The iris-optic distance was not statistically significantly different between eyes with severe negative dysphotopsia symptoms and nonsymptomatic eyes. However, when IOL exchange reduced the iris-IOL distance, the severe negative dysphotopsia symptoms resolved.

The results indicated a significant change in corneal topography during even a short pause in blinking. In follow-up studies using corneal topography, all measurements should be done at a fixed time after a complete blink.

Purpose Retinal changes are poorly described in early treated phenylketonuria (ETPKU). We aimed to investigate possible visual functional and ocular microstructural changes in adult patients with ETPKU. Optical coherence tomography (OCT) and its angiography (OCTA) data from patients with PKU were compared to healthy controls. Methods In this prospective, monocentric, cross-sectional, case-control study 50 patients with ETPKU and 50 healthy subjects were evaluated with OCT and OCTA. Measurements were performed on right eyes. The following visual function parameters were studied: best corrected visual acuity (BCVA), spherical equivalent (SE), contrast sensitivity and near stereoacuity; microstructural parameters: retinal nerve fiber layer thickness (RNFLT), ganglion cell layer (GCC) thickness , focal loss of volume (FLV), global loss of volume (GLV), peripapillary, papillary vessel density (VD), ocular axial length (AL) and intraocular pressure (IOP). Results Among functional tests there were significant differences in contrast sensitivity at 1.5 ( p < 0.001), 6 ( p < 0.013), 12 (p < 0.001), 18 ( p < 0.003) cycles per degree, in near stereoacuity (Titmus Wirt circles, p < 0.001) and in best corrected visual acuity (BCVA, p < 0.001). A statistically significant, moderate positive linear correlation was observed between BCVA and average Phe levels over the last ten years (β = 0.49, p < 0.001). The average (p < 0.001), superior (p < 0.001) inferior GCC (p < 0.001), the FLV ( p < 0.003), GLV (p < 0.001) and the average RNFLT ( p < 0.004) values of the PKU group were significantly lower than the controls. The serum phenylalanine level (Phe) in the PKU group negatively correlated with inferior (−0.32, p < 0.007), superior (r = −0.26, p < 0.028) and average (−0.29 p < 0.014) RNFL and with AL (−0.32, p < 0.026). In AL we detected a significant difference ( p < 0.04) between the good and suboptimal dietary controlled group. There was no significant difference between the ETPKU and control group in the measured vessel density parameters and in IOP. Conclusions Our results suggest that functional and ocular microstructural defects are present in patients with PKU, and some of them may depend on dietary control. The mechanism is unclear, but the correlation indicates the importance of strict dietary control in terms of preservation of retinal functions.

Our topography system is an enhancement of a standard TMS-1 corneal topograph instrument (Computed Anatomy Inc., New York, NY, USA). Topographic images are captured at a rate of 4 s(-1), allowing the recording of a series of 120 images in 30 s after a complete blink. In this prospective preliminary study 15 healthy volunteers were examined. The main outcome measures were the time profile of changes in surface regularity index (SRI), surface asymmetry index (SAI) and simulated keratometry values (K1, K2). After a blink there was a tendency for improvement in ocular surface regularity. Later trends were less clear. Our topography system makes possible the detailed evaluation of tear-film dynamics in the post-blink period. The new technique may play an important role in the diagnosis of various tear-film abnormalities; the results may also have significant implications in the planning of refractive surgeries.

Purpose Macular structure is poorly evaluated in early-treated phenylketonuria (ETPKU). To evaluate potential changes, we aimed to examine retinas of PKU patients using optical coherence tomography (OCT) with additional OCT angiography (OCTA) and compare the results to healthy controls. Methods A total of 100 adults were recruited in this monocentric, case-control study: 50 patients with ETPKU (mean age: 30.66 ± 8.00 years) and 50 healthy controls (mean age: 30.45 ± 7.18 years). Macular thickness, vessel density and flow area of the right eye was assessed with spectral domain OCT angiography SD-OCT(A). Macular microstructural data between the ETPKU and control group was compared. In the ETPKU group, the relationship between visual functional parameters (best corrected visual acuity [VA], spherical equivalent [SE], contrast sensitivity [CS] and near stereoacuity) and microstructural alterations was examined. The dependency of OCT(A) values on serum phenylalanine (Phe) level was analysed. Results There was significant average parafoveal and perifoveal total retinal layer thinning in ETPKU patients compared to healthy controls ( p < 0.016 and p < 0.001, respectively), while the foveal region remained unchanged in the ETPKU group. Whole macular and parafoveal superficial capillary plexus density was significantly decreased in ETPKU compared to controls ( p < 0.001). There were no significant differences in the foveal avascular zone, nonflow area, macular superficial and deep capillary plexus between the groups. The temporal parafoveal inner retinal layer thickness was found to negatively correlate with individual Phe levels ( r = −0.35, p = 0.042). There was no difference in vascular density and retinal thickness in the subgroup analysis of patients with good therapy adherence compared to patients on a relaxed diet. Conclusions Durable elevation in Phe levels are only partially associated with macular retinal structural changes. However, therapy adherence might not influence these ophthalmological complications.

Purpose: To investigate the rapid alterations in value and fluctuation of ocular wavefront aberrations during the interblink interval. Methods: Forty-two volunteers were examined with a WASCA Wavefront Analyzer (Carl Zeiss Meditec AG) using modified software. For each subject, 150 images (about 6 frames/second) were registered during an inter-blink period. The outcome measures were spherical and cylindrical refraction and root-mean-square (RMS) values for spherical, coma, and total higher order aberrations. Fifth order polynomials were fitted to the data and the fluctuation trends of the parameters were determined. We calculated the prevalence of the trends with an early local minimum (type 1). The tear production status (Schirmer test) and tear film break-up time (BUT) were also measured. Results: Fluctuation trends with an early minimum (type 1) were significantly more frequent than trends with an early local maximum (type 2) for total higher order aberrations RMS ( P =.036). The incidence of type 1 fluctuation trends was significantly greater for coma and total higher order aberrations RMS ( P =.041 and P =.003, respectively) in subjects with normal results in the BUT or Schirmer test than in those with abnormal results. In the normal subjects, the first minimum of type 1 RMS fluctuation trends occurred, on average, between 3.8 and 5.1 seconds after blink. Conclusions: We suggest that wavefront aberrations can be measured most accurately at the time after blink when they exhibit a decreased degree of dispersion. We recommend that a snapshot of wavefront measurements be made 3 to 5 seconds after blink. [ J Refract Surg. 2009;25:59–68.]

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