Medical Hypothesis, Discovery & Innovation (MEHDI) Ophthalmology Journal
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Stapler for corneal transplantation: a hypothesis
Full text linkBackground: Corneal transplantation requires exquisite microsurgical precision, particularly during the suturing of donor and recipient tissues. In corneal transplantation procedures such as penetrating keratoplasty, the donor cornea is traditionally secured using ultrafine 10-0 nylon sutures, meticulously placed under an operating microscope to achieve precise tension and promote optimal wound healing. Although this technique remains the reference standard, it is inherently time-intensive and requires advanced microsurgical expertise. To enhance surgical efficiency and maintain clinical outcomes, recent innovations have proposed the use of a modified stapling device equipped with ultrafine nylon staples as an alternative to conventional suturing. Although experimental stapling systems have been engineered to facilitate graft fixation, widespread clinical adoption or regulatory approval has not yet been achieved, largely because of unresolved concerns regarding precision, stability, and long-term safety.
Hypothesis: To address these challenges, we propose an adaptation of the skin stapler mechanism, employing nylon-based staples specifically engineered for corneal application. This study hypothesizes that the development of a specialized corneal stapler as a viable, time-efficient alternative to manual suturing in keratoplasty is feasible, contingent upon addressing critical challenges. These include replicating the biomechanical finesse and tension control of sutures, ensuring the biocompatibility of staple materials with ocular tissues, and minimizing the risk of postoperative complications such as astigmatism, wound dehiscence, and infection. The specialized corneal stapler utilizing ultrafine, biocompatible nylon staples can replicate the precision, tension control, and wound stability achieved by traditional 10-0 nylon suturing in penetrating keratoplasty, while significantly reducing operative time and technical demands. Rigorous preclinical testing and clinical validation are essential to evaluate whether stapling technology can match or exceed the standards established by traditional suturing techniques in corneal transplantation.
Conclusions: The conceptual model for a specialized corneal stapler presents a promising alternative to traditional suturing techniques. However, substantial technological innovation is necessary to meet the intricate anatomical and surgical requirements of the cornea. Further research, including iterative prototyping and preclinical validation, is essential before clinical applications can be realized. Moreover, further research and clinical validation are necessary to determine whether staplers can safely and effectively replace traditional sutures during corneal transplantation
Myopia severity and corneal endothelium: morphological variations across low, moderate, and high myopia
Full text linkBackground: Myopia, a condition of growing concern in Asian populations, has been linked to ocular structural changes that may affect corneal endothelial morphology. Endothelial cell density (ECD), shape, and size changes have been observed in cases of high myopia. However, population-specific data, particularly in Malaysia, remain limited. In this study, we evaluated corneal endothelial morphology across different severities of myopia in young Malaysian adults.
Methods: For this cross-sectional study, we categorized individuals with myopia, aged 19–24 years, attending the International Islamic University Malaysia Optometry Clinic, into low, moderate, and high myopia groups, based on spherical equivalent. They underwent non-cycloplegic refraction, axial length, intraocular pressure, and slit-lamp assessments. Using a non-contact specular microscope, we measured corneal endothelial parameters, ECD (cells/mm²), coefficient of variation (CV) of the cell area, percentage of hexagonal cells (HEX, %), and central corneal thickness (CCT, micrometer) centrally, in triplicate, and averaged the values. All assessments were conducted by an experienced optometrist under controlled environmental conditions.
Results: We analyzed data from 374 eyes of 187 young adults (mean [standard deviation] age: 20.16 [0.75] years) across varying degrees of myopia. Axial length increased with myopia severity, while best-corrected visual acuity remained comparable among groups. Statistically significant differences in mean ECD, CCT, and HEX (all P < 0.05), but not in CV, were observed across the three myopia groups. Post-hoc analysis revealed that, compared to low myopia, the high myopia group had significantly lower ECD, HEX, and CCT (all P < 0.05), while the moderate myopia group showed significantly reduced ECD and HEX (both P < 0.05). ECD, CCT, and HEX did not differ significantly between the moderate and high myopia groups (all P > 0.05).
