Refractive Corneal Surgery
The desire of many ametropic patients to be free of both spectacles and contact lenses has driven the development of refractive surgery to reduce or neutralize ametropia. Earlier procedures that used incisions in the cornea to alter its shape (radial keratotomy) have since been largely abandoned due to complications including corneal perforation ( Kymionis et al, 2006) and the possibility of rupture of the compromised cornea ( Munnerlyn et al, 1988). More recently, the excimer laser has been used in photorefractive keratectomy (PRK) and laser in-situ keratomileusis (LASIK) to reshape the cornea. These procedures are not without risks of compromised vision and complications include stromal haze, regression …show more content…
LASIK results in increased higher-order ocular aberrations; a new wavefront-guided LASIK procedure improves on this result ( McDonald et al , 1990)
Extremely high myopia (over 12.00 D) may be treated by clear lens exchange in which the crystalline lens is extracted and an intraocular lens of suitable power is implanted. Phakic lens implants have also been used in either the anterior chamber or posterior chamber.
Low myopes can achieve visual acuity of better than 20/40 (6/12) when treated with intrastromal corneal rings (ICR). Circular arcs are implanted concentrically to the optical axis of the cornea in the stroma of the peripheral cornea to flatten the corneal curvature mechanically. The procedure is at least partly reversed by removal of the …show more content…
The FDA has considered Collagen Vascular Diseases as a LASIK contraindication, eg. many CVDs (e.g) Sjogren's syndrome, rheumatoid arthritis, systemic lupus erythematosus can have a component of sever degree of dry eye (Simpson et al, 2012). One case report has described two cases of early-stage Sjogren syndrome patients who were well-controlled for both systemic condition and dry eye, but still suffered from severe post-LASIK dry eye with punctate epithelial erosion and even regression of the initial refractive error at 2 and 15 months post-operatively. Despite 10 months of intensive dry eye treatment, the patients' dry eye, improved only marginally (Liang et al, 2008) .
3. Increased severity of pre-operative myopia was shown to be a risk factor for chronic post-LASIK dry eye (De Paiva et al, 2006).
4. While no conducted studies to assess the risk of post-LASIK dry eye in patients with a history of blepharoplasty, it’s believed that patients who have had previous blepharoplasty should be assessed proberly before LASIK, as dry eye may be a common complication after blepharoplasty (Prischmann et al, 2013).
Other patient selection criteria for PRK and LASIK procedures (Sugar et al, 2002):
• Age 18 years or
The desire of many ametropic patients to be free of both spectacles and contact lenses has driven the development of refractive surgery to reduce or neutralize ametropia. Earlier procedures that used incisions in the cornea to alter its shape (radial keratotomy) have since been largely abandoned due to complications including corneal perforation ( Kymionis et al, 2006) and the possibility of rupture of the compromised cornea ( Munnerlyn et al, 1988). More recently, the excimer laser has been used in photorefractive keratectomy (PRK) and laser in-situ keratomileusis (LASIK) to reshape the cornea. These procedures are not without risks of compromised vision and complications include stromal haze, regression …show more content…
LASIK results in increased higher-order ocular aberrations; a new wavefront-guided LASIK procedure improves on this result ( McDonald et al , 1990)
Extremely high myopia (over 12.00 D) may be treated by clear lens exchange in which the crystalline lens is extracted and an intraocular lens of suitable power is implanted. Phakic lens implants have also been used in either the anterior chamber or posterior chamber.
Low myopes can achieve visual acuity of better than 20/40 (6/12) when treated with intrastromal corneal rings (ICR). Circular arcs are implanted concentrically to the optical axis of the cornea in the stroma of the peripheral cornea to flatten the corneal curvature mechanically. The procedure is at least partly reversed by removal of the …show more content…
The FDA has considered Collagen Vascular Diseases as a LASIK contraindication, eg. many CVDs (e.g) Sjogren's syndrome, rheumatoid arthritis, systemic lupus erythematosus can have a component of sever degree of dry eye (Simpson et al, 2012). One case report has described two cases of early-stage Sjogren syndrome patients who were well-controlled for both systemic condition and dry eye, but still suffered from severe post-LASIK dry eye with punctate epithelial erosion and even regression of the initial refractive error at 2 and 15 months post-operatively. Despite 10 months of intensive dry eye treatment, the patients' dry eye, improved only marginally (Liang et al, 2008) .
3. Increased severity of pre-operative myopia was shown to be a risk factor for chronic post-LASIK dry eye (De Paiva et al, 2006).
4. While no conducted studies to assess the risk of post-LASIK dry eye in patients with a history of blepharoplasty, it’s believed that patients who have had previous blepharoplasty should be assessed proberly before LASIK, as dry eye may be a common complication after blepharoplasty (Prischmann et al, 2013).
Other patient selection criteria for PRK and LASIK procedures (Sugar et al, 2002):
• Age 18 years or