[Loss of sight in the postpartum period]. / Verminderd zicht in het kraambed.

BACKGROUND: Vision problems in case of pre-eclampsia or Hemolysis, Elevated Liver, Low Platelets syndrome (HELLP) occur in 25-40% of the cases. Ablatio retinae as a complication occurs in only 0,1-2%. CASE DESCRIPTION: This article describes the case of a healthy 31-year-old woman who gave birth to her first child. A few hours after delivery she experienced vision loss. HELLP was diagnosed. Because of persistent vision loss combined with headache, the ophthalmologist and neurologist were consulted. A bilateral ablatio retinae as a complication of HELLP was diagnosed. Headache was most likely due to the side effect of nifedipine tablets, tension headache or a symptom of HELLP. Vision loss recovered spontaneously within a few weeks. CONCLUSION: Ablatio retinae due to preeclampsia or HELLP is very rare. For all concerned health care providers it is essential to pay attention to vision loss being the first symptom of possible acute underlying diagnosis postpartum.

In vivo quantification of the retinal reflectance spectral composition in elderly subjects before and after cataract surgery: Implications for the non-visual effects of light.

Light is the signal that entrains the biological clock in humans to the 24-hour external time. Recently, it has been shown that short wavelengths play a key role in this process. In the present study, we describe a procedure to measure, objectively and in a quick way, the spectral composition of the light reaching the retina in vivo. The instruments involved are the foveal reflection analyzer (FRA) and the macular pigment reflectometer (MPR). By making use of these reflectometers, we show quantitatively that in subjects with cataracts, the light input is especially reduced in the short wavelength range. After cataract surgery during which the crystalline lens is replaced by a transparent artificial lens, the transmittance of the short wavelengths (between 420-500 nm) improved on average by a factor of 4. We conclude that this technique holds great promises for the chronobiological field because it allows for quantification of the spectral composition and light levels reaching the retina in vivo.

Foveal cone photoreceptor involvement in primary open-angle glaucoma.

BACKGROUND: To test whether foveal cone photoreceptors are impaired in primary open-angle glaucoma (POAG). METHODS: Nineteen POAG eyes with central glaucomatous visual field defects, and 34 age-matched control eyes were included. Fundus reflectometry, together with a model fit procedure, provided information on a set of parameters: lens optical density, macular pigment optical density, melanin, blood, the directional cone reflectance (Rd), a measure for foveal cone photoreceptor integrity, and RILM, the reflectance at the inner limiting membrane. Optical coherence tomography (OCT) was performed to assess macular thickness. A Kolmogorov-Smirnov Z-test was used to compare parameters between the two groups. RESULTS: Median age (range) was 55.1 (24.7-73.3) years in the control subjects, and 60.1 (20.7-77.0) years in the POAG patients (P = 0.24). Of all eight model parameters, only Rd and RILM were significantly lower in POAG. Median Rd (range) was 2.21 (0.64-4.93) % in the control subjects and 1.19 (0.08-3.60) % in the POAG patients (P = 0.003). Median RILM (range) was 0.15 (0.00-1.08) % in the control subjects, and 0.08 (0.01-0.29) % in the POAG patients (P < 0.001). Rd showed no linear relationship with central retinal sensitivity on Visual Field test in POAG patients. Retinal thickness of the inner 1-3 mm ring and the outer 3-6 mm ring on OCT, centered on the fovea, was significantly lower in POAG patients than in control subjects. CONCLUSIONS: The integrity of the foveal cone outer segments, and the reflectance of the central ILM were impaired in POAG with advanced central visual field defects.

Directional model analysis of the spectral reflection from the fovea and para-fovea.

Directional and nondirectional spectral reflection data from 0, 1, 2, 4, and 8 deg eccentricity, and the optic disk, were analyzed from 400 to 950 nm with an existing optical reflection model. The optical model, developed for the fovea, appeared to be also suitable for more eccentric locations. The optical densities of melanin and of the macular pigments zeaxanthin and lutein peaked in the fovea, in correspondence with literature data. The amplitude of the directional component, originating in the cone photoreceptors, had its maximum at 1 deg. The maximum of the directionality (peakedness) occurred at a slightly higher eccentricity.

