Association between prolonged dietary vitamin D deficiency and autonomous hyperparathyroidism

In my hospital epidurals are available virtually on demand and are encouraged for instrumental deliveries. It is interesting that only a quarter of the 1000 women delivered each year have chosen to avail themselves of this facility. E-pidurals are ideal for complicated cases, but I would not recommend them as a first choice for analgesia in labour when safer and simpler methods exist.

parent or unspecified in the ophthalmologist's notes. The table shows that the false positive referral rate was high and challenges the adage that "if the parents suspect a squint then assume one until proved otherwise." When patients were referred Children under 5 vears old referred to community, eve clinics in Barnslev, I May-31 July 1989

B A REAY Ilkl ttiirc, 1'crthslil-c I'll 14 9RQ

Squint

Rcvnolds F. Epidural aniaesthesia in obstctrics. Br AMed 7 1989;299:751-2., 23 Scptemilbcr.

Doctor Health visitor Patient Not specified

Provision of hearing aids SIR,-Messrs Carl Watson and John A Crowther concluded that the service for providing hearing aids should continue to be based in hospitals.' 'lThough we admire the evident efficiency of the Glasgow ear, nose, and throat outpatient service, simply to state that the main cause of delay in providing hearing aids is that of patients in seeking advice seems to miss a central point of the proposals of the Royal National Institute for the Deaf.' It is apparent from the study of Messrs Watson and ('rowther and from a similar retrospective study performed in three London ear, nose, and throat departments that most patients who require hearing aids would not be disadvantaged by the provision of hearing aids in the community. Such a process would not only allow hearing aids to become more readily available but also result in more time being available in ear, nose, and throat outpatient clinics for patients likely to benefit from hospital care. We agree with the doubts expressed by Messrs Watson and Crowther about the proposed training of communitv based technicians and those dispensing hearing aids. One or two days' supplementary training will not be sufficient to equip them to cope with the types of problems that may present. We have suggested that familv doctors who wish to dispense hearing aids should have had a period of ear, nose, and throat training that would allow them to be entered on to a list somewhat analogous to the obstetric list. P PRINSLEY G J MADDEN

t) J PREMACHANt)RA ENT I)cpartncnuts, Roval Frc and Barilaet (icieeral Hospitals.

Watson C, Crowther J. Provision of hliearing aids: )ocs specialist assessinent Cause delav? BrAft(d 7 1989;299:437-9. 12 Anigist. 2 Roval NaIt'lional InstiltC for the D)cat. Hearing aids-ilt ast, flor Change. 1(ttdoil: RNII), 1988. 1 . l)ispettsitg ictritlg 3 Prinislcv P, Pretnaclthandra )J, M\addctn aids ilillie connillttios 1 amPU 1 1989;59ii 50)- 1

Vision screening SIR,-Vision screening in children, at what ages and by whom, continues to be debated. Recent reports have shown the effectiveness of orthoptists screening all children at the age of 31/½ (or earlier if a visual defect is suspected).' Dr Ann Johnson and colleagues have shown the effectiveness of health visitors screening high risk populations to detect vision and ocular defects.' I recently reviewed the referrals to our community eye clinics, by whom the referral was made, and the outcome of the referral. From 1 May to 31 July 1989, of the 150 children under the age of 5 referred to the community eye clinics in Barnsley, 107 were referred because of suspected squint and 43 because of suspected decreased visual acuity. The person who suspected the defect was given as a doctor, health visitor, or

BMJ

VOLUME

299

14

OCTOBER

No (,O)) No Refcrred by! refe'rrcd positive

1989

2 31 5() 24

0 2 (7) 9 (18) 3 (13)

Decrcased visual acuity No rcferrcd

No%) positiVe

1 25 18 6

1(100) 13 (52) 11 73 5 (84)

by doctors or health visitors the tests used before referral were the cover test for suspected squints and Sheridan-Gardiner type for decreased visual acuity. The recognised experts in the use of these test are orthoptists, and when used to screen children in the community, community orthoptists have been shown to have a false positive referral rate of only 4 7%Yo.' I concur with the published evidence2 that community orthoptists are the best agents to screen for visual defects in children. Those of us who have contact with children should ensure we are proficient in performing the cover test, and orthoptic departments are usually very willing to teach these skills. CHARLES ESSEX New Street Hcalth Centre, Barnslc\ S7() IL' I Beardsell R. ()rthoptic visual scrccning at ttirec anld a half years. B Ortzoptj7 19X9;46:7. 2 Edwards R. Ortltoptists as pre-school scrccrnrs. B Ortltopt 7 1989;46: 14. 3 Johnisoni A, Staytc M1, Wortham C. Vision scrcening at X aitd 1X

moniths. BrMlcd7 1989;299:545-9. (26 Algttst.

