Figure 1A. Fundus image of a macular hole
Dr William G Campbell
MRCP (UK) FRANZCO
Head of the Vitreoretinal Unit, Royal Victorian Eye and Ear Hospital
Tanya M Pejnovic
Senior Orthoptist Melbourne Retina Associates Ocular Oncology Clinic, Royal Victorian Eye and Ear Hospital
Macular hole is a condition in which a defect develops at the fovea, resulting in central vision impairment (Figures 1A, 1B).
Figure 1B. OCT of a macular hole
The most common type of macular hole is the so-called `idiopathic' variety, which occurs in older patients, but it may also develop following retinal detachment and as a consequence of blunt ocular trauma.
Idiopathic holes occur in the ageing eye as a result of an abnormally firm adhesion between the cortical vitreous and the fovea, leading to incomplete detachment of the posterior vitreous from the retina (PVD). The current theory of macular hole pathogenesis is that shrinkage of the prefoveal cortical vitreous causes traction on the fovea and dehiscence at the umbo, the point at which the retina is thinnest (Figure 2). Once there is a breach in the inner limiting membrane (ILM), fluid is able to enter the surrounding neuroretina, creating the cystic cavities often found around the margins of a macular hole.
Figure 2. Histological cross-section of macula
The four stages
In the Gass classification1,2 there are four stages of idiopathic macular hole, which are readily differentiated on ocular coherence tomography (OCT), an imaging modality that has enhanced our understanding of the formation, progression and staging of this condition.
Also known as an `impending hole', stage 1 is characterised initially by a yellow spot at the fovea, (stage 1A, Figure 3) and later by a central yellow ring (stage 1B, Figure 4). On OCT there is persistent attachment of the vitreous to the fovea, creating vitreo-foveal traction, loss of the foveal depression with separation of the photoreceptors from the pigment epithelium (RPE) and progressive dehiscence of the outer retina. In about 50 per cent of stage 1 holes, the vitreous detaches completely from the fovea, leading to spontaneous reversal of the macular changes.
Figure 3A. Fundus image of stage 1A macular hole
Figure 3B. OCT of stage 1A macular hole
Figure 4A. Fundus image of stage 1B macular hole
Figure 4B. OCT image of stage 1B macular hole
Figure 5. OCT of stage 2 macular hole
An enlarging defect develops in the innermost layer of the retina and very fine radiating traction striae, as well as intraretinal cystic cavities, may become visible around the hole, which typically has a diameter of less than 400 µm (Figure 5). The vitreous is still attached to the edge of the hole. Most stage 2 holes progress but a few are capable of spontaneous closure (Figures 6A, 6B, 6C).
Figure 6A. May: VA 6/12
Figure 6B. August: VA 6/6
Figure 6C. December: VA 6/5
Figure 6. OCT of spontaneous resolution of stage 2 macular hole
There is further enlargement of the hole to exceed 400 µm in diameter and the vitreous separates completely from the macula. In many cases this results in a small `operculum' suspended anterior to the hole (Figure 7), which may be visualised by the patient as a tiny translucent floater. This `operculum' is made up of glial elements but sometimes contains photoreceptor fragments. Many stage 3 holes do not progress to stage 4, and with the passage of time develop small white deposits of RPE proliferation in the base (Figures 8A, 8B).
Figure 7. OCT of stage 3 macular hole with operculum
Figure 8A. Macular hole with white deposits in base
Figure 8B. Macular hole with white deposits in base
The vitreous detaches from the optic disc (complete PVD), sometimes creating a Weiss ring, but the macular hole may not enlarge much more from this point.
The peak incidence of idiopathic macular holes is in the sixth and seventh decades of life, whereas traumatic holes generally affect younger people. Numerous epidemiological studies3-7 have reported a prevalence of around 1.5 to 3.3 cases per 1,000 head of population, with the highest rate occurring in Caucasians. In a retrospective study conducted over 10 years at the Mayo Clinic,7 researchers found an incidence of eight per 100,000 per year in a predominantly white population. Macular holes are three times more common in females than males and approximately 12 per cent are bilateral.7
Macular holes generally present in one of three ways:
- The patient becomes aware of metamorphopsia or a change of vision in the affected eye.
- The patient realises they have a problem with one eye when they cover the other one.
- Some patients, particularly the elderly, are not aware of a problem until they undergo a routine eye examination and the diagnosis is made by an optometrist.
