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Sep 2020 DOI 10.14302/issn.2470-0436.jos-20-3400
Aim To compare the efficacy of combined anti-VGEF (IVB) with steroids versus pure anti-VEGF for the treatment of macular edema secondary to retinal vein occlusion (RVO). Methods In this prospective study, 51 eyes were randomized into 2 groups according to treatment of clinically identified macular edema secondary to retinal vein occlusion within 4 weeks of onset: Group 1 (19 eyes) was given intravitreal Bevacizumab (IVB) (1.25mg/.05ml) + Triamcinolone (IVTA) (2mg/.05ml); Group 2 (22 eyes) was given pure intravitreal Bevacizumab (IVB) (1.25mg/.05ml) at baseline, at month 1, and at month 2. The outcome of the study represented the EDRTS letters gain, IOP change and (CRT) by using Spectral domain optical coherence tomography (OCT) at month 1, 2, 3 and 6 in each group. Both central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO) patients with at least 6 months FU were enrolled in the study. Results EDRTS letters gain was (20.37±15.28, 28.05±16.68, 35.16±17.12, 36.47±18.17) in group1 and (14.50±14.56, 18.41±14.56, 20.59±16.13, 21.06±15.72) in group2 at month 2,3 and 6 p value (0.18, .04, 0.004, 0.002). Mean IOP pre-injection (14.00±2.67) in group 1 and (13.5±5.89) in group 2. Group 1 has transient increase in IOP at month 1 and then return to baseline over 6 months. CRT from baseline to final FU decrease by 264.82 (µm) ±147.66 in group 1 and 308.42(µm) ±226.78 in group 2 with no significant difference between two group p value 0.57. There was no significant difference in EDRTS letters gain between CRVO patients and BRVO patients at month 1, 2, 3 and 6 p values (0.83, 0.23, 0.29, 0.13). Conclusion Early treatment macular edema in RVO patients by combined anti-VGEF+ steroid effectively improve functional outcome better than pure anti-VGEF injection.
Sep 2019 DOI 10.14302/issn.2470-0436.jos-19-2829
Purpose To study outcome and spectral domain optical coherence tomography (SD-OCT) macular findings in patients who underwent surgery for spared macula giant retinal tear (GRT) retinal detachment. Methods a retrospective study of 12 patients with spared macula giant retinal tear (GRT) retinal detachment who underwent vitrectomy (N=7), vitrectomy with an encircling scleral buckle (n=4) and scleral buckle (n=1) with at least 3 months follow up after silicon oil removal (SOR) . Post-SOR macular SD-OCT scans were studied in all eyes. Results Final reattachment achieved in all eyes with single primary surgery. Post-SOR SD-OCT macular finding was photoreceptors layer disruption in 6 eyes, epiretinal membrane (ERM) in 4 eyes, Macular hole in 1 eye and choroidal neovascularisation in 1 eye. Significant correlation found between final Best-Corrected Visual Acuity (BCVA) and macular pathology on SD-OCT p value (0.048). Conclusion SD-OCT plays a high role in diagnosis of macular alterations that can be associated with poor functional outcome in anatomically successful GRT surgery with spared macula pre-operatively.
Jan 2019
Excessive variability in behavioral performance and neuronal activation is a common finding in studies of schizophrenia. Recent evidence suggests that this may be due to an imbalance in the ratio of excitation to inhibition in brain function, or E/I imbalance. We used computational modeling of visual system activity to determine whether different potential causes of E/I imbalance would generate effects resembling those reported in schizophrenia. Three major findings emerged. First, reductions in retinal and lateral geniculate nucleus signaling initially led to increases in firing rate variability within the context of reduced V1 activation; however, with prolonged adaptation to weakened sensory signaling, compensatory hyper-activation in V1 neurons occurred, but variability was no longer increased. Second, direct increases in V1 excitation, or decreases in inhibition, led to the highest levels of initial activation but not variability; however, with prolonged inhibitory adaptation to increased excitation, overall activity was no longer elevated, but an increase in firing rate variability was observed. Third, the greatest fluctuation in firing rate variability, in response to the same stimulus across increasing contrast levels, was observed with reductions in sensory signaling, but only immediately after model perturbations; with prolonged adaption, the largest fluctuations were associated with increased excitation or reduced inhibition within V1. Implication of these findings are that schizophrenia-related increases in neuronal response variability may arise from at least two sources: 1) weakened sensory signaling and its associated low signal-to-noise ratio; and 2) compensatory but incomplete inhibitory responses to continuous increases in cortical excitation.
