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Brit. J. Ophthal. (I975) 59, 205 Br J Ophthalmol: first published as 10.1136/bjo.59.4.205 on 1 April 1975. Downloaded from

Miotics in closed-angle

F. GANIAS AND R. MAPSTONE St. Paul's Eye Hospital, Liverpool

The initial treatment of acute primary closed-angle Table i Dosage in Groups I, 2, and 3 glaucoma (CAG) is directed towards lowering (IOP) to normal levels as Group Case no. Duration IOP Time rapidly as possible. To this end, aqueous inflow is (days) (mm. Hg) (hrs) reduced by a drug such as (Diamox), and aqueous outflow is increased via the trabecular I I 2 8 5 meshwork by opening the closed angle with miotics. 3 7 21 3 The use of miotics is of respectable lineage and hal- 5 '4 48 7 lowed by usage, but regimes vary from "intensive" 7 8 I4 5 9 I0 I8 6 (i.e. frequent) to "occasional" (i.e. infrequent) instilla- I I 2 12 6 tions. Finally, osmotic agents are used after a variable '3 5 20 6 interval of time if the IOP remains raised. Tlle pur- I5 '4 I8 6 pose of this paper is to investigate the value of '7 '4 i6 6 miotics in the initial treatment of CAG. I9 6 02 2

2 2 8 2I 5 Material and methods 4 20t 20 6 Twenty patients with acute primary closed-angle glau- 6 I i8 5 http://bjo.bmj.com/ coma were treated, alternately, in one of two ways 8 4 i8 5 detailed below: I0 6 I8 6 I2 I0 20 6 (I) Intravenous Diamox 500 mg. stat, plus gutt. Pilo- '4 21 10 5 carpine 2 per cent. every minute for 5 min., every 5 i6 I0 i8 5 min. for I5 min., every I5 min. for i hr, and thereafter i8 3 10 3 6-hrly. 20 I5 hrs 48* 7 (2) Intravenous Diamox 500 mg. stat, plus one drop on September 29, 2021 by guest. Protected copyright. 2 per cent. repeated after I hr and 3 21 2 I2 5 thereafter 6-hrly. 22 3 i6 4 The next ten patients with CAG were treated as follows: 23 2 10 3 24 28 20 6 (3) Intravenous Diamox 500 mg. stat, then 3 hrs later 25 4 21 5 500 mg. Diamox orally and one drop Pilocarpine 26 4 20 4 2 per cent. 27 2 hrs 40t 7 28 7 4 6 If after 7 hrs IOP was greater than 2I mm. Hg, the 29 5 hrs 22 6 treatment was considered a failure. 30 21 20 6

Results * Intravenous Diamox was repeated at I0 hrs and IOP The results for each of the three treatment groups was I2 mm. Hg. are given in the Table. Duration equals the interval t Oral Diamox was inadvertantly omitted at 3 hrs between onset of symptoms and presentation at hospital. IOP refers to either the first recorded Groups I and 2 each had one failure; the failure normal pressure at the time stated after starting in Group 2 had a normal IOP after I0 hrs. Group treatment, or to the raised pressure at 7 hrs. 3 had one failure, in whom the oral Diamox was omitted at 3 hrs. In this case the pressure was sub- Address for reprints: F. Ganias, M.D., Worcester Eye Associates Inc., 340 Main Street, Worcester, Mass. 01608, U.S.A. sequently controlled with further intravenous Diamox. D 206 British oumrnal of Br J Ophthalmol: first published as 10.1136/bjo.59.4.205 on 1 April 1975. Downloaded from

Discussion Are there any advantages in abandoning an intensive The results indicate that no significant difference Pilocarpine regime? It is probable that: exists between the three methods of treatment. The (I) The incidence of variable degrees of Pilocarpine constant feature in each group was intravenous toxicity (Greco and Kelman, 1973; Epstein Diamox; the variable was the frequency of Pilo- and Kaufman, I965) is reduced to zero. carpine instillation. It is therefore a necessary con- (2) In the presence of a mid-dilated and sequence that multiple doses of Pilocarpine are normally functioning , Pilocarpine can unnecessary for the treatment of acute CAG. precipitate an acute angle closure (Mapstone, This conclusion is predictable from theoretical I 974). While there is no evidence ofits occurrence considerations alone. Established CAG is character- in any patient described here, it could-theoretic- ized by sphincter ischaemia and variable ciliary ally-pievent the medical termination of an body function. It is illogical to suppose that an atonic acute attack. sphincter can be goaded into activity by a para- . Again, con- (3) A few litres ofPilocarpine will be saved annually. traction will not produce an increase in aqueous It is therefore concluded that one of drop of outflow since the angle is closed. What is necessary Pilocarpine 3 to 4 hours after intravenous Diamox is is a lowering of aqueous production by an already all that is necessary in the initial treatment of acute ischaemic ciliary body using a carbonic anhydrase primary CAG. inhibitor. Why therefore give Pilocarpine at all? There would appear to be no logical reason for its use in the early treatment of an acute attack. However, Summary once the IOP has been reduced to a lower level The use of intravenous Diamox with variable doses by Diamox, it seems reasonable to suppose that the of Pilocarpine was investigated in the treatment return of sphincter muscle activity--at least in of primary closed-angle glaucoma. It was concluded part-and the ensuing , will open a closed that one drop of Pilocarpine 3 to 4 hrs after intra- angle. This means, in eflect, that Pilocarpine instil- venous Diamox is the only parasympathomimetic lation should be delayed for about 3 to 4 hrs. drug necessary to terminate an acute attack.

References http://bjo.bmj.com/ EPSTEIN, E., and KAUFMAN, I. (I965) Amer J. Ophthal., 59, 109 GRECO, J. j., and KELMAN, C. D. (I973) Ann. Ophthal., 5, 57 MAPSTONE, R. (I974) Brit. J. Ophthal., 58, 46 on September 29, 2021 by guest. Protected copyright.