Clear Lens Extraction
Clear Lens Extraction
== Background == (1,4) Clear lens extraction (CLE) is a procedure in which the lens of the eye is removed in an approach similar to that of cataract surgery(1). The main differences being the absence of a cataract and severe refractory error usually secondary to anatomic ocular abnormality (4) Patients who undergo this procedure usually have significant myopia or hyperopia which can be corrected during the procedure via insertion of a new lens to fix the refractory error. (1)
= Patient Selection = (3) Age tends to be one of the primary factors when considering a patient for CLE. Younger individuals often have not yet lost accommodation or started to develop presbyopia and therefore are not usually good candidates for CLE with lens exchange.
Myopia is another important factor to evaluate when considering a patient for CLE, it is important to evaluate both the axial length of the eye and the patient’s risk for retinal detachment. The risk of retinal complications such as retinal detachment is increased in patients with severe myopia.
== Indications == (4) Clear lens extraction has two main indications correction of severe refractive error due to anatomic abnormalities and presbyopia in older patients who do not wish to have spectacle dependence. Often the refractive error is too severe for other refractive interventions like LASIK or PRK.
== Contraindications == (3) Contraindications to CLE include other ocular conditions such as age-related macular degeneration, uncontrolled diabetes or diabetic retinopathy, uncontrolled glaucoma, previous keratorefractive surgery, recurrent inflammatory eye disease, or corneal disease.
= Surgical Technique = (5) Generally there are 3 different approaches that can be utilized for a CLE.
1. Distance correction
This involves placement of traditional or monofocal lenses enabling distance correction.
2. Mono-vision correction
This involves lens correction of near vision in the non-dominant eye and distant vision in the dominant eye.
3. Multifocal lenses correction
These lenses work through the use of two focal points enabling the correction of both distant and near vision.
= Outcomes = (3) Improved outcomes are seen in patients with uncomplicated surgeries, who are highly motivated, and have a decreased likelihood of fixation on minor visual impairments
= Complications = (2) Complications of clear lens extraction include macular complications (such as subfoveal choroidal neovascularization), posterior vitreous detachment, and retinal detachment. Posterior vitreous detachment (16.3%) had a higher prevalence in older individuals whereas retinal detachment was most likely to be seen in younger patients (8.1%) post operatively.
1. Antony M. Poothullil, Dimitri T. Azar, 1 - Terminology, classification, and history of refractive surgery, Editor(s): Dimitri T Azar, Refractive Surgery (Second Edition), Mosby, 2007, Pages 1-18, ISBN 9780323035996, https://doi.org/10.1016/B978-0-323-03599-6.50063-8. (https://www.sciencedirect.com/science/article/pii/B9780323035996500638)
2. Colin, J., MD, Robinet, A., MD, & Cochener, B., MD. (2003, August 25). Retinal detachment after clear lens extraction for high myopia: Seven-year follow-up. Retrieved from https://reader.elsevier.com/reader/sd/pii/S0161642099905262?token=EA49452C4E06D658A3E17E6EE3E41C8F4D265CAE103C2A11E4F4629E744D917DB5972C39F014F09C6A017FC1C4C4CBA6&originRegion=us-east-1&originCreation=20211126184550
3. Patient Selection Criteria. (n.d.). Retrieved from https://www.aao.org/focalpointssnippetdetail.aspx?id=26e3687d-de9a-4a6d-839f-3e46b053e5ee
4. Alió, J. L., Grzybowski, A., & Romaniuk, D. (2014, December 10). Refractive lens exchange in modern practice: When and when not to do it? Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4655463/
5. Clear Lens Extraction (CLE). (n.d.). Retrieved from https://healthcare.utah.edu/moran/lasik/clear-lens-extraction.php