A retinal detachment developing as a result of a macular hole generally occurs only in highly myopic eyes with chorioretinal atrophy at the posterior pole (Figure 9).
Figure 9. Myopic eye with detachment from macular hole (arrow)
The visual acuity is typically in the range of 6/12 to 6/60 and Amsler grid testing reveals a central scotoma with distortion of the surrounding lines. Macular holes do not generally affect the pupil reactions. Slitlamp biomicroscopy reveals a round central neuroretinal defect, which in larger holes is darker red due to exposure of the underlying RPE and choroid. There is usually a cuff of subretinal fluid surrounding larger holes and a number of tiny white deposits are often present in the base of holes of longer duration.
OCT has become the key investigation in macular diseases in general and is very useful in the staging of macular holes.
Prior to the advent of OCT, the Watzke-Allen test was useful in the diagnosis of macular holes. A positive result is obtained when the patient is able to detect a gap in a vertical slit of light as it crosses the hole during biomicroscopy, but this test has become obsolete in centres in which OCT is available.
Autofluorescence photography reveals a focus of hyperfluorescence corresponding to the macular hole (Figure 10), but in most cases adds nothing to the information provided by OCT and rarely has a role to play in the diagnosis of this condition.
Figure 10. Autofluorescence
History of treatment
Stage 1 holes may simply be monitored, as they frequently resolve spontaneously but treatment is indicated for stages 3 and 4, as well as most stage 2 holes. It is questionable whether surgery should be offered to patients with chronic holes, in other words, of longer duration than a year, as the closure rate is lower and the visual benefit uncertain.
Prior to 1991, it was not appreciated that macular holes could be cured. In that year, Kelly and Wendel8 published a small series on 52 eyes in which they were able to close. Using vitrectomy surgery and gas tamponade, they achieved success with 30 eyes (58 per cent). The success rate was modest but their study demonstrated that something could be done for this condition and the era of macular hole surgery had begun.
The early technique consisted of 20-gauge vitrectomy, separation of the posterior hyaloid face from the optic disc and macula, fluid/air exchange, then replacement of the air with a slightly expansile concentration (15-16 per cent) of perfluoropropane gas (C3F8). The patient was then instructed to posture face-down as much as possible for the next two weeks to ensure the gas was tamponading the hole.
This was a challenging ordeal for frail, elderly patients, so special chairs and bed cushions were developed to facilitate prone positioning, but despite these aids many people found it difficult or impossible for extended periods. In addition, there are problems associated with the prolonged intraocular presence of C3F8 gas. For example, patients are not permitted to fly in an aircraft until the gas has been reabsorbed, which may take up to 10 weeks, and vision is impaired in the operated eye until the gas-fill is less than 50 per cent.
A key advance in macular hole surgery was the idea of peeling the ILM, first introduced by Park and Sipperley9 in 1999, based on the theory that a taut ILM may produce radial traction on the hole, preventing it from closing. They reported a closure rate of 91 per cent in 58 eyes in which the ILM was peeled.
Initially the ILM was peeled without staining, which is technically challenging, but there are now several vital dyes, which make the exercise much easier. Indocyanine Green (ICG) is used in many centres, particularly in Japan and the United States, but concerns have been raised about possible retinal toxicity, so most retinal surgeons in Australia employ one of two blue stains: Trypan Blue (Membrane Blue) or Brilliant Blue G (ILM-Blue, Brilliant Peel). Early concerns that ILM peeling may have an adverse effect on the visual outcome have not been confirmed.
There are four key points to consider when deciding on the best approach to macular hole surgery.
How quickly do macular holes close after surgery?
It is possible to obtain an OCT scan in many gas-filled eyes, particularly in the presence of pseudophakia, by selecting the maximum myopic correction on the instrument. There has been a number of recent studies10-14 using this technique to demonstrate high closure rates within even the first 24 hours after surgery (Table 1). Figures 11A and 11B depict complete closure of a stage 3 hole on the first post-operative day.
Table 1. Rate of closure of macular holes
Figure 11A. OCT scan of macular hole preoperative
Figure 11B. OCT scan demonstrating closure of same macular hole as 11A, one day
Is it necessary to peel the ILM in every case?
As shown in Table 2, most studies15-19 report a higher success rate following ILM peeling, although Tadayoni and colleagues16 found it made no difference in holes smaller than 400 µm. Interestingly, Brooks15 recorded a 25 per cent reopening rate within six months in eyes in which the ILM had not been peeled.
