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Home , Anisocoria, Mydriasis

DILATATION IN THE PSEUDOEXFOLIATION SYNDROME

N.1. WATSON, S. WINDER and F. D. GREEN Aberdeen

SUMMARY MATERIALS AND METHODS

We studied the pupil dilatation of patients with One hundred and fifty-four patierits requiring pseudoexfoliation, normals, diabetics and patients diagnostic pupillary dilatation were selected and with chronic open angle to establish whether tested in the outpatient clinics between January 1989 there was a significant difference in the and October 1993. Those on any topical eye drops achieved with and . were excluded, as were those with obvious anterior segment pathology or a history of intraocular Pseudoexfoliation is a difficult condition to define, surgery. The patients with pseudoexfoliation there­ the most characteristic feature being the deposition fore did not have glaucoma. These patients were of grey-white flakes of material on the pupillary matched for age with diabetic patients and patients border of the and other anterior chamber with chronic open angle glaucoma (COAG). The structures. Other findings in pseudoexfoliation patients with glaucoma were studied at their initial include pupillary ruff defects, pigment deposition visit, prior to treatment. on the iris surface, iris sphincter transillumination For all patients studied, vertical pupillary diameter and pigment deposition in the drainage angle.! was measured (to the nearest 0.2 mm) on a series 900 Pseudoexfoliation has been implicated as an impor­ Haag-Streit with a 1 mm slit width and dim tant risk' factor for vitreous loss during illumination settings in a darkened room. One drop surgery2 and it has been suggested that poor of cyclopentolate 1 % followed 1 minute later by one dilatation is a possible cause? drop of phenylephrine 10% was administered. The Pupil dilatation has been shown, in patients with pupillary diameter was measured immediately 5, 10, 20 unilateral pseudoexfoliation, to be reduced in eyes before instillation of drops, at 15 and minutes, and at the final dilatation achieved at 60 with pseudoexfoliation compared with fellow eyes.4 minutes. has also been found in patients with unilateral glaucoma,s the glaucomatous pupil always being smaller than that in the normal eye. No study RESULTS has specifically compared pseudoexfoliation with There was no difference prior to mydriasis in the other causes of poor dilatation such as advanced pupil size of patients with pseudoexfoliation com­ 6 7 age, diabetes, dark irises, and previous intraocular pared with the other groups studied. After dilatation surgery.s the patients with pseudoexfoliation had significantly In order to establish whether there was a smaller than normals, diabetics or individuals significant difference in the mydriasis achieved with with COAG. It was also noted that the pupils of a standard drop of cyclopentolate and phenyl­ patients with COAG or diabetes dilated less well ephrine, and consequently whether the surgical than those of the control groups (Table I). complications of pseudoexfoliation syndrome can A decrease in pupil dilatation with age was noted be ascribed to poor pupillary dilatation, we initiated in the normal controls but was less obvious in the a controlled study comparing the dilatation of other groups. patients with pseudoexfoliation with that of nor­ mals, diabetics and patients suffering with chronic DISCUSSION open angle glaucoma. This small series shows a statistical difference in final Correspondence to: N. 1. Watson, Department of Ophthalmol­ ogy, Aberdeen Royal Infirmary, Aberdeen AB9 2ZB, UK. pupillary diameter in random samples of patients

Eye (1995) 9, 341-343 © 1995 Royal College of Ophthalmologists 342 N.1. WATSON ET AL.

Table I. Pupillary dilatation in patients with pseudoexfoliation syndrome, normals, diabetics and patients with chronic open angle glaucoma (COAG)

Comparison group Initial pupil size Final pupil size No. of Mean age Mean Mean patients :t: SD (years) (mm) SD (mm) SD Significance

