Macular Hole ICD-9 code: 362.54
A macular hole (MH) is a retinal break commonly involving the fovea.
Etiology and Risk Factors
Idiopathic macular hole is the most common presentation. Risk factors include age, myopia, trauma, or ocular inflammation.
Different findings can be observed depending the stage of the MH. Residual cortical vitreous, retinal glial, and retinal pigment epithelial cells are often found on the retinal surface. They are thought to cause tangential traction on the fovea. Cystoid edema in the outer plexiform and inner nuclear layers and thinning of the photoreceptor layer can also be observed.
It has been hypothesized that MHs are caused by tangential traction as well as anterior posterior traction of the posterior hyaloids on the parafovea. MHs are noted as a complication of a posterior vitreous detachment (PVD) at its earliest stages.
There are no preventative measures for idiopathic MHs. Pars plana vitrectomy has not been clearly demonstrated to be effective in preventing MH formation.
This is a clinical diagnosis based on history and clinical exam, including slit lamp and dilated fundus examination. In some cases, optical Coherence Tomography (OCT) is useful in the diagnosis and management of this condition.
Patients with MHs typically present over the age of 60 and females are more frequently affected. A careful history should be obtained to investigate for any of the risk factors mentioned above.
Slit lamp examination with special attention to the macula is important in the evaluation of this disorder (Figure 1). The Watzke-Allen sign can be used as a clinical test in cases of a suspected full thickness macular hole by shining a thin beam of light over the area of interest. The patient would perceive a “break” in the slit beam in cases of a positive test.
Careful examination of the fellow eye is also recommended given that MHs are bilateral in up to 30% of patients. Special attention should be paid to the vitreoretinal interface, involutional macular thinning, and retinal pigment epithelial window defects because these are risk factors for MH development in the fellow eye. Patients without a PVD in the fellow eye have an intermediate risk (~15%) of developing a MH, whereas patients with a PVD are at low risk for developing a MH.
Depending on the stage of the MH, a subfoveal lipofuscin-color spot or ring can be noted. In more advanced cases, a partial or full thickness macular break is observed.
Metamorphopsia (distortion of the central vision), central visual loss, or central scotoma can be reported.
Stage 1 MH, or impending MH, demonstrates a loss of the foveal depression. A stage 1A is a foveolar detachment characterized a loss of the foveal contour and a lipofuscin-colored spot. A stage 1B is a foveal detachment characterized by a lipofuscin-colored ring.
Stage 2 MH is defined by a full thickness break < 400µm in size. It might be eccentric with an inner layer “roof.” This can occur weeks to months following Stage 1 MHs. A further decline in visual acuity is also noted. In most cases, the posterior hyaloid has been confirmed to be still attached to the fovea on OCT analysis.
Stage 3 MH is further progression to a hole ≥400 µm in size. Nearly 100% of stage 2 MHs progress to Stage 3 and the vision further declines. A grayish macular rim often denotes a cuff of subretinal fluid. The posterior hyaloid is noted to be detached over the macula with or without an overlying operculum (Figure 2 and 3).
Stage 4 MH is characterized by a stage 3 MH with a complete posterior vitreous detachment and Weiss ring.
Other features to note on exam include yellow deposits at the base of the hole, retinal pigment epithelial changes at the base of the hole, and epiretinal membrane adjacent to hole.
Figure 1: Clinical photo demonstrating a full thickness macular hole with a grayish macular rim suggestive of subretinal fluid. Note the retinal pigment epithelial changes at the base of the hole.
Figure 2: Optical Coherence Tomography image of a macular hole with an overlying operculum. The classic “anvil-shaped” deformity of the edges of the retina is noted due to intraretinal edema.
Figure 3: A small full thickness macular hole on Optical Coherence Tomography with intraretinal and subretinal fluid.
Fluorescein angiography demonstrates a hyperfluorescence pattern consistent with a transmission defect due to loss of xanthophyll at base of the MH. This study is not usually necessary for diagnosis or management.
However, OCT is the gold standard in the diagnosis and management of this disorder. This high-resolution image can allow evaluation of the macula in cross section and three-dimensionally. OCT can be helpful detecting subtle MHs as well as staging obvious ones.
OCT can also help guide management. Some cases of MHs there is an associated ERM that can be difficult to determine clinically. OCT can be used the aid in prognosis of the fellow eye. Patients with a full-thickness MH in one eye and foveal abnormalities consistent with a stage 1A MH in the fellow eye have a high risk progression in the fellow eye. In surgical cases, evaluation of each scan can elucidate the best approach for removal of the internal limiting membrane.
No laboratory tests are indicated in cases of idiopathic MHs.
The clinical appearance of a MH is fairly distinctive. However, epiretinal membrane with a pseudohole, lamellar hole, and vitreomacular traction must also be considered. Cystoid macular edema, subfoveal drusen, central serous chorioretinopathy, or adult vitelliform macular dystrophy are also in the differential diagnosis of a stage 1 MH.
The clinical stage and duration of the MH is the most important issue in the management of this entity.
No medical therapy is indicated for idiopathic MHs. However, Stage 1 MH can be followed conservatively given approximately 50% chance of spontaneous closure.
Medical follow up
Surgery involves a pars plana vitrectomy procedure with tamponade. This can be done with or without peeling of the internal limiting membrane. A number of different instruments can be used to facilitate removal including intraocular forceps, pick, diamond dusted instruments, as well as other instruments.
Surgical technique has been debated for many years. While most vitreoretinal surgeons agree that tamponade is important, the type of tamponade and duration of postoperative positioning is debated. The importance of peeling the internal limiting membrane with or without staining has also been debated.
Surgical follow up
The follow up is similar for most eyes following pars plana vitrectomy surgery. It is important that patients understand the importance of postoperative positioning. While the duration of positioning has been debated, most vitreoretinal surgeons advise positioning to improve the rate of hole closure. Visual acuity improvement does not occur immediately in some patients. This is highly dependant on preoperative characteristics, duration of the MH, as well as other factors.
The complications are similar to all eyes undergoing pars plana vitrectomy. In particular, these patients are at a higher risk for retinal tear and detachment. The vitreous is the most adherent to the optic nerve, macula, and ora. Macular holes are caused by an abnormal adherence of the vitreous to the parafoveal area. This abnormal adherence may also be present at the ora and result in retinal tears or detachment during vitrectomy. All cases of macular surgery also include complications such as intraoperative macular trauma and light toxicity.
The visual outcomes following pars plana vitrectomy are very favorable. In general, the better the preoperative visual acuity results in better postoperative visual acuity. However, eyes with worse preoperative visual acuity often experience the greatest postoperative improvement.
- ↑ McDonnell PJ, Fine SL, Hillis AI. Clinical features of idiopathic macular cysts and holes. Am J Ophthalmol 1982;93(6):777-86.