Acute vision changes as the presenting symptom of ocular syphilis - A case series of two.

Introduction: Syphilis, a bacterial infection caused by Treponema pallidum, can affect a wide variety of organ systems of its host. We aim to present the cases of two patients who presented to an urban, tertiary care, academic Emergency Department with ocular symptoms who underwent imaging, laboratory, and specialist evaluation and were ultimately diagnosed with ocular syphilis. Case Report: The first patient is a 46-year-old female who presented to the Emergency Department with painless complete vision loss in a unilateral eye. Her exam was significant for bilateral papilledema, and further workup revealed a retinal detachment in the affected eye. Rapid plasma reagin (RPR) titers resulted positive with 1:128 and a reactive fluorescent treponemal antibody (FTA). Further workup including lumbar puncture and magnetic resonance imaging were unable to be obtained due to patient refusal and multiple discharges against medical advice. The second patient is a 38-year-old female with a history of intravenous drug use who presented for bilateral circumferential peripheral vision loss with central sparing. The examination showed bilateral papilledema. Lumbar puncture was performed with normal intracranial pressure. RPR titers resulted positive with 1:128. MRI and ophthalmology evaluation did not reveal any other etiology or explanation for papilledema. Conclusion: This case series highlights the importance of considering syphilis as a possible cause of ocular symptoms in high risk patient populations and the need for prompt and appropriate treatment given the increasing prevalence of syphilis worldwide.

Ocular Syphilis - Clinical Features and Outcome in HIV Positive and HIV Negative Patients from a Tertiary Eye Center from India - A Comparative Study.

PURPOSE: To study and compare the clinical characteristics and outcome of ocular syphilis between HIV positive and HIV negative patients. METHODS: Retrospective hospital-based case series from a tertiary eye care hospital in India. Patients with uveitis and positive syphilis serology were included. Demographics, clinical features, investigations, imaging and treatment modalities were noted. RESULTS: Hundred and five (105) eyes of 66 patients were analyzed. Males were predominantly affected (n = 57/66, 86.4%). Secondary syphilis was the most common stage of presentation (n = 48/66, 72.7%). Two groups were identified: HIV positive (HIVP) patients (n = 39/66, 59%) and HIV negative (HIVN) patients (n = 27/66, 41%). 12/39 (30.8%) patients were newly diagnosed with HIV at the time of ocular presentation. Panuveitis was the most common presenting feature in both groups (n = 66/105 eyes, 62.8%). Diffuse necrotizing retinitis was more common in HIV patients (HIVP - 15 Vs HIVN - 5 eyes). Ocular co-infections were more common in HIV patients, ocular tuberculosis, the commonest in both groups. Intravenous penicillin and titrated dose of systemic steroids were the mainstay of treatment. Improvement in mean logMAR was noted from 1.415 to 0.828 with p-value < 0.001. At final follow-up, 71.8% patients showed visual improvement. Complete resolution of ocular inflammation was noted in 95.5% patients. CONCLUSION: Ocular syphilis poses a diagnostic challenge considering the varied presentations and clinical course both in immunocompromised and immunocompetent groups. Clinical presentations are not always classical. High index of suspicion with supportive laboratory investigations and with characteristic OCT features helps diagnosis. All uveitis patients, especially with those suspected with infectious etiology, need to be tested for syphilis serology to prevent vision loss in this resurgent disease.

Molecular investigation of Treponema pallidum strains associated with ocular syphilis in the United States, 2016-2020.