Aug 2017 DOI 10.14302/issn.2470-0436.jos-17-1721
A 57-year-old Hispanic female presented with 3 days of blurry vision in the left eye. Eight years prior, she had a branch retinal artery occlusion in the right eye and a hematologic work-up revealed a 4G/4G polymorphism in plasminogen activator inhibitor-1. With the current episode, she was found to have bilateral branch retinal artery occlusions and mild vitritis in the left eye, simulating a toxoplasma infection. An infectious and inflammatory work up, however, was negative and the vitritis resolved after a short course of steroids. Plasminogen activator inhibitor-1 mutations may be associated with an increased risk of retinal vascular occlusions.
May 2017 DOI 10.14302/issn.2470-0436.jos-17-1453
Purpose: High intraocular pressure (IOP) is known to result in retinal ganglion cell (RGC) loss, both with chronically raised intraocular pressure (such as with glaucoma) and with acute raises in pressure (due to injury or acute angle closure). Because IOP is often raised during ocular surgery, the purpose of this study was to evaluate the effect of transient moderate IOP on retinal function, RGC survival and the expression of Connexin 43 (Cx43) and glial fibrillary acidic protein (GFAP), ubiquitously expressed central nervous system (CNS) proteins that are known to be elevated during the retinal inflammatory response to injury. Materials and Methods: Wistar rats were exposed to transient IOP at 40 mmHg for 5 or 30 minutes, and 60 mmHg for 5 minutes (via cannulation of the anterior chamber with a saline reservoir raised to a height corresponding to the desired IOP), mimicking potential IOP rises during surgery such as DSAEK and some laser procedures (LASIK and femtosecond laser cataract surgery). Separate groups of animals had IOP maintained at 10 mmHg for 5 or 30 minutes as cannulation controls, or 120 mmHg for 60 minutes as positive controls. Changes in the optic nerve and retina were assessed immunohistochemically for GFAP and Cx43 expression. Retinal function was assessed using electroretinography (ERG) recorded at baseline and 14 days after the IOP rise and compared with RGC counts. Results: Results showed that there was a differential GFAP labelling pattern observed in the anterior optic nerve in the 40 mmHg 30 minute and 60 mmHg 5 minute groups 4 hours after manipulation. Gap junction protein Cx43 was minimally up-regulated in the retina in the short-term. There was, however, minimal long-term effect on retinal function and no RGC loss. Conclusions: n conclusion, elevations of IOP that are short in duration such as those occurring during surgical procedures, do not cause significant changes long-term in retinal function or RGC survival. Key Messages: Cx43 and GFAP are known to be elevated during the retinal inflammatory response to injury. No previous study has explored the effect of moderate and relatively short increases in IOP on the initial inflammatory response. We observed a mild glial inflammatory response in the anterior optic nerve, but only a minimal up-regulation of Cx43. However, transient and moderate IOP rises did not induce long term disruption to RGC function or number as measured by electrophysiology and RGC counts, respectively. This is applicable to clinical practice, as it means the IOP elevations that occur during some surgical procedures are unlikely to be causing long term damage in retinal function or RGC survival.
Apr 2016 DOI 10.14302/issn.2470-0436.jos-15-710
Idiopathic macular telangiectasia type 2 is a rare retinal condition usually characterized by parafoveal telangiectatic vessels, hyperplastic pigment plaques and seldom a full thickness macular hole or a retinal neovascularisation. Herein we describe an atypical presentation of this disease. Methods Review of the patient’s clinical and angiographic records. Results A 87-year-old white man was diagnosed with idiopathic macular telangectasia type 2. Ophthalmological and angiographic examination disclosed telangiectasia of the parafoveal capillaries together with extensive bilateral granular soft drusen and unilateral retinal angiomatous proliferation (RAP). Initially photodynamic therapy with verteporfin (PDT) and subsequently intravitreal injections of bevacizumab were used to treat RAP lesion. This approach provided visual acuity stabilization up to 24 months. Conclusion This case of ours shows that drusen may be a feature of macular teleangiectasia type 2. It also emphasizes that PDT and anti-VEGF therapy are both safe and effective for treating neovascular complications of this disease.
