P he importance of gonioscopy in diagnosis and management is emphasised.

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Australian and New Zealand Journal of Ophthalmology 1987; 15: 83-87 PERSISTENT SYMPTOMS AFTER PERIPHERAL IRIDECTOMY FOR ANGLE-CLOSURE GLAUCOMA RONALD F. LOWE MD Melbourne.

1 Australian and New Zealand Journal of Ophthalmology 1987; 15: PERSISTENT SYMPTOMS AFTER PERIPHERAL IRIDECTOMY FOR ANGLE-CLOSURE GLAUCOMA RONALD F. LOWE MD Melbourne. Australia Abstract Symptoms that persist after o erations for angle-closure glaucoma arise from different causes. In the presence of open peripheral iriddect0mie.s miotics may be beneficial or may close angles; wide pupil dilatation by phenylephrine used to diminish posterior synechiae may close angles; cycloplegic m driatics will close some angles and open others. Unexpected bizarre reactions to eye drops may occur. bersistent chronic laucoma will be more common after laser iridotomy than after correctly assessed filtering operations. P he importance of gonioscopy in diagnosis and management is emphasised. Key words: Angle-closure glaucoma, peripheral iridectomy, iridotomy, miotics, mydriatics, plateau iris. PAIN AND HALOES After surgery for angle-closure glaucoma some patients say that the eye still aches. The aches are usually mild but may be severe enough to need home analgesics for relief. The ache, like intermittent angle-closure glaucoma, tends to occur when the person is tired or upset, and is relieved by rest. Activities which caused the preoperative distress, such as television viewing, reading or entertaining may continue to be avoided. Gonioscopy shows the iris relaxed and the angle well open, the tension records are normal and the outflow of the aqueous is free. What is the cause of this pain? Is it a persistence of the unknown mechanism which triggered the previous attacks of intermittent angle-closure glaucoma in eyes now rendered innocuous by peripheral iridectomy? Is it merely a sensitivity of the ocular tissue to operative trauma? Some people continue to see haloes after an apparently successful operation. Careful questioning is likely to reveal that the haloes are seen around naked lights whenever the person looks for them, and having seen them with the previous glaucoma they become alarmed. Care is required because the complaint of eye aches and haloes may indicate further glaucoma, as will be explained later, or they may be harmless and lead to an unnecessary filtering operation. Case Report 1 Mrs VW, aged 55 years, had six months of attacks of intermittent angletlosure glaucoma in the right eye, described as pain around the eye, blurred vision and haloes around lights. She then had a sudden attack of right acute angleclosure glaucoma lasting 24 hours before treatment leading to bilateral peripheral iridectomies. After operation she continued to describe pain in her left previously nonglaucomatous eye, and haloes around lights. Ocular tension was normal, and gonioscopy showed an open angle with perhaps some peripheral anterior synechiae. Six months later she had left iridencliesis after which tensions were good, and the angle was wide open, but she still complained of aches in the eye and seeing haloes - lens sclerosis. On the other hand, postoperative blurred vision, haloes and pain may indicate persisting Reprint requests: Dr Ronald Lowe, 82 Collins Street, Melbourne, Victoria 3000, Australia. PERSISTENT SYMPTOMS AFTER PERIPHERAL IRIDECTOMY FOR ANGLE-CLOSURE GLAUCOMA 83

glaucoma as will be described in some of the subsequent cases. PUPIL DILATATION GLAUCOMA: PLATEAU IRIS Peripheral iridectomy does not always cure angle-closure glaucoma.

