Medical Hypothesis, Discovery, and Innovation in Ophthalmology最新文献

{"title":"Finite element analysis of asymmetrical retinal hemorrhages in shaken baby syndrome.","authors":"Elliot H Choi, Jose A Colmenarez, John D Hong, Kourosh Shahraki, Linxia Gu, Donny W Suh","doi":"10.51329/mehdiophthal1514","DOIUrl":"10.51329/mehdiophthal1514","url":null,"abstract":"<p><strong>Background: </strong>Despite the common association between bilateral retinal hemorrhage and shaken baby syndrome (SBS), unilateral retinal hemorrhage does not necessarily exclude this diagnosis. This study used computational simulations to elucidate the biomechanical phenomena within the eye under asymmetrical shaking forces.</p><p><strong>Methods: </strong>Finite element analysis (FEA) incorporating the vitreous, vitreoretinal interface, retinal layers, and retinal vessels was performed under asymmetrical shaking conditions. To assess the stress-strain response at the preretinal, intraretinal, and subretinal locations, we divided the retinal mesh into three equally spaced layers with an element height of 0.083 mm. The remaining space within the retina was filled with the vitreous humor and attached to it via the main retinal vessels extracted from a standard fundus image. The resulting changes in shear stress and intraocular pressure (IOP) were quantified.</p><p><strong>Results: </strong>The FEA model demonstrated that increasing the rotational radius from 10 cm to 14 cm or 17 cm led to a significant increase in shear stress and IOP across the vitreoretinal interface and within the retinal layers. Specifically, shear stress in the preretinal layer increased by 70.2% (8.0 kPa vs. 4.7 kPa), in the intraretinal layer by 20.0% (5.4 kPa vs. 4.5 kPa), and in the subretinal layer by 6.1% (3.5 kPa vs. 3.3 kPa). Simultaneously, IOP in the central region increased by 157.5% (39.4 mmHg vs. 15.3 mmHg) and in the posterior region by 162.3% (41.7 mmHg vs. 15.9 mmHg) when the rotational radius was increased to 17 cm from 10 cm. Increasing the rotational radius to 17 cm led to more pronounced changes in peak IOPs, with the central region showing a change of 39.4 mmHg and the posterior region a change of 41.7 mmHg. These results indicate a direct correlation between the rotational radius and the magnitude of IOP changes in the vitreous.</p><p><strong>Conclusions: </strong>These findings highlight the critical impact of rotational radius on the biomechanical forces exerted within the eye during asymmetrical shaking events, leading to variations in shear stress and IOP that could contribute to unilateral retinal hemorrhage in SBS. These insights reveal the complexity of diagnosing SBS and emphasize the need for careful consideration of the biomechanical evidence in patients presenting with asymmetrical or unilateral retinal hemorrhage.</p>","PeriodicalId":36524,"journal":{"name":"Medical Hypothesis, Discovery, and Innovation in Ophthalmology","volume":"14 1","pages":"231-238"},"PeriodicalIF":0.0,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12121674/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144200328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intracorneal ring segment implantation for eyes with keratoconus and corneas thinner than 400 microns.","authors":"Hazem Mohamed Abdelhameed, Ahmed S Abo Obaia, Akram Fekry Elgazzar, Ramy Saleh Abd Ellatief Amer, Haitham Beshr Soliman, Riad Elzaher Hassan Ahmed, Shaimaa M Mostafa","doi":"10.51329/mehdiophthal1513","DOIUrl":"10.51329/mehdiophthal1513","url":null,"abstract":"<p><strong>Background: </strong>Intracorneal ring segment (ICRS) implantation is a promising and effective treatment option for keratoconus. However, a corneal thickness of less than 400 microns presents a unique challenge. This study assessed the clinical course and visual outcomes in patients with Amsler-Krumeich stage 2 or greater keratoconus and clear corneas, with a minimal corneal stromal thickness of 350 microns but less than 400 microns in the proposed implantation area, up to 6 months after ICRS implantation.</p><p><strong>Methods: </strong>This non-randomized, prospective, interventional case series was conducted at a single tertiary center, consecutively recruiting patients with keratoconus scheduled for ICRS implantation who fulfilled the eligibility criteria. Detailed ophthalmological assessments were performed at baseline and 6 months postoperatively, including measurements of uncorrected distance visual acuity (UCDVA), best corrected distance visual acuity (BCDVA), and manifest refraction with documentation of the spherical component of the refractive error (in diopters [D]), cylindrical component of refractive error (in diopter cylinder [DC]), and axis of astigmatism (in degrees). Corneal topographic and pachymetric evaluations were performed using Pentacam HR, including keratometry (K) values in D (flat K or K1, steep K or K2, and mean K or Km), corneal astigmatism in DC, central corneal thickness (CCT), and corneal asphericity coefficient (Q value).