Mar 2016 DOI 10.14302/issn.2470-0436.jos-15-739
Ciliary neurotrophic factor (CNTF) is a well-tested, neuroprotective agent that has been shown to retard photoreceptor degeneration in several animal models of retinitis pigmentosa. The molecular mechanisms underlying CNTF-mediated neuroprotection are currently not understood. CNTF could act directly on photoreceptors or it could act indirectly by stimulating Müller glial cells to produce photoreceptor neuroprotective agents. To better characterize CNTF action on Müller cells, we have studied signaling pathways activated by CNTF using an established retinal Müller cell line, rMC-1. RNA was isolated from CNTF-treated cultures, and suppressor of signal transducer and activator of transcription (SOCS3) and Glial fibrillary acidic protein (GFAP) transcript levels were assessed by quantitative real-time PCR. Immunoblotting was used to examine activation ofmitogen activated protein kinase (ERK1/2/MAPK) and phosphoinositide 3-kinase (PI3-K)/Aktpathways in response to CNTF. Additionally, the level of5' AMP-activated protein kinase (AMPK), an enzyme that plays a key role in cellular energy homeostasis levels, was determined by immunoblotting. CNTF treatment resulted strong upregulation of SOCS3 and GFAP transcripts that were blocked by expression of a dominant-negative STAT3 mutant. CNTF treatment also resulted in transient activation of ERK1/2/MAPK but not PI3K/Akt signaling pathway. There was no change in activation of AMPK. We conclude that CNTF treatment leads to stimulation of JAK-STAT and MAPK signaling pathways but not the PI3K/AKT pathway, associated with cell death, in Müller cells.
Feb 2016 DOI 10.14302/issn.2379-8572.joa-14-531
Central retinal artery occlusion (CRAO) is a retinal ischemic disorder associated with sudden loss of vision and has a poor prognosis. We report a case of CRAO that occurred during frontal sinus surgery involving craniotomy in a patient with a frontal sinus cyst. The prognosis for treatment after the acute phase is generally unfavorable; however, aggressive treatment is recommended for patients with visual acuity of “hand motion” or better within 1 day after onset. This case highlights the need for informed consent prior to nasal or paranasal sinus surgery, including mention of the possibility of CRAO as a complication.
Jun 2015 DOI 10.14302/issn.2470-0436.jos-14-528
A previously healthy 25 year old Chinese male presented with left eye blurring of vision and was diagnosed to have left eye branch retinal vein occlusion. Initial blood investigations and thrombophilia screen were negative. The patient subsequently improved with observation and conservative management, with no further events over a 2 year follow up period. The blood investigations were repeated 2 years later as part of a health check-up and he was then tested to be heterozygous for the factor V leiden mutation. This was confirmed by sequencing of his genome that identified the mutation. The laboratory was contacted to provide details regarding the testing methods and was noted to have performed the two tests via different methods. While false negative rates in genetic testing are low, we believe that there is greater need to standardize testing methods as ascertaining genetic conditions play a great role in clinical diagnosis, treatment and prognosis. Clinicians should be aware of the limitations of these tests. When clinical suspicion is high, there may be a role for repeat tests with different methods or in different laboratories.
May 2015 DOI 10.14302/issn.2470-0436.jos-14-527
A 66 year old Chinese male with a medical history of hypertension, diabetes mellitus and hepatitis B carrier was diagnosed with hepatocellular carcinoma in 2009. He underwent treatment with selective internal radiation spheres and sorafenib, and multiple cycles of chemotherapeutic agents such as bevacizumab, erlotinib, OXAFI ( intravenous oxaliplatin and doxorubicin given on days 1, 8 and 15 in a 28-day cycle, a daily continuous infusion of fluorouracil and subcutaneous interferon alfa-2b 5 million units administered thrice weekly), thalidomide, capecitabine, and rapamycin over the course of four years. Along the course of treatment, he developed pulmonary embolism and was initially started on anti-coagulation. Two months later, he developed hemoptysis and the anti-coagulants were stopped. During his routine ophthalmology visit for diabetic eye evaluation, he complained of blurring of vision of his left eye for the past four to five weeks. He was found to have central retinal vein occlusion (CRVO) of the left eye, associated with macular edema. Visual acuity was 6/15 for the right eye and 6/60 for the left eye. Eyelids, conjunctiva, cornea, anterior chamber, pupils, lens and ocular motility were normal. Humphrey visual field testing showed a superior arcuate and basal defect. This is the first reported case of CRVO in hepatocellular carcinoma. The etiology of CRVO is multifactorial, withhepatic malignancy, previous major surgery, multiple cycles of chemotherapy and cessation of anticoagulant therapyas possible aetiological factors. His background medical problems of diabetes and hypertension are further contributors.