Ocular syphilis is a serious complication of Treponema pallidum infection that can occur at any stage of syphilis and affect any eye structure. It remains unknown if certain T. pallidum strains are associated with ocular infections; therefore, we performed genotyping and whole genome sequencing (WGS) to characterize strains from patients with ocular syphilis. Seventy-five ocular or non-ocular specimens from 55 ocular syphilis patients in 14 states within the United States were collected between February 2016 and November 2020. Sufficient T. pallidum DNA was available from nine patients for genotyping and three for WGS. Genotyping was done using the augmented Centers for Disease Control and Prevention typing scheme, and WGS was performed on Illumina platforms. Multilocus sequence typing allelic profiles were predicted from whole genome sequence data. T. pallidum DNA was detected in various specimens from 17 (30.9%) of the 55 patients, and typing was done on samples from 9 patients. Four complete strain types (14d10/g, 14b9/g, 14d9/g, and 14e9/f) and five partial types were identified. WGS was successful on samples from three patients and all three strains belonged to the SS14 clade of T. pallidum. Our data reveal that multiple strain types are associated with ocular manifestations of syphilis. While genotyping and WGS were challenging due to low amounts of T. pallidum DNA in specimens, we successfully performed WGS on cerebrospinal fluid, vitreous fluid, and whole blood.IMPORTANCESyphilis is caused by the spirochete Treponema pallidum. Total syphilis rates have increased significantly over the past two decades in the United States, and the disease remains a public health concern. In addition, ocular syphilis cases has also been on the rise, coinciding with the overall increase in syphilis rates. We conducted a molecular investigation utilizing traditional genotyping and whole genome sequencing over a 5-year period to ascertain if specific T. pallidum strains are associated with ocular syphilis. Genotyping and phylogenetic analysis show that multiple T. pallidum strain types are associated with ocular syphilis in the United States.

Ocular syphilis in patients with nonreactive RPR and positive treponemal serologies: a retrospective observational cohort study.

BACKGROUND: Screening for syphilis increasingly relies on positive treponemal rather than nontreponemal tests (rapid plasma reagin [RPR]). We compared ocular syphilis in patients with nonreactive versus positive RPR. METHODS: We conducted a retrospective observational cohort study of ocular syphilis treated at two New England hospitals 1996-2021 based on ophthalmologist-diagnosed eye findings and positive treponemal serology, regardless of RPR. We excluded patients with alternative diagnoses. We categorized RPR into nonreactive RPR, low-titer RPR (<1:8), and high-titer RPR (≥1:8) and compared early and long-term response to therapy. RESULTS: Our sample included 115 patients with ocular syphilis (median follow-up 2.5 years): 25 (22%) nonreactive RPR, 21 (18%) low-titer RPR, 69 (60%) high-titer RPR. Compared with nonreactive and low-titer RPR, people with high-titer RPR were younger (mean 47 years, p<0.001), more likely male (93%, p<0.001) and more likely to be living with HIV (49%, p<0.001). People with nonreactive and low-titer RPR were less likely than high-titer RPR to have posterior/panuveitis (32% and 29% versus 75%, p<0.001) or abnormal CSF (26% and 35% versus 75%, p<0.001), and more likely to present with chronic eye findings (20% and 29% versus 1%, p<0.001). In long-term follow up, eye findings improved and did not recur in most patients (62% nonreactive, 68% low-titer, 96% high-titer RPR); improved but recurred in 29%, 11%, and 4%, respectively; and were stable in 10%, 21%, and 0%, respectively. CONCLUSION: Patients with ocular syphilis and nonreactive RPR are similar to patients with low-titer RPR, and antibiotic therapy is beneficial in most.

Relapsed Mpox Keratitis, St. Louis, Missouri, USA.

We describe a case of a 46-year-old man in Missouri, USA, with newly diagnosed advanced HIV and PCR-confirmed mpox keratitis. The keratitis initially resolved after intravenous tecovirimat and penicillin for suspected ocular syphilis coinfection. Despite a confirmatory negative PCR, he developed relapsed, ipsilateral PCR-positive keratitis and severe ocular mpox requiring corneal transplant.

Anterior Non-Necrotizing Scleritis with Active Uveitis in Cases of Ocular Syphilis.

PURPOSE: To study clinical characteristics and management outcomes of cases of ocular syphilis co-presenting with scleritis and active uveitis. METHODS: A retrospective analysis of cases diagnosed with ocular syphilis between January 2020 and December 2023 was conducted at a tertiary eye care centre. Clinical records, investigations, and outcomes were reviewed to identify cases with scleritis with active uveitis. Demographic data, clinical features, treatment modalities, and resolution patterns were analyzed. RESULTS: Among the 135 eyes of 95 cases of ocular syphilis studied, scleritis with uveitis was observed in 3.70% of eyes (five eyes). All cases with scleritis and uveitis were unilateral and male, with ages ranging from 32 to 61 years. Concurrent features included placoid chorioretinitis, retinal vasculitis, and anterior uveitis. Misdiagnosis with subsequent oral steroid therapy precipitated scleritis as an exacerbation in two cases. Three cases, which were previously undiagnosed, were found to be HIV-positive. Scleritis manifested as anterior, non-necrotizing inflammation, often accompanied by chemosis, and responded rapidly to antibiotic and non-steroidal anti-inflammatory therapy. Scleritis resolution preceded that of chorioretinitis and retinal vasculitis. CONCLUSIONS: Non-necrotizing anterior scleritis with chemosis can be a rare presentation of active syphilitic uveitis. Large placoid chorioretinitis lesions, preceding inadvertent oral steroid and/or undiagnosed HIV status were the possible risk factors for the development of concurrent scleritis.