Table 2. Effect of ILM peeling on macular hole closure
Is long-term gas tamponade with C3F8 required?
The three recent studies20-22 summarised in Table 3, one of which included 1,074 cases, demonstrate that the duration of gas tamponade does not appear to influence the closure rate.
Table 3. Comparison of gas tamponade
Is prone posturing necessary?
No issue in macular hole surgery has aroused as much controversy as this one. In the early days, prone positioning was universally thought to be mandatory and many retinal surgeons still believe it provides a more effective tamponade of the hole.
However, basic physics dictates that the pressure must be equal at any point on the surface of a bubble, which suggests that provided the gas is in full contact with the macula, the position of the eye is irrelevant (Figure 12).
Figure 12. Diagram showing equal pressure effect of a gas
bubble on the macula in the prone and upright positions
Given that most holes close quickly after surgery, prone positioning is theoretically unnecessary and this has been confirmed by several studies23-28 reporting closure rates of greater than 90 per cent without it (Table 4).
Table 4. Effect of posturing on macular hole closure
Based on these principles and reported results, the principal author's technique consists of the following steps:
- Fine gauge (25 g) three port pars plana vitrectomy.
- Detachment of posterior vitreous face from surface of retina using vitrectomy cutter.
- ILM peeling after staining with Trypan Blue or Brilliant Blue G.
- Internal fluid: air exchange with soft-tipped cannula on linear aspiration.
- Replacement of air with 25 per cent SF6 in most cases; C3F8 (15 per cent) is reserved for chronic or larger (> 400 µm) holes.
Patients are instructed to posture upright by day and to sleep on either side at night, not supine. Since the Australian and New Zealand Audit of Surgical Intervention for Macular Hole (a database of the results of surgery in which all Australian and NZ retinal surgeons are invited to enrol) was established in November 2008, the principal author has contributed 53 cases in which the above technique was used.
The closure rate is 98 per cent, which compares favourably with the success rate in published series in which the patients were postured prone. The single case in which the hole did not close after SF6 tamponade then did so following a regassing procedure with C3F8, but still no face-down positioning (Figures 13A, 13B, 13C).
Figure 13A. OCT scan preoperative
Figure 13B. OCT scan preoperative, SF6 used
Figure 13C. OCT scan postoperative, C3F8 used
Figure 13. Successful closure of stage 3 macular hole with C3F8 after initial failure using SF6
Idiopathic macular holes generally affect older patients and are the result of an abnormality in the common ageing process of vitreomacular separation. Surgical repair has become a possibility in the modern vitreoretinal era and has an extremely high success rate. The technique involves pars plana vitrectomy, ILM peeling and gas tamponade.
The majority of macular holes close within a day or two of surgery, so that in most cases a short-acting gas tamponade is adequate and there is clear evidence that face-down positioning is an unnecessary ordeal for patients in the postoperative period.
- Gass JD. Idiopathic senile macular hole. Its early stages and pathogenesis. Arch Ophthalmol 1988; 106: 5: 629-639.
- Gass JD. Reappraisal of biomicroscopic classification of stages of development of a macular hole. Am J Ophthalmol 1995; 119: 6: 752-759.
- Rahmani B, Tielsch JM, Katz J et al. The cause-specific prevalence of visual impairment in an urban population: The Baltimore Eye Survey. Ophthalmology 1996; 103: 11: 1721-1726.
- Mitchell P, Smith W, Chey T et al. Prevalence and associations of epiretinal membranes: The Blue Mountains Eye Study, Australia. Ophthalmology 1997; 104: 6: 1033-1040.
- Wang S, Xu L, Jonas JB. Prevalence of full-thickness macular holes in urban and rural adult Chinese: the Beijing Eye Study. Am J Ophthalmol 2006; 141: 3: 589-591.
- Sen P, Bhargava A, Vijaya L et al. Prevalence of idiopathic macular hole in adult rural and urban south Indian population. Clin Experiment Ophthalmol 2008; 36: 257-260.
- McCannel CA, Ensminger JL, Diehl NN et al. Population based incidence of macular holes. Ophthalmology 2009; 116: 7: 1366-1369.
- Kelly NE, Wendel RT. Vitreous surgery for idiopathic macular holes. Results of a pilot study. Arch Ophthalmol 1991; 109: 5: 654-659.
