340 THE LANCET • Vol 354 • July 24, 1999 for a suitable period, ideally with assessment of autonomic and motor dysfunction and response to levodopa therapy, to evaluate the potential of clonidine–growth-hormone testing for making the correct diagnosis in patients with parkinsonism. *C J Mathias, J R Kimber Autonomic Unit, University Department of Clinical Neurology, National Hospital for Neurology and Neurosurgery, Institute of Neurology, University College London, London; *Neurovascular Medicine Unit, Division of Neuroscience and Psychological Medicine, St Mary’s Hospital, Imperial College School of Medicine, London W2 1NY, UK 1 Clarke CE, Ray PS, Speller JM. Failure of the clonidine growth hormone stimulation test to differentiate multiple system atrophy from early or advanced idiopathic Parkinson’s disease. Lancet 1999; 353: 1329–30. 2 Thomaides T, Chaudhuri KR, Maule S, Watson L, Marsden CD, Mathias CJ. The growth hormone response to clonidine in central and peripheral primary autonomic failure. Lancet 1992; 340: 263–66. 3 Kimber JR, Watson L, Mathias CJ. Distinction of idiopathic Parkinson’s disease from multiple system, atrophy by stimulation of growth-hormone release with clonidine. Lancet 1997; 349: 1877–81. 4 Hughes AJ, Daniel SE, Blankson S, Lees AJ. A clinicopathological study of 100 cases of Parkinson’s disease. A rch N eurol 1993; 50: 140–48. 5 Litvan I, Goetz CG, Jankovic J, et al. What is the accuracy of the clinical diagnosis of multiple system atrophy? A clinico- pathological study. A rch N eurol 1999; 54: 937–44. Transplantation of retinal pigment epithelium with or without submacular surgery has had encouraging results, but has not yet resulted in significant improvement of vision. External radiotherapy has no proven effect, although it remains to be seen what role photodynamic therapy will play in the future. On the other hand, photoreceptor transplantation, retinal-prosthesis implantation, gene therapy, anti- oxidants, and antiangiogenics are under investigation and may prove to be of some benefits. Foveal translocation surgery is currently the only potential treatment that offers gains in visual acuity to the patients with subfoveal CNV who are otherwise destined to become blind. Moving sensory retina of the fovea to a new location before permanent retinal damage occurs allows it to recover or maintain visual function over a healthier bed of retinal pigment epithelium, Bruch’s membrane, and choriocapillaris. Intervention is needed before irreversible damage to the fovea has occurred. 4 Foveal or macular translocation was first developed in the 1980s as ophthalmologists recognised the limitations of therapies for the treatment of subfoveal CNV. 4 S u r ger y was initially applied clinically by Machemer and Steinhorst in 1993. 5 The technique involves detachment of the entire retina from retinal pigment epithelium by means of trans-scleral infusion of fluid beneath the retina, mobilisation of the retina by a 360 degree peripheral retinotomy, and rotation of the macula as far as necessary around the optic nerve head to a new location away from the major subretinal pathology. The retina is reattached with silicone oil tamponade in the same manner as for repair of a giant retinal tear. 5 Since then, other surgeons have subsequently d e ve lo p e d variations on this technique. Improved instruments and refinement of techniques would improve the facility and decrease the most serious complication, proliferative vitreoretinopathy by keeping trauma to the tissues to a minimum. The combination of foveal translocation with torsional muscular surgery could prevent the other side effects, diplopia and tilted image. Metamorphopsia, recurrence of CNV, and loss of peripheral visual field are other postoperative side-effects that need to be resolved. *Osman Cekic, Masahito Ohji, Atsushi Hayashi, Takashi Fujikado, Yasuo Tano Department of Ophthalmology, Osaka Unive rs ity Me dical S cho o l, Os a ka 5 6 5 , Jap an 1 Senior K. Ageing eyes retain their mystery. L an c e t 1999; 353: 8 1 8 . 2 Ninomiya Y, Lewis JM, Hasegawa T, Tano Y. Retinotomy and foveal translocation for surgical management of subfoveal choroidal neovascular membranes. Am J O phthalm o l 1996; 122: 6 1 3 –2 1 . 3 Tsuzikawa M, T suzikawa K, Lewis JM, Tano Y. Change in retinal sensitivity due to excision of choroidal neovascularization and its influence on visual acuity outcome. R e tin a 1999; 19: 1 3 5 –4 0 . 4 Toth CA, Machemer R. Macular translocation. In: Berger JW, Fine SL, Maguire MG, eds. Age-related macular degeneration. St Louis: Mosby, 1999: 3 5 3 –6 2 . 5 Machemer R, Steinhorst UH. Retinal separation, retinotomy, and macular relocation: II. A surgical approach for age- related macular degeneration? Graefe’s A rch Clin Exp Ophthalmol 1993; 231: 6 3 5 –4 1 . Foveal translocation surge ry in age-related macular degeneration Sir—Kathryn Senior’s March 6 news feature (p 818) 1 on age-related macular degeneration (AMD) briefly touches on surgery, but focuses mainly on other types of treatment. AMD is the most important cause of severe visual loss among elderly people in the industrialised countries and most treatment methods are for the exudative form of AMD only. There are even fewer treatment options for patients with recent onset of subfoveal choroidal neovascularisation (CNV) secondary to AMD, especially when the disease is bilateral and associated with poor vision in both eyes. Photocoagulation leads to permanent loss of the central vision and a retinal pigment epithelium d efect . 2 Excision of CNV (submacular surgery) as an alternative to photocoagulation for the management of subfoveal CNV does not improve central retinal sensitivity and results in poor visual outcome in most patients. 3 Hepatitis A vaccine for secondary hepatitis A infection Sir—Luciano Sagliocca and colleagues (April 3, p 1136) 1 report a randomised trial to assess the protective efficacy of hepatitis A vaccine against secondary hepatitis A virus (HAV) infection in household contacts of people with sporadic acute HAV infection. We were surprised that the hepatitis A vaccines assessed in the cited previous trials on human beings (in Thailand and New York) and chimpanzees were attenuated live vaccines. In fact, the vaccines used were formalin-inactivated hepatitis A vaccines. 2–4 Sagliocca and colleagues conclude that “(anti-HAV vaccine) should be considered for household contacts of HAV cases rather than immuno- globulins”. We do not reach the same conclusion on the basis of the evidence presented in the report. In their trial, the option of administering immunoglobulin was not investigated, nor were data on the protective efficacy of immunoglobulins in household contacts from other studies used to substantiate any discussion on the relative efficacy of immunoglobulins compared with hepatitis A vaccine. Such a comparison can be made only if a trial is set up in which a third group of household contacts receives immunoglobulins, and the sample sizes are larger. Moreover, the investigators should have discussed in more detail the limitations of the trial. Indeed, at present the use of immunoglobulins is standard practice for postexposure prophylaxis in many countries. 5 The fact that, as the researchers state, this treatment is not common in Italy, makes it difficult to generalise results