Mitochondria are vital organelles responsible for ATP production and metabolic regulation, essential for energy-intensive cells such as retinal ganglion cells. Dysfunction in mitochondrial oxidative phosphorylation or mitochondrial DNA (mtDNA) pathogenic variants can disrupt ATP synthesis, cause oxidative stress, and lead to cell death. This has profound implications for tissues such as the retina, optic nerve, and retinal pigment epithelium, which are dependent on robust mitochondrial function. In this review, we provide a comprehensive compilation of pathogenic variants in the mtDNA associated with various ophthalmic diseases, including Leber’s hereditary optic neuropathy, chronic progressive external ophthalmoplegia, Leigh syndrome, mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes, among others. We highlight the genetic variants implicated in these conditions, their pathogenic roles, and the phenotypic consequences of mitochondrial dysfunction in ocular tissues. In addition to well-established mutations, we also discuss the emerging evidence of the role of mtDNA’s variants in complex multifactorial diseases, such as non-arteritic anterior ischemic optic neuropathy, primary open-angle glaucoma, and age-related macular degeneration. The review aims to serve as a valuable resource for clinicians and researchers, providing a detailed overview of mtDNA pathogenic variants and their clinical significance in the context of mitochondrial-related eye diseases.

Gene therapy has emerged as a promising treatment for several eye diseases since it may restore vision and stop blindness. Many eye diseases, including retinitis pigmentosa and macular degeneration, have historically been rather difficult to treat and usually cause permanent vision loss. However, thanks to advances in gene therapy, many disorders can now be effectively targeted and genetically changed, providing a safer, more direct, maybe even curative approach. By introducing, altering, or repairing specific genes inside the eye, gene therapy seeks to fix the defective genes causing these disorders, thereby improving general eye health and visual ability. Voretigene neparvovec is one FDA- and EMA-approved treatment for RPE65 mutations. Retinitis pigmentosa, age-related macular degeneration, X-linked retinoschisis, choroideremia, and Stargardt disease are among the several eye disorders still under clinical trials, and experimental treatment is in progress. As research on gene therapy develops, it opens the path for groundbreaking treatments that could fundamentally change the ophthalmic care scene.

Retinoblastoma is a rare but malignant pediatric retinal tumor, affecting 1 in 15,000–20,000 live births annually. It arises from biallelic mutations in the RB1 tumor suppressor gene (chromosome 13q14.2), leading to uncontrolled cell cycle progression. Clinically, it presents as unilateral (60%) or bilateral (40%) disease, with leukocoria and strabismus as hallmark signs. Untreated, retinoblastoma is fatal due to metastatic spread. The disease follows Knudson’s two-hit model: heritable forms (30–40% of cases) involve a germline RB1 mutation (M1) and a somatic second hit (M2), predisposing to bilateral/multifocal tumors and secondary cancers. Non-heritable cases (60–70%) result from somatic RB1 mutations or, rarely, MYCN amplification (2%). Genetic testing is critical to classify risk (H0, H1, and HX categories), guide surveillance, and inform family counseling. Bilateral cases almost always harbor germline mutations, while 15% of unilateral cases may carry germline/mosaic RB1 defects. Advanced techniques (Sanger/NGS sequencing for mutation detection, NGS for copy number alterations, and methylation assays) detect RB1 mutations, CNVs, and epigenetic silencing. Tumor DNA analysis resolves ambiguous cases. H1 patients require intensive ocular and brain MRI surveillance, while H0 cases need no follow-up. Prenatal/preimplantation genetic diagnosis (PGD) can prevent transmission in high-risk families. Emerging research explores additional genes (BCOR, CREBBP) and MYCN-amplified subtypes. Genetic counseling addresses recurrence risks, reproductive options, and long-term cancer monitoring. Integrating genetic insights into clinical practice enhances precision medicine, reducing morbidity and healthcare costs. Future directions include whole-genome sequencing and functional studies to refine therapeutic strategies.

