Article

CLINICAL: GLAUCOMA

ADDING THERAPIES

What do you do when one drop isn’t enough?

Prostaglandin analogues are traditionally the first agents initiated when glaucoma is diagnosed, but what should be done if they aren’t enough to lower IOP?

In this column, I discuss options to consider in specific patient scenarios.

MILD GLAUCOMA PATIENT

The patient has a mean deviation of -3.0 dB on VF, mild thinning of the retinal nerve fiber layer (RNFL) in one quadrant on OCT, central corneal thickness (CCT) of 510 μm, a cup-to-disc ratio of 0.65/0.65, normal gonioscopy findings, IOP of 20 mmHG, maximum IOP (Tmax) of 23 mmHg and 20/20 BCVA. Considerations:

  1. A medication switch within the same drug family to keep the patient on monotherapy.
  2. The addition of a single adjunctive medication.
  3. The addition of a fixed-combination medication.
  4. Selective laser trabeculoplasty.

Remember: This patient has mild glaucoma. So, trying to lower IOP in a conservative manner is a good option. That said, all these options are reasonable, and a target IOP range of 16 mmHg to 18 mmHg may be sufficient.

MODERATE GLAUCOMA PATIENT

The patient has a mean deviation of -9.0 dB on VF, moderate thinning of the RNFL in all quadrants on OCT, CCT of 500 μm, a cup-to-disc ratio of 0.75/0.75, normal gonioscopy findings, IOP of 18 mmHg, Tmax of 22 mmHg and 20/20 BCVA. The patient’s mean deviation in one year went from -7.0 dB to -9.0 dB, and two quadrants of progression were noted on OCT. Considerations:

  1. The addition of a single adjunctive medication.
  2. The addition of a fixed-combination medication.
  3. Selective laser trabeculoplasty.
  4. Minimally invasive glaucoma surgery (MIGS).

This patient’s disease is progressing rapidly, so all options are reasonable. The conservative approach are options one through three. A target IOP range of 13 mmHg to 15 mmHg may be sufficient.

SEVERE GLAUCOMA PATIENT

The patient has a mean deviation of -17 dB, severe RNFL thinning in all quadrants on OCT, CCT of 510 μm, a cup-to-disc ratio of 0.90/0.90, normal gonioscopy findings, IOP of 21 mmHg, Tmax of 24 mmHg and 20/20 BCVA. Considerations:

  1. The addition of a single adjunctive medication.
  2. The addition of a fixed-combination medication.
  3. Selective laser trabeculoplasty.
  4. MIGS.
  5. Filtration surgery.

This patient has significant glaucoma, but still 20/20 BCVA. The first three options are likely not going to result in a timely lowering of IOP, so he’ll need options four or five, which are more aggressive and risky than the other options, but provide more efficacy. A low-teens target IOP range is likely needed to protect from more glaucoma damage.

FINAL THOUGHT

A key question we should ask ourselves when deciding on additional treatment for our glaucoma patients is, “does the treatment I am going to recommend to the patient put him at higher risk of vision loss than the risk of him losing vision from glaucoma?” OM