Nov 2025 DOI 10.14302/issn.2470-0436.jos-25-5503
Purpose Create a new diagnostic and therapeutic framework for patients with Exudative Age-Related Macular Degeneration (ARMD) and choroid imaging biomarkers of non-neovascular choroidal pathology who have persistent neovascular exudation during the course of monotherapeutic interventions. Methods Retrospective, longitudinal case series study of 25 eyes from 23 patients with the referral diagnoses of treatment resistant Exudative ARMD who had persistent neovascular exudation despite various monotherapies. Inclusion criteria required choroidal imaging biomarkers of non-neovascular pathology including a thickened subfoveal choroid (greater than 300 microns) and vessels (subjectively dilated choroidal vessels in Haller’s layer) on Optical Coherent Tomography (OCT), choroidal neovascularization on IVFA and OCT Angiography (OCTA), as well choroidal leakage noted on indocynanine green videoangiography (ICG). Treatment consisted of OCTA and ICG - Directed Photodynamic Therapy (PDT) Triple Therapy, hereafter described as Combination Therapy, to areas of choroidal hyperpermeability and choroidal neovascularization. Combination therapy consisted of an anti-Vascular Endothelial Growth Factor (VEGF) intravitreal injection on Day 0 followed by half-fluence PDT and 2 mg intravitreal triamcinolone acetonide on Day 3-14. Results All study patients had treatment resistant Exudative ARMD defined as persistent subretinal and/or intraretinal fluid during their course of monotherapeutic interventions. Complete resolution of all exudation occurred in 23 eyes (92.0%) at 8 weeks. The mean duration of action was 155.6 weeks, with 72.0% of eyes leak free greater than 100 weeks. The mean vision at baseline was 0.46 ± 0.42 LogMAR, best corrected visual acuity (BCVA). 8 weeks after treatment, the vision was 0.35 ± 0.38 LogMar, an improvement of over one line, and this was maintained at one year. The baseline central subfield thickness (CST) was 296.4 ± 136.1 microns and improved by 111.4 ± 105.4 microns at 8 weeks after treatment. Treatment duration was negatively associated with the Caucasian race. Conclusions Patients with subretinal and/or intraretinal fluid secondary to Exudative ARMD should have a complete baseline multimodality imaging study to confirm the presence of neovascularization and whether choroidal hyperpermeability coexists. This study shows that patients with Exudative ARMD and persistent neovascular exudation despite monotherapuetic interventions often have choroidal biomarkers of non-neovascular choroidal pathology and that ICG and OCTA-directed PDT Triple Therapy resulted in complete resolution of all exudation in 92.0% of patients at 8 weeks with a reduction in central subfield thickness (CST) of 111.4 microns. The vision improvement at 8 weeks was 0.11 ± 0.38 LogMar and was sustained over 1 year. The mean duration of action was 155.6 weeks, with 72.0% of eyes leak free greater than 100 weeks. Additionally, this study shows that the treatment that addresses both pathological processes is successful and should be considered as a primary protocol when the biomarkers are present at baseline or as a secondary protocol if indeed the neovascular leakage is persistent despite monotherapy. Summary Patients with an Exudative ARMD with persistent neovascular exudation despite anti-VEGF monotherapy and who have imaging biomarkers of non-neovascular choroidal pathology often have two pathophysiological processes: choroidal hyperpermeability and angiogenesis. A proposed framework provides the rationale for OCTA and ICG-directed PDT Triple Therapy which successfully resolves 92% of the leakage that was persistent after various monotherapeutics.