1 Normals 30 71.4:t: 8.7 1.9 0.4 8.1 1.3 Pseudoexfoliative 1.9 0.4 5.1 0.9 «0.0001 2 Pseudoexfoliative 18 73.4:t: 7.1 1.9 0.5 5.2 0.8 COAG 2.0 0.7 6.8 0.9 «0.0001 3 Pseudoexfoliative 18 62.4:t: 15.5 2 0.4 5.0 1.0 Diabetics 2 0.6 6.3 1.1 «0.0001 4 Normals 20 70.6:t: 11.0 1.9 0.5 7.8 1.3 COAG 2 0.7 6.8 0.9 «0.0001 5 Normals 12 68.3 :t: 10.3 2.1 0.6 8.2 1.0 Diabetics 1.9 0.3 6.6 1.4 «0.0001 with and without pseudoexfoliation when dilated deposits than in fellow eyes.4 This implies that it is with cyclopentolate and phenylephrine, and also a the presence of the pseudoexfoliative material and difference between patients with pseudoexfoliation not other aspects of the syndrome which cause the compared with diabetics and patients with eOAG. poor dilatation. The problems in inducing mydriasis The smaller size of pupils in patients with eOAG may be (Fig. 1): has been previously reported.s As pseudoexfoliation 1. Stiffening of the iris. Pseudoexfoliative material is associated with glaucoma it could be suggested that can be demonstrated by microscopy to be a similar mechanism causes the small pupil in present in the anterior border layer and crypts of the patients with pseudoexfoliation or glaucoma. The 1O iris. The three-dimensional honeycomb structure of pupillary dilatation problem, however, was more pseudoexfoliative material on the iris basement pronounced in the pseudoexfoliation group (none of membrane and bridging the iris crypts results in a whom had overt glaucoma). rigid iris. Deeper deposition has also been reported, Diabetic patients are reported to respond poorly particularly along the blood vessels. to mydriatics,6 but we have shown that this is less 2. Posterior synechiae. Pseudoexfoliation fibres often pronounced than in patients with pseudoexfoliation. effect an extensive union between the iris pigment Increasing the pupillary dilatation, for example, from epithelium and the pre-equatorial periphery. 5.5 mm to 7 mm results in an almost 60% greater These synechiae correspond to iris transillumination pupillary area. This may be why patients with defects at the sphincter. Fragments of the lrtS pseudoexfoliation have an increased incidence of pigment layer can also be observed bound to the surgical complications, as has been reported else­ anterior lens capsule. where. Other suggestions for causes of surgical difficulties in these patients include the presence of Poor pupillary dilatation is also part of the peripheral anterior synechiae, a zonular dehiscence pseudoexfoliation syndrome and must be accounted or a thin lens capsule. for when considering risk factors for surgery in these Pseudoexfoliation syndrome involves more than patients. simple material deposition, abnormalities occurring ! Key words: Cyc!opentolate, Mydriasis, Phenylephrine, Pseudo­ in the lens, pupillary ruff iris and . Even exfoliation syndrome. though the classic deposits are seen unilaterally the deposits may be bilateral on histological examina­ 9 tion. It has been shown that pupil dilatation is poorer in eyes with obvious pseudoexfoliative REFERENCES 1. Prince AM, Ritch R. Clinical signs of the pseudoexfo­ Pseudoexfoliative material on the posterior surface and infiltrating the iris liation syndrome. 1986;93:803-7. 2. Ruprecht KW, Hoh G, Guggenmoos-Holzman T, Naumann GOH. Pseudoexfoliations-Syndrom: Klin­ isch-statistische Untersuchungen. Klin Monatsbl Augenheilkd 1985;187:9-13. 3. Zetterstrom C, Olivestedt G, Lundvall A. Exfoliation syndrome and extracapsular cataract extraction with implantation of posterior chamber lens. Acta Ophthal­ mol (Copenh) 1992;70:85-9. 4. Carpel EF. Pupillary dilatation in eyes with pseudoex­ foliation syndrome. Am J OphthalmoI1988;105:692-4. Adhesion between the "stiff' iris and the lens capsule 5. Hahnenberger R. Anisocoria in untreated unilateral Fig. 1. The factors in the pseudoexfoliation syndrome that open angle glaucoma. Acta Ophthalmol (Copenh) may cause problems in inducing mydriasis. 1984;62:135-41. PUPIL DILATATION IN PSEUDOEXFOLIATION 343

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