Abstract:
Background: Myopia, commonly known as nearsightedness, is a refractive error that affects a significant portion of the global population. In addition to its impact on visual acuity, myopia can also have detrimental effects on the optic nerve, leading to potential vision loss and other complications. Diagnosing optic nerve damage in myopia poses specific challenges, requiring specialized techniques for accurate assessment. Optical coherence tomography (OCT) has emerged as a valuable tool in ophthalmology, providing high-resolution imaging of ocular structures, including the optic nerve. By utilizing OCT, clinicians can evaluate the thickness of the retinal nerve fiber layer (RNFL) and ganglion cells (RGC), which are critical indicators of optic nerve health. However, the characteristics and diagnostic features of optic nerve damage in myopia remain relatively unexplored. Understanding these features is crucial for accurate diagnosis and differentiation from other neuropathies, as well as for optimizing treatment strategies. This study aimed to investigate the specific features of diagnosing optic nerve damage in myopia using OCT. Three patients with moderate myopia were examined, and various diagnostic methods, including visometry, echo biometry, ophthalmoscopy, computer perimetry, tonometry, and OCT, were employed. Additionally, brain magnetic resonance imaging (MRI) was conducted to identify any potential underlying pathologies. By analyzing the collected data, the study aimed to identify and interpret the signs of optic nerve damage in myopia, such as the formation of myopic cones, posterior staphyloma, white spot syndrome, and oblique entrance of the nerve. Moreover, the study aimed to assess the changes in RNFL and RGC thickness in the affected areas compared to age-related norms. The findings of this study contribute to the understanding of optic nerve damage in myopia and its differential diagnosis from other causes of neuropathies. Ultimately, this research will aid in the development of criteria for accurate diagnosis, enabling clinicians to optimize treatment approaches for patients with myopia-related optic nerve damage.
Methods: We examined three patients with myopia and right eye visual acuities reduced at the Ivano-Frankivsk National Medical University. Patient V., born in 1988, in both eyes (-3.5 diopters) myopia. Patient Yu., born in 1992, refraction in the right eye (-3.5 DPTR), left eye (-4.25 DPTR). Patient M., born in 1990, with myopic astigmatism of the right eye (SPH –2.5 DPTR; CYL -1.0 DPTR; Ax 5°) and mixed astigmatism of the left eye (SPH +0.25 DPTR; CYL -1.0 DPTR; Ax 5°). We observed visometry, echo biometry, ophthalmoscopy and data analysis of computer perimetry, tonometry and OCT, brain magnetic resonance imaging (MRI). We obtained informed consent was from the patients for the processing of personal information and its use for scientific purposes in all cases.
Result: We have investigated three patients with moderate myopia (about 3.5 diopters in both eyes). Signs of damage to the optic nerve have found. These could interpret as a myopia’s complication (formation of a myopic cone, posterior staphyloma, white spot syndrome, oblique entrance of the nerve) or could be because of neuropathies of other genesis (sudden progressive decrease in vision). Patient V.’s optic nerve has showed the posterior staphyloma formation. Patient Yu. optic nerve has glaucomatous excavation. Patient M. optic nerve has an oblique entrance. In all cases, a decrease in the thickness of the layer of nerve fibers (RNFL) and ganglion cells (RGC) was established on the side of the lesion in comparison with the age norm from 5 to 20% (p<0.05). Patient V. all the RNFL and RGC sectoral segments, except the temporal one, thickness reduced compared to the age norm. There was forming sectoral atrophy. Patient Yu.’s the RNFL and RGC vertical sectoral segments reduced thickness. It gave suggesting similar features to glaucoma. Patient M., on the side of the lesion, has only the upper RNFL segment was 5% less thick than the age norm, and the RGCs were all segments except the upper. The use of disk-gradient showed that areas with reduced RNFL thickness in all cases are behind the course of blood vessels, and RGCs in the paramacular area form a ring-shaped focus. MRI of the brain of patient V. did not reveal any pathology. Patient Yu. pineal gland’s cyst diagnosed. Patient M. the pituitary glands microadenoma found. The findings confirm the different genesis of optic nerve damage in all three cases. The myopia complications and other neuropathies signs specific criteria separations is a task for future research.
Conclusion: Studying the diagnostic features of optic nerve damage in myopia will allow to develop criteria for differential diagnosis of complications of myopia and damage to the optic nerve of other genesis and will optimize the choice of treatment measures.