Conclusions: We demonstrated that higher myopia severity in young Malaysian adults was significantly associated with lower ECD, reduced HEX, and thinner CCT, whereas CV did not differ across myopia levels. These findings indicated that increasing myopia severity is associated with notable morphological changes in the corneal endothelium. Thus, progressive axial elongation in myopia may adversely impact corneal endothelial morphology and biomechanical stability. Given the cross-sectional nature and limited demographic scope of the study, further longitudinal and multi-ethnic studies are warranted to clarify the causal pathways and long-term implications of myopia-related endothelial changes
COVID-19 pandemic and ophthalmology: insights from the IVORC Academic Foundation
Full text linkBackground: The coronavirus disease 2019 (COVID-19) pandemic posed unprecedented challenges for the global academic community. The International Virtual Ophthalmic Research Center (IVORC) Academic Foundation, which is committed to advancing vision science through international collaboration, research, and education, played a pivotal role in addressing these disruptions. Central to its mission are 2 affiliated journals in ophthalmology and optometry that serve as key platforms for innovative research on ocular disease management. In response to the pandemic, the IVORC implemented a series of strategic initiatives to support the vision science community, while ensuring research continuity and safety. This report reviews COVID-19-related publications in these journals and highlights the key actions of the IVORC in strengthening preparedness for future global health crises.
Methods: We reviewed COVID-19-related articles published in IVORC-affiliated journals from the onset of the pandemic through February 2025. Key findings were analyzed, focusing on the reported ocular manifestations of COVID-19 and potential ophthalmic complications associated with COVID-19 vaccination.
Results: To sustain academic engagement and research productivity, the IVORC expanded its virtual meetings, webinars, and digital outreach initiatives, with a strong emphasis on academic writing and publication ethics. The foundation actively promoted COVID-19-related ophthalmic research, published a clinical guideline, reported ocular manifestations of the disease, encouraged the adoption of teleophthalmology, and strengthened collaborations with regional and national societies. Between early 2020 and February 2025, IVORC-affiliated journals published 19 COVID-19-related articles from researchers across 10 countries, primarily in North America, Asia, and the Middle East. These comprised 6 original articles, 5 reviews, 2 case reports, 2 editorials, 2 short communications, and 2 letters, most of which appeared in Medical hypothesis, discovery & innovation in ophthalmology. Among the early contributions was a widely cited guideline for ophthalmic practice, published within months of the onset of the pandemic.
Conclusions: The proactive response of the IVORC to the COVID-19 crisis highlights the essential role of academic leadership in maintaining research continuity and scholarly communication during global health emergencies. The diverse and internationally authored IVORC publications reflect a commitment to innovation, collaboration, and the inclusion of perspectives from underrepresented regions. This experience reinforces the importance of prioritizing original research over publication volume—particularly clinical guidelines and studies detailing disease manifestations. Fast-track publication models must maintain rigorous editorial standards to ensure that scientific contributions remain timely and reliable during public health crises
Clinical anatomy: cornea and ocular surface
Full text linkBackground: The cornea and ocular surface serve as a vital barrier and the eye’s primary refractive medium, requiring precise coordination to maintain transparency, structural integrity, and immune protection. Constantly exposed to environmental stressors, this interface relies on the stability of the tear film, epithelial architecture, mucin layers, and limbal stem cells to preserve function. Disruption in any component can impair vision and increase vulnerability to disease. Advances in imaging and molecular diagnostics have deepened our understanding of these structures, offering new avenues for early detection and personalized treatment strategies. A comprehensive review is needed to integrate recent findings and assess their clinical relevance.
Methods: A targeted literature search was conducted using PubMed/MEDLINE and Google Scholar to identify English-language publications from 1 January 2000 to 30 May 2025. Keywords included “anatomy,” “histology,” “cornea,” “ocular surface,” “epithelium,” “Bowman’s layer,” “stroma,” “Descemet’s membrane,” “endothelium,” “conjunctiva,” “lacrimal functional unit,” and “eyelids.” Studies were selected irrespective of design, and reference lists of included articles were manually screened for additional relevant sources.
Results: Eighty-six publications were reviewed. Findings highlight that the cornea and ocular surface constitute an integrated anatomical and physiological continuum essential for optical clarity, visual acuity, and ocular health. This dynamic unit comprises the cornea, conjunctiva, tear film (mucin, aqueous, and lipid layers), meibomian glands, goblet cells, and the limbal stem cell niche. Collectively, these elements provide lubrication, immune defense, epithelial homeostasis, and structural integrity. Disruption in any component—such as in dry eye disease, limbal stem cell deficiency, or meibomian gland dysfunction—can precipitate epithelial breakdown, neovascularization, or stromal scarring, ultimately compromising vision. Recognizing this interdependence has reframed ocular surface disease as a multifactorial condition rather than an isolated disorder. A comprehensive understanding of the structural and immunological dynamics of this system is therefore critical for refining surgical strategies and developing targeted therapies.