- Park DW, Sipperley JO, Sneed SR, et al. Macular hole surgery with internal-limiting membrane peeling and intravitreous air. Ophthalmology 1999; 106: 7: 1392-1397.
- Eckardt C, Eckert T, Eckardt U et al. Macular hole surgery with air tamponade and optical coherence tomography-based duration of face-down positioning. Retina 2008; 28: 8: 1087-1096.
- Gesser C, Eckert T, Eckardt U et al. Macular hole surgery with air tamponade. Does air suffice for short-term tamponade? Ophthalmol 2010; 107: 11: 1043-1050.
- Sano M, Inoue M, Taniuchi S et al. Ability to determine postoperative status of macular hole in gas-filled eyes by spectral-domain optical coherence tomography. Clin Experiment Ophthalmol 2011; 39: 9: 885-892.
- Goto K, Mizukawa K, Kiryu J. Factors affecting imaging of spectral-domain optical coherence tomography in gas-filled eyes after macular-hole surgery. Jpn J Ophthalmol 2012; 56: 3: 236-244.
- Yamashita T, Yamashita T, Kawano H et al. Early imaging of macular hole closure: a diagnostic technique and its quality for gas-filled eyes with spectral domain optical coherence tomography. Ophthalmologica 2013; 229: 1: 43-49.
- Brooks HL Jr. Macular hole surgery with and without internal limiting membrane peeling. Ophthalmology 2000; 107; 10: 1939-1948; discussion 1948-1949.
- Tadayoni R, Gaudric A, Haouchine B et al. Relationship between macular hole size and the potential benefit of internal limiting membrane peeling. Br J Ophthalmol 2006; 90: 10: 1239-1241.
- Tognetto D, Grandin R, Sanguinetti G et al. Internal limiting membrane removal during macular hole surgery: results of a multicenter retrospective study. Ophthalmology 2006; 113: 8: 1401-1410.
- Christensen UC, Krøyer K, Sander B et al. Value of internal limiting membrane peeling in surgery for idiopathic macular hole stage 2 and 3: a randomised clinical trial. Br J Ophthalmol 2009; 93: 8: 1005-1015.
- Lois N, Burr J, Norrie J , Full-thickness Macular Hole and Internal Limiting Membrane Peeling Study (FILMS) Group. Internal limiting membrane peeling versus no peeling for idiopathic full-thickness macular hole: a pragmatic randomized controlled trial. Invest Ophthalmol Vis Sci 2011; 52: 3: 1586-1592.
- Kim SS, Smiddy WE, Feuer WJ et al. Outcomes of sulfur hexafluoride (SF6) versus perfluoropropane (C3F8) gas tamponade for macular hole surgery. Retina 2008; 28: 10: 1408-1415.
- Rahman R, Madgula I, Khan K. Outcomes of sulfur hexafluoride (SF6) versus perfluoroethane (C2F6) gas tamponade for non-posturing macular-hole surgery. Br J Ophthalmol 2012; 96: 2: 185-188.
- Jackson TL, Donachie PH, Sparrow JM et al. United Kingdom National Ophthalmology Database study of vitreoretinal surgery: Report 2, macular hole. Ophthalmology 2013; 120: 3: 629-634.
- Yagi F, Sato Y, Takagi S et al. Idiopathic macular hole vitrectomy without postoperative face-down positioning. Jpn J Ophthalmol 2009; 53: 3: 215-218.
- Heath G, Rahman R. Combined 23-gauge, sutureless transconjunctival vitrectomy with phacoemulsification without face down posturing for the repair of idiopathic macular holes. Eye (Lond) 2010; 24; 2: 214-220.
- Tadayoni R, Vicaut E, Devin F et al. A randomized controlled trial of alleviated positioning after small macular hole surgery. Ophthalmol 2011; 118: 1: 150-155.
- Yagi F, Takagi S, Tomita G. Combined idiopathic macular hole vitrectomy with phacoemulsification without face-down positioning. J Ophthalmol 2012; 2012: 571748.
- Forsaa VA, Raeder S, Hashemi LT et al. Short-term postoperative non-supine positioning versus strict face-down positioning in macular hole surgery. Acta Ophthalmol 2013; 91: 6; 547-551.
- Iezzi R, Kapoor KG. No face-down positioning and broad internal limiting membrane peeling in the surgical repair of idiopathicmacular holes. Ophthalmology 2013 Jul 24.