</p><p><strong>Results: </strong>We included nine eyes of nine patients with keratoconus and a mean (standard deviation) age of 33.2 (8.2) years (range: 25-44 years). Five patients were women (56%), and four were men (44%). All eyes experienced a statistically significant improvement in the mean visual and refractive outcomes at the 6-month postoperative visit, including UCDVA, BCDVA, sphere, and cylinder (all <i>P</i> < 0.05). Similarly, we recorded a statistically significant improvement in the mean corneal tomographic and topographic data, including the K1, K2, Km, CCT, and Q values (all <i>P</i> < 0.05). No serious complications occurred for up to 6 months of follow-up. Only one patient complained of night glare, which was successfully treated with pilocarpine 1% eyedrops for 3 months.</p><p><strong>Conclusions: </strong>ICRS implantation may offer a safe and effective option for selected patients with keratoconus and corneal thickness less than 400 microns, as evidenced by short-term improvements in visual, refractive, topographic, and tomographic parameters. No vision-threatening complications occurred. However, given the case-series study design, limited sample size, and short follow-up period, these findings should be interpreted with caution. Further controlled trials are required to validate these preliminary results.</p>","PeriodicalId":36524,"journal":{"name":"Medical Hypothesis, Discovery, and Innovation in Ophthalmology","volume":"14 1","pages":"223-230"},"PeriodicalIF":0.0,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12121676/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144200329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vascular supply of the eye: clinical anatomy.","authors":"Omer Karti, Isil Saatci, Ali Osman Saatci","doi":"10.51329/mehdiophthal1509","DOIUrl":"10.51329/mehdiophthal1509","url":null,"abstract":"<p><strong>Background: </strong>Eye function is vitally dependent on an adequate blood supply, primarily provided by the ophthalmic artery, an internal carotid artery branch. This review provides an overview of the vascular supply of the eye.</p><p><strong>Methods: </strong>A targeted search of PubMed / MEDLINE was performed using the terms \"central retinal vein,\" \"central retinal artery,\" \"internal carotid artery,\" \"ophthalmic artery,\" \"ophthalmic vein,\" \"posterior ciliary arteries,\" \"retinal capillaries,\" \"vascular supply of the eye,\" \"ocular vascular supply,\" \"external carotid artery,\" and \"vortex vein\". Studies published between 1960 and 2024 were reviewed. Relevant references cited in these publications were also analyzed.</p><p><strong>Results: </strong>Overall, 62 publications were reviewed. The ophthalmic artery branches into several arteries-the central retinal artery supplies the retina, whereas the posterior ciliary arteries supply the posterior choroid and optic nerve. The anterior ciliary arteries mainly supply the conjunctiva, sclera, ciliary body, and iris. Extraocular muscles receive their primary blood supply from the muscular branches of the ophthalmic artery, lacrimal artery, and infraorbital artery. The lacrimal gland is perfused by the lacrimal artery. The eyelids receive blood from both the internal and external carotid arteries. The superficial vascular network of the medial eyelid skin is established primarily through anastomoses between the branches of the internal carotid artery. The superficial vascular network of the lateral upper and lower eyelids is primarily derived from branches emanating from the superficial temporal artery (a branch of the external carotid artery) and the lacrimal artery. Venous drainage follows a complex pathway, beginning with the central retinal vein and the vortex veins, then draining into the ophthalmic veins, and finally into the internal jugular vein.</p><p><strong>Conclusions: </strong>The eye features a complex arterial supply and venous drainage that can vary greatly among individuals. This complex vascular system is critical for the oxygenation and nutrition of ocular tissues and the maintenance of ocular health. The arterial and venous circulation coordinate to support different regions of the eye, including the retina, choroid, and optic nerve. Understanding this intricate vascular network is essential for the diagnosis and treatment of various ocular pathologies. Abnormalities in these pathways can cause substantial problems, including vision loss.