Macular pigment and fixation after macular translocation surgery.

BACKGROUND: After full macular translocation (MT) surgery with 360 degrees retinotomy, the fovea is rarely identifiable. Our aim was to verify the position of the fovea, to determine how patients fixate after MT and to examine distribution and optical density of macular pigment (MP). METHODS: 9 patients after MT were investigated. The Utrecht Macular Pigment Reflectometer was used to quantify the MP optical density. A scanning laser ophthalmoscope (SLO) was used to identify the fovea as the centre of MP distribution and determine the retinal locus of fixation. RESULTS: In all patients, the fovea was identified as the centre of MP distribution. The retinal areas used for fixation were displayed by SLO fixation analysis. Comparing their spatial relationship with the fovea, five patients fixated centrally and four eccentrically up to 7.5 degrees . In those patients, microperimetry showed that the atrophy caused by choroidal neovascularisation (CNV) extraction prevented central fixation. CONCLUSION: The combination of MP distribution and fixation analysis allows fixation behaviour to be quantified, even if the fovea morphologically cannot be localised. Our results suggest that the scotoma caused by spreading chorioretinal atrophy is the main cause for reduced visual acuity after MT, and so the MT rotation angle is crucially important.

Lutein and zeaxanthin measured separately in the living human retina with fundus reflectometry.

PURPOSE: To separately measure the optical densities of lutein (L) and zeaxanthin (Z) in the human retina in vivo. L and Z are the basic constituents of the macular pigment (MP). METHODS: Spectral fundus reflectance was measured in 23 subjects (group 1) at 0 degrees , 1 degrees , 2 degrees , 4 degrees , and 8 degrees eccentricity with a modified macular pigment reflectometer. A model generated the optical densities of L (LOD) and Z (ZOD), using their slightly different absorption spectra. Three other subjects (group 2) took 20 mg/d zeaxanthin for 6 months; they were measured approximately monthly for 18 months. RESULTS: Mean LOD for group 1 at the central fovea was 0.200 +/- 0.061 (range, 0.085-0.305), mean ZOD was 0.494 +/- 0.169 (range, 0.169-0.806), resulting in a mean Z fraction [ZOD/(LOD + ZOD)] of 0.71. ZOD dropped faster toward the periphery than LOD, measuring 0.044 and 0.010 (Z fraction 0.18) at 8 degrees , respectively. Zeaxanthin supplementation in group 2 caused a significant increase in ZOD, and no or minor changes in LOD. ZOD further increased over a 10-month period after supplementation in all subjects. CONCLUSIONS: LOD and ZOD had different spatial profiles that, apart from scaling factors, showed similarity to in vitro literature data. Supplementation with Z caused LOD to decrease and ZOD to increase. These results strongly suggest that the optical densities of L and Z can be assessed in vivo by fundus reflectometry, opening new ways of investigating the putative protective roles of L and Z in retinal disease.

Foveal cone-photoreceptor integrity in aging macula disorder.

PURPOSE: To establish the relation between AMD stage and a quantitative measure for the integrity of foveal cone photoreceptors related to the optical Stiles-Crawford effect. METHODS: Fifty-six AMD eyes and 57 control eyes were included in the final analysis. AMD was graded in accordance with the International Classification System into five mutually exclusive stages. Stages 0 to 1 were labeled no AMD, stages 2 to 3 were labeled early AMD, and stage 4 was labeled late AMD. Fundus reflectometry, together with a model-fit procedure, provided information on directional cone reflectance (Rd), a quantitative measure for the integrity of foveal cone photoreceptors. Optical densities of macular pigment (MPOD) and melanin (MOD) were also obtained. A general linear model analysis was used to compare Rd, MPOD, and MOD among the AMD stages. RESULTS: Mean Rd was lower in early AMD (0.92%, P < 0.001) and late AMD (0.86%, P < 0.001) compared with mean Rd in the no-AMD stage (1.76%). Mean MPOD was not different in early AMD (0.53, P = 0.05), but it was lower in late AMD (0.19, P < 0.001) compared with mean MPOD in the no-AMD stage (0.42). Mean MOD was lower in early (1.09, P = 0.001) and late (1.01, P = 0.004) AMD compared with mean MOD in the no-AMD stage (1.23). CONCLUSIONS: Foveal cones show signs of misalignment and/or outer segment deterioration in early AMD. Melanin rather than macular pigment may play a protective role against AMD, although loss of these ocular pigments can also be caused by AMD.

