0.05), the thickness of nerve fiber layer on the upper temporal side of optic disc was thinner (P<0.05), and the choroidal thickness of average, nasal side and lower temporal side of optic disc was increased (P<0.05). There was significant correlation between visual field MD and retinal nerve fiber layer thickness in different quadrants before and after treatment (P<0.01). Acupuncture could improve visual acuity, increase choroidal thickness in part of optic disc area in patients with optic atrophy.

Long-term performance of packaged fiber Bragg grating sensors for strain monitoring inside creep medium

ABSTRACT To investigate the long-term performance of the packaged fiber Bragg grating (FBG) sensors embedded in civil infrastructure for strain monitoring, in this paper, the influence of host matrix’s creep effect on the behavior of the FBG sensors was systematically studied through theoretical, numerical, and experimental analysis. A theoretical strain transfer analysis between the optic fiber, packaging layer, and host matrix to consider the creep effect of the host matrix was performed accordingly for long-term strain monitoring. Parametric studies were carried out using numerical analysis for FBG sensors packaged with glass fiber reinforced plastic (GFRP), also known as FBG-GFRP sensors in concrete, as an example. The results show that embedded in a creep medium, an acceptable long-term performance of packaged FBG sensors requires the packaging layer to have a minimum length and maximum thickness. Laboratory long-term creep tests using epoxy resin and concrete as host matrix for FBG-GFRP sensors also clearly demonstrated that the influence of creep effect cannot be ignored for strain measurements if the host matrix has a creep potential and the developed correction model performed well to reduce measurement errors of such sensors in creep medium.

Glaucoma: A review for the family physician

Glaucoma is an insidious disease process that causes damage to the optic nerve head and retinal nerve fiber layer, resulting in progressive vision loss. Multiple factors play a role in its pathophysiology, but intraocular pressure is a significant yet modifiable risk factor and therefore is targeted by all current treatment modalities. Its high prevalence and potential for irreversible damage necessitate an understanding of the condition by primary care physicians, who will undoubtedly be managing conditions and medications that can influence glaucomatous progression. This article will explore the pathophysiologic basis of glaucoma, discuss some of the common subtypes and highlight important clinical considerations.

Myelinated retinal nerve fiber layer: an extensive presentation.

Myelinated retinal nerve fiber layer is rare. It is estimated to occur in 0.5% to 1% of the population and is often detected on routine examination without symptoms. It consists of white or gray-white well-demarcated patches on the outermost surface of the retina that obscure the underlying retinal vessels. It can be associated with axial myopia, amblyopia, and strabismus. A 12-year-old girl with normal development presented with ocular deviation of the right eye. There was no past medical or ocular history. Automatic refraction found in the right eye -9 DP and -1 DP in the left eye. The best Visual acuity was 20/600 in the right eye and 20/20 in the left one. Slit lamp examination of the right eye (A) revealed two vast whitish zones extending from the papilla towards the temporal sector sparing the posterior pole. These lesions covered the temporal vessels with fuzzy and scalloped boundaries. Fundus examination of the left eye was without abnormalities (B). Scan of Optical coherence tomography showed isolated hyper reflectivity of the fiber optic layer, an abnormality of the vitreoretinal interface with posterior shadow cone effect (C).

Variation in retinal nerve fiber layer thickness at different stages of Leber’s hereditary optic neuropathy in patients with the ND4 G11778A mutation

ABSTRACT Purpose To investigate retinal nerve fiber layer (RNFL) thickness changes at different stages of Leber’s hereditary optic neuropathy (LHON) in patients bearing the ND4 G11778A mutation. Methods Ninety-eight clinically diagnosed, G11778A-positive LHON patients underwent 538 optical coherence tomography (OCT) examinations from September 2015 to September 2017. Patients were grouped based on disease duration at examination. Fifty healthy volunteers underwent 100 examinations as controls. Differences in RNFL thickness were compared across groups. Results During the onset of LHON patients with G11778A mutation, the thickness of nerve fiber layer in temporal quadrant decreased slowly within 1–3 months (p > .05), then entered in the rapid thinning period, which generally lasted until about 12 months of the course of disease (p < .05), and no obvious change occurred in the stable stage (p > .05); The optic nerve fiber layer in other quadrants was usually stayed in a significant thickening period within 1–3 months (p < .05), then entered in the rapid thinning period, which generally lasted until about 24 months of the course of disease (p < .05), and no obvious change occurred in the stable stage (p > .05) . Conclusion In LHON patients with G11778A mutation, the thickness of optic nerve fiber layer in the temporal side will experience slow thinning stage, rapid thinning stage and stable stage; The thickness of optic nerve fiber layer in other directions varies with the course of disease. Generally, it will experience five periods: significant thickening period, swelling period, recovery period, rapid thinning period and stable period.