Clinical characteristics and outcomes of people living with HIV and ocular syphilis during the COVID-19 health emergency.

BACKGROUND: The global shift in healthcare during the COVID-19 pandemic led to challenges in the care of people living with HIV. METHODS: We conducted a retrospective study that aimed to delineate sociodemographic, clinical characteristics and outcomes, of people living with HIV diagnosed with ocular syphilis. RESULTS: Fifty-three people living with HIV were identified with ocular syphilis. Thirty-eight (71.6%) presented ocular symptoms. Twenty-three (43.3%) underwent lumbar puncture, 5 (9.4%) were positive for neurosyphilis. Forty-seven (88.6%) received treatment, 32 (68%) received standard treatment with aqueous crystalline penicillin G, and 15 (31.9%) were treated with alternative regimens due to the impossibility of hospitalization. Six (11.3%) individuals were lost to follow-up and/or did not receive treatment. Eighteen (56.2%) out of 32 individuals in the aqueous crystalline penicillin G group experienced serological response, 5 (15.6%) experienced treatment failure, and 9 (28.1%) were lost to follow-up. In the alternative therapy group, 12 out of 15 individuals (80%) experienced serological response. One (6.7%) experienced treatment failure, and 2 (13.3%) were lost to follow-up. CONCLUSIONS: During the COVID-19 health emergency in Mexico, alternative treatments for ocular syphilis demonstrated favorable clinical outcomes amid challenges in accessing hospitalization.

Ocular Syphilis as a Primary Manifestation of Neurosyphilis: A Case Report.

Sexually transmitted infectious diseases could affect a variety of organs, generating significant symptomatology. In the elderly population, infectious causes for vision problems are not generally considered. We present the case of an elderly patient with blurred vision and darkening of visual fields. He underwent an unsuccessful biopsy of the temporal artery as his vision disturbances presented also with episodic headaches. He was found to have an elevated rapid plasma reagin (RPR) and venereal disease research laboratory (VDRL) test in his cerebrospinal fluid (CSF) analysis. He was treated for ocular syphilis with a total resolution of his vision loss.

Syphilitic scleritis and episcleritis: A review.

Scleritis and episcleritis are rare, but potentially sight-threatening forms of syphilis. To provide a full description of this neglected subset of ocular syphilis, we evaluated the English literature for reports of syphilitic scleritis and episcleritis, recording the demographics, clinical characteristics, serological data, management practices, treatment responses, and visual outcomes. Previously published descriptions of 44 patients with syphilitic scleritis (50 eyes) and 9 patients with syphilitic episcleritis (14 eyes) were identified. The predominant type of scleritis was anterior scleritis, accounting for 92.9% of cases, with nodular anterior scleritis being the most frequent subtype at 58.1%. Almost one-quarter of patients were co-infected with human immunodeficiency virus (HIV). Initial misdiagnosis was common and led to delays in initiating treatment with appropriate antibiotics. Visual outcomes were often good in both scleritis and episcleritis, irrespective of HIV infection status, although complications including scleral thinning, keratitis, and uveitis, along with permanent visual loss and an association with neurosyphilis, were reported. Response to antibiotic treatment was typically rapid, often within 1 week. With the rising global incidence of syphilis, testing patients with scleritis or episcleritis for this infectious disease is important to ensure prompt diagnosis and treatment for best ocular and systemic outcomes.

Southern African HIV Clinicians Society Guideline for the clinical management of syphilis.