2 glaucoma as will be described in some of the subsequent cases. PUPIL DILATATION GLAUCOMA: PLATEAU IRIS Peripheral iridectomy does not always cure angle-closure glaucoma. It prevents the ballooning of the iris dependent on pupil block, but some patients have recurrent angle closure due to a different mechanism. These eyes have usually, but not necessarily, obviously shallow anterior chambers and in those cases the plateau iris is not revealed until the iris flattens after peripheral iridectomy or iridotomy. The iris need not have a true plateau shape at the periphery, but will be close to the trabeculae, so that when the pupil dilates the iris folds concentrically into the angle despite an open iridectomy. Plateau iris seldom causes trouble after peripheral iridectomy or iridotomy, but glaucomatous symptoms may occur especially with reading or working in dark rooms.2 Case Report 2 Mrs RR came to Australia speaking little English, so only a vague history was obtained although she complained of pain around her left eye. Homatropine and cocaine drops were ordered for refraction, then retinoscopy gave a dull reflex due to corneal oedema. Ocular tensions were right 60 mmhg, left 100 mmhg. Intensive miotics gave a good response, then gonioscopy showed very narrow open angles with ballooned irides. Uneventful peripheral iridectomy was performed on each eye. Recurrent pains continued despite tensions of right 18, left 19; but pupil dilatation with homatropine and cocaine gave tensions of right 47, left 51. Gonioscopy then showed iris folded against the trabecular walls with widely open peripheral iridectomies. Pilocarpine eye drops were prescribed night and morning giving relief of symptoms ( the drops are marvellous ). Miosis was preventing angle closure. Another danger from plateau iris is wide pupil dilatation after peripheral iridectomy performed in order to diminish posterior synechiae formation. With repeated instillation of mydriatics some of these angles will close completely and intraocular pressures (IOPs) in the upper 30s to 50s may occur within an hour or two. Unless the angle closure is relieved it may become permanent and resist late treatment. The risk of this wide pupil dilatation is often not realised. Pupils should not be dilated fully after iridectomy, but if this occurs, tensions should be checked and pupils constricted. Case Report 3 A Causasian woman aged 69 years reported with right acute angle-closure glaucoma, but the angle opened and the tension fell to 6 mmhg with intensive medical treatment. After peripheral iridectomy the pupil dilated readily with 10% phenylephrine, convalescence was uneventful, and after four days the patient was discharged from hospital to continue the use of phenylephrine eye drops once a day. Five days later she telephoned to say the vision in her right eye was blurred. After another two days she returned to hospital because of a painful right eye. The right cornea was oedematous, the pupil dilated, and the IOP was 50. After intensive treatment with acetazolamide the IOP fell to 10 and the cornea cleared, but the angle was closed all around despite a large open peripheral iridectomy. Further intensive applications of physostigmine caused constriction of the pupil, but the angle remained closed. The anterior chamber depth was 1.76 mm, similar to that before operation. The physostigmine drops were replaced by pilocarpine 4% and acetazolamide tablets were continued, but the IOP rose to 33. Adrenaline base eye drops were added night and morning. She instilled the drops that evening and next morning her vision was blurred. After instillation of further adrenaline drops it became worse. On return to hospital her cornea was cloudy with an IOP of 60. Gonioscopy showed the angle to be totally closed except for the open peripheral iridectomy. Subsequently her IOP was controlled at 17 with 6% pilocarpine four times a day, 3% carbachol three times a day and one 500 mg acetazolamide capsule once a day. (Timolol had not arrived.) Her visual acuity was 6/5 and the visual field was normal. This case demonstrates the severely unfavourable effect from phenylephrine and adrenaline eye drops despite an open peripheral iridectomy, but the beneficial effects from miotics. However, phenylephrine is less likely to cause postoperative angle clo~ure~.~ than the tropine alkaloids such as homatropine and cy~lopentolate.~ BENEFITS FROM CYCLOPLEGIC MYDRIATICS Cyclopegic mydriatics are likely to close angles by iris folding against the trabeculae, but on the other hand, they may widen angles. This may occur by two mechanisms: (i) cycloplegia which leads to tightening of the zonules and retraction of the lens which leads to deepening of the anterior chamber, or (ii) as well as the iris dilator 84 AUSTRALIAN AND NEW ZEALAND JOURNAL OF OPHTHALMOLOGY

contracting around the pupil and causing mydriasis, the periphery of the iris is sometimes pulled towards a null line central to the iris root thus widening the angle.