Rates of Circumpapillary Retinal Nerve Fiber Layer Thinning and Capillary Density Loss in Glaucomatous Eyes with Disc Hemorrhage

To investigate longitudinal changes in rates of optic nerve head circumpapillary retinal nerve fiber layer (cpRNFL) thinning and vessel density loss in patients with primary open-angle glaucoma with or without a history of disc hemorrhage (DH). Observational cohort. In this longitudinal study, 34 eyes with DH and 134 eyes without DH that had ≥1.5 years of follow-up and 3 optical coherence tomography and optical coherence tomography angiography follow-up scans were enrolled. A linear mixed-effects model was used to compare the rates of cpRNFL thinning and vessel density loss between DH and non-DH eyes. Rates of whole image capillary density loss were faster in the DH group compared with the non-DH group (mean difference [95% confidence interval] -0.32% [-0.59% to -0.04%] per year; P=.027). Faster mean rates of vessel density loss were found in the inferotemporal, inferonasal, and nasal sectors in eyes with DH than without DH (P < .05). There was no statistically significant difference in the global rate of cpRNFL thinning between the 2 groups (P=.679). The mean rate of cpRNFL thinning was faster in the DH group compared with the non-DH group only in the inferotemporal sector (mean difference [95% confidence interval] -1.01 μm (-1.62 μm to -0.40 μm) per year; P=.001). Mean rates of vessel density loss between DH and non-DH eyes were different not only in the affected area but also in the other regions. In contrast, a significant difference in cpRNFL thinning between the 2 groups was detected only in the inferotemporal sector. Disc hemorrhage is an independent predictor of faster vessel density loss in glaucoma suspects and patients with primary open-angle glaucoma.

The Effect of Ocular Perfusion Pressure on Retinal Thickness in Young People with Presumed Systemic Hypotension.

Low ocular perfusion pressure (OPP) may increase the risk of optic neuropathy. This study investigated the effects of OPP on the ganglion cell complex (GCC) and optic nerve head-retinal nerve fibre layer (ONH-RNFL) thickness in presumed systemic hypotensives (PSH). Fifteen participants with PSH and 14 controls underwent automated sphygmomanometry and Icare tonometry to calculate OPP: mean OPP (MOPP), systolic OPP (SOPP), and diastolic OPP (DOPP). ONH-RNFL and macula GCC thickness were evaluated using the Optovue iVue optical coherence tomographer. Statistical analysis comprised independent t-tests, the Mann–Whitney U test and binary logistic regression analysis. There was no significant difference when comparing ONH-RNFL and macula GCC thickness between both groups. Increased MOPP (OR = 0.51; 95% CI: 0.27–0.97; p = 0.039) and SOPP (OR = 0.79; 95% CI: 0.64–0.98; p = 0.035) were significantly associated with a decreased risk of reductions in GCC total thickness. Increased SOPP (OR = 0.11; 95% CI: 0.01–0.89; p = 0.027) was significantly associated with a decreased risk of reductions in the average ONH-RNFL thickness. The study found no significant retinal thickness changes in PSH’s, in comparison to the controls. The study established that, by increasing MOPP and SOPP, there was a decreased risk of reductions in the total GCC thickness and average ONH-RNFL thickness. Higher SOPP may decrease the possibility of retinal thinning of the GCC and ONH-RNFL. However, higher MOPP may decrease the odds of thinning of the GCC before ONH-RNFL changes.

Study on the Optic Nerve Fiber Layer Thickness and Changes in Blood Flow in Myopic Children.

