Medical Hypothesis, Discovery & Innovation (MEHDI) Ophthalmology Journal
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Acanthamoeba keratitis: from pathophysiology to prevention – a contemporary clinical perspective
Full text linkBackground: Acanthamoeba keratitis represents a devastating corneal infection caused by free-living protozoan organisms. This condition has evolved from an extraordinarily rare disease to a significant public health concern, with increasing global incidence. The infection predominantly affects contact lens wearers and poses substantial diagnostic and therapeutic challenges. This narrative review aims to provide analysis of current knowledge regarding Acanthamoeba keratitis, including epidemiology, pathogenesis, diagnostic approaches, treatment strategies, and prevention methods, to guide clinicians in optimal patient management.
Methods: This review was conducted through a literature search of PubMed-indexed journals from January 2000 to August 2025, incorporating current information on pathophysiology, clinical features, diagnosis, therapy, and outcomes of Acanthamoeba keratitis. Keywords included “Acanthamoeba keratitis”, “contact lens-related keratitis”, “Acanthamoeba diagnosis”, and “Acanthamoeba treatment”. English-language publications including original articles, reviews, case reports, and clinical studies were included based on relevance to current diagnostic and therapeutic practices, with an emphasis on recent advances in the field.
Results: Contact lens wearers comprised the vast majority of cases, with soft contact lens users representing the predominant affected population. Peak occurrence involves young adults aged 20–40 years, with water-based transmission through contaminated domestic supplies representing a significant risk pathway. Clinical manifestations commonly include epithelial abnormalities, stromal infiltration, and ring infiltrates in advanced cases. Traditional culture methods evidence limited sensitivity (33–67%), while advanced diagnostic approaches include polymerase chain reaction (PCR) and in vivo confocal microscopy (IVCM) achieving superior accuracy (sensitivity 77–100%, specificity 84–100%). First-line therapy employs biguanides and diamidines with prolonged administration. Advanced treatment options include oral miltefosine for refractory cases, azole antifungals, and surgical interventions ranging from epithelial debridement to corneal transplantation. Early diagnostic recognition represents the strongest predictor of visual recovery, with diagnostic delays associated with poor prognosis.
Conclusions: Acanthamoeba keratitis management requires high clinical suspicion, rapid diagnosis using advanced techniques such as IVCM and PCR, and prolonged antimicrobial therapy. Early diagnosis remains the most important predictor of visual recovery. Prevention through proper contact lens hygiene and water exposure avoidance is paramount. Future research priorities include development of novel antimicrobial agents and enhanced prevention strategies
Optic nerve sheath diameter as a surrogate for intracranial pressure: a noninvasive follow-up strategy using ocular ultrasonography
Full text linkBackground: Idiopathic intracranial hypertension (IIH), characterized by increased intracranial pressure (ICP) without a clear cause, typically affects obese women of reproductive age. Although lumbar puncture (LP) is diagnostic, its invasiveness limits its repeated use. Consequently, a non-invasive alternative is essential. Therefore, we assessed whether optic nerve sheath diameter (ONSD) measurement via orbital ultrasonography could serve as an alternative method for monitoring changes in ICP in patients with IIH.
Methods: In this prospective observational study, patients with IIH, diagnosed using the modified Dandy criteria, underwent ONSD assessment using B-scan ultrasonography. Bilateral measurements were performed 3 mm posterior to the optic disc with the probe and sterile gel placed on the closed upper eyelid. ONSD was recorded before LP and one month after initiation of medical treatment. Comprehensive ophthalmologic examinations were also conducted. Patients with ocular pathology, neuroimaging abnormalities, or contraindications to LP were excluded.
Results: Twenty-four eyes from 12 female patients with IIH were evaluated. The mean (standard deviation [SD]) age was 27.3 (6.9) years, and the mean ICP was 34.8 (10.3) cm H2O. Although the ONSD decreased one month after LP, changes in mean ONSD of the right eye, left eye, and their average were not statistically significant (all P > 0.05). No significant correlations were observed between baseline ICP and ONSD values (all P > 0.05).
Conclusion: Although ONSD measurement via ultrasonography provides a noninvasive method for assessing ICP in IIH, our findings revealed no significant change one month after treatment initiation. ONSD may gradually decrease following LP; however, a return to baseline values appears to require a prolonged period, even after ICP normalization. This should be considered during patient follow-up. Our findings underscore the limitations of using ONSD as a standalone marker for monitoring therapeutic response. Further research is warranted to explore the factors influencing ONSD dynamics and to establish standardized, patient-centered measurement protocols
Canonical and noncanonical NF-kappa B signaling in uveal melanoma: mechanisms, microenvironment, and therapeutic modulation
No full textBackground: Uveal melanoma (UM) is an aggressive intraocular malignancy with high metastatic potential to the liver and poor prognosis. The nuclear factor kappa B (NF-kB) pathway, comprising the canonical and noncanonical branches, has been involved in UM development, tumor-microenvironment communication, and drug resistance. This review consolidates the evidence for NF-kB involvement in UM pathogenesis and therapeutic target value.
