Causes of intracapsular cataract extraction, explantation of intraocular lenses and suture scleral fixation of intraocular lenses in the modern era

Phacoemulsification: Proposals for Improvement in Its Application

A cataract is defined as opacity of the crystalline lens. It is currently one of the most prevalent ocular pathologies and is generally associated with aging. The most common treatment for cataracts is surgery. Cataract surgery is a quick and painless process, is very effective, and has few risks. The operation consists of removing the opacified lens and replacing it with an intraocular lens. The most common intraocular lens removal procedure that is currently used is phacoemulsification. The energy applied in this process is generated by ultrasonic waves, which are mechanical waves with a frequency higher than 20 kHz. A great deal of research on the different ways to perform the stages of this surgical procedure and the analysis of the possible side effects of the operation has been published, but there is little information on the technical characteristics, the intensities applied, and the use of ultrasound-emitting (U/S) equipment for cataract removal. More studies on the method and depth of absorption of ultrasonic waves in our visual system when performing the phacoemulsification procedure are needed. It would be advisable for health authorities and medical professionals to develop guidelines for the handling and use of ultrasonic wave-emitting equipment, such as those that exist for ultrasound and physiotherapy. This could help us to reduce undesirable effects after the operation.

Outcomes of intraocular lens scleral fixation with the friction knot technique

PURPOSE

To examine the clinical outcomes of intraocular lens (IOL) scleral fixation with the friction knot technique.

METHODS

Retrospective case series of 152 eyes of 152 patients with inadequate capsular bag support operated with the friction knot IOL scleral fixation technique by a single surgeon. The fixated IOLs were one-piece or three-piece models all with open loop haptics. Main outcome measures were change in corrected distance visual acuity (CDVA) and postoperative complications.

RESULTS

The mean follow-up time was 11.7 months (median 4.9, range 0.7-64.8). The mean logarithm of the minimum angle of resolution CDVA improved from preoperative 0.77 ± 0.73 (Snellen 20/118 ± 7.3 lines) to 0.44 ± 0.56 (Snellen 20/55 ± 5.6 lines) at the final visit (p < 0.001). The main postoperative complications were ocular hypertension (30.3%), uveitis-glaucoma-hyphaema syndrome (12.5%; UGHS), vitreous haemorrhage (11.2%) and retinal detachment (8.6%). Two (1.3%) cases of suture breakage were seen. In multivariate Cox regression analysis, age under 60 years [hazard ratio (HR) = 5.41; 95% confidence interval (CI) 1.95-15.01] and scleral fixated one-piece IOL (HR = 4.23; 95% CI 1.44-12.44) were found as significant independent risk factors for developing new UGHS.

CONCLUSION

The friction knot technique provides a firm scleral fixation. Scleral fixation may successfully be utilized in dislocated three-piece IOLs with loop haptics. We recommend avoiding scleral fixation of one-piece IOLs in young patients due to a high risk of UGHS.