Autosomal recessive types of both syndromic and non-syndromic inherited myopia are common in Saudi Arabia (SA) because many people marry their relatives. The prevalence of syndromic myopathies in SA, like Stickler syndrome (SS), Knobloch syndrome (KS), and Marfan syndrome (MFS), further complicates the disease spectrum. The causative genes linked to the Knobloch, Marfan, and Pierson syndromes are COL18A1, FBN1, and LAMB2, respectively. Additionally, we found recessive types of non-syndromic high myopia that have a high chance of causing retinal detachment, like those linked to LRPAP1 and LEPREL1. In these cases, regular evaluation and early intervention, including prophylactic laser photocoagulation and pars plana vitrectomy, may improve the outcome. Advancements in genetic testing for diagnosis and prevention accelerate detection, facilitate early interventions, and provide genetic counseling. The utilization of artificial intelligence (AI), machine learning (ML), and the advancement of gene therapy offer promising avenues for personalized care. We place a high value on using genetic knowledge to create a national screening program and patient registry aimed at understanding the national burden of myopia, knowing that we have a high rate of consanguinity, which reflects pathogenic homozygous alleles and founder mutations. This initiative will incorporate genetic counseling and leverage innovative technologies, which are crucial for disease management, early identification, and prevention in Saudi Arabia’s healthcare system.

Most glaucoma genetic data derive from European and East Asian cohorts, leaving high-consanguinity Middle Eastern populations under-characterized. This review synthesizes 33 Saudi-specific genetic studies (2014–2024, >9000 participants) to define a population-level glaucoma genetic architecture that diverges substantially from global models and carries direct precision medicine implications. Three findings distinguish the Saudi landscape. First, CYP1B1 functions as the dominant causal gene across both primary congenital glaucoma (PCG) and juvenile-onset open-angle glaucoma (JOAG), accounting for 76–86% of cases, with two founder alleles, p.G61E (penetrance 87.7%) and p.R469W (penetrance 93%), driving severe, early-onset phenotypes. Critically, MYOC and LTBP2, the primary JOAG genes in other populations, carry no pathogenic variants in Saudi cohorts, rendering standard multi-ethnic gene panels inadequate for this population. Second, adult-onset glaucoma follows a distinct polygenic architecture where APOE ε2 confers a near five-fold risk for primary angle-closure glaucoma (OR = 4.82), an effect absent or inconsistent in global datasets, and NOS3 variants associate with primary open-angle glaucoma specifically in men, a sex-stratified signal unreported outside Saudi cohorts. The MTHFR T/T genotype, common in European and Asian POAG patients, is entirely absent locally, indicating population-specific allelic distributions that alter folate-metabolism-related optic nerve susceptibility. Third, ACVR1 rs12997 associates across POAG, PACG, and pseudoexfoliation glaucoma (PXG), positioning BMP/TGF-β signaling as a shared mechanistic pathway spanning multiple subtypes. These findings argue for Saudi-specific genetic panels, CYP1B1-centered cascade testing in consanguineous families, and polygenic risk models incorporating local allele frequencies rather than globally derived weights.

Mitochondrial genetic disorders compromise oxidative phosphorylation (OXPHOS) and cellular energy supply, and the eye is among the first organs to feel the deficit. Photoreceptors and retinal ganglion cells (RGCs) sustain among the highest metabolic rates in the body, so ophthalmic features often dominate the clinical picture and arrive before systemic disease is recognized. More than half of all patients with confirmed mitochondrial disease develop sight-threatening complications. This review integrates mtDNA and nuclear genetics; ophthalmic and extraocular phenotypes; the bioenergetic and apoptotic mechanisms that drive vision loss; the clinical examination and investigations that delineate the problem; the differential diagnoses that must be excluded; the contribution of common mtDNA haplogroup variation to age-related retinal disease; and the diagnostic, therapeutic, and counseling approaches that turn a molecular result into useful care. Recurring themes are heteroplasmy, the threshold effect, and the selective vulnerability of RGCs and extraocular muscle across genetically distinct disorders. Treatment remains largely supportive, but idebenone, gene therapy, mitophagy modulation, and targeted antioxidants now offer mechanism-based intervention for several ophthalmic manifestations.