</p>","PeriodicalId":36524,"journal":{"name":"Medical Hypothesis, Discovery, and Innovation in Ophthalmology","volume":"13 4","pages":"176-189"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11890264/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143597953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review on retinopathy of prematurity.","authors":"Pegah Rashidian, Shaghayegh Karami, Seyyed Amirhossein Salehi","doi":"10.51329/mehdiophthal1511","DOIUrl":"10.51329/mehdiophthal1511","url":null,"abstract":"<p><strong>Background: </strong>Retinopathy of prematurity (ROP) is a leading cause of childhood blindness. It predominantly affects preterm infants with very low birth weights or extreme prematurity. Aberrant retinal vascular development, driven by hyperoxia and hypoxia-induced neovascularization, is central to ROP pathogenesis. This review explores the relationship between maternal health and ROP, evaluates current prevention strategies, assesses innovations in diagnostic and screening technologies, reviews contemporary treatments, and identifies future research directions.</p><p><strong>Methods: </strong>A literature review was conducted in the PubMed / MEDLINE, Scopus, Web of Science, and Google Scholar databases using related keywords, i.e., \"retinopathy of prematurity,\" \"retinal development,\" \"pathophysiology,\" \"vascular growth,\" \"complications,\" \"visual outcomes,\" \"maternal health factors,\" \"obstetrics,\" \"preeclampsia,\" \"risk factors,\" \"preterm birth,\" \"corticosteroids,\" \"oxygen management,\" \"treatment strategies,\" \"laser therapy,\" \"anti-VEGF agents,\" \"surgical approaches\", and \"artificial intelligence (AI)\" and targeting English studies published in the last 20 years. Additionally, the references from the selected articles were manually reviewed. Clinical trials, meta-analyses, systematic reviews, case-control studies, case series, narrative reviews, pilot studies, and relevant animal studies were included.</p><p><strong>Results: </strong>Maternal factors, such as diabetes, smoking, and preeclampsia, along with neonatal factors, such as low gestational age and extreme prematurity, are critical contributors to ROP. Key preventative strategies to reduce the risk of ROP and improve neonatal outcomes include: 1. prenatal care involves screening and managing maternal conditions, providing maternal education, and administering antenatal corticosteroids. 2. Neonatal care encompasses nutritional support, supplementation with essential fatty acids, and regulated oxygen administration. By focusing on these strategies, we can enhance the health of newborns at risk for ROP. Advances in screening, including artificial intelligence (AI)-assisted diagnostics and advanced imaging, are improving early detection. Treatment modalities such as laser photocoagulation, cryotherapy, and anti-vascular endothelial growth factor therapies have shown promise but pose challenges, including recurrence risk and systemic side effects.</p><p><strong>Conclusions: </strong>ROP continues to pose a major threat to the vision of preterm infants, particularly in regions with limited healthcare resources. Addressing ROP requires multidisciplinary team approaches that integrate obstetric and neonatal care. Preventative strategies, including prenatal care optimization, oxygen management, and nutritional support, are essential. Future efforts should focus on integrating emerging technologies and recent findings to ensure global relevance and currency.</p>","PeriodicalId":36524,"journal":{"name":"Medical Hypothesis, Discovery, and Innovation in Ophthalmology","volume":"13 4","pages":"201-212"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11890260/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143597922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Topical tacrolimus versus dexamethasone in managing shield ulcer of vernal keratoconjunctivitis.","authors":"Nima Rastegar Rad, Nazanin Rastgarrad","doi":"10.51329/mehdiophthal1507","DOIUrl":"10.51329/mehdiophthal1507","url":null,"abstract":"<p><strong>Background: </strong>Vernal keratoconjunctivitis (VKC) is a bilateral, chronic, allergic inflammation of the ocular surface with debilitating ocular signs and symptoms. We compared the efficacies and safeties of 1% tacrolimus eye drops and 1% dexamethasone eye drops in managing unilateral shield ulcers and corneal epitheliopathy secondary to VKC.