Conjunctivitis (Pink Eye) in Japan: Treatment Guide

Overview: Conjunctivitis in Japan

Conjunctivitis (結膜炎, *ketsumakuen*) — commonly known as "pink eye" — is an inflammation of the conjunctiva, the thin transparent membrane covering the white part of the eye and the inner surface of the eyelids. It is one of the most common eye conditions seen at Japanese ophthalmology clinics and affects travelers frequently due to the high-exposure environment of shared spaces, tourist attractions, and Japan's significant allergen load.

For international visitors, three scenarios most commonly lead to conjunctivitis:

1. Allergic conjunctivitis from cedar pollen (February–April), grass pollen, or other environmental allergens
1. Viral conjunctivitis spread through contact in crowded tourist venues, hotels, or public transport
1. Bacterial conjunctivitis from contact lens hygiene issues, contaminated water, or touching eyes with unwashed hands

Japan's ophthalmology (眼科, *ganka*) network is excellent, with eye clinics in every neighborhood and specialists accustomed to seeing patients with a wide range of conditions. Same-day appointments are generally available, and treatment is effective and affordable relative to many Western countries.

Types of Conjunctivitis and Their Characteristics

Epidemic keratoconjunctivitis (流行性角結膜炎, *ryūkōsei kakuketsumakuen*) — known in Japan as "EKC" — is a particularly severe form of viral conjunctivitis caused by specific adenovirus strains. It can cause corneal involvement and vision changes and is extremely contagious. Japanese schools and workplaces take EKC very seriously; infected individuals are expected to stay home. Travelers who develop rapidly worsening eye redness with pain and light sensitivity should see an ophthalmologist promptly.

Symptoms and Diagnosis

Common symptoms of conjunctivitis:

• Redness of the white part of one or both eyes
• Watery or sticky discharge
• Crusting of eyelids, especially after sleep
• Itching (particularly allergic type)
• Gritty or foreign body sensation
• Light sensitivity (photophobia) in some cases
• Mild eye pain or discomfort

Diagnosis at a Japanese eye clinic:

An ophthalmologist (眼科医, *gankāi*) will typically:

1. Take a detailed history of symptom onset and character
1. Examine the eye with a slit lamp (細隙灯顕微鏡)
1. Check visual acuity
1. In suspected viral cases, a rapid adenovirus antigen test (アデノウイルス迅速検査) may be performed — Japan widely uses this test
1. Swab cultures are taken if antibiotic-resistant bacterial infection is suspected

Treatment in Japan

Viral conjunctivitis:

No antiviral specifically targets adenovirus conjunctivitis. Treatment is supportive:

• Artificial tears / lubricating eye drops (人工涙液, *jinkō ruieki*) for comfort
• Cool compresses to reduce inflammation
• Avoid touching eyes; wash hands frequently
• Some Japanese ophthalmologists prescribe mild steroid eye drops to reduce inflammation (only appropriate in certain cases — follow doctor's instructions)

Bacterial conjunctivitis:

• Antibiotic eye drops are prescribed — common options in Japan include levofloxacin (クラビット点眼薬), ofloxacin (タリビッド点眼薬), or chloramphenicol
• Most bacterial conjunctivitis resolves within 5–7 days of treatment
• Complete the full course even if symptoms improve early

Allergic conjunctivitis:

• Antihistamine eye drops (抗ヒスタミン点眼薬) — available both OTC and prescription strength in Japan
• Cromolyn sodium (sodium cromoglycate) drops for prevention
• Oral antihistamines complement eye drops for severe cases
• Remove yourself from the allergen trigger environment when possible

Over-the-counter eye drops available in Japan:

Japanese pharmacies carry an extensive range of OTC eye drops. Popular brands include: