Medical Hypothesis, Discovery & Innovation (MEHDI) Ophthalmology Journal
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Aflibercept or ranibizumab for diabetic macular edema
Full text linkBackground: Vascular endothelial growth factor (VEGF) is the primary substance involved in retinal barrier breach. VEGF overexpression may cause diabetic macular edema (DME). Laser photocoagulation of the macula is the standard treatment for DME; however, recently, intravitreal anti-VEGF injections have surpassed laser treatment. Our aim was to evaluate the efficacy of intravitreal injections of aflibercept or ranibizumab for managing treatment-naive DME.
Methods: This single-center, retrospective, interventional, comparative study included eyes with visual impairment due to treatment-naive DME that underwent intravitreal injection of either aflibercept 2 mg/0.05 mL or ranibizumab 0.5 mg/0.05 mL at Al-Azhar University Hospitals, Egypt between March 2023 and January 2024. Demographic data and full ophthalmological examination results at baseline and 1, 3, and 6 months post-injection were collected, including the best-corrected distance visual acuity (BCDVA) in logarithm of the minimum angle of resolution (logMAR) notation, slit-lamp biomicroscopy, dilated fundoscopy, and central subfield thickness (CST) measured using spectral-domain optical coherence tomography.
Results: Overall, the 96 eyes of 96 patients with a median (interquartile range [IQR]) age of 57 (10) (range: 20–74) years and a male-to-female ratio of 1:2.7 were allocated to one of two groups with comparable age, sex, diabetes mellitus duration, and presence of other comorbidities (all P >0.05). There was no statistically significant difference in baseline diabetic retinopathy status or DME type between groups (both P >0.05). In both groups, the median (IQR) BCDVA significantly improved from 0.7 (0.8) logMAR at baseline to 0.4 (0.1) logMAR at 6 months post-injection (both P = 0.001), with no statistically significant difference between groups at all follow-up visits (all P >0.05). The median (IQR) CST significantly decreased in the aflibercept group from 347 (166) µm at baseline to 180 (233) µm at 6 months post-injection, and it decreased in the ranibizumab group from 360 (180) µm at baseline to 190 (224) µm at 6 months post-injection (both P = 0.001), with no statistically significant differences between groups at all follow-up visits (all P >0.05). No serious adverse effects were documented in either group.
Conclusions: Ranibizumab and aflibercept were equally effective in achieving the desired anatomical and functional results in patients with treatment-naive DME in short-term follow-up without significant differences in injection counts between both drugs. Larger prospective, randomized, double-blinded trials with longer follow-up periods are needed to confirm our preliminary results. 
Ocular toxocariasis masquerading as toxoplasmosis: a case report and literature review
Full text linkBackground: False-negative and false-positive results in Toxoplasma serology are possible, and this could be misleading. Here, we report the case of a boy with Toxocara-associated panuveitis who was initially treated for toxoplasmosis owing to false-positive Toxoplasma immunoglobulin M (IgM) serology.
Case Presentation: A nine-year-old boy presented with intermittent headaches and blurred vision in the left eye. Close contact with domesticated animals was remarkable in the patient’s history. Upon examination, vision was 20/400 in the left eye. Slit-lamp examination revealed anterior chamber cells and flare without keratic precipitates, with vitreous cells and veils, optic disc edema, and a blurred fundus appearance. A systemic investigation revealed the presence of anti-Toxoplasma IgM antibodies. Treatment was initiated using topical cycloplegic and corticosteroid eye drops, in addition to oral trimethoprim/sulfamethoxazole. Oral corticosteroids were also administered. As the inflammation resolved, an inferior tractional detachment was detected on fundus examination, leading to the ultimate diagnosis of ocular toxocariasis. An enzyme-linked immunosorbent assay was positive for serum Toxocara antibodies. A fourteen-day course of oral albendazole was ordered by the pediatric infectious disease service because of the concern for visceral larva migrans, while topical eye drops were continued and oral prednisone was tapered. One month later, visual acuity in the left eye had improved to 20/70. The anterior chamber inflammation resolved; however, some vitreous cells and optic disc edema persisted. The inferior tractional detachment was much better visualized, and a peripheral granuloma was observed. Four months later, without any oral or topical medications, the patient’s visual acuity had improved to 20/30 and his eye had no active inflammation. The patient has been followed up for two years and has never developed any other lesions.
Conclusions: False-positive results on Toxoplasma serology and diffuse vitritis from toxocariasis that limited retinal visualization complicated the initial diagnosis in this case. In diagnosing the etiology of uveitis, ocular examination and detailed history taking should be emphasized, as laboratory results may be misleading
Application and interpretation of linear-regression analysis
Full text linkBackground: 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.
Methods: 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.
Results: 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.
