Br J Ophthalmol: first published as 10.1136/bjo.61.8.517 on 1 August 1977. Downloaded from British Journal of Ophthalmology, 1977, 61, 517-524 Dilating dangerous pupils R. MAPSTONE From St. Paul's Eye Hospital, Liverpool SUMMARY Altogether 85 eyes from patients at risk to the development of closed-angle glaucoma were dilated with either parasympatholytic or sympathomimetic drugs. Of 21 eyes dilated with cyclopentolate i %, 9 developed angle closure and a significantly raised pressure at some stage during dilatation and subsequent miosis. Of 58 eyes dilated with tropicamide 1 %, 19 developed angle closure and a significantly raised pressure during dilatation. Treatment with intravenous acetazolamide and pilocarpine rapidly returned pressure to normal levels. Six eyes that had previously had a positive provocative test with simultaneous pilocarpine and phenylephrine were safely dilated with phenylephrine alone. Subsequent miosis with pilocarpine produced closed-angle glaucoma in all eyes. The significance of these observations is explained and discussed, and it is suggested that high- risk eyes should never be dilated with cyclopentolate. Tropicamide is safe if elementary precautions are observed. Safest of all, however, is phenylephrine-induced mydriasis and subsequent miosis with thymoxamine drops I %. copyright. Pupillary dilatation is potentially dangerous, since a Material and methods variable proportion of eyes at risk to closed-angle glaucoma develop a rise in pressure of 8 mmHg or (1) Twenty-one eyes at risk to the development of more. A much smaller percentage of narrow-angle closed-angle glaucoma (because the contralateral eyes with no relevant history will respond similarly. eye had had an episode of acute closed-angle Given a particular eye with a narrow angle, how can glaucoma) were on no treatment. All had been the dangers be minimised if the pupil must be previously provoked with simultaneous pilocarpine dilated? and phenylephrine, and 17 had positive provocative http://bjo.bmj.com/ Gonioscopy is of no help, since it gives a sub- tests (that is, a pressure increase of greater than jective assessment of grades of narrowness. While it 8 mmHg). is intuitively obvious that the narrower the angle the They were reprovoked as follows: At zero hours greater is the probability of closure, there is no an anterior segment photograph was taken, intra- published evidence to show that angle appearance is ocular pressure measured, and one drop of cyclo- a reliable indicator of future behaviour on dilatation. pentolate I % instilled. Thereafter at approximately The that can most be known before dilating a 1-hourly intervals pressure was recorded and an on September 25, 2021 by guest. Protected particular pupil is that there exists a certain anterior segment photograph taken. If after 2 hours probability that that eye will develop closed-angle had elapsed pressure had not increased significantly, glaucoma. Anyone who dilates pupils therefore is pilocarpine drops 2 % were instilled at approximately taking a chance. 1-hourly intervals for at least 3 hours, up to a Given this situation, the clinician has two options. maximum of 6. As soon as intraocular pressure Firstly, he can accept that a risk is present, explain began to increase significantly pilocarpine 2% was it, measure it, and devise a scheme for treating the instilled and, after a variable period, intravenous eye that develops closed-angle glaucoma so that any acetazolomide 500 mg too. Thereafter the test was possible damage is,reduced to a minimum. Secondly, continued until pressure was normal or until it was he can refuse to accept the risk and devise a method decided to do a peripheral iridectomy with pressures whereby any pupil can be safely dilated. Both recorded and anterior segment photographs taken options are explored in this paper. at approximately 1-hourly intervals. Subsequently, slides were projected and P/C ratios (P = pupillary, Address for reprints: Mr R. Mapstone, St. Paul's Eye C = corneal diameters) calculated in the horizontal Hospital, Old Hall Street, Liverpool L3 9PF meridian. 517 Br J Ophthalmol: first published as 10.1136/bjo.61.8.517 on 1 August 1977. Downloaded from 518 R. Mapstone C r-Pilocarpine 2cfo C IVA+ P + + 0.8 0b .2 0-6 °U04 A u 0-4 02 0-2 a0I 0I * .. 