Methods: A comprehensive search of PubMed/MEDLINE, Embase, Web of Science, Scopus, and the Cochrane CENTRAL database was performed from inception to June 2025. Studies investigating NF-kB activation, functional dependencies, genetic or microenvironmental modulators, or therapeutic interventions in UM were eligible. Included designs comprised original observational or experimental research, including mechanistic in vitro studies, animal models, and human tissue–based prognostic or correlative studies. English-language articles and relevant review studies addressing the research question were considered. Exclusion criteria included editorials, commentaries, conference abstracts with insufficient data, case reports lacking mechanistic insights, non-UM cancers without validated UM models, studies mentioning inflammation or NF-kB targets without direct NF-kB readouts, and those using pleiotropic inhibitors without genetic validation or pathway-specific evidence. Appropriate design-specific tools were applied to assess risk of bias.
Results: Canonical NF-kB signaling is mechanistically related to UM cell survival, proliferation, and migration, as shown by pharmacologic inhibition like BAY11-7082, and niclosamide and genetic modulation like microRNA-9. Noncanonical signaling is associated with invasive, immune-replenished tumors and liver metastasis yet has limited direct functional data. Deficiency in BRCA1-associated protein-1 (BAP1) and tumor necrosis factor alpha-enriched microenvironments control NF-kB activity, but there is conflicting data on the function of BAP1. Therapeutic targeting of NF-kB consistently suppresses UM phenotypes in vitro and in vivo, but pleiotropic inhibitor effects require confirmation.
Conclusions: NF-kB signaling, particularly the canonical branch, is required for UM malignancy, while noncanonical signaling is linked with high-risk features. Branch-specific genetic manipulations and clinically relevant models should be employed in future research to maximize therapeutic strategies
Blunt facial trauma as a predictor of ocular injury in polytrauma patients: a cross-sectional study
Full text linkBackground: Ocular injury is a clinically significant complication of facial trauma, yet its burden and predictors in polytrauma remain undercharacterized. Understanding these associations is essential for optimizing early ophthalmic assessment, particularly in settings with high rates of road traffic injuries.
Methods: This retrospective cross-sectional study included polytrauma patients (injury severity score [ISS] >15) admitted to a tertiary trauma center over a five-year period. Eligible patients sustained blunt injuries and underwent standardized craniofacial CT and ophthalmic assessment. Facial trauma was identified using International Classification of Diseases, Tenth Revision (ICD-10) codes and radiologic confirmation. Ocular injuries were classified according to Birmingham Eye Trauma Terminology System criteria. Data on demographics, injury mechanisms, and clinical findings were extracted for analysis.
Results: Among 7456 polytrauma patients (mean age 38.7 years), 68.2% (5085) were male and 1491 (20.0%) had blunt facial trauma. Ocular injury occurred in 20.9% (n = 312) of patients with facial trauma versus 4.2% (n = 251) without. Midface fractures were strongly associated with orbital injury, whereas mandibular fractures were associated with ocular adnexal trauma (both P < 0.001). The most frequent ocular findings were orbital fracture (n = 312/142, 45.5%), subconjunctival hemorrhage (n = 312/88, 28.2%), hyphema (n = 312/46, 14.7%), and globe rupture (n = 312/12, 3.8%). Subgroup analyses further demonstrated that road traffic accidents (RTAs) mechanism conferred more than twice the risk of ocular injury compared with other mechanisms. Multivariate logistic regression analysis identified blunt facial trauma (adjusted odds ratio [OR], 3.82; 95% confidence interval [CI], 2.91–5.02; P < 0.001), RTAs (adjusted OR, 2.14; 95% CI, 1.67–2.75; P < 0.001), male sex (adjusted OR, 1.45; 95% CI, 1.12–1.88; P = 0.005), higher ISS (adjusted OR, 1.06 per point; CI, 95%, 1.03–1.09; P < 0.001), and increasing age (adjusted OR, 1.02 per year; 95% CI, 1.00–1.04; P < 0.005) as independent predictors of ocular injury. Baseline visual impairment (VA < 20/40) was present in 38.2% of affected patients. The incidence of facial trauma showed a slight upward trend from 2021 to 2025, albeit not statistically significant (P > 0.05).