Nov 2025 DOI 10.14302/issn.2474-7785.jarh-25-5760
Commotio retinae (CR) is a condition frequently observed in clinical practice, particularly following closed globe trauma (CGT) due to sport, labor, or traffic accident injuries. It is the main cause of unilateral vision loss in male patients aged between. It is characterized by transient gray-white retinal coloration and reduction of visual acuity (VA). Symptoms depend mainly on the location and severity (deep) of the injury, with less complains when only the superficial or peripheral retina is affected. It may be confined to the posterior pole, when it is also called Berlin’s edema, after the first hypothesis of Berlin (1873). There is no specific treatment since the treatment depends on the region of the retina and choroid affected. In this work we report a case of Berlin edema, treated with ǪIAPI 1®, to restore the balance of oxygen, which is generated at the intracellular level.
Aug 2024 DOI 10.14302/issn.2470-0436.jos-24-5162
Introduction Cystoid macular edema (CME) is a sight-threatening condition caused by fluid accumulation in the macula due to blood-retinal barrier disruption. Various factors, including drug reactions, can lead to retinal fluid leakage. Leflunomide, a disease-modifying anti-rheumatic drug, marked significant progress in managing rheumatoid arthritis. Although effective, Leflunomide has rarely been linked to CME. This report presents a unique case of Leflunomide-induced CME, adding to the limited literature on this subject. Methods We report the case of a 75-year-old female with rheumatoid arthritis treated with Leflunomide, presenting with bilateral CME and reduced visual acuity (VA). Comprehensive ophthalmic evaluations, including VA tests, fundus examination, and optical coherence tomography, were conducted. Results The patient presented with CME and decreased VA in both eyes for several months. She had undergone cataract surgery 20 years prior and was using topical nepafenac, dorzolamide, and dexamethasone. Initial VA was OD 20/50 and OS 20/40. VA improved with treatment, but CME recurred upon discontinuation. The patient had been on Leflunomide for one year. After consulting with the Rheumatology department and considering a previous case of bilateral Leflunomide-induced CME, the drug was discontinued. CME resolved without recurrence or the need for topical treatment. At her final visit, VA was OU 20/25. Conclusion This case highlights Leflunomide as a potential, though rare, cause of CME. It emphasizes considering systemic medications in CME diagnosis. Timely discontinuation of Leflunomide may resolve CME and prevent further visual impairment. Further studies are needed to understand this rare side effect comprehensively.
Nov 2023 DOI 10.14302/issn.2470-0436.jos-23-4814
A 40-year-old male presented with visual impairment in the right eye (OD). He had undergone a pars plana vitrectomy for retinal detachment in the OD three years prior. Biomicroscopic examination revealed significant hyperemia, rubeosis iridis, anterior subluxation of the intraocular lens (IOL), and an organized hyphema located in the inferior third of the anterior chamber, characterized by the entrapment of iris tissue between the anterior synechia and the IOL. Figure 1. Intraocular lens anterior subluxation associated with organized hyphema and anterior iris synechia.
Jun 2020 DOI 10.14302/issn.2577-2279.ijha-20-3445
The passage of the posterior tibial nerve in the tarsal tunnel has a great clinical significance, thus detailed anatomical knowledge is mandatory for safe clinical intervention. This study was to identify the morphological appearance of the tibial nerve and its bifurcation. Sixty lower limbs of formalin embalmed cadavers were randomly selected. Data were collected through the application of standard dissection method of the tarsal tunnel of lower limbs (30 rights and 30 left) of formalin embalmed cadavers. The posterior tibial nerve and its branches were exposed from the distal end of the leg toward plantar surface beyond its bifurcation by resecting the skin and flexor retinaculum. The study triggered several findings: The posterior tibial nerve is flattened shaped in 21 specimens 70% and has a rounded shape in 9 specimens 30%in the right foot. In the left foot it is flattened in 17 specimens 56.7% and rounded shape in 13 specimens 43.3%. Posterior tibial nerve bifurcates into medial and lateral planter nerves inside tarsal tunnel in 20 specimens 66.7% in the right foot and in 21 specimens 70% in the left foot. This study concludes that posterior tibial nerve commonly has flattened shape and divided into medial and lateral planter nerves inside tarsal tunnel.
