A second study was performed with juxtafoveal membranes and using a Krypton laser⁽¹¹⁾.

Inclusion criteria allowed treatment of well-defined choroidal neovascular lesions located 1 to 199 µ from the foveal centre, or 200 to 2500 µm from the foveal centre but showing blood or pigmentation less than 200 microns from the foveal centre (resulting in a barrier effect in fluorescence).

As opposed to the study with Argon laser in extrafoveal membranes, this trial did not require treatment of the entire area where bleeding occurred. Under no circumstances should treatment reach the foveal centre.

After 3 years, severe loss of vision (≥6 lines) had occurred in 49% of treated eyes and 58% of non-treated eyes⁽¹⁴⁾.

The efficacy of this treatment in terms of the number needed to treat(20) was very low: 11.1.

This treatment reduced the risk of severe loss of vision by 10%.

However, this benefit was not observed in patients with hypertension or taking antihypertensive medication.

Nevertheless, the MPS maintained the indication to treat for these non-normotensive patients due to the absence of similar findings in other MPS studies.

After 5 years, the number of eyes with final VA ≥ 20/40 was double for treated eyes⁽¹⁴⁾.

Persistence (incomplete treatment) and recurrence (neovascularization later than six weeks after treatment) were responsible for the majority of loss of vision in the treated group.

The MPS reclassified membranes as 100% classic, classic with an occult component and 100% occult.

Results were better in classic membranes: 54% of treated eyes and 72% of non-treated eyes lost 6 or more VA lines.

No statistically significant differences were observed between the treated and non-treated groups in cases of mixed membranes (only the classic component was treated) and 100% occult membranes.

Therefore, treatment of occult membranes and the classic component of mixed membranes was not effective in reducing loss of vision^(14,16).

In conclusion, the MPS showed that laser photocoagulation of well-defined extrafoveal choroidal membranes and classic extra and juxtafoveal membranes secondary to AMD may prevent of delay loss of vision in patients fulfilling the inclusion criteria.