Careful assessment and management of the ocular surface is vital for optimal post operative refractive outcomes. The air-tear film interface is the highest index of refraction and can interfere with preoperative measurements if it is unstable or there is underlying corneal pathology as listed below. Refractive surprises can occur as a result and are often the reason patients are dissatisfied after cataract surgery.
Corneal pathology affecting preoperative measurements due to irregular astigmatism:
- Dry eye
- Pterygia
- Anterior basement membrane dystrophy
- Salzmann’s nodular degeneration
Patients may require, for example, a superficial keratectomy prior to cataract surgery to allow for smoothing of their ocular surface to achieve the best biometry measurements. This is a good opportunity to educate patients that treating the ocular surface may be a long-term process towards yielding the best refractive outcome.
Predisposing risk factors for ocular surface disease:
- Systemic medications
- Sjogren’s syndrome
- Contact lens use
- Prior refractive surgery
- Concurrent use of other ophthalmic medications