Macular thickness measured by spectral-domain optical coherence tomography in healthy Thai eyes

Purpose

To describe the macular thickness measured by spectral-domain optical coherence tomography (SD-OCT) in healthy eyes of Thai people.

Design

Prospective cross-sectional study.

Methods

Three hundred sixty-eight healthy participants underwent a comprehensive ophthalmic examination, including Spectralis SD-OCT scanning, at Chiang Mai University Hospital. The images were obtained over maculae, using a high-speed volumetric raster scan pattern with lines 240?μm apart. Information was collected from both eyes of each person, with only the right one being used unless it was found to be ineligible (in which case the left eye was studied). A mean retinal thickness was calculated based on nine areas that corresponded to the Early Treatment Diabetic Retinopathy Study by OCT mapping software. The relationships between retinal thickness and sex, age, axial length, and spherical equivalence were analyzed.

Results

The mean age of the subjects was 49.17?±?17.24?years. The mean central retinal thickness was 259.18?±?19.08?μm, the mean foveal volume was 0.20?±?0.02, and the mean total macular volume was 8.59?±?0.37?mm³. Central subfield (CSF) thickness and foveal volume were significantly greater in men than in women (both P?<?0.001). When?analyzed for six?age groups by ANOVA, the CSF thickness showed no significant difference among the groups, with a P value of 0.280, and foveal volume showed no significant difference among the six groups, with a P value of 0.341. After age adjustment, axial length was correlated positively with the CSF thickness (P?<?0.001, Pearson correlation).

Conclusions

The normal macular thickness in Thais is thinner than those reported for other populations when measured using the Spectralis SD-OCT. Male gender and axial length were correlated positively with CSF thickness.     

Spielt die Aderhautdicke beim idiopathischen Makulaforamen eine Rolle?

Background

The pathogenesis of idiopathic macular hole (MH) formation is not fully understood and the choroid might be involved in its etiology. Recently published data reported choroidal thickness (CT) to be significantly thinner in eyes with idiopathic MH and in fellow eyes compared to age-matched healthy controls [24].

Methods

The enhanced depth imaging (EDI) modus of the Spectralis OCT (Heidelberg Engineering, Heidelberg) was used to measure subfoveal CT in 12 patients with MH of which 2 suffered from bilateral MH. Measurements were manually acquired preoperatively using the horizontal foveal scan of the 7-line scan (5?×?30? perifoveal) with 100 averaged scans per scan, between the outer border of the retinal pigment epithelium and the inner scleral border. Additional CT measurements were obtained 8 weeks and 6 months postoperatively.

Results

Subfoveal CT of the 12 patients with MH (10 ♀, 2 ♂; 68?±?7 years) was 274?±?65?μm. The CT of the 10 patients with healthy fellow eyes measured 268?±?75?μm and CT of the 2 patients with bilateral MH measured 309?±?34?μm in the non-operated eye. The mean axial length (AL) in eyes with MH was 23.64?±?0.59?mm and in healthy fellow eyes 23.68?±?0.54?mm. After surgery MH closure was obvious in all eyes, the postoperative CT at 8 weeks measured 284?±?77?μm and at 6 months 276?±?73?μm.

Conclusions

The EDI-OCT procedure enables measurements of CT. In the patients studied a reduced CT could not be found neither in patients with macular holes nor in the fellow eyes. There was no significant change in CT comparing preoperative with postoperative measurements. In contrast to recently published data [24] no reduction in CT in idiopathic macular hole could be demonstrated.     

Photoreceptor inner and outer segment layer thickness in multiple evanescent white dot syndrome

Purpose

To evaluate the photoreceptor inner and outer segment layer thickness in eyes with MEWDS.

Design

Prospective, non-comparative, observational case series. The follow-up duration was 4 months.

Methods

Four women were diagnosed with unilateral MEWDS. The ages of the patients were 25, 24, 35, and 40 years. The retinal microstructure was assessed by spectral-domain optical coherence tomography (SD-OCT). The thickness of the photoreceptor inner (IS) and outer (OS) segments and sum of them (IS + OS) at the fovea were analyzed.

Results

The visual acuity was reduced in three of four eyes at the acute phase. SD-OCT showed that the border of IS and OS (IS/OS) line and the cone outer segment tips (COST) line in the macula area were not detected in all four eyes. The IS + OS thickness was 50.3?±?5.6 μm and that of the healthy fellow eyes was 73.5?±?7.0 μm (n?=?4 eyes). The thickness of the IS was 27.8?±?2.6 μm and that of the OS was 45.8?±?7.3 μm. In all eyes, there was a spontaneous improvement of the visual acuity. SD-OCT showed a recovery of only the IS/OS line in the macular area, but the COST line was not visible in three cases. The mean IS + OS thickness increased to 56.0?±?7.9 μm (n?=?4), IS?=?26.0?±?2.0 μm (n?=?3), and OS?=?30.1?±?8.7 μm (n?=?3) in the early recovery phase, and to 64.8?±?9.3 μm (n?=?4), IS?=?28.5?±?1.7 μm (n?=?4), and OS?=?36.3?±?7.9 μm (n?=?4) in the late recovery phase. The mean inner and outer segment thickness remained unchanged in the fellow eyes.

