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Sir,

Gas tamponade with face-down posturing has been regarded as a crucial step in the success of macular hole surgery. Most surgeons using long-acting gases recommend face-down posturing for 45–50 min of each hour for 10–15 days. However, posturing is tiring and demanding for patients and is not without its ill effects.

We present the case report of a professional part-time singer who developed bilateral ulnar nerve palsies as a result of face-down posturing after macular hole surgery.

Case report

A 75-year-old man was referred to the eye casualty department by his GP with a 3-month history of distortion of the central field of vision in the left eye. Best corrected visual acuities were 6/12 OD and 6/36 OS. The right eye was amblyopic. Anterior segment examination was normal. Fundus examination revealed a Grade IV macular hole in the left eye with a positive Watzke Allen sign. A vitrectomy with 16% C3F8 under general anaesthetic was performed. Despite an uneventful surgery and good compliance with the postoperative posturing regimen, the VA failed to improve beyond 6/36.

He attended a follow-up appointment at the orthopaedic clinic for a routine 12-month assessment after a total hip replacement, which had been performed for osteoarthritis. On examination an incidental finding of bilateral ulnar nerve palsies was discovered. There was obvious wasting and weakness of the interrossei, a positive Froment's sign bilaterally, hypoaesthesia along the ulnar border of both hands, and a classical ulnar claw hand deformity worse on the right hand (Figure 1a and b). The patient reported that the onset of the sensory disturbance coincided with his recuperation from ophthalmic surgery. On close questioning, it was found that he was resting his forehead on the dorsal aspects of his wrists with elbows held in approximately 100° flexion.

Figure 1
figure 1

(a) Ulnar claw hand with flexion deformity of the ring and little fingers. (b) Muscle wasting of the first web space (first dorsal interrosseus and adductor pollicis muscles)

Full size image

Nerve conduction studies confirmed bilateral ulnar neuropathy at the elbow with reduced conduction velocities.

An appointment to see the occupational therapist was arranged and static splints were provided for the right hand to prevent further progression. The most recent outpatient review 10 months postophthalmic surgery showed minimal recovery.

Discussion

Face-down posturing is not always possible, especially in the presence of other concurrent systemic illnesses, and alternative techniques have been described to avoid the need for posturing.1 A number of studies have been carried out to explore the success rate of other means which can tamponade the retina and preclude the need for postoperative posturing. Silicone oil has been used with fairly good results.1,2,3 Goldbaum and co-workers, in their multicentre retrospective pilot study performed with silicone oil tamponade and no posturing, showed high seal rates and visual acuities in stage II, III, and IV macular holes, were comparable to the results of the macular hole study group.3,4 However, silicone oil tamponade has the obvious disadvantage of requiring a second procedure for its removal. Kumar et al2 have reported good anatomic results but guarded visual outcomes. However, their study involved a small sample with only stage III and IV macular holes.

Tornambe et al5 reported a pilot study using C3F8 in 33 eyes with stage II, III, and IV macular holes. None of the patients was positioned face down, but all phakic eyes had a cataract extraction with an implant at the time of macular hole surgery. The results showed successful macular hole closure and this technique was suitable for phakic patients who cannot maintain prone positioning.5 Promising results have been shown by Simcock et al,6 with combined surgery as it facilitates the use of a large gas bubble and also precludes the need for posturing and additional cataract surgery that may reopen macular holes. With the exception of a few studies, the results have been found to be fairly similar in terms of final visual acuity as obtained by conventional procedures after vigilant postoperative posturing.

However, posturing still constitutes an important factor in achieving success after macular hole surgery as the floatation force of the gas bubble is greatest at its apex, and face-down positioning with a large bubble results in a greater floatation force on the macular hole than an upright position. A longer duration of intraocular gas tamponade has been found to correlate with a higher rate of macular hole closure.7 This is thought to enhance the tamponading effect of the gas bubble and allow Muller cell processes and glial cells to form a stable plug within the hole.8

It is best to carefully select patients who would be suitable candidates for posturing. The ulnar nerve is vulnerable to compression neuropathy at the elbow as the nerve runs behind the elbow in the condylar groove between the Olecranon and the medial epicondyle of the humerus. Flexion of the elbow narrows the cubital groove by tightening the roof and causing bulging of its floor.

To date, as there are no specific guidelines, a word of caution about avoiding any undue pressure on elbows and signs of warning about any imminent ulnar nerve damage should be given as a take-home message after macular hole surgery. In particular, adopting an attitude with elbow flexion of more than 90° would appear to be contraindicated.