Quality factor based correction for SD-OCT measurements in cataract patients.

PURPOSE: To correct peripapillary retinal nerve fibre layer (pRNFL) measurements performed with spectral domain optical coherence tomography (SD-OCT) for low image quality factor (QF) in patients with cataract, using measurements before and after cataract surgery. METHODS: SD-OCT (Topcon 3DOCT-2000) volume scans of the optic disc of 13 cataract patients were used. A set of three reflective filters with optical density ranging from 0.11 to 0.54 were used. The correlation was calculated between the change in thickness measurements and the change in image quality factor. Changes before and after cataract surgery were analysed. A correction for scans with a lower QF was calculated using an equation which was formulated based on the relationship between the change in thickness measurements and the change in image quality factor. RESULTS: Thirteen right eyes of thirteen cataract patients were included in this study. pRNFL thickness measurements before and after cataract differed significantly (96 versus 99 micron, p < 0.01). Preoperative linear regression lines showed a different slope than postoperative regression lines. Corrected pRNFL thickness measurements of before cataract surgery differed significantly with pRNFL thickness measurements after cataract surgery. CONCLUSIONS: The presence of cataract influences the QF-pRNFL relationship. The lower the image QF, the higher the pRNFL thickness underestimation. We found a rather curvilinear relationship between QF and pRNFL. Our corrected measurements of the pRNFL thickness in case of lower image QF due to cataract still differed significantly from the pRNFL thickness measurements after cataract surgery.

Optical density filters modeling media opacities cause decreased SD-OCT retinal layer thickness measurements with inter- and intra-individual variation.

PURPOSE: To assess the effect of media opacities on thickness measurements of the peripapillary retinal nerve fibre layer (pRNFL) and macular inner retinal layer (mIRL) performed with spectral-domain optical coherence tomography (SD-OCT) using a set of filters with known optical density. METHODS: Spectral-domain optical coherence tomography volume scans of the optic disc and the macular area were performed in 18 healthy volunteers, using Topcon-3DOCT-1000 Mark II. A set of five filters with optical density ranging from 0.04 to 0.69 was used. The correlation was calculated between the percentage change in thickness measurements (%ΔpRNFL and %ΔmIRL) and the change in optical density. All scans and measurements were performed in duplicate by one operator. RESULTS: Eighteen right eyes of 18 healthy volunteers were included in this study. Percentage decrease in pRNFL and mIRL thickness correlated with change in optical density (Spearman's rho r = 0.82; p < 0.001 and r = 0.89; p < 0.001, respectively). The measured decrease in pRNFL thickness differed from the decrease in mIRL thickness, not only between individuals, but also within the same individual. CONCLUSIONS: Optical coherence tomography thickness measurements of both pRNFL and mIRL are influenced by image degradation caused by optical density filters as a model for media opacities. An underestimation of the thickness of these layers was observed, caused by a shift of retinal layer boundary placement due to image quality loss. This underestimation is not the same for each individual and also differed between the pRNFL and mIRL thickness measurements. These individual and interindividual differences demonstrate that an individual approach will be necessary to correct for this underestimation per layer.

Reversible tonic pupils.

A 36-year-old man with a remote history of Hodgkin lymphoma and a recent history of non-Hodgkin lymphoma (NHL) developed tonic pupils and absent deep tendon reflexes in the lower extremities. One year later, pupils were normal except for slight iris segmental contraction to light. Over the next 2 years, the patient remained asymptomatic, and pupils remained unchanged. The NHL went into remission, and no other neurologic manifestations appeared. This is the first report of reversible tonic pupils. They may have a pathogenesis different from that typically seen in irreversible tonic pupils.

Blood pressure, arterial stiffness, and open-angle glaucoma: the Rotterdam study.

OBJECTIVE: To investigate cross-sectional associations among blood pressures (BPs), arterial stiffness, and open-angle glaucoma (OAG). METHODS: Study participants came from the population-based Rotterdam Study. The baseline examination phase took place after an extensive home interview from March 20, 1990, to June 17, 1993, and the third phase between March 19, 1997, and December 16, 1999. Cases were classified into high-tension OAG (htOAG) and normal-tension OAG (ntOAG), according to an intraocular pressure greater than 21 mm Hg or 21 mm Hg or less. Pulse pressure was the difference between systolic and diastolic BP. Diastolic perfusion pressure was the difference between diastolic BP and the intraocular pressure; indicators of arterial stiffness were carotid-femoral pulse wave velocity and carotid distensibility. Associations were evaluated with logistic regression analysis, adjusted for age, sex, body mass index, smoking, diabetes mellitus, serum cholesterol level, and BP-lowering treatment. RESULTS: A total of 5317 participants were included in this study. In participants with a higher pulse pressure, the prevalence of htOAG was elevated (odds ratio [OR] per standard deviation, 1.32; 95% confidence interval [CI], 1.03-1.69). In persons treated for systemic hypertension, low diastolic perfusion pressure (<50 mm Hg) was inversely associated with ntOAG (OR, 0.25; 95% CI, 0.10-0.63) and positively associated with htOAG (OR, 4.68; 95% CI, 1.29-17.01). The lowest tertile of carotid distensibility compared with the highest had an OR for htOAG of 2.84 (95% CI, 0.99-8.10; P=.05). CONCLUSIONS: We found that htOAG was associated with high pulse pressure, possibly with increased carotid arterial stiffness, and, only in persons treated for systemic hypertension, with low diastolic perfusion pressure. In these persons, ntOAG was associated with high diastolic BP, whereas the association between ntOAG and low diastolic perfusion pressure was inverted.

Value of routine funduscopy in patients with hypertension: systematic review.

