Cataract as ‘initial symptom’ of Creutzfeld–Jacob disease
2012-01-23

Editor, A 76-year-old man was referred to cataract surgery complaining of problems in reading and a foggy vision for several months. Best-corrected visual acuity (BCVA) was 20/25 in both eyes. Slit lamp examinations revealed moderate cataracts in both eyes and were otherwise unremarkable. There were no hints for neurological or cognitive impairment. Uncomplicated phacoemulsification was performed on the right eye 1 week later. First postoperative day BCVA (OD) was 20/40 (Table 1), which was ascribed to descemet’s folds and anterior chamber inflammatory reaction. However, 4 days after surgery, BCVA remained at 20/40 (OD) although the descemet folds and the inflammatory reaction had disappeared. There were no signs of macular oedema. A few days later, BCVA continued to decrease from 20/50 to 20/63. A profound loss of vision of the left eye was also observed (20/100). The patient developed problems in reading optotypes. Visual field testing was performed but was inconclusive owing to bad compliance. Apart from that, the patient appeared frustrated and somehow helpless compared to his pleasant and optimistic mood noted at previous visits. The patient was referred to a neurologist with the suspicion of an occipital stroke or another neurological disorder. However, no neurological abnormalities could be detected. When the patient returned a week later, his vision had further decreased and he had clear signs of visual agnosia. Furthermore, the patient now seemed to have developed moderate ataxia and gait problems. In addition, mini-mental state examination was consistent with moderate cognitive impairment. A neuroophthalmologist suspected Creutzfeld–Jacob disease (CJD) as the underlying problem. Lumbar puncture was performed, and results were consistent with sporadic CJD (H-Tau >1500 pg/ml, 181p-Tau was 50 pg/ml, ß-Amyloid 1–42 was 960 pg/ml, test for protein 14-3-3 was positive). The patient developed myocloni, progressive dementia, pyramidal and extrapyramidal dysfunctions. Fifty-two days after the cataract surgery and 26 days after the first onset of non-visual symptoms, the patient died. The patient presented with visual symptoms that seemed to be consistent with the nuclear cataracts. However, in retrospective, the decreased vision was most likely the first symptom of CJD, and thus, cataract surgery represented an unnecessary procedure in this case. Distant visual acuity was surprisingly good. As the amount of nuclear sclerosis was already quite pronounced, we initially failed to take a more detailed history and to test near visual acuity or signs of alexia and agnosia. It turned out later that the patient referred himself to an ophthalmologist because he was ‘afraid of getting blind’. Further questioning and testing the patient during the preoperative visit may have helped to differentiate the assumed cataractogenous visual loss from the underlying neuropsychiatric problem. Creutzfeld–Jacob disease is a neurodegenerative human disorder and belongs to the group of spongiform encephalopathies. The disease remains incurable to date and invariably fatal. In most cases, the first symptoms of CJD consist of rapidly progressive dementia, leading to memory loss, personality changes and hallucinations accompanied by physical changes such as speech impairment, myoclonus, balance and coordination dysfunction (ataxia), changes in gait, rigid posture, and seizures. The duration of the disease varies greatly, but sCJD can be fatal within months or even weeks (Ladogana et al. 2005; WHO November 2002). However, for a small subset of patients with CJD, the first symptoms may be purely visual impairment. A disease course of CJD with the leading signs of a visual disorder has been referred to as the (Heidenhein 1992). The Heidenhain variant can manifest in different ways: disturbed perception of structures/colours, problems in reading, optical hallucinations, cortical blindness and optical agnosia (Anton Syndrome) (Kropp et al. 1999). Visual disturbances misleadingly ascribed to coexisting cataracts might be the leading symptom in patients with CJD.