Biomedical subjects

Patricio G Schlottmann

Publications and source records attributed to Patricio G Schlottmann.

6 recordsLinked to original sources

PubMed2006

Optical coherence tomography analysis of the macula after scleral buckle surgery for retinal detachment.

OBJECTIVE: To define the incidence, pattern, duration, and clinical consequences of persistent localized submacular fluid after scleral buckle surgery for retinal detachment (RD). DESIGN: Prospective observational cohort series. PARTICIPANTS: Ninety-eight patients were identified and recruited to the study. METHODS: Patients aged > or =18 years undergoing scleral buckle surgery for uncomplicated primary RD over an 18-month period were recruited. All patients underwent clinical examination and optical coherence tomography (OCT) scan of the macula preoperatively and at 6 weeks postoperatively. Those patients who had an abnormality on OCT 6 weeks after surgery underwent follow-up with repeat of the study investigations at 3, 6, 9, 12, and 18 months after surgery until the abnormality resolved. If no abnormality was seen at the 6-week examination, no further investigation was undertaken. MAIN OUTCOME MEASURE: Presence of submacular fluid on OCT 6 weeks after surgery. Other outcome measures were duration of persistent fluid and associations with poor visual outcome, type, or duration of detachment. RESULTS: Of the 98 patients recruited into the study, 54 (55%) had subretinal fluid (SRF) on OCT 6 weeks after surgery. We identified 3 patterns of submacular fluid: confluent fluid, a single discrete bleb of fluid, and multiple blebs of fluid. Fluid was associated with delayed visual recovery. Of those with SRF, 78% had persistent fluid at 6 months; resolution of fluid took a median of 10 months and was associated with an improvement in vision. CONCLUSIONS: Optical coherence tomography is a useful noninvasive diagnostic method that can detect SRF not seen on clinical examination. Persistent SRF 6 weeks after scleral buckle surgery occurs in approximately half of patients, may persist for many months, and can cause delayed visual recovery.

Adult↗

PubMed2006

Optical coherence tomography analysis of the macula after vitrectomy surgery for retinal detachment.

OBJECTIVE: To define the incidence, duration, and clinical associations of persistent localized submacular fluid after pars plana vitrectomy (PPV) retinal detachment surgery. DESIGN: Observational cohort series. PARTICIPANTS: One hundred patients were identified and recruited into the study. METHODS: Patients aged 18 years and older who had undergone PPV and gas as a primary procedure for rhegmatogenous retinal detachment and postoperative follow-up were recruited from February through August 2004. All patients underwent clinical examination, optical coherence tomography (OCT) scan of the macula, and retinal thickness analysis scan of the macula. Those patients in whom an abnormality was seen on OCT at 6 weeks after surgery underwent follow-up with repeat of the study investigations at 3, 6, 9, 12, and 18 months after surgery until the abnormality resolved. If no abnormality was seen at the 6-week examination, no further investigation was undertaken. Demographic data, including detachment characteristics, were collected retrospectively from the patient case notes. MAIN OUTCOME MEASURES: The principle outcome measure was the presence of subretinal fluid (SRF) on OCT at 6 weeks after surgery. Other outcome measures included duration of persistent fluid and association with visual outcome and type and duration of detachment. RESULTS: One hundred patients were recruited; 15 of these had SRF on OCT performed at 6 weeks after surgery. Subretinal fluid was associated with significantly worse visual acuity (VA) at 6 weeks (P = 0.033, Wilcoxon rank-sum); those with SRF had a median VA of 0.4, and those with no SRF had a median VA of 0.3. The fluid took a median of 5.5 months to resolve. Seven patients had combined PPV and scleral buckle surgery; none of these had fluid at 6 weeks. CONCLUSIONS: Optical coherence tomography is a useful noninvasive diagnostic method that can detect SRF not appreciated on clinical examination. Persistent SRF after PPV and gas surgery occurred in 15% of patients in this study and was still present in 53% of these at 6 months. The presence of SRF at 6 weeks after surgery was associated with a poorer visual outcome at this time point.

Adult↗

PubMed2006

Optic nerve atrophy and retinal nerve fibre layer thinning following optic neuritis: evidence that axonal loss is a substrate of MRI-detected atrophy.

Magnetic resonance imaging (MRI) measures of brain atrophy are often considered to be a marker of axonal loss in multiple sclerosis (MS) but evidence is limited. Optic neuritis is a common manifestation of MS and results in optic nerve atrophy. Retinal nerve fibre layer (RNFL) imaging is a non-invasive way of detecting axonal loss following optic neuritis. We hypothesise that if the optic nerve atrophy that develops following optic neuritis is contributed to by axonal loss, it will correlate with thinning of the RNFL. Twenty-five patients were studied at least 1 year after a single unilateral attack of optic neuritis without recurrence, with a selection bias towards incomplete recovery. They had MR quantification of optic nerve cross-sectional area and optic nerve lesion length, as well as optical coherence tomography (OCT) measurement of mean RNFL thickness and macular volume, quantitative visual testing, and visual evoked potentials (VEPs). Fifteen controls were also studied. Significant optic nerve atrophy (mean decrease 30% versus controls), RNFL thinning (mean decrease 33% versus controls), and macular volume loss occurred in patients' affected eyes when compared with patients' unaffected eyes and healthy controls. The optic nerve atrophy was correlated with the RNFL thinning, macular volume loss, visual acuity, visual field mean deviation, and whole field VEP amplitude but not latency. These findings suggest that axonal loss contributes to optic nerve atrophy following a single attack of optic neuritis. By inference, axonal loss due to other post-inflammatory brain lesions is likely to contribute to the global MRI measure of brain atrophy in multiple sclerosis.

