Preoperative examination in cataract surgery so the neglect the post operatively complication of surgery and during surgery.there are some basic points should be remember. Cataract full lecture video
A full and pertinent ophthalmic examination is required. Following the taking of a ophthalmic history, the following should be examine carefully:
• Vision
Vision test is usually check using a Snellen chart, it should be measure as accurate.
• Cover test.
A heterotropia may diagnose amblyopia, which carries a guarded visual prognosis, or the possibility of diplopia if the vision is improved.
A squint, usually a divergence, may develop in an eye with poor vision due to cataract, and lens surgery alone may straighten the eye.
• Pupillary reaction
Due to the cataract never produces an afferent pupillary defect, its presence implies substantial additional pathology.
• Ocular condition or disease.
Dacryocystitis, blepharitis, chronic conjunctivitis, lagophthalmos, ectropion, entropion and tear film abnormalities may predispose to endophthalmitis and in most cases should be examine prior to intraocular surgery.
• Cornea.
Cornea with decreased endothelial cell counts have increased postoperative decompensation secondary to operative trauma.
Specular microscopy and pachymetry may be helpful in diagnose risk, and precautions should be taken to protect the endothelium.
A prominent arcus senilis is often associated with a surgical view of decreased clarity, as are stromal opacities.
• Anterior chamber.
A shallow anterior chamber can cause cataract surgery difficult.
Recognition of a poorly dilating pupil allows intensive preoperative mydriatic drops, planned mechanical dilatation prior to capsulorhexis and/or intracameral injection of mydriatic.
A poor red reflex compromises the creation of a capsulorhexis, but can be
largely overcome by staining the capsule with trypan blue.
• Lens.
Nuclear cataracts lead to be harder and may require more power for phacoemulsification, while cortical and subcapsular opacities tend to be softer.
Black nuclear opacities are extremely dense and extracapsular cataract extraction rather than phacoemulsification may be the superior option.
Pseudoexfoliation indicates a likelihood of weak zonules, a fragile capsule and poor mydriasis.
• Fundus examination.
Pathology such as age-related macular degeneration may affect the visual outcome.
Ultrasonography may be required, principally to exclude retinal detachment and staphyloma, in eyes with very dense opacity that precludes fundus examination.
• Sclera.
If a prominent explant/encircling band has been placed during prior retinal detachment surgery, the eye is particularly large or the sclera thin, peri- and retrobulbar local anaesthesia may be avoided and special care taken with sub-Tenon local anaesthetic infiltration.
• Refractive status.
It is hard to get details of the patient’s preoperative refractive error in order to guess intraocular lens (IOL) implant.
The keratometry readings should be noted in relation to the refraction, particularly if it is planned to address astigmatism by means of targeted wound placement, a toric IOL or a specific adjunctive procedure.
It is particularly important to get a postoperative refractive result from an eye previously operated upon so that any ‘refractive surprise’, even if minor, can be taken into account.
PCO-POSTERIOR CAPSULAR OPACIFICATION
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