</p><p><strong>Methods: </strong>We recruited patients with unilateral shield ulcer and corneal epitheliopathy secondary to VKC in a tertiary referral center in southeast Iran during a 12-month period. All eligible patients underwent a detailed eye examination. Participants were randomly assigned to receive either topical tacrolimus 1% or dexamethasone 1% twice daily. We recorded the best-corrected distance visual acuity (BCDVA) in decimal notation, area of the shield ulcer in square millimeters, presence or absence of re-epithelialization, and clinical symptoms of watering, mucus discharge, photophobia, burning, redness, and itching, along with any potential complications at five follow-up visits during a period of four months.</p><p><strong>Results: </strong>Thirty patients (30 eyes) were allocated to each treatment group. The groups had comparable mean ages and sex distributions (both <i>P</i> > 0.05). Both groups experienced a decreasing trend in frequencies of all symptoms, and at most follow-up visits, ocular symptoms were less frequent in the tacrolimus group than in the dexamethasone group, reaching statistically significant differences at some time points (all P < 0.05). No re-epithelialization was detected in either group at the second week post-treatment. However, an increasing trend was observed thereafter in both groups, with significantly more re-epithelialization in tacrolimus-treated eyes at the second and third months post-treatment (<i>P</i> < 0.05). Re-epithelialization remained significantly more frequent in tacrolimus-treated eyes one month after cessation of treatment (<i>P</i> < 0.05). The mean BCDVA was significantly better in tacrolimus-treated eyes than in the dexamethasone group at all follow-up visits (all <i>P</i> < 0.01). The mean shield ulcer size tended to decrease in both groups, with lesser numerical values in tacrolimus-treated eyes at the one-, two-, three-, and four-month follow-up visits. The difference reached statistical significance at the last two follow-up visits (both <i>P</i> < 0.05).</p><p><strong>Conclusions: </strong>Topical tacrolimus is superior to topical dexamethasone with regard to symptoms, visual acuity, shield ulcer size, and corneal epitheliopathy associated with VKC. This suggests that tacrolimus could be administered as monotherapy for managing this debilitating ocular inflammatory condition. Further studies are required to determine the long-term safety and efficacy of this promising treatment modality.</p>","PeriodicalId":36524,"journal":{"name":"Medical Hypothesis, Discovery, and Innovation in Ophthalmology","volume":"13 4","pages":"160-168"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11890262/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143597950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Visio-spatial intelligence skills in non-athletes versus amateur boxers.","authors":"S'bongile Mahlangu, Musa Lewis Mathunjwa, Gerrit Jan Breukelman, Lourens Millard","doi":"10.51329/mehdiophthal1508","DOIUrl":"10.51329/mehdiophthal1508","url":null,"abstract":"<p><strong>Background: </strong>Visio-spatial intelligence (VSI) skills, including abilities such as spatial awareness, visual processing, and motor coordination, are crucial for athletic performance, particularly in combat sports such as boxing. Amateur boxers require efficient visio-spatial skills (VSS) to quickly process visual information, track opponents' movements, and execute precise techniques. However, the extent to which amateur boxing experience enhances VSS remains unclear. This study compared the VSI skills of amateur boxers to those of non-athletes.</p><p><strong>Methods: </strong>This cross-sectional, observational study recruited amateur boxers and non-athletes in the King Cetshwayo District, KwaZulu-Natal, Republic of South Africa. Participants, aged 18 to 27 years, underwent a detailed optometric screening and VSS tests, including accommodation facility, saccadic eye movements, speed of recognition, hand-eye coordination, peripheral awareness, and visual memory.</p><p><strong>Results: </strong>The study included 90 participants, consisting of 45 amateur boxers (28 [62%] men aged 18 to 25 years and 17 [38%] women aged 18 to 27 years) and 45 non-athletes (29 [64%] men aged 18 to 26 years and 16 [36%] women aged 18 to 27 years). The mean (standard deviation) age of the boxers was 20.7 (2.2) years, whereas the mean age of the non-athletes was 21.9 (2.4) years (<i>P</i> < 0.05). Amateur boxers were superior in VSS, with marked advantages in accommodation facility, saccadic eye movement, speed of recognition, peripheral awareness, and hand-eye coordination (all <i>P</i> < 0.001). However, no significant difference was found in visual memory (<i>P</i> > 0.05). The greatest difference was observed in speed of recognition (88% higher in boxers), and the least difference was observed in visual memory (4% higher in boxers).