OBJECTIVE: The present study was aimed to compare the epidemiological and ocular findings of twin children in comparison with non- twin age matched individuals as their control.
METHODS: In this cross sectional study, a total of 90 twins (180 cases) were compared with 182 non- twin matched children. All the study participants were examined by a comprehensive ophthalmic examination including measurement of the best corrected visual acuity (BCVA), cycloplegic refraction, ocular deviation, strabismus as well as the anterior and posterior ophthalmic examinations. Demographic information of children were collected by using an organized questionnaire. Monozygotic twins were considered if there were similarity of their phenotypic characteristics and gender, otherwise the twins were considered as dizygotic.
RESULTS: The mirror- image twins (MIT) was defined according to the laterality of symmetrical ocular characteristics of twins. In this study, the mean age of the study participants was 7.08±4.42 and 7.58±3.99 years in twins and non-twins groups, respectively (P=0.253). Among the twins, 27 (30%) were monozygotic. Refractive form of MIT was seen in 5 twins (2.8%). The spherical refractive error was more hyperopic in twins compared to non- twins (P=0.041). BCVA in the twin group (0.07±0.16LogMAR) was significantly worse than non-twins (0.03±0.08LogMAR, P < 0.001) and higher percentage of them were amblyopic (37.2% versus 10.4%, P=0.005). Twin and controls had strabismus in 17.2% and 1.6%, respectively (P < 0.001). Regarding the comparison between mono- and dizygotic twins, more significant percentage of monozygotic twins had amblyopia (P=0.004) and strabismus (P=0.047). Multivariate analysis showed significant correlation among low gestational age and female gender, low birth weight and seizure.
CONCLUSIONS: Female sex, less gestational age, low birth weight, amblyopia and strabismus were significantly higher in twins. Therefore, it is important to check their refractive error, amblyopia and strabismus to prevent their further complications.

UNASSIGNED: Ocular manifestations are seen in several autoimmune disorders including spondyloarthritis (SpAs). Though acute anterior uveitis (AAU) is the hallmark of SpAs, episcleritis and scleritis are also seen. Genetic and geographical factors impact the prevalence of AAU; however, available evidence support that HLA-B27 positivity is closely associated with it.
UNASSIGNED: The current narrative review is focused on clinical features of AAU and its management.
UNASSIGNED: For the purpose of this narrative review; literature search covered MEDLINE, Google scholar and EMBASE databases and included articles published in English language from January 1980 till April 2022 using the following keywords: \"Ankylosing spondylitis\", \"Spondyloarthritis\", \"Eye manifestations\", \"Ocular\", \"Uveitis\" and \"Arthritis\".
UNASSIGNED: Patients with SpA may suffer from different ocular complications with uveitis being the most common one. Biological therapy is a promising medical strategy enabling in achieving therapeutic goals with minimal adverse effects. An effective management strategy for patients with AAU associated with SpA could be formulated by the collaboration between ophthalmologists and rheumatologists.

UNASSIGNED: To identify ocular findings related to SARS-CoV-2 infection in patients after the resolution of COVID-19 using complete ocular examinations and optical coherence tomography (OCT).
UNASSIGNED: In this cross-sectional study, conducted from May 30 to October 30, 2020, patients who recovered from various stages COVID-19 underwent eye examination and multimodal retinal imaging (Retinographies and Spectral-OCT).
UNASSIGNED: We included 50 patients, 29 (58%) males, median age of 46.5 [standard deviation 15.8]. Of these, 42% (21) had mild, 18% (9) had severe and 40% (20) had critical disease. The median time interquartile range (IQR) between symptom onset and ocular examination was 55 days [IQR 39-71]. Seven patients (14%) reported ophthalmic symptoms, transitory low visual acuity (6%) and retroocular pain (8%). On OCT, one patient without comorbidities had sectoral retinal pallor suggestive of acute retinal ischaemia and oedema of the retina\'s inner layers and atrophy. All findings progressively and spontaneously improved months after resolution of COVID-19.
UNASSIGNED: Patients with COVID-19 present findings compatible with the general population depending on age and comorbidities; nevertheless, acute retinal findings associated with the disease may be present, such as caused either by the direct effects of retinal SARS-CoV-2 infection, by indirect effects of the cytokine storm or by the pro-thrombotic state associated with COVID-19. Therefore, retinal involvement in patients with COVID-19 remains subject to considerable discussion and study.

