Glaucoma

• Glaucoma The mere presence of raised IOP is called ocular hypertension, and it involves an increased risk of developing glaucoma.

• This latter diagnosis is not ascertained by raised IOP alone, it demands the occurrence of either disc cupping or visual field defects.

• Secondary glaucomas are caused by conditions which interfere with the normal passage of the aqueous in the pupil or the chamber angle (e.g. anterior uveitis).

• The first objective signs in the fundus are atrophy of nerve fibre bundles and cupping of the optic disc. Substantial axon atrophy is present when visual field defects are first measurable.

• The C/D ratio (a measure of the diameter of the cup in relation to that of the whole disc) and the rim area (the area of the outer rim of the disc with nerve fibres) is of help to record cup changes.

• If the disease process goes on, the cup usually first reaches the rim of the disc in either the lower or the upper pole. In severe cases, no rim of nerve fibres is seen at all, and the cup is deep or undermines the disc edges.

• With progression of the disease, the scotomas increase in size and coalesce. Visual field testing is essential to prove functional impairment.

• An increased IOP, i.e. above about 22 mm or a difference between the eyes of 6 mm Hg or more should cause a suspicion of glaucoma.

• The diagnosis glaucoma does not per disqualify flying duties. Aircrew with glaucoma should be free of side-effects from the local drug therapy given; the most important is the accommodative reduction of the visual acuity.

• Periodic follow-up examination of the visual function under the guidance of AMA is obligatory.

Flying Fitness

• Aircrew with glaucoma controlled by non miotic drugs or surgery may be considered fit for flying duties only if the results of automated perimetry in the central 30º results conform to mild glaucomatous loss in both eyes or moderate glaucomatous loss in one eye, the other eye being absolutely normal.

• The criteria for mild glaucomatous loss involves

  •  Mean Deviation < -6 dB

  •  Fewer than 18 points depressed below the p<5% level and fewer than 10 points below the p < 1% level.

  •  No point in the central 5 degrees with sensitivity of less than 15 dB.

• The criteria for moderate glaucomatous loss involves

  •  Mean Deviation < -12 dB.

  •  Fewer than 37 points depressed below the p< 5% level and fewer than 20 points below the p < 1% level.

  •  No absolute deficit (0 dB) in the 5 central degrees.

  •  Only one hemi-field with sensitivity of < 15 dB in the 5 central degrees.

• Such aircrew will undergo six monthly reviews by eye specialist for field-testing.

• Aircrew with field defects will be fit for P2 status only (Fit to fly as Pilot-in-Command along with qualified experienced pilot)

• All subsequent reviews will be done at IAM / AFCME