Diagnosis
Stages
There are 4 stages of disease, with stage 4 being the rarest and most severe. Stage 1 Cells infiltrate the periphery of the flap, without involving central cornea. Stage 2 Peripheral cells migrate to the center of the cornea, and impair vision; presentation is usually 2 to 3 days after surgery. Stage 3 Cells at the central cornea form clumps of dense cell aggregates. Stage 4 Otherwise known as central toxic keratopathy, stage 4 characteristically has no inflammatory cells at the anterior chamber or cornea, but there is central stromal necrosis, and the cornea becomes opacified; onset is usually 3 to 9 days after refractive surgery. Treatment
Depending on severity, therapies may range from topical or oral anti-inflammatories to irrigation and surgical repair. References


== External links ==
Treatment
There are a wide range of depigmenting treatments used for hyperpigmentation conditions, and responses to most are variable.Most often treatment of hyperpigmentation caused by melanin overproduction (such as melasma, acne scarring, liver spots) includes the use of topical depigmenting agents, which vary in their efficacy and safety, as well as in prescription rules. Topical treatments
Many topical treatments disrupt the synthesis of melanin by inhibiting the enzyme tyrosine hydroxylase.Several are prescription only in the US, especially in high doses, such as hydroquinone, azelaic acid, and kojic acid. Some are available without prescription, such as niacinamide, l-ascorbic acid, retinoids such as tretinoin, or cysteamine hydrochloride. Hydroquinone was the most commonly prescribed hyperpigmentation treatment before the long-term safety concerns were raised, and the use of it became more regulated in several countries and discouraged in general by WHO. For the US only 2% is at present sold over-the-counter, and 4% needs prescription. In the EU hydroquinone was banned from cosmetic applications. Oral
Oral medication with procyanidin plus vitamins A, C, and E also shows promise as safe and effective for epidermal melasma. In an 8-week randomized, double-blind, placebo-controlled trial in 56 Filipino women, treatment was associated with significant improvements in the left and right malar regions, and was safe and well tolerated. Other treatments that do not involve topical agents are also available, including fraction lasers and dermabrasion. Laser treatments
Laser toning using YAG lasers and intense pulsed light have been used to treat hyperpigmentation such as melasma and post-inflammatory hyperpigmentation. See also
Hypopigmentation
List of skin conditions
Drug-induced pigmentation

References


== External links ==