UNASSIGNED: This study aimed to assess the prevalence of ocular manifestations and associated factors in patients on haemodialysis.
UNASSIGNED: A cross-sectional study of patients on haemodialysis from a haemodialysis unit in Nablus, Palestine, was conducted. Medical examination for ocular manifestations (intraocular pressure, cataract, retinal changes and optic neuropathy) was performed using Tono-Pen, portable slit-lamp and indirect ophthalmoscope. Predictor variables were age, gender, smoking, medical comorbidities (diabetes, hypertension, ischaemic heart disease [IHD], peripheral arterial disease [PAD]) and use of antiplatelet or anti-coagulation medications.
UNASSIGNED: A total of 191 patients were included in this study. The prevalence of any ocular manifestation in at least one eye was 68%. The most common ocular manifestations were retinal changes (58%) and cataract (41%). The prevalence of non-proliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR) and NPDR or PDR was 51%, 16% and 65%. Two patients had PDR in one eye and NPDR in the other, and therefore, they were counted only once making the total for this category 71 rather than 73 patients. An increase in age by one year increased the odds of having cataract by 1.10 (95% confidence interval [CI] = 1.06-1.14). Patients with diabetes had higher odds of having cataract (odds ratio [OR] = 7.43, 95% CI: 3.26-16.95) and any retinal changes (OR = 109.48, 95% CI: 33.85-354.05) than patients without diabetes. Patients with diabetes and IHD or PAD had higher odds of having NPDR than those with diabetes without IHD or PAD (OR = 7.62, 95% CI: 2.07-28.03).
UNASSIGNED: Retinal changes and cataract are common ocular manifestations among patients on haemodialysis. The findings emphasise the importance of periodic screening for ocular problems in this vulnerable population, especially older patients and those with diabetes, to prevent visual impartment and associated disability.

The coronavirus disease 2019 (COVID-19) has become the most critical health crisis at present, and research is continued about the exact pathophysiology, presentations, and complications of this pandemic. It influences several organs, and many studies have addressed the organs, the involvement of which during the COVID-19 results in patients\' death. One of the important organs that can be involved during COVID-19, which is also a transmission route of the disease, is the eye. According to the evidence, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can have ocular manifestations and complications. According to the literature, conjunctivitis is the most common presentation, which can develop at any stage of COVID-19 (during and even after the disease), and the major pathophysiology of the eye involvement during the disease is attributed to the direct effect of the virus on the eyes, tissue damage caused by inflammation, underlying diseases, and the adverse effect of the medications prescribed. There are also reports of life-threatening complications, such as rhino-orbital cerebral mucormycosis, which require urgent treatment and are associated with a great mortality rate. Ocular manifestations may also be the presentation of a life-threatening event, such as stroke; therefore, it is necessary to pay great attention to the ocular manifestations during COVID-19. In this review, after about 2 years of the pandemic started, we present a narrative review on ocular manifestations during COVID-19, categorized into three main categories; ophthalmic, orbital, and neuro-ophthalmological manifestations with a detailed description of the presenting symptoms, risk factor, diagnostic, and therapeutic strategies suggested for each.