Conclusions: The cornea and ocular surface components function synergistically to maintain a transparent, stable refractive surface essential for vision. Their coordinated roles in protection, lubrication, immune defense, and tissue repair reveal the importance of anatomical understanding for developing targeted therapies and improving clinical outcomes. A comprehensive understanding of this anatomy is essential for clinicians and researchers aiming to develop more precise therapeutic strategies and surgical techniques to enhance patient outcomes and preserve visual function. Future research should focus on advancing regenerative strategies and personalized treatments to address complex ocular surface disorders more effectively
Accommodative functions in opium users and non-users
Full text linkBackground: Emerging evidence highlights a concerning prevalence of accommodative and convergence anomalies in individuals with opioid use disorder. However, there remains a significant scarcity of data comparing accommodative functions of opium users and non-users. Hence, we investigated potential changes in accommodative functions of opium users compared to that of non-users. Furthermore, we evaluated changes in these parameters after administering 5% phenylephrine eye drops, both within and between the two groups.
Methods: This cross-sectional case-control study recruited opium users and non-users. The binocular amplitude of accommodation (AA), monocular estimate method (MEM), negative and positive relative accommodation (NRA and PRA, respectively), and monocular and binocular accommodative facility (AF) were assessed and documented. All measurements were repeated 30 min after instillation of one drop of 5% phenylephrine hydrochloride eye drops.
Results: We recruited 103 opium users and 107 non-users, with comparable mean ages (P > 0.05) but significantly different sex ratios (P < 0.05), with men outnumbering women among the opium users. All accommodative functions measured before and after the instillation of 5% phenylephrine, along with the differences in their values between the two time points, were comparable between the two groups (all P > 0.05), with the exception of the right-eye AF, which was significantly higher in non-users than in opium users after instillation (P < 0.05). Within the opium user group, all accommodative functions exhibited significant differences between pre- and post-instillation measurements (all P < 0.05), except for NRA, which did not change (P > 0.05). In contrast, the non-user group showed no significant differences between pre- and post-instillation measurements for all accommodative functions (all P > 0.05), except in the AA and the right-eye MEM (both P < 0.05).
Conclusions: We observed small but significant changes in most baseline accommodative functions after the application of 5% phenylephrine eye drops in opium users. In contrast, most parameters remained unchanged in healthy non-users. When comparing the results between the two groups pre- and post-application of phenylephrine, we found similar accommodative functions overall. However, non-users had a significantly higher value for the right-eye AF following the instillation. To better understand potential binocular anomalies in opium users, further longitudinal studies that are matched for age and sex should be conducted, focusing on additional aspects of binocular vision and ocular motility
Choroidal melanoma treatment: a shift towards vision preservation
Full text linkBackground: Choroidal melanoma is the most common primary intraocular malignancy in adults, and is known for its aggressive nature and potential for metastasis. Historically, enucleation was the primary treatment, which resulted in significant morbidity and psychological distress. Recent advances have led to a paradigm shift towards vision-preserving therapies. This review aimed to explore advances in choroidal melanoma treatment and their impact on patient care and quality of life.
Methods: For this narrative review, we conducted a literature search of major databases, including PubMed/MEDLINE, Embase, and Scopus, from January 1, 1998, to December 30, 2024. The search strategy employed the following keywords: “choroidal melanoma,” “vision preservation,” “plaque brachytherapy,” “proton beam therapy,” “stereotactic radiosurgery,” “enucleation,” “ocular oncology,” “retinal health,” “visual acuity,” “quality of life,” “computational intelligence,” and “AI (artificial intelligence).” We included English-language studies of any design focusing on choroidal melanoma treatment, particularly treatment involving vision-preserving strategies.
Results: Advances in vision-preserving therapies, such as plaque brachytherapy, proton-beam irradiation, and stereotactic radiosurgery, have revolutionized the management of choroidal melanoma. These modalities offer improved patient outcomes by reducing the need for enucleation and preserving visual acuity. Plaque brachytherapy achieves high tumor-control rates with minimal side effects, while proton-beam irradiation provides precise tumor targeting, which is particularly beneficial for large tumors. Stereotactic radiosurgery is effective for smaller tumors, but may result in decreased visual acuity over time. Emerging therapies, such as Bel-Sar (AU-011), show promise in controlling tumor growth while preserving vision. The ability of Bel-Sar to control tumors while preserving vision could provide patients with a more favorable prognosis and improved quality of life. Immunotherapy holds significant promise, particularly with the potential for use of immune checkpoint inhibitors and vaccine therapies. Additionally, artificial intelligence (AI) is becoming increasingly important in the management of choroidal melanoma.
