What is Clear Lens Extraction
Background
Clear lens extraction (CLE) is a procedure in which the crystalline 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. It is often performed as an elective surgery in the setting of severe refractory error such as high myopia or hyperopia but can also be performed in patients who are presbyopic and wish to have a multifocal IOL implanted, or in patients secondary to anatomic ocular abnormality such as angle closure glaucoma. (1,4)
Patient Selection
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. (3)
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
Clear lens extraction has two main indications – correction of severe refractive error and/or presbyopia in patients who wish to have spectacle independence. Often the refractive error is too severe for other refractive interventions like LASIK or PRK. (4) In is also performed in patients with anatomic abnormalities such as angle closure glaucoma.
Contraindications
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.(3)
Surgical Technique
CLE is performed in a similar manner to cataract surgery with lens implant. Due to the soft nature of the lens, a subracapsular technique can often be utilized without fear of endothelial damage. In certain cases, the I/A hand-piece can be used for removal of the nucleus, avoiding any phaco power. (5)
IOL targets can be customized to the patient’s desires:
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
Improved visual function can be seen in patients with uncomplicated surgeries, who are highly motivated, and have a decreased likelihood of fixation on minor visual impairments (3)