</p><p><strong>Conclusions: </strong>VSS differ between amateur boxers and non-athletes, indicating the importance of these skills for athletic performance. These findings emphasize the potential advantages of boxing training in enhancing VSS, which could impact athletic training and performance-enhancement strategies. This underscores the value of integrating visio-spatial training into athletic programs. The observed superiority of boxers in specific VSS areas has broad implications for theories of sports vision, the selection of appropriate tests, and the development of sport-specific VSS testing protocols. Further longitudinal studies with larger sample sizes are required to verify these findings and assess changes in these skills over time.</p>","PeriodicalId":36524,"journal":{"name":"Medical Hypothesis, Discovery, and Innovation in Ophthalmology","volume":"13 4","pages":"169-175"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11890263/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143597958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ocular Surface Disease Index questionnaire in different languages.","authors":"Mohammed Aljarousha, Waleed M Alghamdi, Sara Attaallah, Mohammed Abdelfatah Alhoot","doi":"10.51329/mehdiophthal1510","DOIUrl":"10.51329/mehdiophthal1510","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;The Ocular Surface Disease Index (OSDI) questionnaire was first introduced and developed in 1997 by the Outcomes Research Group, and was adopted by Allergan, Inc. (Irvine, Goleta, CA). While several tools are available for evaluating dry eye syndrome (DES), the OSDI questionnaire is known to have high reliability and validity. Additionally, although more complex questionnaires are available, the goal of the OSDI is to ensure a rapid diagnosis of ocular surface disease. The OSDI consists of a 12-item questionnaire designed to assess the visual disability caused by DES. The OSDI score can range from 0 to 100, with higher scores indicating greater disability. This language-inclusive mini-review aimed to provide a comprehensive overview of previous studies that translated the OSDI into various languages and validated the translated versions.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;OSDI validation studies were identified through a PubMed / MEDLINE and Google Scholar search spanning the 27 years since the establishment of the OSDI, using the broad term \"Ocular Surface Disease Index-12 questions\" and keywords that is \"ocular surface disease index-12,\" \"translation and validation,\" \"transcultural validation,\" \"development,\" \"cross-cultural adaptation,\" and \"reliability and validity.\" We included original studies that validated the translated version of the OSDI in various languages, presenting the key findings with a focus on reliability and repeatability outcomes.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;Thirteen full-text articles were thoroughly reviewed, including those identified through targeted keyword searches and the reference lists of these studies. The papers examined the translation of the English version of the OSDI-12 questionnaire into nine languages: Italian, Arabic, Chinese, Chilean Spanish, Japanese, Filipino, Farsi, Bahasa Melayu, and Brazilian Portuguese. Key details regarding the development, translation, and validation phases were summarized. Most of the included studies adhered to standard guidelines throughout the translation process to create a final version of the OSDI questionnaire. This was followed by clinical validation of the final translated version. The majority of the translated versions were assessed for internal consistency, reliability, test-retest repeatability, and discriminant validity.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;The original English version of the OSDI was translated into validated versions to achieve a final version in nine different languages. The majority of the translated versions demonstrated high reproducibility and reliability. The different language versions of the questionnaire removed language barriers in informing the eye-care community, evaluating DES, and assisting physicians in advising and managing their patients more suitably. Therefore, the validated versions of OSDI can be used as tools for clinical practice and DES research. Validating the OSDI questionnaire in various la","PeriodicalId":36524,"journal":{"name":"Medical Hypothesis, Discovery, and Innovation in Ophthalmology","volume":"13 