Pini D. Gaisiner 

The reasons for consultation that, due to their frequency and hierarchy lead the patient to the ophthalmologist are: 

1) vision disorders ; 2) eye redness ; 3) pain , and 4) abnormality observed by the patient in front of the mirror or reported by his relatives. 

Visual disturbances

The existence of normal vision requires proper functioning of the eye, as well as the parts of the vascular and nervous system related to it.

A decrease in visual acuity may indicate:

1. An eye disease that can be treated with possibilities of visual recovery (cataract, uveitis).
2. An important systemic disease to detect and treat (diabetes, hypertension).
3. Vices of refraction, which without threatening the vision or life of the patient will allow, once corrected, a better quality of life (myopia, astigmatism, presbyopia).

The color vision test is not so important since almost all the alterations of this type are inherited and not remediable. However, it is useful to record them in relation to certain activities, including military ones.

Faced with a decrease in vision reported by the patient, some questions are de rigueur:

1. If it is a sudden or slow decrease.
2. If the alteration is central, pericentral or peripheral.
3. What character does it have and what other elements does it consist of (image distortion, deformation, clouds, flying flies).
4. Age of the patient.

From an anatomical and physiological point of view, it is useful to remember the existence of three links in the chain of visual events: 

1. Light originating from an object is focused through the eye to form an image on the retina. A faulty image may be due to uncorrected refractive errors or opacities of the transparent media.
2. A neural impulse originates from the retina that passes through the optical pathway to the brain. Any pathology of the optic pathway will alter vision.
3. The object is recognized and causes a response through the acquired cognitive functions of the brain. If for some reason (strabismus not treated promptly) the stimuli do not reach the brain from the first months of life, permanent visual loss occurs (amblyopia)

 In the presence of an eye and a visual system that appear normal.

Sudden visual disturbance.

The patient realizes its appearance early when it is monocular or when it happens in the eye with which he sees better.

The fastest visual loss is due to occlusion, usually by embolism, of the central retinal artery, which is confirmed by the characteristic ophthalmoscopic image: cherry red spot in the macular area contrasting with a pale background.

The bilateral loss caused by the same cause is exceptional and is more likely to be due to the presence of retinopathy due to gravidic toxemia or to a cerebral vascular hemorrhage or occlusion.

Less sudden and non-total loss of vision is caused by occlusion of the central retinal vein, almost always by thrombosis, which offers an ophthalmoscopic image characterized by multiple hemorrhages in candle flame lining the retina and with a slightly less severe prognosis. than arterial occlusion.

Optic neuritis, in any of its forms, can produce a marked decrease in visual acuity in a few hours, for which fundoscopic and campimetric alterations and the study of evoked visual potentials are useful.

Another frequent cause of sharp and sudden loss of visual acuity is due to vitreous hemorrhage. The fact that the details of the fundus cannot be visualized, and the history of diabetes, arterial hypertension or myopia, favoring the formation of retinal continuity solutions that begin with retinovitreal hemorrhage, will guide the connected diagnosis, which may be confirmed by ultrasound study.

When the patient reports having noticed a decrease in hours to days of his vision, with antecedents of having previously observed the appearance of lightning flashes (photopsias) or flying flies (myodesopsias). retinal detachment should be suspected, which is confirmed by ophthalmoscopic examination.

Study methodology

• Measure visual acuity: It is performed by placing the patient in front of a poster of optotypes, alternately occluding each eye. To determine if the decrease in vision is due to a refractive vice, visual acuity is examined by interposing an occluder with a very small central hole (pinhole).
• Examination of the fundus
• Papillary reflexes
• Visual field examination
• Referral to ophthalmologist

Progressive visual disorder

The usual origin of this symptom is the vices of refraction. In a young person * who does not see well from afar it will be a myopia, an astigmatism or a hyperopia of a high degree. If it is a person over 40 years of age with good distance vision, who begins to have difficulty with near vision, it will be due to physiological alterations of accommodation known as presbyopia.

A second group of causes are opacities of the transparent media of the eye. The most common is senile cataract (clouding of the lens). Inflammations of the uvea, by dumping exudates into the vitreous cavity, blur the vision. Less frequently the cause is a leucoma (corneal opacity) secondary to trauma or keratitis.

A third group of causes of progressive decrease in visual acuity reside in retinopathies (vascular, metabolic, degenerative), neuropathies (inflammatory, vascular) and choroidopathies, usually as part of uveitis.

Glaucoma deserves a particular mention as a cause of progressive decrease in vision; it is irreversible when it is due to the action of ocular hypertension on the optic nerve; on the other hand, it is reversible that caused by corneal edema and that is manifested by the observation of iridescent halos.