Conclusions: Ocular injury represents a substantial and clinically important component of polytrauma involving the face. Patients with blunt facial trauma, particularly those with RTAs mechanisms, are at markedly elevated risk of ocular injury. Age, sex, fracture pattern, injury mechanism, and overall trauma severity are key determinants of ocular morbidity, underscoring the need for integrated maxillofacial-ophthalmic management strategies within trauma care systems
A review on retinopathy of prematurity
Full text linkBackground: 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.
Methods: 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.
Results: 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.
Conclusions: 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
Multilayered fresh amniotic membrane transplantation in resistant fungal corneal ulceration
Full text linkBackground: Resistant fungal keratitis is a major cause of corneal blindness, particularly in resource-limited regions where donor tissue is scarce. Amniotic membrane transplantation (AMT) offers potential benefits through its anti-inflammatory, anti-proteolytic, and epithelialization-promoting effects. This study evaluated the efficacy and safety of AMT for treatment-resistant fungal corneal ulcers.
Methods: This prospective, single-arm study enrolled consecutive patients with microbiologically confirmed, treatment-resistant fungal corneal ulcers at Al-Azhar University Hospital, Damietta, between January 2022 and October 2023. All patients underwent standardized single- or double-layer AMT. Baseline and follow-up assessments included best-corrected distance visual acuity (BCDVA, logarithm of the minimum angle of resolution [logMAR]), ulcer size, anterior chamber reaction and depth, and presence of blepharospasm or pain (visual analog scale). Clinical evaluations were performed at baseline, 1 day, and 1, 3, and 6 months postoperatively. Treatment success was defined as complete resolution or significant improvement over 6 months.
Results: A total of 24 patients (mean [standard deviation] age, 59 [7.5] years; 3:1 male-to-female ratio) with resistant fungal corneal ulcers were studied. Most were rural residents (n = 17, 70.8%), and nearly half were farmers (n = 11, 45.8%). Common comorbidities included hypertension and diabetes mellitus. The median baseline ulcer area was 3 mm²; most ulcers were central (n = 10, 41.7%) or paracentral (n = 8, 33.3%), and 12.5% (n = 3) had perforations. At 6 months, significant improvements were observed: median BCDVA improved from 3.0 logMAR to 2.0 logMAR (P = 0.001), ulcers completely closed (P = 0.001), and the pain score dropped from 2 to 0 (P = 0.001). Anterior chamber reaction and blepharospasm also improved significantly (both P = 0.001). Overall, 91.7% (n = 22) achieved complete resolution or marked improvement, and two patients required further surgery. The results showed progressive benefits throughout the follow-up period.
Conclusions: AMT is a safe and effective adjunctive treatment for resistant fungal keratitis, particularly when corneal donors are scarce. The procedure promotes ulcer healing, relieves pain, and improves visual outcomes. Controlled trials are required to confirm these findings and refine patient selection
Efficacy of Rose-K lens in enhancing visual acuity and contrast sensitivity in keratoconus
Full text linkBackground: Keratoconus is a progressive, noninflammatory corneal ectasia that is characterized by corneal thinning and conical deformation, which leads to irregular astigmatism, myopia, and reduced visual quality. As the disease progresses, spectacles often become inadequate, necessitating the use of rigid gas-permeable or specialty contact lenses to restore vision. Traditional evaluations rely on high-contrast visual acuity tests, which alone do not capture functional vision impairments. A more comprehensive assessment includes contrast sensitivity (CS), a key predictor of real-world visual performance. The ROSE K2 XL semi-scleral lens offers tailored optical correction for irregular corneas. We investigated its efficacy in enhancing best-corrected distance visual acuity (BCDVA) and CS in patients with keratoconus.
Methods: In this prospective study, we recruited adults with varying keratoconus severities from the Armed Forces Hospital in Oman, between February and December 2024. The patients were fitted with ROSE K2 XL semi-scleral lenses to assess changes in BCDVA and CS. Participants who had undergone prior ocular surgery (except for corneal crosslinking) or who had other corneal pathologies were excluded. Baseline and post-fitting BCDVA were measured using a crowded Keeler logarithm of the minimum angle of resolution (logMAR) chart. CS was assessed using the Pelli–Robson chart under standardized photopic conditions. Keratoconus severity was graded using the Amsler–Krumeich classification system. All examinations were performed by the same experienced optometrist to ensure consistency and to reduce measurement variability.
