Ophthalmology

Age-Related Macular Degeneration
Age-related macular degeneration is a common, chronic, progressive, degenerative disease that causes central loss of vision due to abnormalities that occurs in the pigment, neural and vascular layers of the macula.
The macular disorder may have one or more of the following:
- Formation of drusen which are localized deposits of extracellular material usually concentrated in the macula
- Abnormalities in the retinal pigment epithelium (eg hypopigmentation or hyperpigmentation)
- Retinal pigment epithelium and choriocapillaris geographic atrophy
- Neovascular (exudative) maculopathy
Decreased central vision and distortion of seeing straight lines are the most common symptoms.
Blepharitis
Blepharitis is an inflammation process affecting the eyelid margins, eyelash follicles or openings of the anteriorly-placed accessory lacrimal glands and the posteriorly-placed Meibomian glands that causes ocular irritation and redness acutely but usually chronically.
It may have periods of exacerbations and remissions.
It usually occurs in middle-aged adults but can also start in childhood.
Can affect vision by disrupting the surface of the cornea and the bulbar conjunctiva; may influence tear film composition.
Cataract
Cataract is the presence of opacity in the crystalline lens of the eye. It causes painless, progressive blurring of vision.
It is the leading cause of blindness worldwide and the most prevalent ocular disease.
The initiating events that lead to loss of transparency of both the cortical and nuclear lens tissue is the oxidation of the membrane lipids, structural or enzymatic proteins or DNA by peroxidases or free radicals induced by UV light.
Conjunctivitis - Allergic, Seasonal & Perennial

Conjunctivitis is the inflammation of the conjunctiva.

Allergic conjunctivitis happens when the direct exposure of the ocular mucosal surfaces to the environment causes an immediate hypersensitivity reaction in which triggering antigens couple to reaginic antibodies (IgE) on the cell surface of mast cells and basophils, leading to the release of histamines that causes capillary dilation and increased permeability and thus conjunctival injection and swelling.
Seasonal allergic conjunctivitis is the most common form of allergic conjunctivitis in temperate climates. It usually occurs and recurs at a certain period of the year (eg summer).
Perennial allergic conjunctivitis manifests and recurs throughout the year with no seasonal predilection. It is most common in tropical climates.

Conjunctivitis - Viral
Viral conjunctivitis is the inflammation of the conjunctiva of viral etiology.
Signs and symptoms include unilateral or bilateral eye redness, foreign body sensation and follicular conjunctival reaction.
It may be caused by adenovirus, herpes simplex or molluscum contagiosum.
Diabetic Retinopathy
Diabetic retinopathy is an abnormality of the microvasculature of the retina that occurs to almost all patients with chronic diabetes mellitus.
It is one of the leading cause of blindness worldwide and principal cause of impaired vision in patients aged 25-75 years of age.
The abnormality causes microaneurysms, retinal hemorrhages, lipid exudates, macular edema & neovascular vessel growth that may lead to blindness.
Dry Eye Syndrome

Dry eye syndrome is a clinical condition wherein the patient experiences ocular and conjunctival irritation due to decreased tear production and/or excessive tear evaporation.
It is associated with increased osmolarity of the tear film and inflammation of the ocular surface.

Goal of treatments are to relieve symptoms of patients, to improve visual acuity & quality of life of patients, to restore ocular surface & tear film to normal homeostatic state and to correct the underlying defect.

Ophthalmia Neonatorum
Ophthalmia neonatorum is conjunctivitis occurring in a newborn during the first month of life.
It is also called neonatal conjunctivitis.
Organisms causing neonatal conjunctivitis are usually acquired from the infected birth canal of the mother during vaginal delivery, though some may acquire the infection from their immediate surroundings.
It is one of the leading cause of blindness in infants via corneal ulceration and subsequent opacification or perforation and endophthalmitis.
Primary Angle-Closure Glaucoma
Primary angle-closure is the synechial or appositional closure of the anterior chamber angle secondary to multiple mechanisms resulting in raised intraocular pressure and structural changes in the eyes.
Iridotrabecular contact is the hallmark of primary angle-closure  and the most commonly identified sign which indicates that treatment is required.
It is defined by at least 180 degrees of iridotrabecular contact together with an elevated intraocular pressure or peripheral anterior synechiae or btoh
Primary angle-closure glaucoma is the presence of glaucomatous optic neuropathy.
Primary Open-Angle Glaucoma
Primary open-angle glaucoma (POAG) is a chronic, progressive, usually bilateral disease of the eye with an insidious onset.
It is most often characterized by optic nerve damage, defects in the retinal fiber layer and subsequent visual field loss in the absence of underlying ocular disease or congenital abnormalities.
It is generally asymptomatic until it has caused a significant loss of visual field.
Occasionally, patients with very high intraocular pressure may complain of nonspecific headache, discomfort, intermittent blurring of vision or even halos caused by corneal edema.