Study methodology

• Measure visual acuity
• Focal illumination examination
• Ophthalmoscopy
• Tonometry
• Campimetría
• Referral to ophthalmologist

Other visual disorders

A cause of consultation is that referred to by the patient as deformation of the image (metamorphopsia), which is usually accompanied by reduction in size (micropsy) and decrease in central vision, which is due to diseases of the macula (vascular , degenerative, inflammatory).

Sometimes the patient complains of double vision (diplopia). This occurs when the parallelism of the ocular axes that focus on different objects is lost and originates in paralysis of an ocular muscle. It is accompanied by headaches, nausea and compensatory torticollis and disappears when either eye is occluded. Its appearance may indicate the presence of a neurological or orbital disease.

More rarely, diplopia is monocular and due to some corneal or lens opacity, which modify the passage of light rays, forming two retreating images, or due to lens subluxation. Diplopia disappears covering the affected eye.

Study methodology

• Measure visual acuity
• Examination with focal lighting
• Ophthalmoscopy
• Examination of monocular and binocular extrinsic ocular motility
• Referral to ophthalmologist

Eye redness (Table 23-1)

In front of a patient who consults for a red eye, it must be established if it is a minor irritation or if it is the manifestation of a serious eye condition.

Apart from the reddening of the palpebral edges (blepharitis, stye), which generally does not show severe pathology, it is properly spoken of red eye when the area that acquires that color is the visible area of ​​the sclera and the conjunctiva that covers it , which is normally white.

One of the causes is subconjunctival hemorrhage, which alarms the patient and in whom, if repeated, it is necessary to measure their blood pressure and study capillary permeability.

Hyperemia, the cause of the greatest amount of eye redness, requires important qualitative differentiation for differential diagnosis. 

1. Conjunctival hyperemia:  There is engorgement of the most superficial vessels of the bulbar conjunctiva, which decreases from the periphery to the center. They move along with the conjunctiva. This disorder is observed in almost all the inflammatory processes of the eye. N 

2. Ciliary hyperemia: Dilation of the deep intrascleral vessels can be seen, which form like teeth around the corneoscleral limbus. They do not move with the conjunctiva. It shows an important pathology, usually located in the cornea or in the uvea.

3. Mixed hyperemia: It compromises the superficial and deep vessels. When a vasoconstrictor is instilled, the conjunctival hyperemia disappears and reveals the pericarp. It is found in significant inflammations of the anterior segment of the eye and in acute glaucoma.

A less common cause of eye redness is that caused by vascularization of the cornea, which is usually avascular. A superficial vascularization is recognized, which comes from the conjunctiva and continues with the vessels of the conjunctiva and that appears in the superficial corneal inflammations * and a deep vascularization - like tufts of arborization - coming from the scleral vessels and that is observed in the inflammations deep. Also, and usually due to trauma, red eye is due to the formation of a hypema (blood in the anterior chamber).

We are now in a position to summarize the symptoms and signs of the most important causes of red eye: a) acute glaucoma (serious disease); b) acute (serious) iridocyclitis; c) keratitis (potentially serious); d) episcleritis (rare and usually allergic); e) the scleans (rare and that may indicate the beginning of a systemic disease, for example collagen disease); í) conjunctivitis (common, generally it would not be); and g) other conditions such as subconjunctival hemorrhage, stye, pterygium.

To reach the differential diagnosis of a red eye, it is essential to study the symptoms and accompanying signs.

Associated symptoms

• Blurred vision that does not disappear with blinking indicates serious ocular pathology such as keratitis, iritis, glaucoma. It never appears in simple conjunctivitis.
• The pain signals keratitis, iritis, or glaucoma. Pure conjunctivitis is only manifested by foreign body sensation.
• Photophobia (hypersensitivity to light) is a third alarm symptom that appears in iritis and keratitis.
• The presence of iridescent halos around a lumen is usually a symptom of corneal edema, associated with increased endo-ocular tension and therefore suggests that it is acute glaucoma.
• The discharge is typically a symptom of conjunctivitis and less commonly of blepharitis.
• Pruritus is usually present in allergic conjunctivitis.

Associated signs

• Ciliary injection is a warning sign seen in major eye inflammations such as corneal, iridocyclitis, or acute glaucoma. It is not seen in conjunctivitis.
• Corneal opacities in a red eye always indicate disease.
• Superficial foreign body of cornea.
• Corneal erosion or ulcer that occurs in inflammations or after trauma.
• Papillary abnormalities. In iridocyclitis the pupil is smaller in diameter than the contralateral and can be distorted in chronic iritis by inflammatory adhesions of the iris to the lens. In acute glaucoma, the pupil is usually dilated and oval.
• A flat anterior chamber, in a reddened eye, always suggests the presence of acute glaucoma.
• An abrupt exophthalmia suggests a severe orbital condition or cavernous sinus disease.
• Secretion. If it is purulent, it makes us suspect bacterial conjunctivitis. When it is aqueous, it suggests a viral etiology.