Conclusions: 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
Corneal and anterior segment parameters in patients with clinically unilateral pseudoexfoliation syndrome
Full text linkBackground: Pseudoexfoliation syndrome (PES) is an age-related systemic condition that predominantly affects ocular structures and is characterized by the deposition of material on the lens, ciliary body, zonules, corneal endothelium, iris, and pupillary margin. We compared the corneal endothelial morphology, anterior segment parameters, corneal densitometry, and corneal topographic characteristics between the clinically affected and apparently normal fellow eyes of patients with clinically unilateral PES.
Methods: This was a comparative, cross-sectional study of 34 patients with clinically unilateral PES. The anterior segment was examined using a Scheimpflug imaging system, and the corneal endothelium was assessed using a noncontact specular microscope. Corneal endothelial cell density, polymegathism, and pleomorphism were assessed using the specular microscope. Furthermore, the Scheimpflug camera was used to measure the corneal power of the flat and steep axis, mean corneal power, maximum keratometry, anterior chamber angle, anterior chamber depth, anterior chamber volume, corneal volume, and the corneal thickness at the apex point, center of the pupil, and the thinnest point. Corneal densitometry was evaluated at two concentric zones (0–2 mm and 0–12 mm).
Results: In total, 68 eyes from 34 patients were ultimately included in the study. The mean (standard deviation) age of the patients was 73.38 (8.75) years (range: 50–87 years). Among the included patients, 17 (50%) were male and 17 (50%) were female. The anterior segment parameters did not significantly differ between eyes with PES and their clinically unaffected fellow eyes (all P > 0.05). Similarly, no statistically significant difference was observed in corneal endothelial morphology (all P > 0.05).
Conclusions: Our measured parameters do not differ between the clinically affected eye and the clinically unaffected fellow eye. This supports the theory that PES is a bilateral disorder. Considering the variety of complications associated with PES, bilateral involvement should be assumed in the clinical and surgical management of patients with clinically unilateral PES. In the future, new research could increase our understanding of this syndrome
Clinical characteristics, etiologies, co-injuries, and visual outcomes of eyelid lacerations
Full text linkBackground: Eyelid trauma may be accompanied by open globe injury, canalicular injury, hyphema, angle recession, or retinal detachment. Therefore, a detailed assessment should be performed during the associated ophthalmological examinations. We assessed the demographic and clinical characteristics, etiologies, co-injuries, and visual outcomes in patients with eyelid lacerations.
Methods: This retrospective, cross-sectional study included individuals 18 years of age and older who underwent repair of an eyelid injury at our tertiary referral center between January 2021 and March 2023. Patients with known structural eyelid disorders or previous ocular surgery were excluded. Demographic and clinical data, including injury site and type, mechanism of injury, and presence of additional ocular injuries, were noted. Best-corrected visual acuity (BCVA) was recorded as the logarithm of the minimum angle of resolution (logMAR) notation at the initial and final follow-up visits.
Results: Of 195 included patients with a mean (standard deviation [SD]) age of 42.5 (5.6) years, 164 (84.1%) were men. The most common etiology was accidental (n = 70, 35.9%) and almost half of these injuries occurred at the workplace (n = 32 out of 70, 45.8%). Nine patients (4.6%) had no co-injury, 47 (24.1%) had imaging evidence of orbital bone fractures, 25 (12.8%) had nasolacrimal system involvement, and 11 (5.6%) had an open globe injury. The right upper eyelid (n = 62, 31.8%) was the most commonly affected site. Tissue loss was observed in 77 (39.5%) patients; however, no grafting was required. Five patients (2.6%) underwent lateral canthotomy to improve tissue apposition. On initial examination, 24 patients (12.3%) had traumatic myogenic ptosis, 13 (6.7%) had traumatic aponeurotic ptosis, and ptosis persisted in 7 of these 37 patients (18.9%) 6 months after laceration repair. We observed significant improvement in BCVA at the final follow-up visit (P < 0.001); at the preoperative and final visits, mean (SD) BCVA measurements were 0.21 (0.15) and 0.12 (0.07) logMAR, respectively.
Conclusions: Eyelid injuries are more common in men, and the most common etiology is accidental. These injuries occur most commonly in the workplace. Isolated eyelid lacerations are rare. Early ocular assessment and prompt management ensure better visual outcomes. We recommend preventive safety precautions for workplaces to reduce the incidence of avoidable injuries. Identifying risk factors in further population-based studies could prevent loss of labor in a productive population. Further multicenter, nationwide, longitudinal studies could estimate the actual burden and prognosis of ocular trauma, particularly that of eyelid lacerations
Sustaining private eye care practices during initial days of the coronavirus pandemic
Full text linkBackground: The coronavirus disease 2019 (COVID-19) pandemic created new challenges for private eye care practices. Safety issues were encountered by both the healthcare workers and patients. This short communication addresses the changes made in our private eye care practice during the pandemic and the valuable lessons learned for the future.
