866 



NATURE 



[IJLC 



»5. »92, 



The Treatment of Disease by Artificial Light. 



|)II()T()THKRAI*Y, or the treatment of disease by 

 i li^lit, wjis first prominently brought to the notice 

 of the medijul profession by the work of Finsen in 

 1895, Jl^' demonstrated that the rays of the visible 

 spectrum, and also those invisible radiations which we 

 call ultra-violet rays, have varyinj,' therapeutic (jualities. 

 He showed that the exclusion of the ultra-violet rays 

 from the skin of patients suffering from smallpox cut 

 short the secondary fever characteristic of this disease, 

 and diminished the suppurative stage, and, thereby, 

 shortened the duration of the illness and lessened the 

 risk of ugly scarring. On the other hand, he proved 

 that the local application of concentrated actinic light 

 had a powerful mfluence on certain affections of the 

 skin, particularly on the common type of cutaneous 

 tulwrculosis known as lupus vulgaris. Before his 

 death he had already appreciated the value of a more 

 general application of light, namely, the exposure of 

 the whole body to radiation. 



In his earlier experiments with concentrated light, 

 Finsen used the sun ; and a simple apparatus consist- 

 ing of a large hollow lens containing a blue solution 

 was the means by which the actinic rays of light were 

 brought to a focus upon the skin. Even with a blue 

 medium used as a filter it was found necessary to 

 interpose a cooling apparatus at the focus of the lens. 

 This apparatus consisted of a small circular chamber 

 with quartz faces through which a current of cold 

 water constantly circulated. In addition to its value 

 as a method of preventing excessive heating of the 

 part, this apparatus was also used as a compressor to 

 render the area under treatment bloodless, as it had 

 been found by experiment that the actinic rays 

 penetrated a blanched skin, whereas in that through 

 which the blood was circulating the red colouring 

 matter of the blood prevented the passage of the blue 

 and ultra-violet rays. In Denmark, as in other 

 countries in northern latitudes, the' number of days on 

 which the sun could l)e utilised was so limited that 

 Finsen soon abandoned the sun as an illuminant and 

 substituted powerful electric arc lights. 



Following on Finsen 's discover\% a number of workers 

 in this field devised other forms of illuminant, and 

 several lamps of high actinic power became available. 



It is interesting at this point to consider the work of 

 Rollier at Leysin. For more than twenty years he has 

 been treating cases of tuberculosis, particularly in 

 children, by exposing the surface of the body to the 

 alpine sun, and his efforts have achieved a striking 

 success. At first it was believed that the air of the 

 high altitude was the determining factor in the admir- 

 able results obtained, but it has since been shown that 

 it is the light which is the important agent. Rollier's 

 success stimulated others in this branch of phototherapy, 

 and at the Treloar Homes at Alton and Hayling, Hants, 

 Sir Henr)^ Gauvain has shown the practical value of 

 this measure, even in this climate, in the treatment of 

 tuberculous disease of the bones, joints, and skin. 

 More recently, Reyn, in Copenhagen, has shown that 

 the carbon arc light can be used as a substitute for the 

 sun, and that the results of an electric light bath are as 

 efficient as the sun bath. 

 The treatment of disease by artificial light, therefore, 



NO. 2824, VOL. I 12] 



mil • idercd from two j>omls ol view. First tin 



lo<.. tion of the radiations to the disease*! In. . 



and second, the application of light to the whole of tiit 

 surface, which for convenience we may call the " li ! ! 

 bath," First, the local appli< ation of light to 

 area ; here we find two methods in use, one 

 the light is concentrated by means of lenses, and the 

 other in which reliance is placed on the intensitv ..f ti„. 

 actinic radiations, without concentration. 



Local Trkatment by Conxentrated Lighj. im 

 typical apparatus for treatment by concentrated 

 actinic light is the Finsen lamp, or its modification the 

 Finsen-Reyn lamp. The essentials in these are a 

 powerful carbon arc with an automatic adjustment to 

 approximate the carlwns as they bum away. The 

 light from the arc is focusscd through a series of ro< k- 

 crj'stal lenses in a tube containing distilled water. 

 The rays are focussed on an area the size of a shilling, 

 and at the focus is placed the combined compressor 

 and cooling apparatus with a cold-water circulation 

 described above. This tN^pe of apparatus is used 

 mainly in the treatment of the form of tuberculosis 

 of the skin known as lupus vulgaris. After an hour's 

 application of the concentrated rays an inflammatory 

 reaction occurs in the skin. The inflammation is so 

 acute that a blister forms which may take several 

 days to a couple of weeks to heal. It is interesting that 

 this reaction does not begin till about six hours after 

 the treatment. Repeated applications are usually 

 necessary to destroy the effects of the invasion of the 

 skin by the tubercle bacillus, but in 60 to 70 per cent, 

 a permanent cure is obtained, many of the p:ft;»nf< 

 treated having been watched for twenty year- 



In the original Finsen app>aratus the current u.->iu i> 

 70 volts and 50 amperes. It is therefore ad\asable 

 to use a transformer when the available current has 

 a high voltage, say 240 to 220. The carbons used are : 

 positive, cored, 25 mm. in diameter and 12 inches 

 long; negative, solid, 18 mm. in diameter and of the 

 same length. By this apparatus four patients can he- 

 treated simultaneously. 



In the Finsen-Re}Ti lamp the illuminant is of the 

 scissors type, the current employed being 70 volts, 

 20 amperes. The positive carbons are cored 12 mm., the 

 negative solid 10 mm. in diameter and 8 inches long. 

 These lamps can be worked from the lighting mains, 

 say of 240 volts in series, with appropriate shunts. 

 One patient only at a time is treated with each 

 Finsen-Reyn lamp. 



Local Treatment by Unconcentrated Light. — 

 The most convenient tv-pe of apparatus for the local 

 treatment of diseased areas of the skin by uncon- 

 centrated light is that devised by Kromayer. It 

 consists of a u -shaped envelope of rock cr\-stal contain- 

 ing mercur>' vafK)ur. This is surrounded by a second 

 envelope with a rock-crystal window. Between the 

 two envelopes, which are fitted in a metal box, cold 

 water circulates, to absorb the heat rays. The window 

 of the apparatus is pressed firmly against the area of 

 skin to be treated, the pressure being of value in render- 

 ing the skin bloodless, and thus increasing the penetra- 

 tion of the ultra-violet rays. The apparatus is fixed 

 on a mobile stand, and can be used off any ordinary 