Study methodology

• Focal illumination examination
• Insulation of a vasoconstrictive eye drop
• Corneal examination with instillation of vital dyes (for example, sodium fluorescein solution)
• Examination of the pupil
• Visual acuity test
• Tonometry
• Referral to ophthalmologist

Pain

It can be difficult to interpret since the eye receives the sensory innervation from the trigeminal nerve and therefore there are multiple ocular and intracranial conditions that can cause pain in the eye or in the orbital area. Therefore, it is necessary to create a detailed history in which the following questions are essential: 1) location of the pain; 2) characteristics of pain; 3) time of onset of pain.

1. Location of pain. The pain in the eyelid is due to a stye, while, when it is located in the inner eyelid commissure and spreads towards the bases of the nose, it suggests an inflammatory process of the tear ducts. When the pain is located at the base of the nose or in the supra or infraorbital regions and increases when tilting the head forward, it indicates the possibility of sinusitis.

The pains of the anterior segment of the eye are due to pathologies of the cornea (superficial foreign body, keratitis) or the sclera (episcleritis, scieritis) and increase with compression of the eyeballs.

Intraocular pain is usually due to iridocyclitis or glaucoma. In this disease, pain radiates over the entire territory of the first trigeminal branch.

Retroocular pain originates from inflammations, bruises and tumors of the orbit.

2. Characteristics of pain. Foreign body, burning, stinging, or pricking sensation is usually caused by inflammation of the eyelid, conjunctiva, or cornea. "Sicca" keratitis (Sjógren's disease) generates similar sensations.

Photophobia is frequently accompanied by tearing and blepharospasm and is observed in corneal conditions and iridocyclitis.

When the patient reports deep pain, it is due to irido-ciliary inflammations or an access of acute glaucoma; in this case the pain is particularly violent and irradiated and is usually accompanied by nausea and vomiting.

Sometimes the pain becomes intense when moving the eye, especially towards the extreme positions of the gaze, which is observed in tenonitis, in some scleritis and in prodromes of retrobulbar neuritis.

A very common reason for consultation is headache. Some vices of refraction — farsightedness, astigmatism, and anisometropia — can cause headaches that are located around the eyes, but these never become disabling and are diagnosed when they disappear with a suitable optical prescription. The symptoms that accompany all headaches should always be carefully evaluated.

3. Time of onset of pain. When the patient reports pain, photophobia, and tearing upon awakening, recurrent corneal erosion should be suspected.

Headaches that increase with visual work suggest the presence of some ametropia. Likewise, small intraocular pains that manifest in the early hours of the morning suggest more pronounced ocular hypertension during those hours, in which the endo-ocular tension is higher.

Exam Methodology

• Focal illumination examination
• Examination of the cornea with vital dyes (sodium fluorescein solution, for example)
• Examination of the pupil
• Tonometry
• Visual acuity
• Examination of extrinsic eye motility
• Visual field examination
• Referral to ophthalmologist

Abnormality observed by the patient in front of the mirror or reported by his relatives

Exophthalmia

When it is unilateral, it is due to the increase in the orbital content due to inflammatory exudates, vascular pathology, hemorrhages or tumors. Depending on its origin, it can be accompanied by pain, redness of the eye, limitation of motility, decreased vision, visual field compromise, alteration of the papillary reflexes.

When proptosis is bilateral, it is usually due to Basedow's disease, and is usually accompanied by other muscular and eyelid signs.

Study methodology

• Exophthalmometry
• Visual acuity
• Examination of pupillary reflexes
• Examination of the fundus
• Eye motility test
• Visual field examination
• Referral to the ophthalmologist.

Strabismus

Under normal conditions the lines of sight of the eyeballs are parallel, which is known by the name of orthophoria.

Sometimes there is a latent tendency to deviation that is neutralized by the fusion mechanism and is called latent heterophoria or strabismus.

Manifest squint is a permanent lack of parallelism in both eyes, so that only one eye is directed at the object being observed.

Concomitant strabismus is referred to when the angle of deviation is the same regardless of the direction of the gaze, which differentiates it from paralytic strabismus. Since it usually begins in childhood, it has sensory sequelae such as amblyopia (defective vision in an apparently normal eye).

Study methodology

• Inspection
• Study of corneal reflexes
• “Cover test”
• Eye motility test
• Ophthalmoscopy
• Referral to ophthalmologist