Greater public awareness and less STI stigma around eye health is needed

The London Clinic Eye Centre‘s Consultant Ophthalmologist Dr Ilaria Testi explains some of these complications, the symptoms, and dangers if left untreated and why more people need to put health not stigma, first. Read more about STIs that can affect the eyes and STI eye infections symptoms and treatments.

Q: In the UK and globally STIs (sexually transmitted infections) are on the increase, why do you think this is?

A: STI rates in the UK are rising for a combination of reasons. There’s been a real shift in sexual behaviour and social mixing, including the increased popularity of dating apps, which has enabled people to find sexual partners much more easily than previous generations across ages. That means a greater diversity of partners, more sexual mixing and higher rates of partner change, which naturally increases transmission.

Another key factor is that many STIs are asymptomatic, so people don’t realise they’re infected, and if they’re not tested, they can unknowingly pass infections on.

There may also be less partner notification after a positive diagnosis, which allows further onward spread. We’ve also seen major advances in HIV prevention and treatment, which is hugely positive, but it can reduce fear around sexual risk. Unfortunately, other STIs are still circulating, and we’re seeing less consistent condom use as a result. Finally, improved access to testing, including online testing kits, has increased detection, so we are diagnosing more infections that may previously have gone unrecognised.

With STI rates increasing overall, it’s inevitable we’ll see more eye involvement and ocular complications too, especially when diagnosis is delayed. That’s why integrated services matter, because the eye can be the first sign that something bigger is going on, and that’s exactly why a dedicated service is needed, to speed up diagnosis and reduce missed cases, protecting sight.

Q: Is it correct that chlamydia is the highest STI? And that syphilis has the largest number of cases reported since 1948?

A: Yes. According to the latest UKHSA (UK Health Security Agency), chlamydia remains the most commonly diagnosed STI in England. In 2024, UKHSA reported 168,889 chlamydia diagnoses, which is higher than any other STI. For comparison, gonorrhoea was 71,802 diagnoses.

UKHSA 2024 data shows infectious syphilis diagnoses rose to 9,535, and including all stages of infection there were 13,030 cases in 2024, the highest annual total recorded since 1948. This demonstrates a significant resurgence of syphilis in recent years and underscores the need for improved detection, public awareness and integrated sexual-health services.

Q: The British Association for Sexual Health and HIV (BASHH) has warned that increasing rates of syphilis mean that eye-related symptoms are being missed, leading to long-term complications

A: Syphilis is sometimes called ‘the great imitator’ because it can mimic many other eye conditions and has multiple, varied clinical presentations. It can affect almost every part of the eye: the conjunctiva, causing conjunctivitis; the clear front layer which is the cornea, causing keratitis, and the tough white outer layer of the eye causing a painful inflammation of the sclera (scleritis).

The most serious damage happens at the back of the eye, where it can cause uveitis (inflammation inside the eye), affecting the retina (which detects light) and the optic nerve (which carries visual signals to the brain). If this inflammation is missed or not treated, it can permanently damage these structures and cause long-term vision loss. That’s why early diagnosis and treatment are so important to protect sight.

Q: Do you think people aware of these conditions – and the dangers if left untreated?

A: In my experience, awareness of these eye-related complications of STIs like syphilis is generally quite low among the public. Most people think of STIs as affecting sexual or reproductive health, and they don’t realise that infections can also seriously affect the eyes. As a result, symptoms such as blurred vision, floaters or eye pain or redness are often ignored or misattributed to minor eye problems.

The danger is that if left untreated, conditions like ocular syphilis, chlamydia or gonorrhoea can cause permanent damage to the cornea, retina and optic nerve, leading to long-term or even irreversible vision loss. That’s why raising awareness, early detection and prompt treatment are absolutely critical.

Q: Is it true there have been calls for clinicians to consider testing for ocular syphilis in cases of unexplained red eye or visual disturbances?

A: Yes, absolutely. There have been strong calls for clinicians to consider testing for syphilis in any patient presenting with unexplained red eye or visual disturbances. In my uveitis clinic, every patient who presents with uveitis, that is inflammation inside the eye, is tested for syphilis as part of our standard work-up.

In many cases, we as ophthalmologists are the first to make the diagnosis. Some patients are completely unaware they have a STI, while others may know they’re at risk but hadn’t connected their eye symptoms to an infection. Identifying syphilis in this way is crucial, because early detection and treatment can prevent serious and potentially permanent vision loss.

Q: Do you think people are leaving eyes untreated due to embarrassment – if so – what reassurance can you give?

A: Yes, I do think embarrassment or stigma can sometimes stop people from seeking help. Many patients are worried about being judged for having a sexually transmitted infection, and they may delay visiting a clinic even when they notice eye problems like redness, pain or blurred vision.

The reassurance I give is that eye health and sexual health are both medical issues, not moral ones. In our clinic, everything is handled confidentially and professionally, and patients are treated with care and understanding. Early assessment and treatment are absolutely key, addressing the problem promptly can prevent serious, permanent damage to vision, so there’s a strong medical incentive to seek help without delay.

Q: What groups of people are largely affected?

A: Sexually transmitted infections can affect anyone, but higher rates are seen in certain groups. Young adults, especially those aged 15-24, have the highest rates of chlamydia and gonorrhoea.

Historically, syphilis rates have been highest among bisexual and men who have sex with men, but recent UKHSA data show a significant rise in syphilis diagnoses among heterosexual men and women as well. People with multiple partners and inconsistent condom users are also at higher risk. It’s important to remember that eye-related complications don’t only occur in these high-risk groups. Anyone with an untreated STI can develop uveitis or other ocular problems, so awareness and testing are important for everyone.

Q: Is it better to be treated in person or do people think they can get treated online?

A: For eye-related complications like ocular syphilis, in-person assessment is essential. Many eye problems can’t be diagnosed remotely because subtle signs of inflammation, retinal involvement or optic nerve changes require a specialist examination.

Some people may think they can manage an infection online, but if ocular symptoms are present, delaying an in-person visit can lead to permanent vision loss. Being assessed face-to-face allows for a full eye examination, accurate diagnosis and immediate treatment, which is crucial for protecting sight.