Adult↗

PubMed2005

Analysis of the macula with optical coherence tomography after successful surgery for proliferative vitreoretinopathy.

OBJECTIVE: To use optical coherence tomography to assess the in vivo pathologic findings associated with incomplete visual recovery in patients who have undergone anatomically successful surgery to treat proliferative vitreoretinopathy. METHODS: Eligible patients were recruited in vitreoretinal outpatient clinics between April 1, 2002, and July 31, 2003. Patients were included who had undergone anatomically successful vitreoretinal surgery to treat proliferative vitreoretinopathy and, at least 3 months after surgery, had postoperative vision worse than expected (< or =6/12) with no identifiable cause at clinical examination. Patients underwent optical coherence tomography, stereo fundus fluorescein angiography was performed in a cohort of patients, and angiographic findings were compared with those on the optical coherence tomograms. Relevant clinical data were collected retrospectively from patient case notes. RESULTS: A total of 35 patients were recruited. Optical coherence tomograms revealed cystoid macular edema in 23 patients (66%) but did not identify any other specific intraretinal disease. Location of edema (outer or inner retina), determined with stereo fundus fluorescein angiography and optical coherence tomography, correlated well. CONCLUSIONS: Optical coherence tomography is a useful diagnostic tool for assessing poor postoperative visual acuity and can reveal disease undetected at clinical examination. Cystoid macular edema is a common finding on optical coherence tomograms in eyes with incomplete visual recovery after anatomically successful surgery to treat proliferative vitreoretinopathy.

Adolescent↗

PubMed2005

Retinal nerve fiber layer axonal loss and visual dysfunction in optic neuritis.

Axonal loss is thought to be a likely cause of persistent disability after a multiple sclerosis relapse; therefore, noninvasive in vivo markers specific for axonal loss are needed. We used optic neuritis as a model of multiple sclerosis relapse to quantify axonal loss of the retinal nerve fiber layer (RNFL) and secondary retinal ganglion cell loss in the macula with optical coherence tomography. We studied 25 patients who had a previous single episode of optic neuritis with a recruitment bias to those with incomplete recovery and 15 control subjects. Optical coherence tomography measurement of RNFL thickness and macular volume, quantitative visual testing, and electrophysiological examination were performed. There were highly significant reductions (p < 0.001) of RNFL thickness and macular volume in affected patient eyes compared with control eyes and clinically unaffected fellow eyes. There were significant relationships among RNFL thickness and visual acuity, visual field, color vision, and visual-evoked potential amplitude. This study has demonstrated functionally relevant changes indicative of axonal loss and retinal ganglion cell loss in the RNFL and macula, respectively, after optic neuritis. This noninvasive RNFL imaging technique could be used in trials of experimental treatments that aim to protect optic nerves from axonal loss.

Adult↗

PubMed2004

Relationship between visual field sensitivity and retinal nerve fiber layer thickness as measured by scanning laser polarimetry.

PURPOSE: To evaluate the strength and pattern of the relationship between visual field (VF) sensitivity and retinal nerve fiber layer (RNFL) thickness measurements by scanning laser polarimetry (SLP). METHODS: Fifty-four eyes of 54 normal subjects (age, 42 +/- 15 years; VF mean deviation [MD], -0.69 +/- 1.01 dB) and 51 eyes of 51 glaucoma patients (age, 66 +/- 14 years; VF MD, -6.92 +/- 5.43 dB) were imaged with an SLP using fixed corneal compensation (FCC) and variable corneal compensation (VCC). VF sensitivity was recorded in the dB and the 1/L scales. Linear and logarithmic relationships were sought globally and in six VF sectors. Relationships of VF and RNFL thickness with age were sought in normal subjects. RESULTS: Both VF sensitivity and RNFL thickness declined with age (as determined by the regression slope): -0.13% (P = 0.0005) and -0.64% (P = 0.0001) per year for dB and 1/L VF sensitivity, respectively, and -0.25% (P = 0.003) per year for VCC RNFL thickness. FCC RNFL thickness was not statistically significantly related to age. The relationship of VF sensitivity to VCC global (R(2) = 0.49) and sectoral (R(2) = 0.00-0.47) RNFL thickness was greater than for FCC global (R(2) = 0.12) and sectoral (R(2) = 0.00-0.21) RNFL thickness. Relationships were curvilinear with the dB scale, with logarithmic regression of dB VF sensitivity against RNFL thickness being significantly better than linear regression. Logarithmic regression of 1/L VF sensitivity against RNFL thickness was no better than linear regression for all sectors. There was no relationship between VF sensitivity and RNFL thickness in the temporal peripapillary RNFL sector. CONCLUSIONS: The strength of the structure/function relationships compare well with previous reports in the literature. The relationships were curvilinear with the dB scale and linear with the 1/L scale, and were much stronger with VCC than with FCC RNFL thickness measurements.

Adult↗