PRESENTATION OF RETINOBLASTOMA AS PHTHISIS BULBI

Purpose: We sought to determine the incidence of retinoblastoma patien ts who presented with phthisis bulbi. Methods: The medical records of 272 patients in the King Khaled Eye Specialist Hospital Retinoblastoma Registry were retrospectively studied. Clinical records, radiological investigations and histopathological slides were reviewed, Results: W e found that 2.7% of patients had retinoblastoma coincident with phthi sis bulbi, Five of 10 patients had bilateral retinoblastoma; in the ot hers it was unilateral. Radiologically, intraocular calcification was present in all except one case. All enucleated phthisical globes had r esidual viable tumour cells; optic nerve extension was found in 2 pati ents who had longstanding phthisis bulbi, Conclusion: Phthisis bulbi i s an uncommon presenting sign of retinoblastoma which often occurs aft er an ocular inflammatory episode possibly related to intraocular tumo ur infarction. In most cases the tumour is not visible because of intr aocular disruption. That every enucleated eye in this series harboured well-differentiated tumour cells underlies the seriousness with which phthisis bulbi of unknown origin in children should be investigated f or retinoblastoma.