Eye disorders are treated with corrective lenses, contact lenses, antibiotics, and surgery:

Refractive Errors

• Hyperopia (Far-Sightedness) is corrected with convex lenses; myopia (nearsightedness) with concave lenses; astigmatism with cylindrical lenses.
• Contact Lenses: rigid (gas-permeable) and soft contact lenses can correct refractive errors as well as manage eye disorders of the conjunctiva, cornea, or lids:
• Risk of infection is a major problem with contact lenses. They increase susceptibility to bacterial, amoebic, and fungal infection
• Extended wear soft contact lens wearers stands a five fold chance of developing corneal ulcers than wearers of daily-wear soft contact lenses 
• Soft lenses come in two forms – extended wear and disposable soft lenses
• To minimize risk of infection, either wearing rigid lenses – much easier to clean – or remove soft contact lenses at night and thoroughly cleanse them 
• Contact lenses can be chemically sterilized to remove protein deposits
• For patients with an allergic reaction to preservatives used in contact lenses, preservative-free contact lenses are available and
• Ocular discomfort and red eyes warrant for the removal of contact lenses and for consulting with an ophthalmologist
• Surgical Correction: 16 million successful eye surgeries have been performed worldwide, though outcomes differ on individual patients. 15% of patients required repeat surgery while 5% developed complications:
• An excimer laser is used to reshape the mid portion of the cornea (the stroma) in laser corneal refractive surgery
• Laser based eye corrective surgery includes:
• Laser assisted in situ keratomileusis (LASIK)
• Femtosecond laser assisted LASIK (IntraLASIK)
• Surface ablation techniques epithelial LASIK (Epi-LASIK)
• Laser epithelial keratomileusis (LASEK) and
• Photorefractive keratectomy
• LASIK is preferred over most other techniques for it has very little associated postoperative complication and because recovery is fast
• LASIK is not a recommended procedure in patients with thinner cornea 
• Other surgical techniques for correcting refractive errors includes:
• Removing the clear crystalline lens and inserting a single vision, multifocal or accommodative intraocular lens
• Inserting an intraocular lens without removing the crystalline lens (phakic intraocular lens)
• Intrastromal corneal ring segments (INTACS) and
• Conductive keratoplasty (CK)
• Overnight rigid contact lens wear is being investigated as a possible corrective  treatment for nearsightedness

Hordeolum

Surgically incising a hordeolum abscess is recommended if it does not resolve within 48 hours of applying hot compress. Bacitracin and erythromycin ointment every three hours to the eyelids can treat acute hordeolum.

Chalazion

Surgically incising swollen lids, curettage, and corticosteroid injection can treat chalazion.

Blepharitis

• Anterior Blpharitis: the antistaphylococci  antibiotics bacitracin and erythromycin can be beneficial:
• The easiest way to control anterior blepharitis is by keeping eyelid margins, scalp, and eyebrows clean
• Hot wash cloth or a damp cotton applicator and a baby shampoo can be used to remove scales from eyelids
• Posterior Blepharitis: corneal and conjuctival inflammation is an indication for more aggressive treatment:
• Long-term management may require use of low-dose oral antibiotic therapy on a daily basis:
• 250 Milligram tetracycline
• 100 milligram doxycycline
• Between 50 and 100 milligram minocycline
• 250 milligram erythromycin three times daily
• Topical corticosteroids such as prednisolone, 0.125% twice daily, and Topical antibiotics such as ciprofloxacin (0.3%) ophthalmic solution twice daily can provide short-term benefits to patients with posterior blepharitis  

Entriopion and Ectropion

• Entropion: surgery may be required if eye lashes rub against the cornea. Botulinum toxin injections can be used to treat involutional lower eyelid entropion in older patients
• Ectropion: surgery is required if excessive tearing and exposure keratitis pose problems, or for aesthetic reasons   