3 contracting around the pupil and causing mydriasis, the periphery of the iris is sometimes pulled towards a null line central to the iris root thus widening the angle. This mechanism is best seen after peripheral iridectomy when iris convexity is not present. ANGLE CLOSURE WITH MIOTICS Acute glaucoma caused by the instillation of miotics, with an intact iris, has been known since soon after their introduction a little over 100 years ago. Very much later, this adverse reaction was explained by pupil block from the posteriorly directed force of the contracting sphincter pupillae against a forwards position of the anterior lens surface. In other cases with or without a peripheral iridectomy, Levene observed, after the instillation of pilocarpine, a marked shallowing of the anterior chamber resulting in angle closure despite the production of miosis. Relief of angle closure occurred after the administration of cycloplegic mydriatics due to posterior displacement of the lens: He considered such actions to be a form of malignant glaucoma.6 Case Report 4 Mrs YG, at the age of 31, had left acute glaucoma in England. Presumably this did not respond satisfactorily because she had a corneo-scleral trephine which led to intractable malignant glaucoma. She was prescribed 1% pilocarpine eye drops prophylactically for her right eye and remained symptom-free until 16 years later when, while using the pilocarpine, she developed episodes of acute angle-closure glaucdma. Between attacks her anterior chamber angle was open, although some peripheral anterior synechiae were present. Following an uneventful sealed peripheral iridectomy her 1OP rose to 28 mmhg. Pilocarpine 2% drops, four times daily, was prescribed. She returned in two weeks stating that when she used the drops, a blue streak appeared across her right vision, and that her vision was clear when she stopped the drops. Her IOP measured 33 and the angle was closed all around with the peripheral iridectomy remaining open. (This was peculiar considering she had used pilocarpine, though in a less concentrated preparation, for 16 years previously.) When the pilocarpine was stopped her IOP fell to only 30, but her angle was open, and her IOP fell to 17 with 1% adrenaline base drops. Unfortunately, within a year her IOP was again 30 with an open angle. Ecothiopate iodide was instilled, but the angle closed all around. She could only tolerate 125 mg (half a tablet) of acetazolamide twice daily, but with that and the adrenaline her 1OP fell to 17 and her angle remained open. Three years later, on a trial of stopping the acetazolamide, the tension rose to 25. Two years later the strength of the adrenaline eye drops was reduced from 1% to 0.5%, and over the next five years were able to be stopped without a rise of IOP. With only 125 mg of acetazolamide twice daily her IOP has remained at 15, but it rose to 25 with a trial of stopping. In this way her IOP has remained well controlled for 16 years. Lately her IOP has been as low as 8 mmhg with the relatively small dose of acetazolamide, but it rose to 24 without it. A trial of timolol would be of no benefit to her and would be difficult for her to use, as she is now aged 73 and will soon need cataract extraction. SUMMARY OF CASES These glaucomas show the prolonged care and persistence that is sometimes required after peripheral iridectomy, and the necessity to meet the bizarre and sometimes unexpected actions of any postoperative medical therapy. SEVERE POSTOPERATIVE REACTIONS Uveitis. I have seen two patients who had disastrous reactions after surgery for treatment and prophylaxis. The uveitis was so severe as to resemble the worst cases of sympathetic ophthalmia except that the onset was within a few days of surgery and each eye appeared to react individually. Severe pain accompanied ciliary injection, heavy aqueous flare and keratitic precipitates. The iris stuck to the lens, exudate blocked the peripheral iridectomy (though it did not spread across the iridencleisis), the iris totally occluded the angle with strong adhesions and the IOP was high. Despite full anti-inflammatory treatment, including corticosteroids, one patient lost all vision; the other needed removal of one eye for intractable pain and was left with very poor vision in the remaining eye. Malignant Glaucoma From 427 filtering operations for angle-closure glaucoma, three (0.7%) developed malignant glaucoma. From 465 peripheral iridectomies following angle-closure glaucoma only one (0.2%) developed malignant glaucoma, but from PERSISTENT SYMPTOMS AFTER PERIPHERAL IRIDECTOMY FOR ANGLE-CLOSURE GLAUCOMA 85

4 372 prophylactic peripheral iridectomies where no previous glaucoma occurred, none developed malignant glaucoma. These statistics show that there is a small risk of malignant glaucoma from operations on eyes with present or previous angle-closure glaucoma, but so far this complication has not been reported with prophylactic iridectomy on eyes free from any glaucoma. FAILED IRIDECTOMY OR IRIDOTOMY The iridectomy may fail, first because it is incomplete: only the anterior stroma has been removed leaving intact posterior pigment epithelium. This may be perforated by a knife-needle or laser. Second, the iridectomy may fail because the pillars of the iridectomy are incarcerated in the incision so they are drawn across the opening of the iris. Laser iridotomy may fail because (i) the laser is insufficiently powerful to penetrate the iris; or (ii) the iridotomy may heal over if it is small - this may occur soon after the iridotomy or weeks later. If the iridotomy is incomplete, especially after numerous applications of the laser, the inflammation caused can precipitate very destructive acute angle-closure glaucoma. Further, the patient may delay reporting, thinking that the reaction is only the direct result of the laser and that it will settle down. Case Report 5 Mrs MM, aged 77, had an uneventful right intracapsular cataract extraction and one week later developed left acute angleclosure glaucoma. She was treated medically, the angle opened and she was sent home to continue 4% pilocarpine drops four times a day. Corrected left vision was 6/9. After a month she had another mild attack of left angle-closure glaucoma which was readily controlled. Three months later left laser iridotomy was attempted with an early model argon laser. The periphery of the anterior chamber deepened markedly. Afterwards she had some discomfort which was considered to be a mild uveitis; this subsided with 1070 prednisolone drops. If an iridotomy had been achieved, it healed and four weeks later the process was repeated. Again the peripheral anterior chamber deepened, but this time the reaction was more severe and she developed severe left acute angle-closure glaucoma. Even with intensive medical treatment the angle remained firmly closed and the IOP was 37 to 40 mmhg. Surgery was performed - trabeculectomy with rectangular scleral flap. As the preoperative IOP was 40, just over 1 ml of fluid vitreous was aspirated through the pars plana, and after the trabeculectomy, air was injected into the anterior chamber. Despite a favourable IOP and a large filtering bleb, the iris remained stuck to the peripheral cornea, corneal oedema ensued, and an infected ulcer developed and resisted treatment, so that finally the eye was eviscerated. CHRONIC GLAUCOMA AFTER PERIPHERAL IRIDOTOMY Until recently, for those cases of acute angleclosure glaucoma where the angle did not open adequately with medical therapy, many surgeons preferred to do an initial filtering operation to achieve optimum control of the IOP; but since the introduction of powerful lasers, an iridotomy tends to be preferred for all cases of angle-closure glaucoma. A significant number of these will be left with a post-laser raised IOP. These will need to be controlled by appropriate medications provided there is an awareness of possible bizarre reactions. Those with severe outflow obstruction will need filtering surgery. The opening should be placed more forwards than usual to ensure entry into the anterior chamber and to avoid the intrusion of vitreous into the wound when the peripheral iridectomy is performed. The three major conditions falling into this group are: (i) chronic angle closure, where the peripheral iris which was stuck to the trabeculae has not retracted sufficiently when the pressure was lowered; (ii) creeping angle-closure glaucoma, where the peripheral anterior synechiae have formed silently in the angle before the acute attack, thus causing a raised base pressure which may be accompanied by optic disc cupping and visual field defects; and (iii) associated chronic simple glaucoma - the uncommon mixed glaucoma. A quiet obstruction of the angle is more likely to occur in Asiatics or Blacks than in Caucasians, with an acute attack of angle-closure glaucoma occurring after considerable damage to the angle. CONCLUSIONS Peripheral iridectomy brought an immense benefit to the treatment of angle-closure 86 AUSTRALIAN AND NEW ZEALAND JOURNAL OF OPHTHALMOLOGY