Results: We enrolled 180 eyes from 90 participants with keratoconus (mean [standard deviation, SD] age: 29.2 [5.4] years; 65.6% [n = 59] female). Disease severity was classified as follows: stage I (n = 16, 8.9%), stage II (n = 52, 28.9%), stage III (n = 70, 38.9%), and stage IV (n = 42, 23.3%). After ROSE K2 XL lens fitting, the mean (SD) BCDVA improved significantly, from 0.90 (0.48) logMAR to 0.10 (0.11) logMAR (P < 0.001). The mean (SD) CS also increased significantly, from 0.96 (0.47) log CS to 1.90 (0.16) log CS (P < 0.001). Significant improvements in BCDVA and CS were observed across all disease stages (all P < 0.001), with the most pronounced gains found in cases of advanced keratoconus (stage IV).
Conclusions: Fitting ROSE K2 XL semi-scleral contact lenses in patients with keratoconus resulted in significant improvements in both BCDVA and CS across all disease severity levels. These findings show the clinical value of semi-scleral lenses for visual rehabilitation of keratoconus, particularly in the advanced stages, where conventional spectacles or lenses may offer limited benefits. Incorporating CS assessment with visual acuity evaluations provides a more comprehensive investigation of real-world visual function, supporting evidence-based lens selection to optimize patient outcomes. Future studies should explore the long-term effects of these lenses on corneal physiology and patient-reported quality of life
Topical tacrolimus versus dexamethasone in managing shield ulcer of vernal keratoconjunctivitis
Full text linkBackground: 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.
Methods: 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.
Results: Thirty patients (30 eyes) were allocated to each treatment group. The groups had comparable mean ages and sex distributions (both P > 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 (P < 0.05). Re-epithelialization remained significantly more frequent in tacrolimus-treated eyes one month after cessation of treatment (P < 0.05). The mean BCDVA was significantly better in tacrolimus-treated eyes than in the dexamethasone group at all follow-up visits (all P < 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 P < 0.05).
Conclusions: 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
The impact of coronavirus disease on ocular trauma: a review of 5065 cases from Kuwait
Full text linkBackground: Early reports during the lockdown associated with the coronavirus disease 2019 (COVID-19) pandemic indicated a shift in the trends of ocular injuries. This study examined the demographics and clinical characteristics of patients who presented with ocular trauma during the lockdown period in 2020, and compared them to those seen during the same months in the next year, after the lockdown had been lifted, at Farwaniya Hospital in Kuwait.
Methods: This retrospective hospital-based chart review was a comparative observational study that examined individuals who presented to the Ophthalmology Department's emergency room during two distinct periods: from March 22, 2020, the day quarantine measures were announced, until August 30, 2020, when the quarantine ended, and the same time frame in the following year. Demographic characteristics, diagnoses, mechanisms of ocular trauma, and the locations where the eye injuries had occurred were recorded. Local injuries were classified as either mechanical or non-mechanical. Mechanical injuries were further subdivided by their cause. Non-mechanical injuries encompassed those caused by burns or corrosive substances.
Results: The incidence of ocular trauma increased from 18.9% (1470 out of 7763 cases) during the lockdown to 21.5% (3595 out of 16 748 cases) in the post-lockdown period. The mean age of the study population was slightly lower during the lockdown compared to the post-lockdown period, although this difference did not reach statistical significance (P > 0.05). Ocular trauma among children < 18 years was significantly higher during the lockdown period, accounting for 39.1% (575 of 1470 cases), compared to 36.0% (1293 of 3595 cases) in the post-lockdown period (P < 0.05). During both periods, injuries predominantly occurred at home, but the percentage of injuries decreased significantly during the post-lockdown period (P < 0.05). Workers were the most affected group, representing nearly 50% of cases during both periods. During the lockdown, 29.9% (439 cases) of ocular trauma cases involved work-related injuries, but this percentage increased significantly to 33.7% (1213 cases) post-lockdown (P < 0.05). Mechanical injuries constituted the majority of cases in both periods, accounting for almost 95% of the incidents, with a significant difference between the two periods (P < 0.05). Non-mechanical eye injuries did not differ between the two periods (P > 0.05). Most ocular trauma cases involved the anterior segment of the eye, with superficial corneal and conjunctival injuries being predominant, accounting for > 50% of cases during both periods.
Conclusions: The COVID-19 pandemic significantly impacted the trends in cases visiting ophthalmic emergency departments. After the lockdown, the incidence of ocular trauma increased. Ocular trauma among children was significantly higher during the lockdown period. The frequency of home-related ocular injuries was greater during the lockdown than in the post-lockdown phase. Work-related injuries showed a marked increase after the lockdown. Long-term, retrospective multicenter epidemiological studies in Kuwait could shed light on changes in the use of eye emergency department services during pre- and post-pandemic periods