Syphilis, 'the great imitator', caused by Treponema pallidum infection, remains a complex and multifaceted disease with a rich history of clinical diversity. This guideline aims to be a comprehensive guide for healthcare workers in Southern Africa, offering practical insights into the epidemiology, pathogenesis, clinical manifestations, diagnostic testing, therapeutic principles, and public health responses to syphilis. Although the syphilis burden has declined over the years, recent data indicate a troubling resurgence, particularly among pregnant women and neonates. This guideline highlights the diagnostic challenges posed by syphilis, stemming from the absence of a single high-sensitivity and -specificity test. While treatment with penicillin remains the cornerstone of treatment, alternative regimens may be used for specific scenarios. We highlight the importance of thorough patient follow-up and management of sex partners to ensure optimal care of syphilis cases. In the context of public health, we emphasise the need for concerted efforts to combat the increasing burden of syphilis, especially within high-risk populations, including people living with HIV.

Co-infectious Uveitis With Syphilis and Lyme Disease: A Case Report.

Uveitis is the inflammation of the uveal tract (i.e., iris, ciliary body, and choroid). Uveitis is categorized into the following three types based on the anatomical location of inflammation: anterior, intermediate, and posterior uveitis. Severe cases may lead to panuveitis, where all three layers may become inflamed potentially resulting in permanent vision loss. Uveitis can arise from different underlying disorders, including infectious causes or autoimmune disorders. Syphilis and Lyme disease are uncommon causes of uveitis. Eye involvement can occur at any stage in Lyme disease, characterized by diverse manifestations such as conjunctivitis, episcleritis, keratitis, uveitis, neuroretinitis, and retinal vasculitis. Patients may present with symptoms of blurred vision, eye pain or discomfort, visual floaters, headache, or intolerance to light. Patients can risk vision loss if not diagnosed and treated promptly.

Ocular Syphilis and Syphilitic Meningitis as the Initial Symptoms of Neurosyphilis in an HIV-Negative Patient: A Case Report.

Syphilis is an infectious disease caused by the spirochete bacteria Treponema pallidum and is most commonly transmitted via contact of mucous membranes with infectious lesions during sexual intercourse. It is called the "great mimicker" due to its ability to infect a wide variety of organs and, as a result, produce a multitude of symptoms. Neurosyphilis, an infection of the central nervous system, can occur at any stage of infection. Cases of early neurosyphilis may not present with any prior history of syphilis infection or classical symptoms of primary or secondary infection. Homosexual men are disproportionately affected by the increasing rate of transmission.In this case, a 43-year-old man was diagnosed with neurosyphilis, initially presenting with bilateral papilledema concerning for idiopathic intracranial hypertension. A detailed social history revealed that the individual was sexually active with a male partner. Despite nonreactive results from the rapid plasma reagin and CSF Venereal Disease Research Laboratory tests, further serum workup yielded positive results for treponemal antibodies. Evidence of facial nerve involvement was also found on MRI. These findings were consistent with a diagnosis of ocular syphilis with syphilitic meningitis involving cranial nerve VII. This case demonstrates the importance of clinical suspicion for syphilis when indicated by social history, even when screening tests are negative, due to the potential for false negatives and highly variable clinical presentation.

Could ceftriaxone be a viable alternative to penicillin for the treatment of ocular syphilis?

This study was conducted to compare the effectiveness of ceftriaxone with that of aqueous crystalline penicillin G in treating ocular syphilis. We conducted a retrospective study from 2010 to 2021. Syphilis patients were administered either ceftriaxone (2 g intravenously daily for 14 days) or aqueous crystalline penicillin G [4 million units (MU) intravenously every 4 h for 14 days] as therapeutic interventions. Subsequently, we utilized these two groups to assess the serological results, cerebrospinal fluid analysis, and visual acuity at time intervals spanning 3 to 6 months post-treatment. A total of 205 patients were included, with 34 assigned to the ceftriaxone group and 171 to the penicillin group. The median age of patients was 56 years, with an interquartile range of 49-62 years, and 137 of them (66.8%) were male. Between 3 and 6 months after treatment, 13 patients (38.2%) in the ceftriaxone group and 82 patients (48.0%) in the penicillin group demonstrated effective treatment based on the clinical and laboratory parameters. The crude odds ratio (OR) was 0.672 (95% confidence interval [CI]: 0.316-1.428, P = 0.301), indicating no significant difference in effectiveness between the two groups. Thirty patients (17.5%) in the penicillin group and six patients (17.6%) in the ceftriaxone group did not experience successful outcomes. Notably, no serious adverse effects were reported in both the groups. There was no significant difference in the effectiveness of ceftriaxone and aqueous crystalline penicillin G in treating ocular syphilis. The administration of ceftriaxone without requiring hospitalization presents a convenient and safe alternative treatment option for ocular syphilis.