Methods: We describe the challenges faced at our tertiary private eye care practice in India with respect to treating patients and preventing the transmission of COVID-19, considering the economic hardship within this area. We discuss the emerging economic, medical, legal, educational, and psychological issues and their solutions, which eye care hospitals could follow in the future to ensure safety without compromising quality of care.
Results: Eye hospitals required efficient operation with reduced fixed expenses. Clinical practices were followed in the hospital as per the recommendations of the country’s apex ophthalmic body. Proper triage and prescreening of patients at the entrance, digitalization, teleophthalmology, staggered appointments, and role-appropriate personal protective equipment were important preventive measures. The operating room protocols were modified to ensure the safety of the operating staff. Special consent was obtained from patients to safeguard against legal repercussions arising from the pandemic. The training of residents and fellows led to new avenues, including the use of digital tools. Hospitals attempted to provide counseling and psychological support to their doctors and staff during these trying times.
Conclusions: The COVID-19 pandemic will not be the last pandemic to occur in an ever-changing world. This event provided us with many new insights into the economic, clinical, legal, and psychological challenges of the COVID-19 pandemic and with ways to overcome these challenges and emerge intact. Clinical and surgical training suffered during the pandemic; however, the impact was only temporary. Clinical research gained respect because of the efforts undertaken during the pandemic. The pandemic was exceptionally harsh on many private eye care practices, and we hope to provide useful and comprehensive solutions on how to successfully navigate a similar situation if encountered in the future
Slowing myopia progression in children
Full text linkBackground: A large proportion of individuals develop myopia, which is recognized as a global health concern and is predicted to increase in prevalence. Long-term eye problems are associated with myopia, particularly in young individuals. Retinal detachment and choroidal degeneration are among the causes of visual impairments associated with myopia. In this narrative review, we summarized the current measures for slowing myopia progression in children, including their safety profiles and potential drawbacks.
Methods: We conducted an English literature search for articles published between January 1, 2000, and October 31, 2023, using various combinations of keywords related to myopia, myopia progression, childhood myopia, myopia control, atropine, orthokeratology, and contact lenses. We included original or review articles pertaining to lifestyle changes and pharmacological, optical, or laser interventions for managing myopia progression in children. Our search was conducted using PubMed/MEDLINE, Google Scholar, and the Wiley Online Library. We reviewed the full text of included articles and qualitatively summarized the results of relevant studies using a narrative synthesis approach.
Results: Multiple meta-analyses indicated that increased outdoor time is associated with a lower myopia prevalence, with each extra hour spent outside each week reducing the risk of myopia by 2%. Candidate drugs, such as atropine, pirenzepine, and 7-methylxanthine, and certain intraocular pressure-lowering medications, such as timolol, have been studied in human trials for their ability to manage myopia. The nonselective antimuscarinic drug atropine, followed by the M1-selective antimuscarinic drug pirenzepine, displayed positive results in slowing myopia. Oral 7-methylxanthine, a nonselective adenosine receptor antagonist, reduces axial myopia caused by hyperopic defocus in a primate model. Low-intensity laser therapy using low doses of red and near-infrared light, visual biofeedback training, bifocal or multifocal spectacles, orthokeratology using a rigid gas-permeable contact lens, combined orthokeratology and atropine, soft contact lenses with a central distance zone and higher positive power in the periphery, and peripheral defocus contact lenses are among the interventional therapies with promising results in managing myopia progression in children.
Conclusions: The current literature supports the efficacy of increased outdoor time, administration of pharmacological agents, and special contact lenses as treatment modalities for slowing myopia progression in children. The effectiveness of orthokeratology alone and in combination with topical atropine therapy has also been assessed. Further research is needed to pinpoint the precise mechanisms of action of these therapies and to determine the best course of treatment. The increasing global prevalence of childhood myopia necessitates robust interventional studies into slowing myopia progression and preventing high myopia and related sight-threatening conditions in adulthood
Ocular injuries sustained at home in five metropolitan cities: a review of 5008 cases
Full text linkBackground: In Iran, ocular injuries sustained at home are a growing public health issue, and few studies have explored their prevalence and the frequencies of different causes of these injuries. We investigated the features of ocular injuries at home among children and adolescents (aged < 18 years), adults (18 – 64 years), and the elderly (greater than or equal to 65 years) in five metropolitan cities.
