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Editor,—In a recent issue of theBJO, we had the opportunity to read the interesting case report on pupillary abnormality, by Malla.1 The author reported a gross persistent pupillary membrane (PPM) in both eyes of a 33 year old Nepalese female. The patient was asymptomatic and near as well as distant visual acuity were normal. Although the author mentioned that the membrane bulged forward into the anterior chamber when the pupil constricted to light, it was not clear if the patient noticed any decrease in vision with bright sunlight and if the author attempted to record the visual acuity in simulated conditions (by shining the light of an indirect ophthalmoscope into the eye at an angle of 45º or after instillation of 2% pilocarpine eye drops).
We have recently reported a case of persistent pupillary membrane in both eyes of an 8 year old male child.2 The brownish membranes were detected by a school teacher. The child confirmed the presence of poor vision in bright sunlight after a precise questionnaire concerning this symptom. The visual acuity in our case under ordinary room illumination was 20/40 in both eyes. Nevertheless, when measured while the light of the indirect ophthalmoscope was shone into his eyes at an angle of 45°, visual acuity was surprisingly reduced to 20/100 in both eyes. Similarly, Kumar et al 3 also reported two cases (aged 15 and 17 years) of hyperplastic pupillary membrane presenting with marked decrease of visual acuity in bright sunlight. In the latter case, these authors recorded a reduction in visual acuity from 20/40 to 20/200 after instillation of pilocarpine eye drops or projecting the indirect ophthalmoscope light at a 30° angle.
It is widely accepted that asymptomatic cases of PPM usually don't require excision beyond the sensitive period of amblyopia.4 Nevertheless, some cases presenting with significant visual loss in bright sunlight required surgical2 or Nd:YAG laser3 intervention. Besides visual acuity concerns, cosmetic ocular disfigurement caused by PPM may also be considered as a reason for intervention in some patients.
Editor,—I have just reviewed the patient with the bilateral persistent pupillary membrane. Visual acuity both for distance and near remained unchanged (6/6 partly and N5 in each eye) with pupils constricted by shining the light of an indirect ophthalmoscope at an angle of 45°. The patient has no visual complaints and is unaware of any decrease in vision in bright light.