Symptoms and Signs – Differential Diagnosis of Photophobia

Symptoms and Signs – Differential Diagnosis of Photophobia
Photophobia is a prevalent ailment characterized by an unusual sensitivity to light. In numerous instances, photophobia merely signifies heightened ocular sensitivity absent any underlying illness. For instance, it may arise from the excessive use of contact lenses or the utilization of inadequately fitted lenses. Nonetheless, in some cases, this symptom may arise from a systemic ailment, an ocular condition, trauma, or the administration of specific medications.

Medical History and Physical Assessment
Inquire about the onset and severity of the patient's photophobia. Did it result from ocular trauma, a chemical exposure, or irradiation from a sunlamp? If photophobia is caused by trauma, refrain from manipulating the eyes. Inquire with the patient regarding ocular discomfort and request a description of its location, duration, and intensity. Does he experience the sensation of a foreign body in his eye? Does he exhibit additional signs and symptoms, such as heightened lacrimation and alterations in vision? Subsequently, obtain the patient's vital signs and evaluate his neurological condition.

Evaluate visual acuity, except in cases of chemical burns. Subsequently, do a meticulous eye examination, scrutinizing the exterior structures of the eyes for any anomalies. Assess the conjunctiva and sclera, observing their coloration. Describe the volume and uniformity of any discharge. Subsequently, assess the pupillary response to illumination. Assess extraocular muscle function by examining the six cardinal fields of gaze and evaluate visual acuity in each eye. During your evaluation, remember that while photophobia may coexist with life-threatening meningitis, it is not a primary indicator of meningeal irritation.

Etiological Factors
Burn
A chemical burn may result in photophobia and ocular pain, along with erythema and blistering on the face and eyelids, miosis, generalized conjunctival injection, and alterations in the cornea. The patient has hazy vision and may be unable to maintain eye closure. Ultraviolet radiation burns result in photophobia accompanied by moderate to severe ocular discomfort. These symptoms manifest approximately 12 hours following exposure to the radiation from a welding arc or sun lamp.

Conjunctivitis
Moderate to severe conjunctivitis may induce photophobia. Additional prevalent manifestations of conjunctivitis encompass conjunctival injection, heightened lacrimation, a sensation of foreign body presence, a feeling of fullness surrounding the eyes, as well as ocular pain, burning, and pruritus. Allergic conjunctivitis is characterized by a viscous white ocular discharge and a diffuse erythema of the conjunctiva. Bacterial conjunctivitis typically results in abundant, mucopurulent, crusty ocular discharge that may adhere the eyelids together, accompanied by vivid red conjunctiva. Fungal conjunctivitis results in a viscous, purulent discharge, severe erythema, and crusted, adhesive eyelids. Viral conjunctivitis results in excessive tearing with minimal discharge and swelling of the preauricular lymph nodes.

Corneal abrasion
Photophobia is typically associated with corneal abrasion, often accompanied by increased lacrimation, conjunctival hyperemia, observable corneal injury, and a sensation of a foreign body in the eye. Blurred vision and ocular discomfort may also manifest.

Corneal ulceration
A corneal ulcer is a vision-threatening condition that induces intense photophobia and ocular pain exacerbated by blinking. Compromised visual acuity may be associated with blurriness, ocular discharge, and adhesive eyelids. Conjunctival injection may manifest despite the cornea exhibiting a white and opaque appearance. A bacterial ulcer might exhibit an uneven form. A fungal ulcer may have gradually clearer concentric rings.

Acute iritis
Acute iritis may lead to severe photophobia, accompanied by significant conjunctival injection, moderate to severe ocular discomfort, and blurred vision. The pupil may exhibit constriction and demonstrate a diminished response to light.

Interstitial keratitis
Keratitis is an inflammation of the cornea characterized by photophobia, ocular discomfort, impaired vision, significant conjunctival injection, and opacification of the corneas.

Acute bacterial meningitis
Photophobia, a prevalent symptom of meningitis, may accompany with indicators of meningeal irritation, including nuchal stiffness, hyperreflexia, and opisthotonos. Brudzinski's and Kernig's signals may be elicited. A fever, a first symptom, may be followed by chills. Associated signs and symptoms may encompass cephalalgia, emesis, ocular palsies, facial paresis, pupillary irregularities, and auditory impairment. Severe meningitis may result in seizures, stupor, and progression to coma.

Migraine cephalalgia
Photophobia and phonophobia are salient characteristics of a typical migraine. This intense headache may also induce exhaustion, impaired vision, nausea, and vomiting.

Uveitis
Anterior and posterior uveitis may induce photophobia.Typically, anterior uveitis results in moderate to severe ocular pain, pronounced conjunctival injection, and a constricted, nonreactive pupil. Posterior uveitis progresses gradually, resulting in visual floaters, ocular discomfort, pupil irregularity, conjunctival hyperemia, and impaired vision.