Dacrocystitis

• Acute Dacrocystitis: surgery may be required to reverse obstruction in emergency cases, but acute dacrocysitis responds well to systemic antibiotic therapy
• Chronic Dacrocystitis: dacryocystorhinostomy is an only means of cure, although disease progression can be slowed  with antibiotic therapy:
• Dacryocystorhinostomy an alternative flow channel into the nasal cavity is created. The procedure can be augmented with nasolacrimal intubation
• Laser-assisted endoscopic dacryocystorhinostomy or balloon dilation or probing of the nasolacrimal system are alternatives and
• Congenital nasolacrimal duct obstruction can be reversed by nasolacrimal probing, sometimes augmented with balloon catheter dilation or nasolacrimal intubation, if it does not resolve spontaneously

Conjunctivitis

• Viral Conjunctivitis: cold compresses and topical antibiotics such as sulfonamides can prevent secondary infection. Except for herpes simplex virus, complete cure is an impossibility with viral conjunctivitis. Weak topical corticosteroids or topical cyclosporine can be used to treat corneal infiltrates due to adenovirus infection, though their effectiveness is in doubt
• Bacterial conjunctivitis: topical sulfonamides and flouroquinolones can cure infection within 2 to 3 days:
• Gonococcal Conjunctivitis: topical antibiotics such as bacitracin and erythromycin in combination with 1 gram intramuscular ceftriaxone can treat gonococcal conjunctivitis
• Chlamydial keratoconjunctivis: oral, single-dose azithromycin is the main stay of treatment in both trachoma and inclusion conjunctivitis – 20 milligram per kilogram and 1 gram respectively. Improved living conditions and better personal hygiene have contributed to the decline in trachoma cases over the past 25 years. Surgery can be used to correct eyelid deformities and for corneal transplantation in patients with trachoma. Patients with inclusion conjunctivitis should be assessed for sexually transmitted diseases before commencement of treatment
• Dry Eyes (keratoconjunctivitis Sicca): aqueous deficiency can be treated with artificial tears. Artificial tear preparations are generally without side effects, except for allergic reaction and potential toxicity emanating out of preservatives (to maintain sterility) used in these preparations. Frequent users may get affected with keratitis and cicatrizing conjunctivitis, which can be misdiagnosed as worsening dry eye. Misdiagnosis can lead to more frequent use of artificial tears with preservatives, worsening the patient’s condition:
• The simplest and most often used artificial tear preparation are physiologic or hypo-osmotic sodium chloride solution – in concentration of 0.9 and 0.45% respectively
• Both physiologic and hypo-osmotic solutions can be used as often as every 30 minutes, though in most cases, it is only used three or four times a day
• Sustained therapeutic benefit can be gained out of drop preparations containing methylcellulose, polyvinyl alcohol, polyacrylic acid (carbomers), petrolatum ointment, or hydroxypropyle cellulose (Lacrisert) insert
• If mucous is produced in adequate quantity, mucolytic agents such as acetylcysteine (20% one drop six times daily) can be used
• For severe dry eye cases, autologous serum eye drops can be used
• For moderate to severe dry eye, cyclosporine in 0.05% opthalmic emulsion twice a day can be effective treatment. Cyclosporin is known to act on ocular surfaces and have potent anti-inflammatory effect on lacrimal glands. The drug has only very few side effects and can be used on a long-term basis
• In extremely severe dry eye cases, surgery or lacrimal punctal occulsion by canalicular plugs can be beneficial and
• Botulinum toxin injection can treat associated blepharospasm
• Allergic Eye Disease: histamine H₁- receptor antagonists are the main stay of treatment for mild to moderate allergic eye disease; corticosteroids for acute exacerbations and severe allergic reactions:
• For Mild to Moderate Allergic Eye Disease: H₁- receptor antagonists levocabastine hydrochloride 0.05% or emedastine difumarate 0.05% or ketorolac tromethamine 0.05% in combination with non-steroidal anti-inflammatory drugs four time a day can be effective:
• Drugs with H₁-receptor blocking, mast cell stabilizer, and eosinophilic inhibitor activity such as ketotifen 0.025% two to four times a day and bepotastine 1.5% twice daily
• Olopatadine (0.1% twice daily or 0.2% once daily), azelastine (0.05% twice daily), epinastine (0.05% twice daily) bestow identical therapeutic benefits as drugs with an effect on H₁-receptors, mast cells, and eosinophilic activity
