Скачать или смотреть Ocular Factors Causing risk of Posterior Capsular Rent (PCR) and precautions in Cataract surgery

In cataract patients undergoing phacoemulsification surgery, certain ocular findings can increase the risk of posterior capsular rent (PCR), which is a potential complication during the procedure. These findings may include:
Zonular Weakness: Patients with weak zonules, which are the tiny fibers that hold the lens in place, are at an increased risk of posterior capsular rent. Zonular weakness can be caused by conditions such as pseudoexfoliation syndrome, Marfan syndrome, and trauma.


Advanced Cataract: Dense and mature cataracts can be associated with weaker zonules, making it more challenging to perform the surgery without damaging the posterior capsule.


Pseudoexfoliation Syndrome: This condition is characterized by the accumulation of abnormal material on various ocular structures, including the lens capsule. It can lead to zonular weakness and an increased risk of PCR.


Axial Myopia: Patients with high levels of nearsightedness (axial myopia) may have elongated eyes and thinner zonules, making them more susceptible to zonular weakness.


Trauma: Previous ocular trauma, especially if it has affected the zonules, can increase the risk of PCR during cataract surgery.


Small Pupil: Patients with a small or poorly dilating pupil can pose challenges during surgery, increasing the likelihood of inadvertent damage to the posterior capsule.


Pseudophacodonesis: This refers to the lens wobbling or moving excessively due to weak zonules. Pseudo-phacodonesis can indicate zonular instability and an increased risk of complications like PCR.


Glaucoma or Prior Glaucoma Surgery: Patients with glaucoma or those who have had previous glaucoma surgeries may have weakened zonules due to the nature of their conditions or surgical interventions.
It's important for the operating surgeon to carefully assess these risk factors and take appropriate precautions during surgery to minimize the risk of posterior capsular rent. In some cases, additional techniques or devices may be used to provide additional support to the posterior capsule and prevent complications. Precautions should be taken in these patients to minimize this risk. Some important precautions include:
Zonular Assessment:
Careful preoperative evaluation of zonular integrity is crucial. Use techniques like retroillumination and gonioscopy to identify any zonular weakness or abnormalities.


Capsular Staining:
Use vital dyes like trypan blue or indocyanine green to enhance visualization of the anterior capsule, facilitating better identification of the capsular edge during surgery.


Hydrodissection Technique:
Gentle hydrodissection can help separate the lens nucleus from the capsule, reducing stress on the zonules. Avoid excessive force, which could lead to zonular dehiscence.


Viscoelastic Use:
Skillful use of viscoelastic substances helps maintain anterior chamber depth and stabilize the capsular bag during surgery, reducing the chances of inadvertent capsule damage.


Capsulorhexis Technique:
A well-controlled continuous curvilinear capsulorhexis (CCC) can minimize stress on the zonules. Consider a smaller-than-usual CCC to provide more capsule support.


Divide and Conquer Technique:
This phacoemulsification approach reduces stress on the zonules by breaking the nucleus into smaller fragments before removal.


Pupil Management:
Ensure adequate pupil dilation to prevent iris-lens diaphragm retropulsion syndrome (ILDRS), which can stress the zonules during surgery.


Low Vacuum Settings:
Use low vacuum levels during phacoemulsification to minimize stress on the zonules while emulsifying the lens.


Viscoelastic Removal:
Be cautious while removing viscoelastic from the capsular bag to prevent abrupt changes in intraocular pressure that could stress the zonules.


IOL Placement:
Consider implanting the intraocular lens (IOL) in the bag if zonular integrity allows. If zonular support is compromised, alternative locations like the sulcus or anterior chamber can be considered.
Suture Support:
In cases of extensive zonular weakness, techniques like capsular tension rings (CTRs) or iris hooks can provide additional support to the capsular bag.


Anterior Vitrectomy:
If a PCR occurs, preventing vitreous prolapse is important. Be prepared to perform an anterior vitrectomy and consider using a three-piece IOL to minimize vitreous interaction.


Surgeon Experience:
Surgeons with experience and expertise in handling complicated cases are better equipped to navigate challenging scenarios and minimize complications.
Remember that each patient is unique, and the approach should be tailored to the individual's ocular findings and risk factors. Close communication between the surgeon and patient, along with thorough preoperative assessment, is key to a successful outcome in cataract surgery, especially in cases with increased risk of posterior capsular rent.