Conclusion

Eyes with MEWDS have changes in the photoreceptor microstructures. The change in the IS + OS thickness during the natural recovery course might be due to an increase in the OS length.     

Comparing central retinal thickness in diabetic macular edema measured by two different spectral-domain optical coherence tomography devices

Purpose

We evaluated central retinal thickness (CRT) in diabetic macular edema (DME) using two different spectral-domain (SD) optical coherence tomography (OCT) instruments: the Cirrus and Spectralis OCTs.

Methods

CRT was measured in 63 eyes of 32 patients with DME using both instruments on the same day.

Results

CRT measurements were significantly greater for the Spectralis than the Cirrus (p < 0.0003, n = 63, paired t test); mean CRT values were 382 ± 136 ??m with the Cirrus and 394 ± 139 ??m with the Spectralis. In eyes with poor best-corrected visual acuity (BCVA) (<20/40), mean CRT was 378 ± 130 ??m with the Cirrus and 395 ± 139 ??m with the Spectralis (p < 0.007, n = 29). In eyes with good acuity (equal to or better than 20/40), the mean CRT was 385 ± 142 ??m with the Cirrus and 393 ± 140 ??m with the Spectralis (p < 0.005, n = 34).

Conclusions

Foveal retinal thickness measurements may vary among SD-OCT devices. The differences between instruments could affect the results of a multicenter study.     

Laser in situ keratomileusis enhancements with the Ziemer FEMTO LDV femtosecond laser following previous LASIK treatments

Background

The aim of this paper is to present the accuracy, predictability, and safety outcomes of LASIK enhancements performed with the FEMTO LDV femtosecond laser (Ziemer Ophthalmic Systems, Port, Switzerland) and the Allegretto Wave Concerto 500 Hz excimer laser (Wavelight AG, Erlangen, Germany), following previous LASIK treatments.

Methods

FEMTO LDV was used for flap creation in 85 previously LASIK-treated eyes of 62 patients. The intended flap thickness was 90 μm in 81 eyes and 140 μm in 4 eyes. The size of the suction ring was 9.0 mm in 72 eyes and 9.5 mm in 13 eyes. Flap dimensions were measured and correlated to preoperative characteristics.

Results

With the intended flap thickness of 90 μm in previously LASIK-treated eyes, the actual flap thickness was 90.2?±?6.6 μm (range 80–122), and the flap diameter was 9.2?±?0.2 mm (range 8.7–9.9). The mean hinge length was 4.0?±?0.2 mm (range 3.0–4.8). Flap thickness correlated positively with patient age and hinge length. Complications were reported in 12 eyes (14.1 %). Most of the complications were very mild, and none of them prevented further refractive laser treatment. One eye lost two Snellen lines of best spectacle-corrected visual acuity.

Conclusions

Femtosecond LASIK enhancement is warranted only in rare cases. Surgical experience is needed and special caution must be practiced. For cases of a primary free cap, femtosecond LASIK is not recommended.     

Normative values of peripheral retinal thickness measured with Spectralis OCT in healthy young adults

Background

To evaluate the range of peripheral retinal thickness (PRT) in young healthy human subjects by Spectralis HRA?+?OCT, and to analyze a potential association between the peripheral location, spherical equivalent (SE), axial length (AL), and gender.

Methods

After pupil dilation, the peripheral retina was scanned by means of six volume protocols (9?×?7.5 mm), each consisting of 31 B-scans. PRT was determined at 4,500, 5,500, 6,500 and 7,500 μm eccentricity from the fovea and the optic nerve head (ONH). Data points were collected every 22.5°. Six additional data points at a distance of 9,000 μm were included. In 11 subjects, OCT measurements were performed twice to evaluate reproducibility. Coefficients of variation (COV) were calculated.

Results

Randomly selected eyes of 50 subjects (19–30 years) with AL of 21–27 mm (SE: ?5.75 to +5.25 dpt) were included in the study. Mean PRT decreased significantly (p?≤?0.001, r?=??0.99) towards the periphery, reaching a minimum at 9,000 μm eccentricity (mean PRT: 187.7?±?8.9 μm). Multiple regression analysis revealed a significant association of PRT with AL at nasal and temporal locations as well as gender for temporal locations. COVs ranged from 0.44 to 2.90 %, with highest COVs found nasal to the fovea.

Conclusions

This is the first study to report normative data of PRT outside the ETDRS grid and to show a significant continuous almost linear decrease of the RT from the center into the periphery. The data will be valuable to detect peripheral pathologies of the retina in early stages of peripheral retinal dystrophies.     

Evaluation of rigid gas permeable lens fitting in keratoconic patients with optical coherence tomography

Purpose

To assess fitting of rigid gas permeable (RGP) lenses in patients with keratoconus, using spectral domain optical coherence tomography (SD-OCT).

Methods

The study was conducted on 30 eyes of 30 keratoconic patients fitted with RGP lenses, namely Rose K2 lens. Biomicroscopic examination with and without RGP lens was done. Fluorescein pattern was examined to determine the fitting, if ideal (three-point light touch), steep (central fluorescein pooling) or flat (central heavy bearing touch). Post-lens tear film thickness was measured centrally and at the lens edges using SD-OCT. Patient’s comfort was assessed and graded.

