Br J Ophthalmol: first published as 10.1136/bjo.57.4.274 on 1 April 1973. Downloaded from

Brit. j. Ophthal. (I973) 57, 274 Choroidopathy produced by pressure on the by synthetic buckling material

ALY MORTADA Department of Ophthalmology, Faculty of Medicine, Cairo University, Egypt

The pressure of the synthetic buckling material used in surgery may produce uveal vascular engorgement followed by mild uveopathy, and the choroidopathy so formed aids in sealing the retinal tear. The effect of scleral buckling by synthetic material on the uveal tract has been studied by the observation of human and by experiments on rabbit eyes.

(A) Human eyes (i) A silastic encircling 3-mm. band tightened at the equator of the (Schepens, Okamura, and Brockhurst, I957) will indent the sclera (without affecting the retinal circulation or causing ) and produce a grey circle of chorio-retinal reaction which in time becomes a white circle surrounded by pigmentation. (2) A localized silicone rod 5 mm. in diameter and 2 to 3 cm. long may be pressed on to the sclera

(Custodis, I952) to push the against the edges of the retinal tear and relieve vitreous traction; http://bjo.bmj.com/ this seals the retinal tear even if some of the diathermy or cryotherapy applications are not visible in the during the operation or postoperatively. Fine mottling and pigmentation are seen all over the area under pressure about 20 days after the operation. In about I0 per cent. of cases excessive dense yellow retino-choroidopathy of the buckled area, unrelated in degree to the intensity of the treatment usually applied, may be seen from 7 to 24 days after the operation. The dense retino-choroidopathy resolves in a month leaving a retino-choroidal scar. In 5 per cent. of cases,

however, severe exudative choroidopathy of the buckled area occurs, and this re-opens the retinal on October 1, 2021 by guest. Protected copyright. tear with recurrence of the detachment. (3) If a very sensitive choroid is treated with either a band or a rod, the pressure of the synthetic implant may produce very severe choroidopathy with increased subretinal fluid, retinal or choroidal punctate haemorrhages, macular lesions, or vitreous haze that may obscure the view of the fundus. (4) When either the band or the rod is used, the ocular tension immediately after the operation rises to about 20 to 30 mm. Hg (Schi6tz) above the normal preoperative level (usually 5 to 10 mm. Hg), but this does rnot affect the retinal circulation (arterial or venous), press on the two long pos- terior ciliary , produce glaucoma, or cause severe pressure on the vitreous or loss of corneal transparency. At the first dressing, 24 hours after the operation, the ocular tension will be found to have returned to the preoperative level. In subsequent days, because of the mild uveopathy in- duced by the scleral indentation, the ocular tension will fall to 5 mm. Hg (Schiotz) or below. After I or 2 months, with resolution of the uveal vascular engorgement, the ocular tension gradually rises to the normal level. (5) A few minutes after the sclera is compressed by the band or rod, the compressed area becomes bluish-red because of the dilation of the underlying choroidal vessels.

Received for publication January 2i, 1972 Address for reprints: Prof. A. Mortada, i8A 26th July Street, Cairo, Egypt Br J Ophthalmol: first published as 10.1136/bjo.57.4.274 on 1 April 1973. Downloaded from Choroidopathy produced by pressure on the sclera by synthetic buckling material 275

(B) Experimental studies on rabbit eyes Fig. i shows the and