Limbal relaxing incisions versus penetrating limbal relaxing incisions

Limbal relaxing incisions versus penetrating limbal relaxing incisions for the management of astigmatism in cataract surgery Sara Akram Azzam M. B. B. ch

Goals of modern cataract surgery n n n Cataract removal Total spherical correction Cylinderical correction (Astigmatism) Restoration of accomodation Prevention of posterior capsular opacification

Astigmatism and cataract n An optical defect whereby vision is blurred due to inability of the optics of the eye to focus a point object into a sharp focused image on the retina. This may be due to an irregular or toric curvature of the cornea or lens.

Surgical correction of astigmatism with cataract n n n n Manipulation of cataract incision Limbal relaxing incisions (LRIs) Astigmatic keratotomy Paired opposite clear corneal incision Implantation of toric intraocular lenses Penetrating limbal relaxing incisions (PLRIs) Post-operative LASIK

AIM OF WORK n The aim of this study is to compare between limbal relaxing incisions (LRIs technique) and penetrating limbal relaxing incisions (PLRIs technique) as regards the simplicity and efficacy in the treatment of preexisting corneal astigmatism at the time of cataract surgery.

PATIENTS AND METHODS n Group A: LRIs 20 eyes n Group B: PLRIs 20 eyes Kasr EL Aini, surgical unit

$PREOPERATIVE EVALUATION n n n n History taking Best corrected visual acuity (BCVA) Refraction$

PREOPERATIVE EVALUATION n n n n History taking Best corrected visual acuity (BCVA) Refraction Intraocular pressure (IOP) Slit lamp examination Fundoscopy using indirect ophthalmoscope Corneal topography

PATIENTS AND METHODS Inclusion criteria: n Age: 20 -80 years n Both sexes enrolled n Topographic astigmatism: 1. 0 -4. 0 diopters n Clear cornea Exclusion criteria: n Preexisting ocular condition such as: Corneal opacities Keratoconus Glaucoma, uveitis, retinal, optic nerve disease n Topographic astigmatism <1. 0 diopter or more than 4. 0 diopters

LIMBAL RELAXING INCISIONS n Two limbal incisions were performed along the steepest meridian using preset guarded stainless steel knives with preset guards of 550 µm depth. The length of the incision depended on the degree of the astigmatism, and was calculated using a “Limbal relaxing incisions nomogram”.

AMO LRI Calculator

PENETRATING LIMBAL RELAXING INCISIONS n Two full thickness incisions were performed using a keratome knife along the steepest meridian, in addition to the clear corneal stab incision of the phacoemulsification.

Mackool Nomogram

FOLLOW- UP Patients were evaluated 1 day and 1 week postoperative for: n n n Visual acuity Corneal topography Presence or absence of any complications.

RESULTS n n n In the LRI group, mean cylinder preoperative was 1. 8 D (SD range 0. 636) however mean cylinder postoperative was 0. 62 D (SD range 0. 421). In the PLRI group, mean cylinder preoperative was 1. 6 D (SD range 0. 619) however mean cylinder postoperative was 1. 7 D (SD range 0. 798). The average change in corneal cylinder (∆change) was found to be 1. 178 D, SD 0. 338 in the LRI group and -0. 095 D, SD 0. 846 in the PLRI group.

RESULTS

RESULTS A B Changes in corneal topography (LRI case) A: preoperative, B: 1 week postoperative

RESULTS A B Changes in corneal topography (PLRI case) A: preoperative, B: 1 week postoperative

CONCLUSION n Limbal relaxing incisions are safe and effective method in reducing preexisting corneal astigmatism up to 4 diopters, however penetrating limbal relaxing incisions failed to achieve any improvement in correcting preexisting astigmatism.

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