Does use of isotretinoin rule out a career in flying?

AIM: To evaluate whether previous isotretinoin use induces permanent, measurable, and clinically significant abnormalities in night vision such that flying is precluded, and whether potential military and civilian commercial aviators should be screened routinely. METHODS: A retrospective, non-interventional, consecutive case series of 47 individuals with a confirmed history of oral isotretinoin use were compared to 20 age and sex matched controls. RESULTS: 47 individuals (44 males and three females), age range 17-33, underwent Goldmann-Weekers dark adaptation (DA) and standard electroretinogram (ERG) according to ISCEV protocols. 34 patients showed no abnormality in any parameters. Two patients had abnormal DA and ERGs. The mean scotopic ERG b wave amplitude of the isotretinoin group was 496.5 microV (SD 51.3 microV) compared with 501.7 microV (62.3.1 microV) among the controls. The group mean a:b ratio was 0.55 (0.04) compared to 0.69 (0.08) in the controls. CONCLUSION: Previous use of isotretinoin may have caused retinal toxicity in two subjects and laboratory evidence of night blindness in 11 further subjects. One subject had subclinical changes remaining in the ERG 96 months after cessation of isotretinoin. This may justify the directed use of electrophysiological screening in professions that are night vision critical.

Laser photocoagulation alters the pattern of staining for neurotrophin-4, GFAP, and CD68 in human retina.

AIMS: To investigate the staining pattern of neurotrophin-3 (NT3), neurotrophin-4 (NT4), and brain derived neurotrophic factor (BDNF) as well as glial fibrillary acid protein (GFAP) and CD68 in lasered human retina. METHODS: Retinal laser photocoagulation was performed on four patients (two males, two females) with choroidal malignant melanoma 1-6 days before enucleation. Three other enucleated eyes with malignant melanoma and three normal cadaveric donor eyes were used as controls. Immunohistochemistry was performed to investigate the pattern of staining of NT3, NT4, BDNF, GFAP, and CD68 in 7 mm sections of fixed specimens. RESULTS: Expression of NT4 was detected in the inner and outer nuclear layers of all the retinal sections examined but no NT3 and BDNF staining was seen. NT4 staining was found to be less intense in lasered and melanoma controls compared to normal cadaveric donor retinas. There was an upregulation of GFAP expression in both lasered and control eyes with melanoma in comparison with normal controls. CD68 staining was only observed in retinal pigment epithelium and choroid of lasered eyes. CONCLUSION: NT4 is expressed in inner and outer nuclear layers of normal human retina and its expression is downregulated following laser photocoagulation. This occurs in parallel with an increased expression of GFAP suggesting that reactive changes in Muller cells may be responsible for reduced NT4 staining. Expression of CD68 at the site of laser injury is consistent with a wound healing process as a response to local damage.

Ophthalmic injuries in British Armed Forces in Iraq and Afghanistan.

AIM: British military ophthalmologists have not been deployed in support of operations since 2003. Eye injuries in British forces receive definitive treatment on return to the United Kingdom. We report the injury patterns, management strategies, and outcomes for eye injuries in British Armed Forces in Iraq and Afghanistan. METHODS: Retrospective consecutive case series of eye injuries in British Armed Forces in Iraq or Afghanistan from July 2004 to May 2008. Outcomes assessed by final best-corrected visual acuity (VA; few patients lost to follow-up), rates of endophthalmitis, and proliferative vitreoretinopathy (PVR). RESULTS: There were 630 cases of major trauma, 63 sustained eye injuries (10%), and 48 sustained significant eye injuries. There were 21 open-globe injuries: 9 ruptures and perforating injuries, of which 7 were enucleated/eviscerated; 11 intraocular foreign body (IOFB) injuries, of which 1 was eviscerated. Primary repair was combined with posterior segment reconstruction in 9/11 cases with IOFB. Mean time to primary repair was 1.9 days (range 0-5). Intravitreal antibiotics were given at primary repair in five cases. All cases received early broad-spectrum systemic antibiotics. Median final VA was logMAR 0.25 excluding evisceration/enucleations. There were two cases of PVR and none of endophthalmitis. CONCLUSIONS: The number of eye injuries as a proportion of all casualties is lower than recently reported. The injuries are more severe than in civilian practise. The outcomes were comparable with previous reports, this demonstrates that, in certain cases, primary repair can be safely delayed beyond 24 h in the patient's best interests, in order to optimise the conditions for treatment.

Contact lens-related microbial keratitis in deployed British military personnel.

AIMS: To quantify the effect of contact lens-related microbial keratitis (CLMK) in the British Defence personnel particularly those in active service in the Arabian Gulf and Afghanistan between June 2001 and January 2007. METHODS: A retrospective review of all British military personnel who developed contact lens-related keratitis during deployment. RESULTS: A total of 27 cases (27, eyes, 23, male; median age 26 (range 19-41) years) were identified, of whom 19 cases were evacuated from Iraq alone. Twenty cases were associated with soft contact lens wear. Seven cases were culture positive, of which five grew Pseudomonas aeruginosa. The overall incidence of CLMK in contact lens wearer in the British military in Iraq was 35 per 10,000. There was an increased incidence during the summer months. Seventeen eyes (63%) lost more than one line of visual acuity with a resultant permanent medical downgrading in duty capability in nine cases. CONCLUSIONS: CLMK has a poorer outcome in a deployed military environment when compared to the civilian setting. Increased awareness of the health risks of contact lens wear together with standardised treatment regimens based on improved pathogen detection using molecular diagnostics have improved outcomes.

Cytomegalovirus retinitis in chronic lymphocytic leukaemia.

PURPOSE: To describe a rare association of cytomegalovirus (CMV) retinitis. PATIENTS AND METHODS: Report of three patients with chronic lymphocytic leukaemia (CLL) who developed CMV retinitis. RESULTS: The diagnosis was established by the detection of CMV DNA by polymerase chain reaction analysis of aqueous and/or vitreous humour. CD4+ T-lymphocyte count was reduced in two patients and normal in the third one. There was bilateral involvement in two of the three patients. There was delay of 8-10 months in diagnosis. The visual outcome was poor in four out of the five eyes involved owing to optic atrophy or total retinal detachment with proliferative vitreoretinopathy. CONCLUSION: Increased awareness of CMV retinitis in patients who have received immunosuppression for haematological malignancies, such as CLL, could lead to earlier diagnosis and possibly better visual outcome.

Surgical treatment and outcome of patients with giant retinal tears.

OBJECTIVE: To report the management and outcome in retinal detachments associated with giant retinal tears (GRTs). METHODS: Retrospective, case note analysis of patients treated between November 1991 and June 2002 at a tertiary referral hospital. RESULTS: The case notes of 29 patients (24 males, 5 females) with a follow-up ranging from five months to 7 years were reviewed. In all, 25 eyes had retinal detachments with macular involvement and 10 patients had myopia more than 6 D. All patients underwent vitrectomy. A total of 23 patients had heavy liquid and 16 had scleral explants; 28 patients had silicone oil and one had C3F8 tamponade. Intraoperative complications included lens trauma and iatrogenic GRT. Six eyes had recurrent retinal detachment and needed multiple surgical procedures. At the last follow-up, 25 patients had anatomically attached retinas. In all, 18 fellow eyes were treated prophylactically. Three patients had total retinal detachment and marked PVR. The visual acuity improved in 20 eyes. CONCLUSION: GRTs are more common in patients with high myopia. With newer techniques of surgical treatment of GRTs, the anatomical and visual outcomes are more favourable.