4","pages":"190-200"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11890261/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143597864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application and interpretation of linear-regression analysis.","authors":"Narges Roustaei","doi":"10.51329/mehdiophthal1506","DOIUrl":"10.51329/mehdiophthal1506","url":null,"abstract":"<p><strong>Background: </strong>Linear-regression analysis is a well-known statistical technique that serves as a basis for understanding the relationships between variables. Its simplicity and interpretability render it the preferred choice in healthcare research, including vision science, as it enables researchers and practitioners to model and predict outcomes effectively. This article presents the fundamentals of linear-regression modeling and reviews the applications and interpretations of the main linear-regression analysis.</p><p><strong>Methods: </strong>The primary objective of linear regression is to fit a linear equation to observed data, thus allowing one to predict and interpret the effects of predictor variables. A simple linear regression involves a single independent variable, whereas multiple linear regression includes multiple predictors. A linear-regression model is used to identify the general underlying pattern connecting independent and dependent variables, prove the relationship between these variables, and predict the dependent variables for a specified value of the independent variables. This review demonstrates the appropriate interpretation of linear-regression results using examples from publications in the field of vision science.</p><p><strong>Results: </strong>Simple and multiple linear regressions are performed, with emphasis on the correct interpretation of standardized and unstandardized regression coefficients, the coefficient of determination, the method for variable selection, assumptions in linear regression, dummy variables, and sample size, along with common mistakes in reporting linear-regression analysis. Finally, a checklist is presented to the editors and peer reviewers for a systematic assessment of submissions that used linear-regression models.</p><p><strong>Conclusions: </strong>Medical practitioners and researchers should acquire basic knowledge of linear-regression such that they can contribute meaningfully to the development of technology by accurately interpreting research outcomes. Incorrect use or interpretation of appropriate linear-regression models may result in inaccurate results. Appointing an expert statistician in an interdisciplinary research team may offer added value to the study design by preventing overstated results.</p>","PeriodicalId":36524,"journal":{"name":"Medical Hypothesis, Discovery, and Innovation in Ophthalmology","volume":"13 3","pages":"151-159"},"PeriodicalIF":0.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11537238/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142591804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Crocus sativus</i> (saffron) and age-related macular degeneration.","authors":"Ahmad Shamabadi, Hassan Asadigandomani, Kimia Kazemzadeh, Kimia Farahmand, Razman Arabzadeh Bahri, Shahin Akhondzadeh","doi":"10.51329/mehdiophthal1505","DOIUrl":"10.51329/mehdiophthal1505","url":null,"abstract":"<p><strong>Background: </strong>Age-related macular degeneration (ARMD) leads to impaired vision and potential blindness. Globally, it accounts for approximately 9% of vision loss cases, and a projected 288 million individuals will be affected by 2040. Current treatments have limitations such as variable effectiveness, high costs, and potential side effects. Additionally, atrophic ARMD management remains challenging. As saffron has shown promising neuroprotective and antioxidant effects by potentially delaying disease progression, this study aims to review the mechanistic, pre-clinical, and clinical evidence of the effects, safety, and tolerability of saffron in ARMD treatment.</p><p><strong>Methods: </strong>The Scale for the Assessment of Narrative Review Articles was applied in this narrative review. To find relevant literature, the syntax \"(saffron OR crocus) AND (retin* OR \"geographic atrophy\" OR \"choroidal neovascular*\" OR \"macular degeneration\")\" was searched in PubMed/MEDLINE. Pre-clinical and clinical original investigations of the effects of saffron in ARMD along with the eligible studies cited in their reference lists were identified and included.