ObjectiveThe present study aims to observe the optic nerve fiber layer thickness and blood flow density in the papillary area and investigate the effects of axial length (AL) and the refractive state of the optic papilla blood flow density in children with different refractive conditions.MethodsThe present study was a clinical control study. The right eyes of 204 minors aged 6–17 years were studied. The eyes were divided into four groups according to myopic refractive states. OCTA analyzed the data to compare the radial peripapillary capillary (RPC) density and the difference in the retinal nerve fiber layer (RNFL) thickness adjacent to the optic papilla between the four refraction groups.ResultsThe intra-optic disc blood flow density was significantly and negatively correlated with the AL and was negatively correlated with the AL in the inferior temporal quadrants. The RNFL in the superior, nasal, and inferior quadrants was negatively correlated with the AL. The RNFL in the temporal quadrant was positively correlated with the AL.ConclusionOur present study revealed that aAs myopia increased and the AL grew in children, the blood density of the entire image of the optic papilla, in the optic disc, and the retinal capillaries in the inferior parapapillary and temporal quadrant would change significantly. With increasing AL, a significant decrease in the intra-disc and para-disc RNFL was observed in the superior, nasal, and inferior quadrants, while a substantial increase in RNFL was observed in the temporal quadrant.

Corneal hysteresis as a risk factor for optic nerve head surface depression and retinal nerve fiber layer thinning in glaucoma patients

To evaluate the role of corneal hysteresis (CH) as a risk factor for progressive ONH surface depression and RNFL thinning measured by confocal scanning laser ophthalmoscopy (CSLO) and spectral-domain optical coherence tomography (SD-OCT), respectively in glaucoma patients. Prospective study. A total of 146 eyes of 90 patients with glaucoma were recruited consecutively. The CH measurements were acquired at baseline and 4-months interval using the Ocular Response Analyzer (Reichert Instruments, Depew, NY). Eyes were imaged by CSLO (Heidelberg Retinal Tomograph [HRT]; Heidelberg Engineering, GmbH, Dossenheim, Germany) and SD-OCT (Cirrus HD-OCT; Carl Zeiss Meditec AG, Dublin, CA) at approximately 4-month intervals for measurement of ONH surface topography and RNFL thickness, respectively. Significant ONH surface depression and RNFL thinning were defined with reference to Topographic Change Analysis (TCA) with HRT and Guided Progression Analysis (GPA) with Cirrus HD-OCT, respectively. Multivariate cox proportional hazards models were used to investigate whether CH is a risk factor for ONH surface depression and RNFL progression after adjusting potential confounding factors. All patients with glaucoma were followed for an average of 6.76 years (range, 4.56–7.61 years). Sixty-five glaucomatous eyes (44.5%) of 49 patients showed ONH surface depression, 55 eyes (37.7%) of 43 patients had progressive RNFL thinning and 20 eyes (13.7%) of 17 patients had visual field progression. In the cox proportional hazards model, after adjusting baseline diastolic IOP, CCT, age, baseline disc area and baseline MD, baseline CH was significantly associated with ONH surface depression and visual field progression (HR = 0.71, P = 0.014 and HR = 0.54, P = 0.018, respectively), but not with RNFL thinning (HR = 1.03, P = 0.836). For each 1-mmHg decrease in baseline CH, the hazards for ONH surface depression increase by 29%, and the hazards for visual field progression increase by 46%. The CH measurements were significantly associated with risk of glaucoma progression. Eyes with a lower CH were significantly associated with an increased risk of ONH surface depression and visual field progression in glaucoma patients.

Global Neurotoxicity: Quantitative Analysis of Rat Brain Toxicity Following Exposure to Trimethyltin.

The organotin, trimethyltin (TMT), is a highly toxic compound. In this study, silver-stained rat brain sections were qualitatively and quantitatively evaluated for degeneration after systemic treatment with TMT. Degenerated neurons were counted using image analysis methods available in the HALO image analysis software. Specific brain areas including the cortex, inferior and superior colliculus, and thalamus were quantitatively analyzed. Our results indicate extensive and widespread damage to the rat brain after systemic administration of TMT. Qualitative results suggest severe TMT-induced toxicity 3 and 7 days after the administration of TMT. Trimethyltin toxicity was greatest in the hippocampus, olfactory area, cerebellum, pons, mammillary nucleus, inferior and superior colliculus, hypoglossal nucleus, thalamus, and cerebellar Purkinje cells. Quantification showed that the optic layer of the superior colliculus exhibited significantly more degeneration compared to layers above and below. The inferior colliculus showed greater degeneration in the dorsal area relative to the central area. Similarly, in cortical layers, there was greater neurodegeneration in deeper layers compared to superficial layers. Quantification of damage in various thalamic nuclei showed that the greatest degeneration occurred in midline and intralaminar nuclei. These results suggest selective neuronal network vulnerability to TMT-related toxicity in the rat brain.

