시신경부종의 원인

우선적으로 시신경이 붓는 원인을 생각해 보면

첫번째 원인으로는 사상판 이후의 부종으로 인해 axoplasmic flow가 차단되어 시신경이 붓게 됩니다. anterior ischemic optic neuropathy가 이에 해당된다고 봅니다.

두번째로는 염증에 의해 시신경자체가 붓는 것입니다.

세번째로는 마치 부어 보이지만 실제로는 붓지 않고 시신경유두의 기저부에서 드루젠등에 의해 올라와 보이는 양상을 보이는 경우 입니다.

이러한 이유로 시신경이 붓게 되는데 저의 임상적 경험으로는 다음 순으로 원인을 꼽을 수 있을 것 같습니다. - 저는 신경안과 의사여서 환자의 selection bias가 있습니다.

1. non-arteritic ischemic optic neuropathy
2. optic neuritis
3. pseudopapilledema
4. compressive optic neuropathy
5. intracranial hypertension
6. vasculopathy such as BRVO, CRVO
7. inflammatory disorders such as Harada
8. diabetic optic neuropathy
9. others

각각의 시신경유두부종은 생김새가 조금씩 다르고 환자의 증상자체에서도 차이가 있기 때문에 병력을 자세히 청취하고 시신경유두를 유심히 들여다 보면 추가 검사를 하지 않아도 어느정도 판가름이 나는 것 같습니다. - 저는 전공의들에게 시신경과 대화를 나누어야 한다고 합니다.^^

다음 포스팅에서는 각각의 질환에 대해 알아보도록 하겠습니다.

Treatment of NAION

Topics about treatment of NAION are very controversy.
100 articles about treatment of NAION were searched in Pubmed so far.

Prof Hayreh, one of the leading professors in the field of ischemic optic neuropathy, suggested that high-dose systemic corticosteroid therapy improved visual field defect. 
However, several ophthalmologists do not agree with prof. Hayreh.

Recently, Intravitreal ranibizumab injection is being considered to treat NAION.
Bajin et al. reported that Intravitreal ranibizumab injection may be a treatment option in eyes with non-arteritic anterior ischemic optic neuropathy and a short disease history.

I think that the results of systemic corticosteroid or intravitreal ranibizumab injection may be affected by severity of disc swelling or optic disc vascular insufficiency. Thus, we need more well designed randomized control study.

Some reports presented the effectiveness of Aspirin to prevent recurrence of NAION.

Optic disc of non-arteritic ischemic optic neuropathy

Non-arteritic anterior ischemic optic neuropathy (NAION) is most common disc swelling disorder in Korea.

NAION is resulted from vascular insufficiency of optic disc, especially circle of Zinn-Haller. The vascular insufficiency induces the optic disc swelling with splinter hemorrhage.

Figure 1. The optic disc of NAION. Diffuse optic disc swelling is detected and hemorrhage is shown in infero-temporal area.
















NAION is usually associated with optic disc hemorrhage ( about 70%), so the  hemorrhage is one of the key features in NAION and it is a very helpful to diagnose NAION.

When it comes to optic disc swelling, we should also consider optic neuritis. Although the patients with optic neuritis have pain on ocular movement (up to 90%). patients with NAION usually did not complain ocular pain. In my opinion, some patients with NAION  complained of dull pain around affected eye.

I think that optic disc margin of NAION is more irregular than that of ON. Also, some cases of NAION were shown sectorial disc swelling. However, total blurred disc swelling is more common in the acute stage.

Figure 2. Inferior sectorial disc swelling with hemorrhage is shown.

Causes of optic disc swelling

I work for Kim's Eye Hospital, Konyang University.
Kim's Eye Hospital is the biggest hospital for eye in Korea.

My major is neuro-ophthalmology. so, I'm interested in optic disc.

The optic disc is a window of central nervous system and also gives a lot of information about optic neuropathy.

In my experience, the most common cause of optic disc swelling in Korea is non-arteritic anterior ischemic optic neuropathy and followed by optic neuritis, papilledema and  pseudopapilledema.

Please, refer to my article "Analysis of the Causes of Optic Disc Swelling" in Kor J Ophthalmol 2011.

Thus, I will post cases of optic disc swelling with photography.

If you have any comment or question, feel free to email to me "ungsookim@kimeye.com"