Capillary pressure may predict preclinical changes in the eye.

AIMS/HYPOTHESIS: Microvascular dysfunction is associated with end-organ damage. Macular oedema is an important component of diabetic retinopathy. Macular thickness can be accurately quantified by optical coherence tomography (OCT), enabling accurate assessment of the macular prior to clinically apparent abnormalities. We investigated whether macular (fovea) thickness in non-diabetic individuals is related to the microvascular variables controlling fluid filtration across a blood vessel wall, in particular capillary pressure and the microvascular filtration capacity (Kf). METHODS: We recruited 50 non-diabetic individuals (25 men, 25 women; age range: 26-78 years; BMI range: 20-46 kg/m(2)). Fovea thickness was assessed by OCT. Microvascular assessments included: finger nailfold capillary pressure; Kf; microvascular structural assessments, i.e. skin vasodilatory capacity, minimum vascular resistance (MVR) and microvascular distensibility; and endothelial function. RESULTS: At 214.6 (19.9) microm (mean [SD]), fovea thickness was within normal range. Capillary pressure, adjusted for BMI, was associated with fovea thickness (standardised beta 0.573, p = 0.006, linear regression). Fovea thickness was not associated with Kf, microvascular structural assessments or endothelial function. Capillary pressure was still associated with fovea thickness when adjusted for microvascular variables (Kf, vasodilatory capacity, MVR, microvascular distensibility or endothelial function), or for risk factors for diabetes (systemic blood pressure, insulin sensitivity, inflammation, glycaemic status and lipids) and age. CONCLUSIONS/INTERPRETATION: Capillary pressure, a key determinant of movement of fluid across a blood vessel wall, is associated with fovea thickness in non-diabetic individuals. This suggests that with regard to potential preventative or therapeutic targets, attention should be directed at the mechanisms determining retinal microvascular pressure.

Displacement of nuclear fragments into the vitreous complicating phacoemulsification surgery in the UK: clinical features, outcomes and management.

AIMS: To study the clinical features, management and outcomes of displacement of nuclear fragments into the vitreous (DNFV) complicating phacoemulsification in the UK. METHODS: Cases were collected prospectively between March 2003 and March 2004 inclusive by active surveillance through the British Ophthalmological Surveillance Unit. Details were obtained using incidence questionnaires and follow-up questionnaires after 6 months. The data used in this paper were obtained from the follow-up questionnaires. RESULTS: 610 cases were confirmed during the reporting period, for which 387 follow-up questionnaires were received. In 67% of cases, a best-corrected visual acuity of 6/12 or better was reported at final follow-up. The most common immediate sequelae of DNFV were intraocular inflammation (85%), corneal oedema (55%) and an intraocular pressure >30 mm Hg (34%). Pars plana vitreolensectomy was used in 97% of cases, and fragmatome ultrasound lensectomy was used in over half of these procedures. The median time from cataract surgery to pars plana vitrectomy for the removal of DNFV was 3 days, and most patients (68%) had vitrectomy within 1 week of the first procedure. An intraocular lens had been inserted at the time of the complicated cataract surgery (defined as a "primary IOL") in 40% of cases, and over three-quarters of these primary IOLs were subsequently removed (with or without a replacement IOL). Only 67% of eyes that had a primary IOL inserted after DNFV were pseudophakic at final follow-up, in contrast with 79% of eyes that were left aphakic after DNFV (p = 0.008). A best-corrected visual acuity of 6/60 or worse was reported in 14% of cases at final follow-up and was most commonly associated with persistent uveitis, corneal oedema, cystoid macular oedema, optic atrophy or retinal detachment. CONCLUSIONS: DNFV complicating cataract surgery was followed by a secondary procedure in 97% of cases. About three-quarters (77%) of "primary IOLs" inserted at the time of DNFV were subsequently removed or replaced, and eyes that had received a primary IOL had significantly less chance of being pseudophakic at final follow-up than eyes that had been left primarily aphakic at the time of the complicated cataract surgery. The delay before secondary intervention was shorter, fragmatome ultrasound lensectomy use was higher, and the retinal detachment rate was lower than in previous studies. Affected eyes still had a worse outcome in terms of visual acuity compared with eyes after uncomplicated cataract surgery.

Displacement of nuclear fragments into the vitreous complicating phacoemulsification surgery in the UK: incidence and risk factors.

AIMS: To study the epidemiology and risk factors contributing to displacement of nuclear fragments into the vitreous (DNFV) complicating phacoemulsification in the UK. METHODS: Cases were collected prospectively between March 2003 and March 2004 by active surveillance through the British Ophthalmological Surveillance Unit (BOSU). Case-control analysis of risk factors was performed by visiting 10 randomly selected centres using a total of 521 cases of uncomplicated phacoemulsification. Validation analysis to assess under-reporting was performed in a total of 13 randomly selected units. RESULTS: 610 cases of DNFV were confirmed during the reporting period. The estimated incidence of DNFV was 0.19-0.28%. The group with complications was significantly older than the control group (mean 76.8 vs 74.3 years: p<0.001). Significant preoperative risk factors were posterior synechiae (5.1% vs 2.2%), incomplete pupil dilation (59.5% vs 8.8%), pseudoexfoliation (5.6% vs 1.4%) and previous vitrectomy (7.8% vs 2.2%). Significant operative variables related to surgical experience, topical (14.3% vs 3.1%) and sub-Tenon's (51.4% vs 37.2%) anaesthesia, and requirement for vision blue (trypan blue ophthalmic solution) (13.7% vs 2.4%). CONCLUSIONS: The estimated incidence of DNFV during phacoemulsification surgery in the UK is two or three per 1000 operations. Risk factors have been identified that should help to guide case selection for phacoemulsification surgery and modify techniques.

Retinal lead toxicity.

A 35-year-old female who had suffered from acute lead poisoning when she was 22 years old, presented 13 years later with loss of vision in the right eye and normal vision in the left eye. She had a pale disc, narrowed arterioles and mid-peripheral heavy pigmentation, right eye being more affected than the left eye. Electrodiagnostic tests identified marked asymmetry of visual function. We would postulate lead retinal toxicity as the cause of the asymmetric findings.