GLAUDIA: A predicative system for glaucoma diagnosis in mass scanning.

Glaucoma is a serious eye disease characterized by dysfunction and loss of retinal ganglion cells (RGCs) which can eventually lead to loss of vision. Robust mass screening may help to extend the symptom-free life for the affected patients. The retinal optic nerve fiber layer can be assessed using optical coherence tomography, scanning laser polarimetry (SLP), and Heidelberg Retina Tomography (HRT) scanning methods which, unfortunately, are expensive methods and hence, a novel automated glaucoma diagnosis system is needed. This paper proposes a new model for mass screening that aims to decrease the false negative rate (FNR). The model is based on applying nine different machine learning techniques in a majority voting model. The top five techniques that provide the highest accuracy will be used to build a consensus ensemble to make the final decision. The results from applying both models on a dataset with 499 records show a decrease in the accuracy rate from 90% to 83% and a decrease in false negative rate (FNR) from 8% to 0% for majority voting and consensus model, respectively. These results indicate that the proposed model can reduce FNR dramatically while maintaining a reasonable overall accuracy which makes it suitable for mass screening.

Modifies Hummer’s Method of Graphene Oxide Nanostructures for Fibre Optic Sensors Application

For optical fibre sensors applications, nanomaterials have been widely used to enhance sensor performance. Here, the fibre optic uses the transmission of light by total internal reflection along with the fibre and depending on the diameter of the fibre and the wavelength of the light used. Among others, graphene oxides nanostructures (GO) would offer exceptional advantages on the sensing mechanism due to 2D properties of the monocellular layer originally from graphite. The main objectives of this research are to successfully synthesis of GO using a chemical reduction method known as modifies Hummer’s method and later, deposited the GO onto the modified fibre optic layer to create a sensing platform. Prior than that, the standard plastic of fibre optic (POF) was modified by removing the cladding layer (1 cm) using a mechanical etching technique, thus the sensing platform can be created. The morphology and optical properties of the system were characterised using scanning electron microscopy (SEM) and ultraviolet-visible (UV-Vis) spectroscopy. Result of the preparation and characterisation of GO-optical fibre coatings was presented, considering its potential use for sensing applications. The stable GO was prepared by 3 hours of stirring time during the synthesis and longer dipping time was preferred to fully coat the core of the exposed POF. Aiming to explore this scheme for sensing applications, GO-coated tilted fibre will be later measuring via refractive index variations. An improvement on the sensitivity should be obtained and thus become a promising sensing platform for the development of a new line of sensors.

Long-term follow-up of retinal sensitivity assessed by microperimetry in patients with internal limiting membrane peeling.

To evaluate anatomical and functional changes in patients with vitreomacular interface disease after internal limiting membrane (ILM) peeling, using microperimetry along with usual clinical and multimodal retinal imaging. Patients with vitreomacular interface disease requiring vitrectomy underwent multimodal retinal evaluation, including visual acuity assessment, fundus color photograph, Spectral-Domain Optical Coherence Tomography, Optical Coherence Tomography-Angiography, and microperimetry. They were examined at baseline (M0), 6 months (M6) and 18 months (M18) after surgery. Retinal sensitivity was subdivided into three concentric polygons: Large, Medium, Small. Eleven eyes of 11 patients were analyzed, including 10 epiretinal membranes (ERMs). Best-corrected visual acuity (BCVA) improved in all patients from 0.51 logarithm of the minimal angle of resolution (logMAR) to 0.067 (p = 0.0074). Retinal sensitivity improved between M0 and M6 in all polygons and continued to improve between M6 and M18 for polygons Medium (M) and Small (S) with no statistical significance. At M18, BCVA and retinal sensitivity were similar in the operated eye compared with the fellow eye for all patients. Dissociated optic nerve fiber layer appearance was observed in 8 patients at M18. It was not correlated with either retinal sensitivity or BCVA or microscotomas. No recurrence of ERM or macular hole occurred during follow-up. After surgery, the retinal sensitivity assessed by microperimetry gradually improved until the 18th month and was not different from the values of the fellow eye. These results seemed to confirm that ILM peeling can be an effective and safe technique to treat patients with vitreomacular interface disease.

