Intracameral pilocarpine in topical phacoemulsification.

PURPOSE: To evaluate the efficacy and corneal toxicity of intracameral pilocarpine. METHOD: A randomized, control trial using contralateral eye as control was designed to evaluate the effect of intracameral pilocarpine during phacoemulsification in 30 patients. 0.13 mg/ml pilocarpine in BSS was used as an irrigating solution to remove viscoelastic agents at the end of the operation while BSS was used in the control group. The outcome measurements composed of intraoperative pre and post irrigation pupil diameter, pre and post operative endothelial cell count and corneal thickness. SETTING: Priests Hospital. RESULTS: The pre-irrigation pupil size in the pilocarpine group and the control group was 7.62 +/- 0.75 mm and 7.60 +/- 0.77 mm respectively. The post-irrigation pupil size in the pilocarpine group and the control group was 5.40 +/- 0.79 mm and 7.18 +/- 0.79 mm. There were no statistically differences in pre and post-operative endothelial cell density, central corneal thickness, and the average corneal thickness between the pilocarpine group and the control group during six months follow-up. CONCLUSION: Intracameral pilocarpine in a low concentration (0.13 mg/ml) effectively constricts the pupil without significant changes of corneal endothelium compared to the control group.

The snapped inferior rectus.

PURPOSE: To evaluate the management and possible aetiology of the snapped inferior rectus muscle in strabismus surgery. METHODS: Three patients are described whose inferior rectus muscle broke across its width some 8-10mm behind the insertion while being held on a squint hook without excessive force during strabismus surgery. The proximal part of the muscle was not found. The distal part of the snapped muscle was excised for pathological examination. Transposition of the inferior halves of the adjacent horizontal muscles to the insertion of the inferior rectus (a modified inverse-Knapp procedure) was performed in all cases. RESULTS: After the transposition surgery, one patient was orthotropic in the primary position, one patient required a prism correction to produce a range of single vision and the third patient was orthotropic after a further operation. There was good depression in one case and the other two had a limitation of depression. In all cases, horizontal movements remained intact and there were no signs of anterior segment ischaemia. CONCLUSIONS: The unique relations of the inferior rectus to the surrounding tissues may be a factor in causing the breaking of this muscle. Two of the patients were elderly and this may be a factor also. Transposition surgery is the appropriate management when the proximal part of the snapped muscle cannot be located and has satisfactory but imperfect results.

Diplopia following subcutaneous injections of botulinum A toxin for facial spasms.

PURPOSE: To study the incidence, cause, recovery time, and prevention of diplopia following subcutaneous injection of botulinum A toxin for the treatment of facial spasms. METHODS: Patients who experienced diplopia after botulinum A toxin injections had their deviations examined in detail. When the muscle that caused diplopia was identifiable, the injection closest to that muscle was omitted in the next treatment in an attempt to prevent diplopia. RESULTS: Of 250 patients receiving about 1500 sets of injections, 25 (1.7%) incidents of diplopia occurred in 10 patients. Excluding two patients who declined further treatment after having diplopia on their first botulinum A toxin treatment, seven of the remaining eight patients had multiple incidents of diplopia. The most common pattern of diplopia was "uncertain diagnosis." The most common identifiable cause of diplopia was paresis of the inferior oblique muscle. Omission of the injection into the central portion of the lower eyelids in the next treatment prevented recurrence of diplopia in only one of the four patients. No significant correlation between botulinum A toxin doses injected and times to recovery was noted. CONCLUSIONS: Diplopia following botulinum A toxin treatment is uncommon. Seven patients (3% of patients studied) had 22 episodes of diplopia (88% of episodes). When diplopia occurs, it tends to recur on reinjection, sometimes with a prolonged recovery time. This response may not be dose dependent. The extraocular muscles of some patients may be more susceptible to chemodenervation than others, or botulinum A toxin may diffuse to extraocular muscles more easily in some patients than in others.

Posterior polymorphous dystrophy and Alport syndrome.

Seventeen Thai patients from nine families with Alport syndrome underwent complete ocular examination and specular microscopy. Fourteen (82.3%) patients had ocular changes. Eleven (64.7%) had endothelial vesicles compatible with posterior polymorphous dystrophy. Four of these also had subepithelial opacities, a previously undescribed phenomenon. Other ocular changes included lenticonus and macular and midperipheral retinal flecks. A second group of 18 consecutive patients from 14 families with posterior polymorphous dystrophy detected during routine ocular examination underwent renal evaluation. Five had hematuria, four of whom had sensorineural hearing loss. Two of the four patients also had characteristic renal biopsy findings. Another had sensorineural hearing loss without hematuria, and renal biopsy showed a thin glomerular basement membrane. Posterior polymorphous dystrophy is a common but frequently overlooked finding in Alport syndrome. The frequent association of these two hereditary conditions suggests a common defect in basement membrane formation. Patients with posterior polymorphous dystrophy should be examined for renal abnormalities and hearing loss.