Methods: In this cross-sectional study, we recruited individuals with ocular injuries sustained at home who presented to 12 public/teaching hospitals in five metropolitan cities during a 5-month period. Using clinical records within the emergency department archives, we collected the following data: age, sex, frequency of injuries requiring hospital admission or surgical intervention, and causes of eye injuries, documented as 1) cleaning products, 2) chemical products, 3) kitchen items, 4) cooking activities, 5) toys, 6) falls from height, 7) sports equipment, 8) penetrating or cutting, 9) abrasions, 10) foreign bodies, and 11) direct blows by other individuals.
Results: Of 5008 participants from the five cities, 74% (n = 3711) were male and 26% (n = 1297) were female. The most frequent causes of injury among children and adolescents, adults, and the elderly were toys, kitchen items, and cooking activities, respectively. In children and adolescents, injuries were caused by kitchen items, toys, foreign bodies, and direct blows by other individuals more frequently than in adults or the elderly, and by cleaning products and abrasions more frequently than in the elderly (all P < 0.05). In adults, injuries were caused by cleaning products, cooking activities, falls from height, sports equipment, penetrating or cutting, and abrasions more frequently than in children and adolescents or the elderly (all P < 0.05), and by kitchen items, toys, and blows by other individuals more frequently than in the elderly (all P < 0.05). In the elderly, injuries were caused by chemical products more frequently than in children and adolescents or adults, and by cooking activities, falls from height, and sports equipment more frequently than in children and adolescents (all P < 0.05). In adults, the frequency of ocular injuries was significantly higher in Tehran and lower in Mashhad when comparing each with that of the other four cities (all P < 0.05). We found a significantly higher frequency of ocular injuries by cleaning and chemical products in Tehran, by toys in Shiraz, by falls from height in Isfahan, and by direct blows by other individuals in Ahvaz when comparing each to that of the other four cities (all P < 0.05). Regarding the prevalence of severe ocular injuries among the children/adolescent and adult age groups, conditions were relatively better in Shiraz and relatively unfavorable in Mashhad.
Conclusions: Ocular trauma was more common in male individuals and the younger age groups. Approximately half of the causes were kitchen items, toys, and foreign bodies, which are avoidable by enhancing public eye health awareness. The prevalence of severe ocular injuries in individuals aged < 18 years was high, highlighting the necessity of nationwide preventive strategies for pediatric ocular injuries
Clinical characteristics and outcomes of band keratopathy: a 10-year retrospective analysis
Full text linkBackground: Band keratopathy is a chronic, degenerative corneal disease resulting from gradual calcium deposition in the superficial cornea. Herein, we report the spectrum of causes, treatment outcomes, and recurrence rates of band keratopathy at a tertiary referral center throughout one decade.
Methods: This retrospective study included patients with clinical diagnoses of band keratopathy who were treated with combined ethylenediaminetetraacetic acid (EDTA) and superficial keratectomy with or without amniotic membrane transplantation (AMT). Patient medical records were reviewed, and detailed demographic and ophthalmological data, such as baseline and last follow-up best-corrected distance visual acuity (BCDVA), ocular or medical comorbidities, type of intervention, postoperative follow-up duration, relevant complications, and recurrence were recorded.
Results: A total of 32 eyes of 29 patients with 3 (10.3%) bilateral and 26 (89.7%) unilateral cases of treatment-requiring bank keratopathy were included. The mean (standard deviation [SD]) (range) age was 39.4 (22.4) (2–74) years, and most patients were female. The most common secondary cause was previous vitreoretinal surgery with silicone oil tamponade (15.6%); however, idiopathic cases were the most common (18.8%). Systemic comorbidities were present in 27.6% of patients, consisting of hypertension, diabetes mellitus, epilepsy, coronary artery disease, Behcet’s disease, and juvenile idiopathic arthritis; however, none of the patients had systemic diseases associated with hypercalcemia. Two of the 3 patients with bilateral involvement had chronic uveitis secondary to systemic rheumatological disease. The mean (SD) follow-up duration was 5.6 (4.0) years, and no serious postoperative complications occurred. The mean (SD) baseline and final BCDVA in logarithm of the minimum angle of resolution (logMAR) were 1.98 (1.0) and 1.7 (1.0), respectively (P > 0.05). Combined EDTA chelation and superficial keratectomy with and without AMT were performed in 12.5% and 87.5% of eyes, respectively. Recurrence was observed in 37.5% of eyes within the mean (SD) (range) follow-up of 9.4 (9.1) (1–32) months. Seven of the 12 eyes with recurrence underwent re-EDTA chelation combined with superficial keratectomy and AMT; however, 5 patients managed conservatively.
Conclusions: In this study, band keratopathy requiring intervention more commonly affected female individuals and was unilateral. Most cases were idiopathic. Systemic comorbidities were present in approximately one-third of cases. Managing band keratopathy using a combination of EDTA chelation and superficial keratectomy with or without AMT could be a potential treatment modality. Further large-scale studies are required to provide robust conclusions regarding the efficacy and safety of this management approach