• For long-term prevention, topical mast cell stabilizers such as cromolyn sodium 4% or lodoxamide tromethamine 0.1% applied four times a day, or nedocromil sodium 2% (applied twice daily) can be used
• Systemic antihistamines such as loratadine 10 milligram daily can be beneficial in chronic atopic keratoconjunctivitis
• Topical vasoconstrictors and antihistamines have very limited efficacy in the treatment of allergic eye disease, and in some cases such drugs can cause rebound hyperemia (burning sensation) and follicular conjunctivitis
• Cooler environment can provide relief in vernal keratoconjunctivitis
• The best method to alleviate the dangers of allergic eye disease is avoidance of allergens 
• For Acute Exacerbation and Severe Allergic Eye Diseases: topical corticosteroids are commonly used to control both topical and vernal keratoconjunctivitis:
• Topical cyclosporine and tacrolimus are also effective
• In severe vernal keratoconjunctivitis, systemic corticosteroids or other immunosuppressants or plasmapheresis can be used
• Cataracts, glaucoma, and exacerbation of herpes simplex keratitis are a few of the side effects associated with corticosteroid use and
• Side effects of corticosteroids can be countered with loteprendol 05%, an ester corticosteroid
• Pinguecula and Pterygium: surgically excising pterygium is required if growth into the visual axis cause visual problems, easily identifiable astigmatisms, or severe ocular irritation. Inflammation of pinguecula or pterygium do not need treatment but artificial tears and topical non-steroidal anti-inflammatory drugs and corticosteroids may be beneficial  
• Corneal Ulcers: topical and systemic antivirals and antibiotics are the main stay of treatment:
• Bacterial Keratitis: antibiotic drops for the first 48 hours after diagnosis can treat bacterial keratitis:
• Fourth generation flouroquinolones such as moxifloxacin 0.5% and gatifloxacin 0.3% are preferable over first-line flouroquinolones such as levofloxacin 0.5%, ofloxacin 0.3%, norfloxacin 0.3%, or ciprofloxacin 0.3% , for they also act on myobacterium
• Gram-positive cocci can be treated with cephalosporines such as fortified cefazolin 10% 
• Gram-negative bacilli can be treated with an aminoglycoside such as fortified tobramycin 1.5%. If no pathogen can be isolated in samples, these two drugs can be used in regions where resistance flouroquinolone is common and
• Augmentative topical corticosteroid therapy should only be initiated by an opthalmologist
• Herpes Simplex Keratitis: debridement and patching might suffice in some cases, though for rapid recovery topical antvirals – trifluridine drops, ganciclovir gel, acyclovir ointment, or oral acyclovir at 500 milligram five times daily – can be used:
• In atopic disease, rate of recurrent epithelial disease can be reduced  by administering acyclovir at 400 milligram twice daily or valcyclovir at 500 milligram once daily
• Oral acyclovir at doses between 200 and 400 milligram five times a day can be beneficial to treat herpetic keratitis
• Stromal herpes simplex keratitisa can be treated with topical antivirals in combination with topical corticosteroids. Topical corticosteroids can create a favorable environment for viral replication and recurrence of stromal herpes simplex keratitis, increasing severity of corneal opacity. Only an opthalmologist shold prescribe topical corticosteroids
• Severe stromal scarring might require corneal grafting
• Herpes Zoster Opthalmicus: neurothropic  keratitis is a long-term complication of herpes zoster opthalmicus:
• For anterior uveitis, cyclopegics and topical corticosteroids can be used and
• Within the first 3 days of diagnosis and appearance of a rash, high-dose oral acyclovir (at doses of 800 milligram five times daily), valacyclovir (at doses of  1 gram three times daily), or famciclovir (at doses between 250 and 500 milligram) therapy should commence 
• Fungal keratitis: topical agents such as natamycin 5%, amphoterecin between 0.1 and 0.5%, sysetmic amidazoles, and voriconazole 1% can be used. Corneal grafting may be required in few cases
• Acanthamoeba Keratitis: systemic anti-inflammatory drugs may be required, if the sclera is involved. Topical biguanides are the most effective treatment, though topical corticosteroids can also be of some benefit. Corneal grafting may be required to restore vision, once the infectious pathogen has been isolated