Complex visual hallucinations in the visually impaired: a structured history-taking approach.

OBJECTIVE: To study complex visual hallucinations in visually impaired individuals. METHODS: A prospective comparative study involving structured history taking and cognitive assessment in 48 consecutive visually impaired individuals with best-corrected visual acuity of 20/200 or worse and an age-matched cohort of 48 consecutive patients with visual acuity of 20/40 or better in at least 1 eye. RESULTS: Thirty visually impaired subjects (63%) experienced hallucinations, unrelated to specific ocular pathology. None volunteered the symptom; 2 admitted hallucinations on nonleading questioning and 28 on direct questioning. All displayed insight into the unreality of their hallucinations, although 18 (60%) achieved this after initial deception. Seventeen (57%) expressed concern; 7 (23%) experienced disturbing images. Nineteen (63%) feared being labeled as insane were they to admit to hallucinations, while 10 (33%) were fearful of impending insanity. Sixteen (94%) of 17 concerned patients derived comfort from sympathetic reassurance that their hallucinations did not represent sinister pathology. In contrast, none of the individuals with normal vision experienced any hallucinations (P<.001). Cognition was intact in all groups. CONCLUSIONS: Complex visual hallucinations with insight commonly occur in visually impaired, cognitively intact individuals due to acquired visual impairment and are unrelated to chronological age. Hallucinatory experiences are almost invariably admitted to only on direct questioning, due to fears of being considered insane. Although generally pleasant, hallucinations may cause distress, because of content or implications of the hallucinatory activity. Sympathetic explanation affords significant emotional relief.

Complex visual hallucinations in the visually impaired: the Charles Bonnet Syndrome.

Visually impaired patients may experience complex visual hallucinations, a condition known as the Charles Bonnet Syndrome. Patients usually possess insight into the unreality of their visual experiences, which are commonly pleasant but may sometimes cause distress. The hallucinations consist of well-defined, organized, and clear images over which the subject has little control. It is believed that they represent release phenomena due to de-afferentation of the visual association areas of the cerebral cortex, leading to a form of phantom vision. Cognitive defects, social isolation, and sensory deprivation have also been implicated in the etiology of this condition. This condition, which is most common in the elderly, frequently goes unrecognized in clinical practice, due to both lack of awareness among doctors and patients' reluctance to admit to hallucinatory experiences, for fear of being labeled mentally unstable. Furthermore, patients who comprehend the unreality of their hallucinations may be distressed by the real fear of imminent insanity. Sensitive and sympathetic history taking is essential to ascertain the existence of hallucinations. Reassurance and explanation that the visions are benign and do not signify mental illness have a powerful therapeutic effect. Hallucinatory activity may terminate spontaneously, on improving visual function or on addressing social isolation. There is no universally effective drug treatment but anticonvulsants may play a limited role in aborting the hallucinations. Physician awareness and empathy are the cornerstones of management.

Diode laser cycloablation in adult glaucoma: long-term results of a standard protocol and review of current literature.

BACKGROUND: To study the long-term efficacy and safety of diode laser cycloablation under a standard protocol in refractory glaucoma. METHODS: A retrospective study involving 42 eyes (39 patients), observed for 36-84 (mean 65.7) months after cycloablation involving 14 burns of 2-W power and 2-s duration, over 270 degrees of the ciliary body. RESULTS: By final review, mean intraocular pressure (IOP) had dropped by 50.3% from 31.4 +/- 8.8 mmHg before treatment to 15.6 +/- 6.3 mmHg (P < 0.0001). Thirty-seven of the 42 eyes (88.1%) achieved IOP < 22 mmHg. Thirty-five of the 42 eyes (83.3%) eyes achieved IOP reduction > or = 30% from baseline levels. The mean number of antiglaucoma medications per eye dropped from 2.55 +/- 0.83 to 1.71 +/- 1.44 (P = 0.0004). The percentage of eyes requiring oral acetazolamide dropped from 92.9% to 11.9% (P < 0.0001). About 59.6% of eyes required multiple treatment sessions (mean 2.17). Twenty-seven (64.3%) eyes suffered deterioration, 11 (26.2%) maintained stability and 4 (9.5%) exhibited improvement of visual acuity. No relationship between the number of treatment sessions and visual outcome was evident. CONCLUSIONS: This conservative repeatable protocol affords delivery of the minimum dose of photocoagulation necessary to achieve a safe, long-term ocular hypotensive response, while minimizing the risk of serious adverse effects, and is valuable in the difficult treatment of refractory glaucoma.

Direct referral of posterior capsular opacification by optometrists.

PURPOSE: To study referrals of posterior capsular opacification (PCO) for laser capsulotomy by optometrists and compare direct referral with that via the general practitioner (GP). METHODS: A prospective analysis of optometrist referrals with regard to diagnostic accuracy, appropriateness of referral, quality of letters and patient waiting times. RESULTS: Of 222 referrals, 156 were direct and 66 via the GP. Forty-five (20.3%) letters were of good quality, 141 (63.5%) were average and 36 (16.2%) were poor. Waiting times for direct referrals ranged from 2 to 30 weeks (mean 8.3 weeks, S.D. 4.1); that for referrals via the GP ranged from 4 to 25 weeks (mean 10.3 weeks, S.D. 3.6). Directly referred patients thus waited 2 weeks shorter than patients referred via GPs (95% confidence interval 0.7-3.1, p = 0.002). Diagnostic concurrence was 99% (211/213 patients). The rate of laser capsulotomy was 98.2% (215/219); 103 (46.4%) letters utilised a referral form (GOS18); 146 (65.8%) discussed subjective visual problems and five (2.3%) incorporated patient consent for provision of feedback to the referring optometrist. CONCLUSION: Direct optometrist referral is effective, accurate and reduces patient waiting time and GP workload. Referral letters should be typed or printed to optimise legibility. Patient consent for feedback should be obtained by the referring optometrist.