This paper analyzes, from a bibliometric viewpoint, those publications that relate COVID-19 and eye indexed in Scopus since the beginning of the pandemic, and it identifies the resulting main research lines. A bibliographic search in the Scopus database was conducted for publications that simultaneously include ocular and visual manifestations and aspects with COVID-19, from 1 January 2020 to 16 March 2021, and the obtained bibliographic information was processed with VOSviewer (v. 1.6.16). A total of 2206 documents were retrieved, and 60% were original articles. The USA published the most studies (24.6%). The retrieved documents had a total of 18,634 citations. The h index of the set of retrieved documents was 58. The Indian Journal of Ophthalmology was the most productive journal, while JAMA Neurology and The Lancet accounted for 20% of citations. Three keyword clusters representing hotspots in this field were identified. Eye-related COVID-19 research is an emerging field with plenty of scientific evidence whose growth is expected to increase as the aspects and manifestations of the disease, its treatment and the effect of vaccination on it become known.

BACKGROUND: Ocular involvement in patients with transfusion-dependent β-thalassemia is quite common, and its frequency differs among studies. This case series aimed to describe the ocular abnormalities occurring in β-thalassemia patients who need regular blood transfusions and receive iron chelation therapy.
METHODS: This is a case series prospectively studied 32 β-thalassemia patients from Northern Greece receiving regular blood transfusions and iron-chelating therapy. Patients\' average age was 35.5 years. Eighteen patients with major phenotypes and fourteen patients with intermedia type underwent comprehensive ophthalmic examination at the time of enrolment, including visual acuity evaluation, refraction and color vision tests, Amsler grid test, slit-lamp, and dilated-pupil fundus examination. Additionally, we performed visual field testing and optical coherence tomography in all patients and fluorescein angiography only in selected cases. After six months, patients\' complete ophthalmic examination was repeated for any new ocular findings due to the disease process and iron chelation therapy. Ocular involvement was detected in 46.87 % of the patients. Lesions were most frequently seen in elderly patients with thalassemia major. Lens opacities were present in 21.8 %, and degeneration of the retinal pigment epithelium was described in 15.6 % of the patients, representing the commonest fundus alteration observed, followed by fundus atrophy. The most severe and vision-threatening condition described in this study was the presence of angioid streaks with choroidal neovascularisation. Six months follow-up of patients did not reveal any new ocular findings.
CONCLUSIONS: Early detection of severe ocular abnormalities is important in patients with thalassemia; thus, an ophthalmologic examination should be included at regular check-ups. An annual examination is currently indicated for asymptomatic patients, while in symptomatic and complicated cases, patients should be closely followed-up. HIPPOKRATIA 2021, 25 (2):79-82.

Down syndrome (DS) is a chromosomal anomaly that is characterized by an extra chromosome 21. Ophthalmological manifestations have a high prevalence in patients with DS.
To review the scientific evidence and estimate the prevalence of ophthalmological manifestations in the pediatric population with DS.
Electronic databases including MEDLINE, Cochrane Library, EMBASE, ScienceDirect, and LILACS.
Published observational studies with available and original data were included. Articles were excluded if the study design was a review, letter to the editor, case report, case series, or systematic review and if the subjects had ophthalmological manifestations secondary to other conditions.
Pediatric and adolescent population with DS and with ophthalmological evaluation.
A data collection form was designed in Excel. Five reviewers extracted relevant details about the design and results of each study. The quality of the studies was assessed by applying the tools for systematic reviews of prevalence and incidence from the Joanna Briggs Institute. We calculated the weighted prevalence of ophthalmological manifestations, considering only the studies reporting the measurement of each manifestation.
Twenty-two articles (from 15 countries, published during 1994-2020) were included in the present systematic review. Ocular manifestations were observed in 85% of the studied pediatric and adolescent populations with DS. The most frequent ones were slanting fissures, oblique fissures, epicanthus, and epiblepharon.
The ocular manifestations in the pediatric and adolescent populations with DS are varied, and some can irreversibly affect visual development. Screening of the pediatric population with DS should be conducted from the first months of age and continued annually.
PROSPERO CRD42019127717.