All Eyes and Ears: A Case of Neurosyphilis Presenting With Simultaneous Ocular and Otic Involvement.

This report details a case of neurosyphilis manifesting as concurrent ocular and otosyphilis, an uncommon presentation of the disease. Here, we describe the diagnosis and treatment of a 27-year-old immunocompetent Caucasian male who presented with uveitis and tinnitus. Physical exam was consistent with uveitis and audiometric testing revealed bilateral sensorineural hearing loss. Serum rapid plasma reagin (RPR) was reactive at 1:512 with a follow-up cerebrospinal fluid (CSF) venereal disease research laboratory (VDRL) test likewise reactive at 1:2, confirming neurosyphilis. The patient was treated with intravenous penicillin G with improvement of symptoms and with subsequent improvement of serum and CSF RPR. However, he ultimately represented with recurrent symptoms and fluctuating serum RPR levels, necessitating repeat treatment and ongoing clinical monitoring. Neurosyphilis can occur at any point during the course of a syphilis infection and may present with a variety of nonspecific findings. This case documents a particularly uncommon instance of simultaneous ocular and otosyphilis, a presentation of neurosyphilis that has only been described a handful of times.

The Great Imitator Masquerading as Autoimmune Hepatitis and Demystifying as Fulminant Syphilitic Retinitis.

PURPOSE: Syphilis is a "Great Masquerader" because of its versatile clinical manifestations. We aim to report a patient whose first presentation was with presumed autoimmune hepatitis. Fulminant retinitis subsequently ensued, thus enabling correct diagnosis and treatment. METHODS: Case description. RESULTS: A 62-year-old male presented with bilateral drop in vision. One month earlier, right eye (RE) arteritic ischemic optic neuropathy was suspected because of severe headache, sudden drop in vision, relative afferent pupillary defect, and elevated inflammatory markers. Systemic steroids were instituted. Brain imaging and temporal artery biopsy were unyielding. Four months earlier, liver biopsy performed because of elevated cholestatic liver enzymes, revealed granulomatous hepatitis. After ruling out viral hepatitis, autoimmune etiology was presumed, and prednisone was started. On presentation, visual acuity (VA) was counting fingers in RE and 6/20 in the left eye (LE). Bilateral panuveitis with punctate inner retinitis, placoid chorioretinitis was diagnosed. Serological tests were strongly positive for syphilis. Lumbar puncture confirmed the existence of neurosyphilis. Systemic penicillin was initiated. One month later, VA improved to RE 6/10, LE 6/7.5, with marked resolution of posterior uveitis. No recurrence was observed over 27-month-period. CONCLUSION: Acquired syphilitic hepatitis is rarely reported. Administering steroids potentially aggravated the infection. The characteristic features of placoid chorioretinitis and punctate inner retinitis connected the pieces of the puzzle together to the diagnosis of ocular and neurosyphilis. Intrahepatic cholestasis with negative serological panel of hepatotropic pathogens should raise the suspicion of non-hepatotropic pathogens especially syphilis.

Insights into ocular syphilis in Nepal.

PURPOSE: This study aims to elucidate the demographic characteristics, clinical features, diagnostic approaches, and medical management of patients with ocular syphilis, known as 'the great masquerader,' at a tertiary eye care center in Nepal. METHODS: We conducted a retrospective review involving 15 eyes from ten patients with ocular syphilis treated at a uveitis referral center between 2020 and 2022. Lumbar puncture was performed if neurosyphilis was suspected. Treatment success was defined as the absence of ocular inflammation in both eyes and a decrease in Veneral disease research laboratory (VDRL) titres after completing therapy. RESULTS: A total of 15 eyes of 10 patients were diagnosed with syphilitic uveitis based on positive treponemal and non-treponemal serological tests. The mean age of the patient was 39.9 years (range 22-54 years) with an equal distribution between males and females. HIV coinfection was not found in any of the patients. Syphilitic uveitis was the primary presentation in nine patients (90%), while one patient presented with recurrent nodular scleritis. Ocular involvement was bilateral in 50% (5 patients). The mean duration between the initial symptom and the first presentation was 8.7 weeks (range: 4 days to 24 weeks). The most common ocular findings was panuveitis (6 eyes). Eight patients with early syphilis received weekly intramuscular injections of benzathine penicillin G for 3 weeks whereas 2 patients with neurosyphilis were treated with intravenous ceftriaxone 1 gm twice a day for 14 days. Signs and symptoms of majority of patients improved with systemic therapy for syphilis. CONCLUSIONS: Syphilitic uveitis should be included in the differential diagnosis of any form of ocular inflammation.

