Özgül Ocak

Department of Neurology, Çanakkale Onsekiz Mart University Faculty of Medicine, Çanakkale, Türkiye

Dear editor,

We are happy to receive feedback regarding our research results on “An insidious clinical picture: Optic nerve involvement in patients with COVID-19”.[1]

The coronavirus disease 2019 (COVID-19), which possesses neurotropic and neuroinvasive properties, has been reported to involve all cranial nerves in infection.[2]

There are some reports regarding optic nerve involvement and visual evoked potential (VEP) findings. Rodriguez et al.[3] reported a 62-year-old male who was asymptomatic after COVID-19, with optic neuropathy in the left eye and a prolonged left P100 latency. Köşkderelioğlu et al.[4] assessed 76 patients who recovered from COVID-19 and compared these patients with 44 healthy controls, noting that there were no significant differences between the two groups in terms of VEP parameters. However, prolonged P100 latency, which represents subclinical anterior visual pathway dysfunction, was reported in 12 patients with COVID-19.

In our study, we took a different perspective by focusing on individuals who were asymptomatic in terms of cranial nerve involvement symptoms due to COVID-19, rather than those who exhibited symptoms.

As we have stated in our manuscript, it is not possible to obtain decisive information on the subject with the available data study method. Our study still provides comprehensive insights into the scientific literature. We eagerly await new research and data about the subject.

Cite this article as: Ocak Ö. Response to Letter to the Editor: Optic nerve involvement and COVID 2019. Turk J Neurol 2024;30(2):121. doi: 10.55697/tnd.2024.81.

Data Sharing Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Conflict of Interest

The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

Financial Disclosure

The authors received no financial support for the research and/or authorship of this article.


  1. Ocak Ö, Şahin EM, Şener A, Ocak B. An insidious clinical picture: Optic nerve involvement in patients with COVID-19. Turk J Neurol 2022;28:158-61. doi:10.4274/ tnd.2022.67026.
  2. Doblan A, Kaplama ME, Ak S, Basmacı N, Tarini EZ, Göktaş ŞE, et al. Cranial nerve involvement in COVID19. Am J Otolaryngol 2021;42:102999. doi: 10.1016/j. amjoto.2021.102999.
  3. Rodriguez B, Branca M, Gutt-Will M, Roth M, Söll N, Nansoz S, et al. Development and early diagnosis of critical illness myopathy in COVID-19 associated acute respiratory distress syndrome. J Cachexia Sarcopenia Muscle 2022;13:1883-95. doi: 10.1002/jcsm.12989.
  4. Koskderelioglu A, Eskut N, Ortan P, Ozdemir HO, Tosun S. Visual evoked potential and nerve conduction study findings in patients recovered from COVID-19. Neurol Sci 2022;43:2285-93. doi: 10.1007/s10072-021-05816-9.