Sep 2019 DOI 10.14302/issn.2577-2279.ijha-19-3013
The medial calcaneal nerve (MCN) is the first branch of the posterior tibial nerve (PTN) in the porta pedis, enervates the skin of the heel and medial side of the foot. Heel pain is a common condition encountered by physicians, and this may have a significant clinical association with the MCN’s branching pattern. This study was to identify branching pattern variations in the medial calcaneal neurovascular bundle. This study was carried out using 60lower limbs of formalin-embalmed cadavers, using the tarsal tunnel dissection method for 30right and 30 left lower limbs. The medial calcaneal neurovascular bundle course was identified by exposing the PTN and its branches from the distal end of the leg toward the plantar surface beyond its bifurcation and resecting the skin and flexor retinaculum. Many MCN branching pattern variations (specifically concerning origins, numbers, and levels of branching) were observed. In the right foot a single branch was present in 21 specimens (70%), while two branches were observed in nine specimens (30%). In the left foot, a single branch was present in 22 specimens (73.3%) and two branches were present in 8 specimens (26.7%). In this study, two branches originate from lateral planter artery is the most common observation. This study concludes that a single MCN originating from the TN is the most common variant. Two medial calcaneal arteries (MCAs) originating from the LPA is also common.
Jul 2019 DOI 10.14302/issn.2470-0436.jos-19-2904
This case series presents 2 patients (67 and 58 year old females) with resolving vitreous hemorrhage in the setting of diabetic retinopathy. Both patients had around 50% of the retina still visible and the hemorrhage was confined at the posterior vitreous cavity near the retina, hence, a partial pan retinal photocoagulation (PRP) was feasibly applied. On B-scan, both cases showed a liquified vitreous with posterior vitreous detachment (PVD). For both patients, vitreous hemorrhage resolution occurred at less than 4 months from onset and consequently PRP was completed. Vitreous hemorrhage differs with bleeding in other tissues due to the presence of vitreous collagen matrix which promotes rapid clotting and hinders resolution of hemorrhage by preventing passive diffusion and delay in inflammatory cellular response. The prognosis for clearing hemorrhage was better when the fundus reflex was brighter and the retina adjacent to the ora serrata was visible. Clearing occurred sooner when hemorrhage was retrohyaloid rather than in the vitreous gel. In diabetic eye, the vitreous undergoes metabolic derangements resulting in premature liquefaction and abnormal vitreoretinal adhesion leading to traction and membrane formation. Partial PVD has also been associated with higher rate of diabetic retinopathy progression since it serves as scaffold for growth of neovascular tufts.
Apr 2019 DOI 10.14302/issn.2470-0436.jos-19-2480
Purpose To describe spectral domain optical coherence tomography (SD-OCT) and enhanced depth image OCT (EDI-OCT) findings of multifocal serpiginoid choroditis (MSC) , including affected layer of retinal involvement, changes at the vitreoretinal interface, and response to therapy. Methods A retrospective review of 20 eyes (14 patients) with MSC. Each patient underwent a complete ophthalmologic examination, fundus photography, fundus autoflorecence (FAF) and OCT imaging of the affected retina at the initial visit and on each follow-up. Results In acute stage, SD-OCT showed hyperreflective areas involving the outer retinal layers which include retinal pigment epithelium (RPE), photoreceptor outer segment tips (POST), inner segment–outer segment (IS/OS) junction, external limiting membrane (ELM), and outer nuclear layer (ONL) with choroidal and intraretinal layer cells infiltrate. EDI-OCT showed increase choroidal thickness. As the lesions began to heal, irregular, knobby elevations of outer retinal layers appeared (RPE, POST, IS/OS junction, and ELM could not be distinguished) with significant decrease in choroidal and intraretinal cells. On complete healing, loss of RPE, POST, IS/OS junction, and ELM in SD-OCT scan and absent of the choroidal and intraretinal cells and continous hyperreflactivity of the choroid (increased penetrance). Conclusion SD-OCT and EDI-OCT provides high-resolution detail regarding ultrastructural changes in vitreoretinal interface, outer retina and choroid during the course of the lesion. Serial SD-OCT and EDI-OCT also provides further insight into response to therapy by observing choroidal and intraretinal cells.