Conclusions: The shift from enucleation to vision-preserving therapies has significantly improved outcomes and quality of life for patients with choroidal melanoma. Future research should focus on optimizing current therapies for better visual acuity preservation and on exploring new targeted therapies to enhance tumor control while minimizing side effects. Moreover, studies on AI applications for managing this sight- and life-threatening eye condition could significantly transform treatment outcomes
Impact of phacoemulsification with posterior chamber intraocular lens implantation on intraocular pressure and retinal structural parameters in pseudoexfoliation glaucoma and primary open-angle glaucoma
Full text linkBackground: Glaucoma, a leading cause of irreversible blindness, is increasingly prevalent, with pseudoexfoliation glaucoma (PEXG) presenting more severe optic nerve damage than primary open-angle glaucoma (POAG). Phacoemulsification reduces intraocular pressure (IOP), especially in PEXG; however, its effects on retinal structure remain unclear. This study compared the effects of IOP reduction post-phacoemulsification on the ganglion cell complex (GCC) in eyes with PEXG and cataract, POAG and cataract, and cataract alone over 12 months.
Methods: This prospective, quasi-experimental study included age- and axial length-matched patients with PEXG, POAG, or cataract alone undergoing standardized phacoemulsification with posterior chamber intraocular lens (PCIOL) implantation by a single surgeon using consistent techniques. Comprehensive ophthalmic assessments and spectral-domain optical coherence tomography imaging were performed preoperatively and at 3, 6, and 12 months postoperatively. Outcome measures included IOP, GCC thickness, retinal nerve fiber layer (RNFL) thickness, and vertical cup-to-disc ratio (CDR).
Results: Ninety eyes (30 per group) were analyzed. The mean (standard deviation [SD]) ages were 57.8 (5.8) years in the PEXG group, 58.0 (6.3) years in the POAG group, and 56.2 (4.6) years in the control group. There were 14 men (46.7%) and 16 women (53.3%) in both the PEXG and POAG groups, and 12 men (40.0%) and 18 women (60.0%) in the control group. The mean (SD) axial lengths were statistically similar at 23.9 (1.2) mm in the PEXG group, 23.9 (1.8) mm in the POAG group, and 23.8 (1.2) mm in the control group. Preoperatively, the PEXG group displayed higher IOP and thinner RNFL, whereas the POAG group featured thinner GCC and greater vertical CDR. Phacoemulsification significantly reduced IOP in both glaucoma groups (both P < 0.05), with a greater reduction in PEXG. However, no significant postoperative changes were observed in GCC thickness, RNFL thickness, or vertical CDR within any group (all P > 0.05). Despite this, intergroup differences in GCC, RNFL, and vertical CDR persisted at all follow-up points (all P < 0.05), although the PEXG and POAG groups did not significantly differ from each other (P > 0.05).
Conclusions: Phacoemulsification with PCIOL implantation significantly reduced IOP in eyes with PEXG and POAG, with a greater reduction observed in PEXG. However, this IOP reduction did not translate into significant changes in GCC thickness, RNFL thickness, or vertical CDR over 12 months. These findings suggest that although cataract surgery offers IOP-lowering benefits in early-stage glaucoma, it may not influence short-term structural progression, highlighting the need for ongoing postoperative monitoring and adjunctive management in glaucomatous eyes.
 
Reactive oxygen species and oxidative stress in ocular disease: from molecular mechanisms to targeted therapies
Full text linkBackground: Reactive oxygen species and oxidative stress are increasingly recognized as central drivers in the development of major ocular diseases, including cataracts, age-related macular degeneration, glaucoma, and diabetic retinopathy. The eye’s unique environment—continuous light exposure, high oxygen tension, and abundant photosensitizers—renders it particularly vulnerable to ROS-mediated damage. This narrative review aims to synthesize current evidence on the molecular mechanisms of oxidative stress in ocular disease and highlight emerging therapeutic approaches.