40I 18 r 301- lb E I -± 20 I E 14 ° 10- CL 0 12 01 0 2 3 4 5 6 10 Hours 0 Fig. 2 Response of4 eyes to dilatation with 0 2 3 4 5 8 cyclopentolate drops I %, a significant pressure increase Hours occurred within i hour-as the pupil moved up to Fig. 1 Response of 12 eyes to dilatation with mid-dilatation. C = cyclopentolate, IVA = intravenous cyclopentolate drops i %, no significant increase in acetazolamide, P = pilocarpine. Mean and standard error pressure developed. C = cyclopentolate, P/C ratio recorded pupillary and corneal diameters in horizontal meridian. Mean and standard error recorded pilocarpine drops 2 % were instilled. As soon as pressure had increased significantly intravenous (2) eyes from 49 with either Fifty-eight patients acetazolamide 500 mg, pilocarpine drops 2 %, and copyright. primary closed-angle glaucoma in the contralateral thymoxamine drops jI% were instilled. The test was eye (40) or intermittent closed-angle glaucoma in continued until pressures had returned to normal one or both eyes (9) had provocative tests with levels. pilocarpine and phenylephrine; 70% were positive. At a later date they were provoked as follows: At Results zero hours an anterior segment photograph was taken and tropicamide drops i% were instilled. At 21 EYES DILATED WITH CYCLOPENTOLATE approximately '-hourly intervals thereafter pressure Twelve eyes developed no significant increase in http://bjo.bmj.com/ was recorded and an anterior segment photograph pressure measured over an 8-hour period. Fig. I taken. If after 2 hours intraocular pressure had not records the results and shows that repeated doses of increased, pilocarpine 2% was instilled and the test pilocarpine 2% had little effect on pupil diameter. terminated. In eyes that developed a significant rise All 12 were seen 24 hours later, and none had in pressure intravenous acetazolamide 500 mg and developed a significant rise in pressure. pilocarpine drops 2 % x 1 were instilled; pressure Nine eyes developed a significant increase in recordings and anterior were segment photographs pressure but there were three distinct patterns of on September 25, 2021 by guest. Protected taken until pressure was back to normal levels. response: (3) Six eyes from 6 patients with closed-angle (a) In 4 eyes (Fig. 2) pressure had increased glaucoma in the contralateral eye had positive significantly after 36 minutes (from a mean of 19-3 provocative tests with simultaneous pilocarpine and to a mean of 30 5 mmHg); 1 hours from the start phenylephrine. Subsequently they were dilated with intravenous acetazolamide and pilocarpine were phenylephrine, and the pupil was returned to miosis given, but even after 51 hours the mean pressure was by the instillation of thymoxamine drops A% still 25-3 mmHg. In addition pupil diameter was without the development of a significant pressure little affected. increase (see Mapstone, 1974b4)- The same 6 eyes (b) In 2 eyes the pupil moved rapidly up to wide were then provoked as follows: At zero hours dilatation and there remained for 3 hours with no pressure was recorded, an anterior segment photo- change in pressure. As the pupil moved down to graph taken, and phenylephrine drops 10% were mid-dilatation pressure increased significantly. An instilled. One hour later this-was repeated. Two example is shown in Fig. 3. hours after the start of the test-- h anterior segment (c) In 3 eyes the pattern of response was a photograph was taken, pressure recorded, and combination of a and b. As the pupil moved up to Br J Ophthalmol: first published as 10.1136/bjo.61.8.517 on 1 August 1977. Downloaded from Dilating dangerous pupils 519 C P P P IVA t P T Outflow 019- 031 002 08 1 C o + Pilocarpine IVA+P Z 0-6 1 / 0-- a- 0.]04j/ 0._ 0-2- I 0 0-2 0O - 50 40 E E 30 - a- 0 2 3 4 5 6 O 20 - Hours Fig. 3 Response of I eye to dilatation with l1i cyclopentolate drops a % As the pupil moved to wide - dilatation no significant change in pressure occurred. 0 2 3 4 5 6 7 8 After 4 hours as the pupil moved down to mid-dilatation Hours pressure increased. C = cyclopentolate, P = pilocarpine, Fig. 5 Response of I eye to dilatation with T thymoxamine, IVA = intravenous acetazolamide cyclopentolate drops i % (see text) C P P P P IVAP +T Female age 56, no symptoms, but her mother had closed-angle glaucoma. Provocative tests in this copyright. 06 T I T T 1 patient with pilocarpine and phenylephrine were negative but with tropicamide positive (see Mapstone, 1976b). She was reprovoked with cyclopentolate, .02 - with the result shown in Fig. 5. As the pupil moved 01 up to wide dilatation outflow fell from 0 19 to 0 07; 21 hours later pressure was 14 mmHg and the corneal 401 diameter had increased to 0-31. However, 5! hours http://bjo.bmj.com/ 30-I after the start of the test the corneal diameter had E decreased to 0-02 and pressure increased to 42 mmHg. E 20120I 10 58 EYES DILATED WITH TROPICAMIDE If11 Thirty-nine eyes developed no significant increase in pressure measured over a 2-hour period (Fig. 6). 0 2 3 4 5 6 The instillation of pilocarpine 2% at this point Hours produced a fall in pupil diameter over the next hour. on September 25, 2021 by guest. Protected Fig. 4 Response of 3 eyes to dilatation with Nineteen eyes developed a significant increase in cyclopentolate drops i %.