Apr 2019 DOI 10.14302/issn.2998-4211.jalr-19-2658
Alzheimer’s Disease (AD) is one amongst the overwhelming types of dementia that distresses the brain nerve cells leading to a perpetual loss in memory and creating a lot of difficulties for the family members in caretaking. The prediction of the disease at an earlier stage is a common problem. The most prevalent imaging modalities used for diagnosing AD are Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT). They can provide valuable information regarding the changes in internal and external brain regions and activities for diagnosing AD. But the relevant studies made on retina reveals that in addition to brain changes there are some variations on the retina layers of the AD patients. Therefore, the retina can be used as a biomarker for diagnosing AD. There are different techniques available for an eye examination. Most noticeable of them are Fundus Imaging and Optical Coherence Tomography (OCT). In this paper, we have focused on OCT retinal images of AD patients for the early diagnosis of AD.
Aug 2018 DOI 10.14302/issn-2470-0436.jos-18-2222
Objective: The aim of the present study is to determine the efficiency of third year ophthalmology residents from a tertiary hospital in performing preliminary retinal examination to identify eyes at risk retinopathy of prematurity on the basis of retinal fundus findings up to International Classification of Retinopathy of Prematurity (ICROP) Zone II. Methods: This is a single-center, cross-sectional, prospective comparative research conducted from June to October 2015 at a tertiary training hospital in the Philippines. All infants referred for retinopathy of prematurity screening within the study period where included. The presence of retinal vessel dilatation and tortuosity were identified by third year ophthalmology residents using indirect funduscopy. The residents’ fundus findings were then compared to that of a retina consultant who is proficient in the diagnosis and management of retinopathy of prematurity (ROP). The Kappa index was used to rate inter-observer agreement. The correlation between ROP risk factors and the presence of abnormal retinal vessels were assessed using odd ratio computations. Fisher’s exact test was used to determine the correlation between retinopathy of prematurity and the presence of retinal dilatation and tortuosity. The McNemar’s test was also applied to determine significant differences in the retinal findings of the consultant and ophthalmology residents. Results: A total of 82 eyes of 41 premature infants were evaluated to determine if retinal findings observed by ophthalmology residents were comparable to that of a retina consultant. Odds ratios show that age of gestation, birth weight, and history of blood transfusion are significantly associated with the presence of retinopathy of prematurity. Retinal vessel tortuosity and dilatation are also more common among infants diagnosed with retinopathy of prematurity. There was no significant difference between the retinal vascular findings of the retina consultant and the third year ophthalmology resident in terms of identifying retinal vessel dilatation and tortuosity (P < 0.05). Conclusion: After sufficient and in-depth ophthalmology training, third year ophthalmologists, who will be general ophthalmologists in the future, can reliably identify eyes at risk for severe retinopathy of prematurity on the basis of retinal vascular dilatation and/or tortuosity.
Jan 2018 DOI 10.14302/issn.2578-8590.ipj-17-1910
Following ocular trauma and retinal detachment, gliotic changes in the retina may develop over the subsequent month, a process known as PVR (proliferative vitreoretinopathy). There have been no successful therapeutic interventions to inhibit PVR. The protein CTGF (Connective Tissue Growth Factor) has been associated with retinal PVR and other fibrotic diseases of the retina in clinical studies but the mechanistic link between different pathologies and retinal gliosis has not been determined. In addition, CTGF has been previously noted to be associated, in some cases, with YAP/TAZ (Yes-associated protein and Tafazzin protein complex), transcriptional regulatory proteins that change subcellular localization in response to mechanical cues, such as the stiffness of the underlying material. We have previously shown that the mRNA for CTGF is markedly (100-fold) upregulated in retinal Müller cells grown on soft substrates. In order to evaluate if the mechanism by which mechanotransduction modulating CTGF production in retinal Müller cells involves the YAP/TAZ complex, this study tests the influence of substrate stiffness on the time dependence of CTGF protein expression, as well as subcellular localization of YAP/TAZ using a conditionally-immortalized mouse retinal Müller cell line plated on laminin-coated, polyacrylamide substrates of varying elastic modulus. Changes were assayed using immunohistochemistry and ELISA (Enzyme-Linked ImmunoSorbent Assay). In retinal Müller cells, the relationship between elastic modulus and the pattern of CTGF protein expression was bimodal, with CTGF levels rising more rapidly for cells on hard substrates and more slowly for cells grown on soft substrates. In addition, nuclear localization of YAP/TAZ corresponded directly to the maximum CTGF expression.
