32.1.6 ILM Removal in Eyes with Detached Macula

The ILM is usually easier to remove from areas of detachment, but the detachment also presents unique challenges. The surgeon has two options to peel the ILM over a detached macula.22

32.1.6.1Reattaching the Macula First

• Stain the ILM with ICG (see Chap. 34).23

• Inject enough PFCL to reattach the macula.24

• Peel the ILM. There are two major differences compared to peeling under BSS and over previously not detached retina.

– The ILM tears easily, and the free edge instantly gets pressed against the retina by the weight of the PFCL, making the regrabbing technically more difficult.

– The retina is mobile25: the forceps drags the retina along, however minimally.

32.1.6.2Peeling When the Macula Is Still Detached

•Stain the ILM with ICG.

•Drain the subretinal fluid as much as possible to reduce the height of the detachment, but do not perform F-A-X.

•Begin the peeling just above the maculopapillary bundle at the disc margin (see

Fig. 32.8).26

•The direction of the peeling is always away from the disc, where the retina is fixated.

–Even though the ILM will separate in atypically large sheets, regrabbings are still necessary; it is easier to grab too deep if the retina is detached.27

32.2EMP

Although some ophthalmologists try to “treat” the patients with anti-VEGF injections, this obviously addresses only one of the consequences of the membrane (ME), not the cause. What offers definite cure is PPV with removal of the EMP.

22RD, PVR, PDR, and staphyloma-spanning posterior detachment.

23It is a little more difficult to stain the detached retina as the dye tends to accumulate in the deeper points of the eye.

24Do not use air: visibility is too poor to peel, and the PFCL bubbles will condensate on the back surface of the lens (see Sect. 31.2 and Fig. 25.2).

25Broken IPM (see Sect. 26.3.2).

26For example, at ~1 o’clock at the disc margin in the left eye.

27Whether the peeling is done over reattached or still detached retina, try to extend the centrifugally oriented peeling beyond the major vessels, especially inferiorly. In the latter case, it may become necessary to periodically drain more subretinal fluid to reduce retinal movement as the detachment’s height may increase as the result of the peeling.

Fig. 32.8 Peeling the ILM over detached retina. The peeling is started much closer to the disc margin than is usual (see Fig. 32.2a). The peeling direction is always away from the disc to reduce the movement of the retina and to provide a counterforce against the vector of the peeling. The retina is lifted (tenting) as the forceps is dragging the ILM and the retina temporally: a white line is visible at the border of ILM separation. The same phenomenon is noticed if a strongly adherent ILM is peeled in an eye with severe macular edema (see Fig. 49.3)

Pearl

In the vast majority of eyes with EMP, a spontaneous PVD is present at the time of PPV.

32.2.1 The Clinical Characteristics of the EMP28

•The membrane may be any of the following “pairs” – or something in between.

–Very thin or extremely thick.

–Small or large, spreading outside the field accessible through the contact lens without moving the microscope.

–Made up of a single or multiple layers.29

–Surrounded by retina that has several or no folds.30

–Located in the epicenter or parafoveally.

28Only those features are discussed here that are relevant to make technical (removal) decisions; the rest are detailed in Chap. 50.

29This is not known until the membrane is actually being peeled.

30Cellophane maculopathy is understood as a fine, clinically invisible (and surgically “ungrabbable”) epiretinal membrane, which creates folds (wrinkling) in the ILM (see Chap. 50).