Interocular agreement in melanin and macular pigment optical density.

Macular pigment (MP) and melanin possibly protect the macular area by absorbing blue light and acting as antioxidants. Because little is known about the interocular correlation of melanin, we determined its optical density (MOD) in both eyes of healthy subjects using fundus reflectometry. The measuring method also provided optical densities of MP (MPOD). In addition to evaluating its interocular correspondence we checked its dependency on central retinal thickness as measured with optical coherence tomography (OCT). Spectral fundus reflectance was measured in 69 eyes of 37 healthy participants. Both eyes of 32 subjects (15 males and 17 females, aged 57.9+/-14.6 years) were used to evaluate interocular correspondences. MPOD data from 35 right eyes of 18 males and 17 females, aged 55.7+/-15.7 years, was used to evaluate the relation between central retinal thickness and MPOD. MOD was 0.99+/-0.30 (range: 0.57-2.07) for the left eyes and 1.02+/-0.28 (range: 0.62-2.07) for the right eyes. The intraclass correlation coefficient (ICC) was 0.89 (P<0.001). MPOD was 0.49+/-0.19 for the left eyes (range: 0.12-0.81) and 0.47+/-0.17 (range: 0.14-0.73) for the right eyes. The ICC was 0.91 (P<0.001). Macular retinal thickness (MRT), representing the average macular thickness in the central 1000 microm zone, was 210+/-28 microm. Foveal retinal thickness (FRT), representing the retinal thickness at the crossing of the 6 radial scan lines on OCT, was 175+/-34 microm. Pearson's correlation coefficient showed no significant linear association between MRT and MPOD (r=-0.04, P=0.82), and between FRT and MPOD (r=0.05, P=0.78). The optical density of melanin showed a high interocular correspondence in healthy white participants. Similar results were found for MPOD. Relative interocular differences of more than 32% in MOD, or more than 34% in MPOD, may point to pathology. No relation between central retinal thickness and MPOD was found.

Influence of macular pigment and melanin on incident early AMD in a white population.

BACKGROUND: The protective effect of macular pigment (MP) and melanin against age-related macular degeneration (AMD) is still controversial from cross-sectional studies. In an attempt to clarify this issue, we performed a population-based longitudinal study. METHODS: MP optical density (MPOD) and melanin optical density (MOD) data were collected during the second follow-up phase of the Rotterdam Study in 1999 in a random subset of 435 participants. Data from 419 participants (98% white) was available for analysis. AMD diagnosis was based on standardized fundus photographs according to the International Classification System, and AMD cases were subdivided into five mutually exclusive stages. In the three follow-up phases, incident AMD (iAMD), defined as absence of any AMD at baseline and the presence of stage 2 or higher at follow-up, was determined. We used Cox regression analysis to study the effect of an assumedly stable MPOD and MOD on early iAMD. RESULTS: During a mean follow-up of 9.82 years, 13 male and 17 female participants developed early iAMD and two male participants late iAMD. Because only two participants developed late iAMD, we had to restrict our analyses to early iAMD. Cox regression analysis adjusted for age and gender showed no significant effect of MPOD [hazard ratio (HR) 0.37; 95% confidence interval (CI) 0.04, 3.57] and MOD (HR 0.56; 95% CI 0.09, 3.60) on early iAMD. Additional adjustment for smoking did not change these associations. CONCLUSIONS: This unique but quantitatively limited material leads to the conclusion that no major protective effect of MPOD or MOD was seen on early iAMD.