後極部後嚢下混濁から進展した後円錐水晶体の1家系

Posterior subcapsular lens opacity initiated posterior lenticonus in siblings

　後極部後嚢下混濁より初発し，後円錐水晶体へ進展した兄弟2例3眼を報告した。兄弟と母親がアトピー素因を有していた。アトピー性後嚢下混濁により脆弱となった後嚢が，調節の結果として，後方に突出し，後円錐水晶体を形成したものと考えた。治療としては，経毛様体扁平部水晶体摘出術（pars plana lensectomy, PPL）の2ポート法が術中合併症への対応の容易さからみて最適であると考えた。

A 7-year-old male child presented with posterior subcapsular opacity of the lens in both eyes. Spon-taneous posterior lenticonus developed in the right eye 3 weeks later and in the left eye 11 months later. Pars plana lensectomy was effective for both eyes. He had a history of bronchial asthma and atopic dermatitis.

His younger brother manifested posterior subcap-sular opacity of the lens in both eyes when examined at the age of 5 years. Spontaneous poste-rior lenticonus developed in the right eye 15 months later. The condition was treated by pars plana lensectomy. He and his mother had a history of bronchial asthma.

Posterior subcapsular lens opacity seemed to be causatively related with the atopic factors in the two cases. Fragile posterior lens capsule and addi-tional accommodative efforts would have initiated posterior lenticonus.