Cataract

Developed in collaboration with CASA Medical.

Cataract is an opacity of the lens of the eye that may cause blurred or distorted vision, or glare. The development of cataract is common with aging and affects more people who have been particularly exposed to UV light. For this reason, it is common in pilots. Smoking may be a risk factor.

Nuclear cataract - This condition is seen principally with advancing age.

Cortical cataract - Is less common and is found in a ratio of roughly 2:3 when compared to nuclear cataract. Exposure to UVB is a risk factor. Abdominal obesity also appears to add to the risk of developing cortical cataract. There is some evidence suggesting an association between cortical cataract and dementia.

Subcapsular cataract - Is mainly seen in younger adults and is a posterior opacity. If central, the reduction in visual acuity can be severe and rapid. Systemic corticosteroid use, inhaled corticosteroid use after the fourth decade of life and alcohol use may increase the risk of developing subcapsular cataract. 

Cataract may result in problems with glare. In addition, if the visual axis is affected, visual performance may be severely impaired in bright light, when the pupil is narrow. In some cases, deterioration below vision standards can occur in as little as six to twelve months. Colour vision may also be affected.

This guideline applies to the presence of cataracts, and to the surgical treatment for the condition.

The choice of IOL – multifocal, extended depth of field (EDoF), or monofocal types – is to be made between the pilot or controller and their ophthalmic surgeon, based on the likely adverse effects of the type of the lens and its potential impact on their occupation. Multifocal IOL have characteristics that may prevent certification or may result in restrictions on the medical certificate. Monovision IOLs are a technique where one eye receives a different IOL than the other, typically one for distance vision and the other for near vision. This means that pilots or controllers will not meet CASA/ CAA NZ visual standards in both eyes. Thus, monovision IOLs are unacceptable for medical certification.

Pilot and controller information

• If pilots or controllers suspect they might have or have been diagnosed with cataracts they should obtain a ME review
• If pilots or controllers diagnosed with cataracts notice a change in their vision or difficulties with tolerating glare, they must contact their ME
• When eye surgery (cataract removal and intra-ocular lens (IOL) implants) is being considered pilots or controllers should seek advice from their MEs or CAA NZ
• A period of grounding will be required until post-surgical recovery is complete and a satisfactory review from the operating surgeon has been received. This typically 3 weeks for monofocal, and 3 months for multi-focal, including EDoF IOLs. For private and recreational pilots, all lenses are acceptable for return to flying provided the ophthalmology assessment and CAA NZ Special Eye Reports are normal.

For more information, see Medical Manual: Cataract.