Ocular syphilis masquerading as refractory retinal diseases.

PURPOSE: To report two cases of syphilis masquerading as chronic refractory macular diseases. CASE DESCRIPTIONS: Two patients had been diagnosed with neovascular age-related macular degeneration (neovascular AMD) and diabetic macular edema (DME), respectively. The disease worsened despite repeated intravitreal injections of anti-vascular endothelial growth factor (VEGF) and also surgical treatment (in suspected case of DME). Systemic evaluations were positive for syphilis. Intravenous penicillin was started, and the macular diseases improved. The lesions were well controlled afterward. CONCLUSIONS: The current two cases demonstrated that ocular syphilis can masquerade as refractory chronic retinal diseases such as DME and neovascular AMD. Laboratory evaluations for syphilis may be needed, not only for uveitis but also for refractory retinal diseases. Indocyanine green angiography may be helpful to reveal occult syphilis.

Through the Eyes: A Case of Ocular Syphilis.

Syphilis is a bacterial disease caused by Treponema pallidum and is sexually transmitted via vaginal, anogenital, or orogenital contact. Vertical transmission between mother and unborn child is also possible, but transmission via skin-to-skin or blood contact is rare. The objective of this case is to highlight this rare ocular manifestation of syphilis as it manifests as a multisystemic disease affecting many organ systems. This is a case of a 46-year-old male with vision loss who was referred to the emergency department by an ophthalmologist. Two days before the presentation at the emergency department, the ophthalmologist observed the presence of optic disc edema in the left eye. At the emergency department, he complained of bright light spots in the left eye and complete darkness in the central aspect of the eyes. He reported having a non-pruritic erythematous rash on the anterior abdomen that began one week before his presentation at the emergency department. The patient also reported having multiple sexual partners. Physical examination findings showed a visual field defect in the left eye, normal bilateral eye movement, and a non-tender skin reticulation over the anterior abdominal wall. Lab results showed complete blood count (CBC) and comprehensive metabolic panel (CMP) within normal limits, fluorescent treponemal antibody (FTA) antibody reactive, human immunodeficiency virus (HIV) test and hepatitis panel negative, rapid plasma reagin (RPR) titer 1:64, and imaging results negative for any significant abnormalities. The infectious disease specialists were consulted, and the recommended IV penicillin of four million units every four hours was given. The patient reported an improvement in his blurry vision over three days. By six months, his vision was back to baseline. This case report is significant due to the rare occurrence of ocular complications as an initial presentation of syphilis. Considering the rising cases of syphilis in the United States, it is important to highlight the possibility of this uncommon clinical presentation of syphilis.

Presentation of Ocular Syphilis with Bilateral Optic Neuropathy.

A 60-year-old otherwise healthy male presented with a 1 year history of bilateral progressive visual loss. His best-corrected visual acuity was counting fingers at 2 m with his right eye and counting fingers at 0.5 m with his left eye. Visual field testing revealed bilateral near-total loss of visual fields. Slit-lamp examination was unremarkable, apart from bilateral grade two nuclear sclerotic cataracts. Both optic discs were pale-looking with some retinal pigment epithelial alterations at the left papillomacular region. Enhanced depth imaging optical coherence tomography depicted punctate hyperreflective dots at the inner choroidal level corresponding to the retinal pigment epithelial changes in the left eye. Fundus autofluorescence imaging revealed patchy hyper-autofluorescent and hypo-autofluorescent areas, and there was mild staining in the early and late phases of the fluorescein angiogram at the papillomacular region in the left eye. A diagnosis of bilateral optic neuropathy was made. A full systemic work-up was carried out, and serological tests pointed out the presence of syphilis with normal cranial magnetic resonance imaging. He was treated accordingly. Our case clearly demonstrates the importance of a high clinical suspicion for syphilis in cases of optic neuropathy.