Effets à long terme du pelage de la membrane limitante interne sur la sensibilité et l’anatomie rétinienne lors de la chirurgie des trous maculaires

To study the functional and anatomical effects of internal limiting membrane (ILM) peeling in macular hole surgery with a minimum follow-up of 10 years. Retrospective study of patients who underwent successful macular hole surgery prior to 2010. All patients underwent vitrectomy and ILM peeling after staining. Functional assessment included measurement of visual acuity and retinal sensitivity using microperimetry (NIDEK MP-3) as well as a subjective visual function questionnaire. Anatomical assessment was based on evaluation of the macular region and optic nerve using spectral domain optical coherence tomography (SD-OCT) with comparison to the fellow eye. Fourteen women and five men were included. Visual acuity of operated eyes (0.07±0.08logMar) was not significantly different from that of fellow eyes (0.04±0.08logMar) (P=0.10). The mean retinal sensitivity of the operated eyes was 25.1±1.9dB with no difference from the fellow eyes 25.2±1.6dB (P=0.82). However, 2 patients exhibited 2 relative scotomas >10dB. On questioning, 3/19 patients (16%) described a disturbing scotoma in monocular vision, while 11/19 (58%) described metamorphopsia, and 3 subjectively assessed their visual loss at more than 60%. The external limiting membrane was present and intact in all patients, and the ellipsoid zone was restored in 16/19 patients (84%). The cone interdigitation zone was intact in 9 patients, altered in one patient and not interpretable in 9 patients. Retinal optic nerve fiber layer thickness showed a moderate loss of fibers in the operated group 95.9±9.5 versus 101.5±10.9 (P=0.001) in the fellow eyes. The ganglionic complex thickness in the operated eyes (90.1±8.3) was not significantly different from that of fellow eyes (91.9±8.8) (P=0.37). ILM peeling in macular hole surgery induces anatomical changes in the inner layers of the retina, still visible on SD-OCT 10 years after the procedure. However, this remodeling of the inner layers does not appear to have significant deleterious effects on patients' retinal sensitivity or vision.

EVALUATION OF INTERNAL LIMITING MEMBRANE GRAFT TECHNIQUE WITH NO FOVEAL PEEL IN IDIOPATHIC MACULAR HOLE

A macular hole is a full-thickness retinal tissue defect involving anatomical fovea and, in particular, foveola in the eye.The inverted ILM flap technique prevents a macular hole from appearing flat-open post-operatively and increases both the functional and anatomical results of vitrectomy for macular holes with a diameter greater than 400 μm. Spectral optical coherence tomography with the inverted ILM flap technique after vitrectomy suggests improved foveal anatomy relative to regular surgery.Dissociated optic nerve fiber layer (DONFL) appearance is defined as arcuate retinal striae along the optic nerve fibers in the macular region. Is associated with ILM peeling, with visual acuity, visual field testing, and SLO microperimetry showed no abnormalities. The authors propose that the presence of DONFL could be secondary to mere movement of optic nerve fibers rather than degradation due to loss of support for Muller cells or postoperative regenerative processes of Muller cells or astrocytes. The correspondent image on B-scan OCT is seen as “dimples” in the inner retinal layers that seem to be the result of an interplay between trauma and healing processes constrained by nerve fiber layer and it is not associated with adverse effects on the visual function, as detected by visual acuity and scanning laser ophthalmoscopy microperimetry.

Involvement of Anoikis in Dissociated Optic Nerve Fiber Layer Appearance.

Dissociated optic nerve fiber layer (DONFL) appearance is characterized by dimpling of the fundus when observed after vitrectomy with the internal limiting membrane (ILM) peeling in macular diseases. However, the cause of DONFL remains largely unknown. Optical coherence tomography (OCT) findings have indicated that the nerve fiber layer (NFL) and ganglion cells are likely to have been damaged in patients with DONFL appearance. Since DONFL appearance occurs at a certain postoperative period, it is unlikely to be retinal damage directly caused by ILM peeling because apoptosis occurs at a certain period after tissue damage and/or injury. However, it may be due to ILM peeling-induced apoptosis in the retinal tissue. Anoikis is a type of apoptosis that occurs in anchorage-dependent cells upon detachment of those cells from the surrounding extracellular matrix (i.e., the loss of cell anchorage). The anoikis-related proteins βA3/A1 crystallin and E-cadherin are reportedly expressed in retinal ganglion cells. Thus, we theorize that one possible cause of DONFL appearance is ILM peeling-induced anoikis in retinal ganglion cells.