5 glaucoma, but with the advent of laser iridotomy some surgeons appear to think that the problems are completely solved. While this is often so, nevertheless continued postoperative care may sometimes test the ingenuity and dedication of the ophthalmologist concerned. Further, all the situations described emphasise the importance of gonioscopy in diagnosis and management. The cases described were selected from a number referred in difficulty to the Glaucoma Unit of The Royal Victorian Eye and Ear Hospital. References 1. Higgitt A, Smith R. Reading test in glaucoma. Br J Ophthalmol 1955; 39: Wand M, Grant WM, Simmons RJ, Hutchinson BT. Plateau iris syndrome. Trans Am Acad Ophthalmol Otolaryngol 1977; 83: Lowe RF. Primarv anele closure elaucoma. PostoDerative acute glaucoma Hfte; phenylephine eye drops: Am J Ophthalmol 1968; 65: Lowe RF. Primary angle closure glaucoma. Postoperative tests with ten per cent phenylephrine eye drops. Am J Ophthalmol 1965; 60: Lowe RF. Primary angle closure glaucoma. Investigations after surgery for pupil block. Am J Ophthalmol 1964; 52: Levene R. A new concept of malignant glaucoma. Arch Ophthalmol 1972; 87: Lowe RF. Malignant glaucoma related to primary an le closure glaucoma. Aust J Ophthalmol 1979; 7: 11-1i. CHLORSIG Eye Drops-Eye Ointment Abridged product data. Full information is available on request and should be consulted before prescribing. Composition Drops: ChloramphenicolO.5% in asterile base vehicle which includes hypromellose. Ointment: Chloramphenicol 1% in a sterile oculentum base. Indication Topical antibiotic treatment of susceptible ocular bacterial infections. Contraindications Allergy to Chloramphenicol, or other product components. Precautions Prolonged or frequent treatment should be avoided. On rare occasions blood dyscrasias have been reported following topical ophthalmic chloramphenicol treatment. Administration Drops: Usually one or two drops in the affected eyes every 2 to 6 hours. Continue therapy for 48 hours after the eyes appear normal. Ointment: Apply at bedtime. Use of ointments during the day may blur vision. Presentation Drops IOmL, Ointment 4g NHS Drops IOmL, and 2 repeats. Ointment 4g tube. Sigma Pharmaceuticals Ply Ltd a m ny incorporatedm Vctoria (-) 1408~ntreRoad.Clayton.Victorid 3168 ms*iwlm~mraw, PERSISTENT SYMPTOMS AFTER PERIPHERAL IRIDECTOMY FOR ANGLE-CLOSURE GLAUCOMA 87

PRIMARY ANGLE-CLOSURE GLAUCOMA*t A REVIEW OF PROVOCATIVE TESTS

Brit. J. Ophthal. (1967) 51, 727 PRIMARY ANGLE-CLOSURE GLAUCOMA*t A REVIEW OF PROVOCATIVE TESTS BY RONALD F. LOWE From The Glaucoma Unit of The Royal Victorian Eye and Ear Hospital, Melbourne, and The