</p><p><strong>Results: </strong>Saffron and its active compounds, crocin and crocetin, have shown promising results in improving visual function and delaying ARMD progression. Several clinical studies have found that daily supplementation with 20-50 mg of saffron or 5-15 mg of crocin for 3-12 months significantly improved best-corrected visual acuity, contrast sensitivity, and retinal function as measured by electroretinogram and microperimetry, with benefits observed in both dry and wet forms of ARMD. The effects were independent of genetic risk factors and maintained during the follow-up periods, suggesting the potential role of saffron as a long-term treatment option. Saffron reduces ARMD progression via anti-angiogenic, neuroprotective, and antioxidant mechanisms. Moreover, saffron is safe and well tolerated.</p><p><strong>Conclusions: </strong>Although further research is needed to confirm long-term safety and efficacy, current evidence supports the use of saffron or crocin supplements as a safe and tolerable adjunct therapy for ARMD management.</p>","PeriodicalId":36524,"journal":{"name":"Medical Hypothesis, Discovery, and Innovation in Ophthalmology","volume":"13 3","pages":"139-150"},"PeriodicalIF":0.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11537240/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142591799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thyroid gland dysfunction and keratoconus.","authors":"Omar M Said, Mohammed Iqbal, Ahmed El-Massry, Mervat Elshabrawy Elgharieb, Mohamed Mady, Ahmed M Sharawy, Khaled Abdelaziz","doi":"10.51329/mehdiophthal1501","DOIUrl":"10.51329/mehdiophthal1501","url":null,"abstract":"<p><strong>Background: </strong>The association between keratoconus and thyroid gland dysfunction (TGD) remains controversial. We aimed to determine the frequency of keratoconus among patients with laboratory-confirmed, treatment-naive TGD compared with that of age- and sex-matched healthy controls. Moreover, we investigated the potential relationship between TGD and corneal topographic and tomographic parameters.</p><p><strong>Methods: </strong>This multicenter, cross-sectional study recruited individuals with treatment-naive, laboratory-confirmed TGD and sex- and age-matched healthy controls. Demographic and ophthalmic data of all participants were recorded. All participants underwent comprehensive ocular examinations and corneal tomography. Patterns of symmetric bowtie, asymmetric bowtie, asymmetric bowtie/superior steep, asymmetric bowtie/inferior steep, or asymmetric bowtie pattern with a skewed radial axis were documented if present. Furthermore, the maximum simulated keratometry value (Kmax), corneal thinnest thickness (CTT), and back elevation (BE) values were recorded. We measured the serum concentrations of thyroid-stimulating hormone (TSH) and thyroid hormones (free thyroxine [FT4] and free tri-iodothyronine [FT3]) using an immunoassay method.</p><p><strong>Results: </strong>We included 200 eyes of 200 individuals with TGD and 200 eyes of 200 healthy age- and sex-matched controls, with female predominance in both groups. The mean FT4 concentration was significantly higher and the TSH concentration was significantly lower in the TGD group than in the control group (both <i>P</i> < 0.0001), whereas the FT3 level was comparable between groups (<i>P</i> > 0.05). In the TGD group, the frequencies of hyperthyroidism and hypothyroidism were 190 (95%) and 10 (5%), respectively. We found significantly lower mean CTT, higher Kmax, and greater BE values with a significantly higher frequency of abnormal topographic patterns among eyes in the TGD group than in controls (all <i>P</i> < 0.05). The frequency of eyes with keratoconus was significantly higher in the TGD (7.5%) group than in the control (0.5%) group (<i>P</i> < 0.0001). Except for a statistically significant correlation of Kmax (r = - 0.23, <i>P</i> < 0.05) and CTT (r = + 0.15, <i>P</i> < 0.05) with TSH level in the TGD group, no significant correlation was found between corneal characteristics and thyroid profile in either group (all <i>P</i> > 0.05).</p><p><strong>Conclusions: </strong>We observed a higher frequency of keratoconus, with female predominance, in the TGD group. TGD was associated with significant changes in certain corneal topographic and tomographic parameters. Compared with healthy controls, individuals with TGD demonstrated increased Kmax and BE values with more corneal thinning, highlighting the potential association between keratoconus and TGD. However, further large-scale longitudinal studies are essential to confirm our findings.</p>","PeriodicalId":36524,"journal":{"name":"Medical Hypothesis, Discovery, and Innovation in Ophthalmology","volume":"13 3","pages":"104-111"},"PeriodicalIF":0.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11537235/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142591832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}