Jun 2017 DOI 10.14302/issn.2470-0436.jos-17-1442
Objective: Determining the effects on macular ganglion cell layer thickness in patients using isotretinoin by utilization of optical coherence tomography. Material and Methods: Sixty eyes of 30 patients using isotretinoin and 60 eyes of 30 control group patients in the same age range were included in this study. The average age of the patients using isotretinoin was; 21.2 ± 3.62 years, whereas the average age of the patients in the control group was 22.7 ± 3.7 years. The thickness of the macular ganglion cell layer (GCL), the retinal nerve fiber layer (RNFL) and subfoveal macular thickness of all patients were measured with optical coherence tomography (OCT). Results: The macular ganglion cell layer thickness in the OCT of the patients using isotretinoin was measured as 61.6±4.6 µm, 62.4±4.4µm, for the right and left eye respectively, whereas the thickness in the control group was measured as 60.6±4.1µm, 61.2±4.9µm respectively. The retinal nerve fiber layer thickness in the OCT of the patients using isotretinoin was measured as 74.8±11.3µm, 76.2±12.3µm, for the right and left eye respectively, whereas the thickness in the control group was measured as 72.2±10.5µm, 74.1±1.9µm, respectively. Conclusions: No statistically significant difference was observed in the macular ganglion cell layer thickness, retinal nerve fiber layer thickness and macular thickness in terms of both the right and left eyes between the control group and patients using isotretinoin.
Apr 2017 DOI 10.14302/issn.2470-0436.jos-17-988
Photorefraction (PR) methods have beenwidely used for pediatric vision screening since the 1980’s. While PR is easy to implement, the accuracy of refractive error measurements in humans has been unsatisfactory, largely due to the variations of intraocular scattering, the retinal reflectance, and pupil size. The objective of our studies was to clinically evaluate the accuracy of refraction measurements of an improved PR-based device, the Dynamic Ocular Evaluation System (DOES), and to investigate whether the accuracy is affected by the patient’s age, race, and pupil size, which are relevant to individual intraocular scattering and retinal reflectance. We performed DOES measurements in 99 volunteers (198 eyes) under two environmental light conditions and using four fixation targets. These results were compared to the standard clinical refraction testing performed the same day. The correlation and standard deviation were determined by Bland-Altman analysis. The influence of intraocular scattering, retinal reflectance, and pupil size was evaluated by comparing results from different age groups, races, and lighting conditions. In the region between -4 diopter (D) and +4D, the device showed a binocular refraction measurement accuracy of 0.45 D, 0.3 D, and 0.18 D root-mean-square (RMS) error (n=1337) for spherical equivalent and cross cylinders Jo and J45, respectively. Inaccuracy increased at high refraction (>4D). Age, race, and pupil size did not appear to significantly affect DOES PR measurement. This suggests that enhancements in the PR system and analysis may satisfactorily correct intersubject variability that currently limits the clinical use of PR devices and measurements.
Apr 2016 DOI 10.14302/issn.2470-0436.jos-15-763
Background: Optic nerve head drusen are acellular hyaline deposits located anterior to the lamina cribrosa, frequently associated with visual field defects. Sometimes rapid worsening of vision may occur due to complications such as acute vascular events, choroidal neovascularization, or serous maculopathy. Case Presentation: Although there are no proven treatments for Optic nerve head drusen associated field loss, we present the case of a patient with Optic nerve head drusen and bilateral rapid progression of visual field loss that has stabilized on intraocular pressure lowering medication. This suggests a role for IOP-mediated retinal ganglion cell loss in this individual. The mechanism of progressive Optic nerve head drusen associated field loss is poorly understood, however experimental glaucoma models and human in vivo imaging studies have shown that structural differences within the optic nerve head are likely to contribute to individual susceptibility to IOP-mediated damage. Conclusion: We propose that eyes with Optic nerve head drusen may be less able to dampen IOP mediated stress, contributing to loss of retinal ganglion cells in some patients.