OBJECTIVE: To evaluate the additional value of funduscopy in the routine management of patients with hypertension. DESIGN: Systematic review. PARTICIPANTS: Adults aged 19 or more with hypertensive retinopathy. DATA SOURCES: Medline, Embase, and the Cochrane Library from 1990. REVIEW METHODS: Studies were included that assessed hypertensive retinopathy with blinding for blood pressure and cardiovascular risk factors. Studies on observer agreement had to be assessed by two or more observers and expressed as a kappa statistic. Studies on the association between hypertensive retinopathy and hypertensive organ damage were carried out in patients with hypertension. The association between hypertensive retinopathy and cardiovascular risk was carried out in unselected normotensive and hypertensive people without diabetes mellitus. RESULTS: The assessment of microvascular changes in the retina is limited by large variation between observers. The positive and negative predictive values for the association between hypertensive retinopathy and blood pressure were low (47% to 72% and 32% to 67%, respectively). Associations between retinal microvascular changes and cardiovascular risk were inconsistent, except for retinopathy and stroke. The increased risk of stroke, however, was also present in normotensive people with retinopathy. These studies did not adjust for other indicators of hypertensive organ damage. CONCLUSION: Evidence is lacking that routine funduscopy is of additional value in the management of hypertensive patients.

Is there a direct association between age-related eye diseases and mortality? The Rotterdam Study.

PURPOSE: To study mortality in subjects with age-related maculopathy (ARM), cataract, or open-angle glaucoma (OAG) in comparison with those without these disorders. DESIGN: Population-based prospective cohort study. PARTICIPANTS: Subjects (n = 6339) aged 55 years and older from the population-based Rotterdam Study for whom complete information on eye disease status was present. MAIN OUTCOME MEASURES: Vital status continuously monitored from 1990 until January 1, 2000. METHODS: The diagnosis of ARM was made according to the International Classification System. Cataract, determined on biomicroscopy, was defined as any sign of nuclear or (sub)cortical cataract, or both, in at least one eye with a visual acuity of 20/40 or less. Aphakia and pseudophakia in at least one eye were classified as operated cataract. Definite OAG was defined as a glaucomatous optic neuropathy combined with a glaucomatous visual field defect. Diagnoses were assessed at baseline. Mortality hazard ratios were computed using Cox proportional hazard regression analysis, adjusted for appropriate confounders (age, gender, smoking status, body mass index, cholesterol level, atherosclerosis, hypertension, history of cardiovascular disease, and diabetes mellitus). RESULTS: The adjusted mortality hazard ratio for subjects with AMD (n = 104) was 0.94 (95% confidence interval [CI], 0.52-1.68), with biomicroscopic cataract (n = 951) was 0.94 (95% CI, 0.74-1.21), with surgical cataract (n = 298) was 1.20 (95% CI, 0.86-1.68), and with definite OAG (n = 44) was 0.39 (95% CI, 0.10-1.55). CONCLUSIONS: Both ARM and cataract are predictors of shorter survival because they have risk factors that also affect mortality. When adjusted for these factors, ARM, cataract, and OAG were themselves not significantly associated with mortality.

Family score as an indicator of genetic risk of primary open-angle glaucoma.

OBJECTIVES: To assess the genetic risk of open-angle glaucoma (OAG) in individuals by calculating a family score (FS), which summarizes the information of all relatives including their disease status, age, sex, and degree of kinship and to examine the genetic contribution to OAG with and without an increased intraocular pressure. METHODS: Case and control probands, derived from the Rotterdam Study, underwent the same ophthalmologic examination as their relatives. The FS of each proband was the sum of the differences between observed and expected values of OAG for all relatives. The FSs were compared between case and control probands using logistic regression analysis, adjusted for intraocular pressure. RESULTS: Of 37 case probands, 44 (half-) siblings and 86 children were available, and of 83 control probands there were 97 (half-) siblings and 155 children. Family scores ranged from -0.44 to 7.08 in case probands and from -0.98 to 2.46 in control probands. One unit increase in FS was significantly associated with a higher risk of OAG (odds ratio, 1.59; 95% confidence interval, 1.14-2.23). Adjustments for intraocular pressure did not change the odds ratio. CONCLUSIONS: These data show that the FS strongly predicts OAG, independent of the intraocular pressure. Therefore, the FS is useful to identify individuals with a high genetic risk.

Myocilin mutations in a population-based sample of cases with open-angle glaucoma: the Rotterdam Study.

PURPOSE: To investigate the prevalence of myocilin (MYOC) mutations in a population-based sample of open-angle glaucoma (OAG) cases and to describe a family with both juvenile and adult onset OAG caused by a mutation in MYOC. METHODS: MYOC was screened in cases derived from the Rotterdam Study in the Netherlands. Definite OAG was defined as a glaucomatous optic neuropathy together with a glaucomatous visual field defect. Upon the identification of the Asn480Lys mutation in one case, seven additional family members were studied. To test for a founder effect with earlier reported families with this mutation, the haplotypes of MYOC flanking markers D1S2851, D1S242, D1S218, and D1S1165 were compared. RESULTS: Seven sequence alterations in MYOC were found in 14 of 47 OAG cases; six of these were also found in controls. In one case, an Asn480Lys mutation was found. In relatives of the latter patient, the phenotype ranged from a glaucomatous optic neuropathy without visual field defect in a 70-year-old patient to severely affected optic discs and a remaining temporal remnant in a 34-year-old patient; those without the mutation had no signs of OAG. Haplotype analysis suggested a different origin of the mutation. CONCLUSIONS: The prevalence of MYOC mutations (2.2%) was similar to that found in hospital-based studies. Although mutations in MYOC are rare, relatives carrying this mutation run a high risk of developing the disease. Instead of submitting all members of a family with the Asn480Lys mutation to frequent follow-up, medical care can be restricted to those carrying the mutation.