Advantages

• effective and relatively economical refractive option for up to 4 degrees of myopia (procedure is adjusted depending on age)

• long-term instability of the refractive error
  
• reduction of corneal integrity

Advantages

• treats up to 3 degrees of astigmatism
  
• generally reserved for eyes with a spherical equivalent close to piano

Disadvantages

• often undercorrects astigmatism

Myopic Automated
Lamellar Keratoplasty

Advantages

• effective for minimal to moderate myopia

Disadvantages

• difficulty making the second “power” cut
  
• difficult management of the corneal flap
  
• significant unresolving loss of best corrected visual acuity (BCVA)

Hyperopic Automated
Lamellar Keratoplasty

Advantages

• effective for minimal to moderate hyperopia

Disadvantages

• progressive controlled corneal ectasia
  
• postoperative myopia and irregular astigmatism

Myopic Photorefractive Keratectomy

Advantages

• more effective for low to moderate myopia and astigmatism

Disadvantages

• corneal haze
  
• regression
  
• prolonged postoperative discomfort and need for medication

Hyperopic Photorefractive
Keratectomy

Advantages

• treats up to 4 degrees of hyperopia, less than 3 degrees of astigmatism

Disadvantages

• limited to lesser degrees of hyperopia because of possible postoperative regression, corneal haze, and loss of BCVA

Myopic Laser In Situ Keratomileusis

Advantages

• effective for low to moderate and (sometimes) high myopia
  
• rapid visual rehabilitation (1 day)

Disadvantages

• potential flap complications
  
• regression

Hyperopic Laser In Situ Keratomileusis

Advantages

• effective to at least 6 degrees of hyperopia
  
• less regression
  
• little risk for corneal haze
  
• treats higher degrees of astigmatism (especially when used with an astigmatic scanning excimer laser using cross-cylinder techniques to steepen the flat axis and flatten the steep axis)

Advantages

• effective for up to 2.5 D of hyperopia with the Sunrise holmium laser (Freemont, CA)

Disadvantages

• unable to effectively treat astigmatism
  
• regression (sometimes)
  
• induces astigmatism (≤20% of cases with retreatment of higher corrections)

Advantages

• complete treatment of large spherical refractive errors
  
• effective for high hyperopia and myopia

Disadvantages

• no treatment of astigmatism
  
• association of anterior chamber phakic IOLs with endothelial cell loss
  
• cataracts or anterior subcapsular lens opacities (1-10%, short and long term)
  
• angle closure and pigmentary glaucoma (rare)
  
• papillary block glaucoma (rare)
  
• decentrations (may occur with all phakic IOLs)

Advantages

• complete treatment of large spherical refractive errors
  
• effective for treatment of high myopia and hyperopia
  
• piggy-back IOL insertion allows treatment for extreme hyperopia
  
• acceptable risk for well-informed patients who are poor candidates for hyperopic LASIK

Disadvantages

• retinal detachment, especially for high myopes (prophylactic treatment of peripheral retinal pathology has reduced risk to the normal lifetime level of 2.4%)
  
• posterior capsular rupture
  
• dislocation of the IOL

American Academy of Ophthalmology. Automated lamellar keratoplasty, preliminary procedure assessment. Ophthalmology 1996;103: 852-861.

American Academy of Ophthalmology. Radial keratotomy for myopia, ophthalmic procedure assessment. Ophthalmology 1993;100:1103-1115.

Assetto V, Benedetti S, Pesando P. Collamer intraocular contact lens to correct high myopia. J Cataract Refract Surg 1996;22:551-556.

Drews RC. Clear lensectomy and implantation of a low-power posterior lens for the correction of high myopia (discussion). Ophthalmology 1997;104:77-78.

Fechner PU, Haigis W, Wichmann W. Posterior chamber myopia lenses in phakic eyes. J Cataract Refract Surg 1996;22:178-182.

Koch DD, Kohnen T, McDonnell PJ, et al. Hyperopic correction by noncontact holmium:YAG laser thermal keratoplasty, United States phase IIA clinical study with 1-year follow-up. Ophthalmology 1996;103:1525-1536.

Lyle WA, Jin GJC. Clear lens extraction for the correction of high refractive error. J Cataract Refract Surg 1994;20:273-276.

Perez-Santonja JJ, Iradier MT, Sanz-Iglesias L, et al. Endothelial changes in phakic eyes with anterior chamber intraocular lenses to correct high myopia. J Cataract Refract Surg 1996;22:1017-1022.

Siganos DS, Pallikaris IG, Siganos CS. Clear lensectomy and intraocular lens implantation in normally sighted highly hyperopic eyes: three year follow-up. Eur J Implant Ref Surg 1995;7:128-133.