Effect of hysterectomy on bowel function SIR,-I would like to put in perspective comments in the letters regarding the paper by Dr T Taylor and colleagues on the effects of hysterectomy on bowel function.' Firstly, Dr R C Henshaw' and Mr S L Stanton' state that there is no evidence that urinary function is compromised by simple hysterectomy. This is not true. Both authors quote the prospective symptomatic study by Jequier.' Although in this analysis there was no overall difference in the incidence of urinary symptoms before and after hysterectomy, one quarter of the women who were asymptomatic before operation developed vesicourethral dysfunction postoperatively. A further prospective study recently published that used objective urodynamic and neurophysiological techniques as well as subjective assessment showed conclusively that simple hysterectomy is associated with a significant incidence of lower urinary tract dysfunction after operation. Secondly, Dr Henshaw states that after simple hysterectomy there is little risk of damage to the vesicourethral innervation,) but there is evidence to the contrary.' Although neuropathy may not be the only contributory factor, it is no doubt important, for 73% of women with urinary dysfunction after hysterectomy had abnormal pelvic nerve function. Classically, suggestions that a surgical procedure may be associated with certain complications have come initially from retrospective analyses, and conclusive evidence has come from prospective studies. Therefore the study reported by Dr Taylor and colleagues rather than being dismissed for its deficiencies should be regarded as

valuable in that it alerts the medical profession to a hitherto unrecognised possible complication of simple hysterectomy that merits full and proper investigation before a final conclusion can be made. B T PARYS

l)epartment of Urology, Royal Liverpool Hospital, Liverpool 17 5XPl I lavlor T', Smith AN, 1ulton PM1. Effect of h\sterectomy on bowel fu'Llction. Br lied]7 199;299:300- 1. (29 July. 2 Hcnshaw RC. Ef'fcct of' hstcrcctom\y oni bowel f'uniiction. BrMeMdj 1989;299:680. (9 Septeinbcr.) 3 Staniton St. Effect ot' hNsterectomr oil bowel fnLnction. B3rlfed] 1989;299:680. (9 Septetber. 4 Jcquier AM. Urinary symptoms and total hysterectomy. 3rJ L'rol 1976;48:437-41. 5 Parvs BT, Havlen BT, Woolfenden KA, Parsons KF. \'esicoturethral dcsfunction af'ter sitple hysterectomy. Neurourology and Urodyttamics 1989;8:315-6.

Prolonged vitamin D deficiency and autonomous hyperparathyroidism SIR,-Dr V A Fonseca and colleagues highlight the problem of differentiating between primary hyperparathyroidism masked by nutritional osteomalacia on the one hand and tertiary hyperparathyroidism following prolonged nutritional osteomalacia on the other.' Because of the shortage of space, we were unable to include all the information we would have wished in our paper, but we have follow up data on serum parathyroid hormone in our second patient. She has had five measurements of this hormone in the 21/2 years following her parathyroidectomy all above the upper limit of normal (0 50 [tg/1). The range was 0 53-1 00 ptg/l (mean 0 68). During this time she had persistent hypercalcaemia. These findings suggest hyperplasia of the residual parathyroid glands (which might be expected in tertiary hyperparathyroidism after parathyroidectomy) or a second parathyroid adenoma. A second parathyroid gland removed at the time of operation was histologically normal, however, and weighed 60 mg, making the latter explanation more likely. A H SULTAN F E BRUCKNER J B EASTWOOD St (ieorge's Hospital, London SW17 OQT

'Thomas M, Giil D)S, Dandona 1' I'rolonged vitamitt D) deficiency and auitonomous hyperparathyroidism. BrAMed7 1989;299:626. ,2 September.) 2 Suiltan AH, Bruckner FE, Eastwood JB. Associationi between prolonged dietary vitamin D deficiency anid atutollomous h\pecrparathyroidism. Br Mled7 1989;299:236-7. (22 Jttly.) I Fonscca VA,

Treatment of benign prostatic hyperplasia SIR,-I had always naively assumed that replacing the standard open operation by the endoscopic procedure had been based on carefully controlled experience and that very careful cost benefit analyses had been made and had shown unequivocally the advantage of the endoscopic approach. I now find to my dismay that this has never been the case and that a retrospective comparison of a large series has shown an excess risk of reoperation and an excess risk of mortality from unanticipated causes in the group treated by the transurethral method. I am, therefore, rather disappointed by Professor G D Chisholm's response' to Dr Klim McPherson's letter: he implies that ethical committees and patients will not allow a formal evaluation of the new technology to be made. I wonder if patients are

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