Morphologic analysis of stage 3 and stage 4 macular holes: Implications for treatment

Purpose

To determine whether the observed anatomy of macular holes can be explained by a hydrodynamic model in which fluid flow through the hole is balanced by fluid pumping across the retinal pigment epithelium. We use this model to draw conclusions about the possible role of vitreomacular traction in determining the anatomy of macular holes and their resolution after vitreous surgery.

Design

Cross sectional.

Methods

Retrospective study in a clinical practice. The study included 42 eyes of 42 patients with a stage 3 or 4 macular hole (Gass classification). We measured the radius of the macular hole and the radius of the surrounding cuff of subretinal fluid from color or red-free fundus photographs and determined the relationship between these two variables.

Results

The mean age of the patients was 68.0 ± 7 years (range, 51 to 80). Twenty-five patients had stage 3 macular holes and 17 patients had stage 4 macular holes. The neurosensory detachment radius was related to the square of the macular hole radius for stage 3 and stage 4 holes, with no significant difference between the stage 3 and stage 4 linear trend lines (P = .999). There was no correlation between patient age and the area of the macular hole (r = 0.0645) or neurosensory detachment plus hole (r = 0.156) over the range of age in this study. However, the area of the doughnut-shaped cuff of subretinal fluid increased with increasing patient age (P = .0493), thus suggesting an age-dependent decline in the pumping ability of the retinal pigment epithelium.

Conclusions

Our data are consistent with a hydrodynamic model in which macular hole anatomy is determined by a balance between fluid flow through the hole and fluid outflow across the retinal pigment epithelium. Because stage 3 and stage 4 macular holes exhibit a similar relationship between the size of the macular hole and the size of the cuff of subretinal fluid around the hole, simple relief of vitreomacular traction would not lead to resolution of the subretinal fluid cuff unless it is accompanied by a reduction in hole diameter due to approximation of wound edges.