Methods: Targeted searches of PubMed, Scopus, and Google Scholar for literature published between 2000 and June 2025 were conducted. Keywords included “oxidative stress”, “reactive oxygen species”, “ocular disease”, “cataract”, “age-related macular degeneration”, “glaucoma”, and “diabetic retinopathy”. Only English-language, peer-reviewed articles were considered. Relevant primary studies, clinical trials, reviews, and experimental reports were selectively incorporated, with an emphasis on recent publications and high-impact contributions to the field.
Results: Evidence consistently demonstrates that ROS induce lipid peroxidation, protein oxidation, DNA damage, mitochondrial dysfunction, and disruption of redox-sensitive cellular signaling pathways across ocular tissues. In cataracts, oxidation of crystalline proteins and glutathione depletion are primary drivers of lens opacification. In age-related macular degeneration, mitochondrial dysfunction and lipofuscin accumulation promote retinal pigment epithelium degeneration and neovascularization. Glaucoma involves both trabecular meshwork oxidative injury, contributing to elevated intraocular pressure, and mitochondrial-driven retinal ganglion cell apoptosis. In diabetic retinopathy, hyperglycemia-induced ROS overload activates pathogenic pathways, leading to microvascular damage and neuronal dysfunction. Clinical and experimental studies support antioxidant therapies as adjunctive strategies, with the strongest evidence for Age-Related Eye Disease Study-based formulations in age-related macular degeneration and promising results for agents such as Coenzyme Q10 in glaucoma and sulforaphane in diabetic retinopathy. For cataracts, supplementation trials have yielded mixed outcomes and surgery remains the definitive treatment.
Conclusions: Oxidative stress represents a unifying mechanism in the pathogenesis of vision-threatening ocular diseases. Antioxidant-based interventions show potential, particularly when integrated with existing treatment regimens, but their translation into routine practice remains limited by heterogeneous trial results and the absence of robust biomarkers for patient selection. Future research should focus on precision antioxidant therapy, leveraging stage-specific interventions, novel delivery systems, and pathway-targeted compounds, to transform ocular care from reactive management toward prevention
Outcomes of orthokeratology: a nine-year retrospective review from a university-based optometry clinic in Malaysia
Full text linkBackground: Orthokeratology (Ortho-K) is a non-surgical approach to myopia management that uses specially designed gas-permeable lenses to reshape the cornea temporarily and improve vision. While its efficacy is established, real-world data from diverse clinical settings remain limited. In this study we aimed to support evidence-based, individualized Ortho-K practice in routine optometric care by evaluating corneal and visual outcomes, lens designs, and treatment costs at a university-based optometry clinic in Malaysia.
Methods: In this retrospective study, we analyzed clinical records of individuals fitted with Ortho-K lenses at SEGi EyeCare, SEGi University, between January 2015 and October 2024. Eligible individuals were identified via electronic health records and included if they completed key follow-up visits at 1-night, 1–2-weeks, and 1–3-months post-dispensing. Exclusion criteria included incomplete records or missed follow-up visits. Data extracted included unaided distance visual acuity (UADVA) in logarithm of the minimum angle of resolution (logMAR), corneal topography (flat and steep keratometry, eccentricity), pupil size, treatment-zone diameter, age, lens design, and total treatment cost. Measurements were obtained using the Tomey TMS-5 topographer. For each patient, both eyes were analyzed independently.
Results: Data from 30 eyes of 15 patients (mean age and standard deviation [SD]: 23.3 [9.1] years) were analyzed. Significant improvements in corneal curvature and UADVA were observed across follow-up visits (all P < 0.05). Mean (SD) steep keratometry decreased from 43.79 (1.87) D to 42.08 (2.17) D, and flat keratometry from 42.40 (1.61) D to 40.59 (2.31) D at the final visit (both P < 0.05). UADVA improved from 0.93 (0.36) logMAR to 0.23 (0.24) logMAR (P < 0.05) at the final visit. Pupil size and treatment-zone diameter remained stable (both P > 0.05), indicating consistent lens centration. The mean (SD) Ortho-K cost per patient was RM 3736.67 (514.25), equal to USD 846.20.
Conclusions: Ortho-K treatment at this university-based optometry clinic significantly improved corneal curvature, refractive error, and UADVA, with most clinical changes stabilizing within the first month of lens wear. The stability of pupil size and treatment-zone diameter suggests consistent lens performance. These findings affirm the effectiveness of Ortho-K as a non-surgical option for myopia management in real-world practice. Future studies should incorporate axial length measurements and extended follow-up to validate treatment efficacy in slowing myopia progression