OBJECTIVE: This study aimed to detect SARS-CoV-2 in conjunctival samples of COVID-19 patients to investigate the transmission route of COVID-19 and its correlation with laboratory indexes.
METHODS: In this cross-sectional study, 44 COVID-19 patients were tested for conjunctival PCR in Ayatollah Rouhani hospital of Babol, Iran, in January and February 2021. The conjunctival samples were collected using a conjunctival swab and suspended in a viral transport medium. After RNA extraction and cDNA synthesis, real-time PCR was performed to investigate the SARS-CoV-2 genome in samples. The ocular manifestations and laboratory indexes were evaluated for all patients.
RESULTS: Among 44 COVID-19 patients, 6 samples (13.63%) were positive in terms of conjunctival PCR. The mean ± SD age of conjunctival PCR-positive patients was 76.17 ± 16.61-year-old, while conjunctival PCR-negative COVID-19 patients were aged 57.54 ± 13.61-year-old (p <0.05). D-dimer serum level is significantly higher in conjunctival PCR-positive COVID-19 patients (4001.00 ± 3043.36 μg/ml) compared to normal individuals (496.80 ± 805.92 μg/ml, p <0.01).
CONCLUSIONS: Our study showed that the conjunctiva and tear contain the SARS-CoV-2 in COVID-19 patients as a possible transmission route.

BACKGROUND: Since the first cases of human immunodeficiency virus (HIV), ocular manifestations secondary to infection have been known and these have been related to the CD4+ lymphocyte count.
OBJECTIVE: To describe the correlation between ocular manifestations in patients with HIV and the CD4+ lymphocyte count.
METHODS: Analytical cross-sectional study of patients with HIV whose CD4+ count was correlated with the presence of ophthalmological manifestations.
RESULTS: 21 patients between 26 and 67 years were studied. Only 3 patients were not on antiretroviral therapy. 67% of the patients presented some type of ocular manifestation, 42% presented non-infection related manifestations, 47% related manifestations and 24% both. Conjunctival microangiopathy was the most frequent ocular manifestation (35.7%). There was a statistically significant correlation (r = 0.76, p = 0.0001) between eye manifestations related to infection and CD4+ lymphocyte count.
CONCLUSIONS: Patients with HIV frequently present ocular manifestations, the majority related to infection; there is a correlation between the presence of these with the CD4+ count. However, a similar number of manifestations not related to infection occurred without correlation with the count; therefore, HIV patients should have periodic ophthalmological examinations, independently of CD4+ count.
UNASSIGNED: desde los primeros casos de virus de inmunodeficiencia humana (VIH), se conocen manifestaciones oculares secundarias a la infección y estas se han relacionado con el conteo de linfocitos CD4+.
OBJECTIVE: describir la correlación entre las manifestaciones oculares en pacientes con VIH y el conteo de linfocitos CD4+.
UNASSIGNED: estudio transversal analítico de pacientes con VIH, en quienes se analizó la correlación entre conteo de CD4+ y manifestaciones oftalmológicas.
RESULTS: se incluyeron 21 pacientes entre 26 y 67 años de edad. Solo tres no se encontraban en terapia antirretroviral. El 67% presentó algún tipo de manifestación ocular, 42% presentó manifestaciones no relacionadas con la infección, 47% manifestaciones relacionadas y 24% ambas. La microangiopatía de la conjuntiva fue la manifestación ocular más frecuente (35.7%). Hubo una correlación estadísticamente significativa (r = 0.76, p = 0.0001) entre las manifestaciones oculares relacionadas con la infección y el conteo de linfocitos CD4+.
CONCLUSIONS: los pacientes con VIH presentan con frecuencia manifestaciones oculares, la mayoría asociadas a la infección. Existe correlación entre la presencia de estas con el conteo de CD4+; sin embargo, un número similar de manifestaciones no asociadas a la infección se presentaron sin correlación con el conteo, por lo que los pacientes con VIH deberían tener revisiones oftalmológicas periódicas, independientemente del conteo de CD4+.