Results

Mean central post-lens tear film thickness was 35.1?±?7.3 μ in patients with ideal fitting. Mean post-lens tear film thickness of 50.4?±?8.2 μ and 25.3?±?6.1 μ was noted in patients with steep and flat fitting, respectively. Mean post-lens tear film thickness of 102.5?±?12.1 μ, 85.4?±?11.4 μ, 135.6?±?13.3 μ was demonstrated in eyes with ideal, steep and flat edge lift, respectively. Tear film thickness under the edges was significantly (p?=?0.04) lower in patients unsatisfied with their contact lenses.

Conclusion

SD-OCT can image and measure the tear film thickness in keratoconic patients with different fitting patterns of RGP lenses. OCT- guided fitting can be used to evaluate and modify the lens parameters to increase patient satisfaction. Lens intolerance may be related to edge lift rather than central fitting.     

Calculating the predicted retinal thickness from spectral domain and time domain optical coherence tomography – comparison of different methods

Purpose

To compare the accuracy of different methods of calculating predicted central retinal thickness values in order to allow comparison between results of spectral-domain optical coherence tomography (SD-OCT) and time-domain OCT (TD-OCT) devices.

Methods

In a prospective cohort study, 100 consecutive healthy individuals without ocular disease underwent sequential scanning with SD-OCT (Spectralis OCT) and TD-OCT (Stratus OCT). A group of 60 eyes was used to generate the conversion equations, which were tested on the remaining 140 eyes. Four equations were used: 1. Mean difference between SD-OCT and TD-OCT; 2. Multiplying a ratio by the original retinal thickness; 3. Linear regression analysis using retinal thickness; and 4. Regression analysis using retinal thickness and spherical equivalent. All four methods were used to calculate predicted SD-OCT values from TD-OCT measurements, and vice versa.

Results

For all four equations, the predicted SD-OCT central retinal thickness values were similar to the actual SD-OCT, with mean difference ranging from 0.78 to 1.01 μm, and intraclass correlation coefficients >0.88. Both regression equations and mean difference showed greater accuracy, with variation between calculated and actual retinal thickness values ≤5 μm in 60 % of eyes. In contrast, the ratio method was less accurate, with 15.8 % of eyes showing differences >15 μm. Similar results were found for predicted TD-OCT values.

Conclusions

Several methods can be used to convert central retinal thickness values from SD-OCT to the predicted TD-OCT value, or vice versa, with high degrees of accuracy and reliability. These methods may allow comparison of OCT values from SD-OCT and TD-OCT devices in clinical trials and standard patient care.     

Repeatability and comparability of corneal thickness measurements obtained from Dual Scheimpflug Analyzer and from ultrasonic pachymetry

Background

To assess the repeatability and comparability of central corneal thickness (CCT) measurements obtained from the Galilei Dual Scheimpflug Analyzer (Galilei-DSA) and from ultrasonic pachymetry (USP) in normal eyes and in eyes following laser refractive surgery.

Methods

In this prospective observational study, 77 eyes of 39 patients with normal corneas and 39 eyes of 20 patients with prior laser refractive surgery were enrolled. All 116 eyes had three repeated measurements of central CCT with the Galilei-DSA first and then with USP by the same examiner. Reliability of both devices was assessed statistically, and CCT measurements by each were compared.

Results

The mean CCT measurement of normal eyes was 549.2 ± 30.5 μm and 548.5 ± 33.1 μm by the Galilei-DSA and USP respectively; the difference between the two modalities was ?0.7  ± 7.1 μm (P?=?0.365). In post-refractive surgery eyes, the mean CCT measured by the Galilei-DSA and USP was 500.4 ± 44.8 and 494.3 ± 50.3 respectively; the difference between the two devices was ?6.2 ± 9.9 μm (P?<?0.001). For the three repeated measurements, the mean standard deviation was 2 μm with the Galilei-DSA and 1.8 μm with USP in normal eyes, and 2.4 μm with the Galilei-DSA and 1.9 μm with USP in post-refractive surgery eyes.

Conclusion

The Galilei-DSA has high repeatability and excellent to moderate agreement with ultrasonic pachymetry when measuring CCT in normal and post-refractive surgery eyes.     

Effectiveness of averaging strategies to reduce variance in retinal nerve fibre layer thickness measurements using spectral-domain optical coherence tomography

Background

Automated detection of subtle changes in peripapillary retinal nerve fibre layer thickness (RNFLT) over time using optical coherence tomography (OCT) is limited by inherent image quality before layer segmentation, stabilization of the scan on the peripapillary retina and its precise placement on repeated scans. The present study evaluates image quality and reproducibility of spectral domain (SD)-OCT comparing different rates of automatic real-time tracking (ART).

Methods

Peripapillary RNFLT was measured in 40 healthy eyes on six different days using SD-OCT with an eye-tracking system. Image brightness of OCT with unaveraged single frame B-scans was compared to images using ART of 16 B-scans and 100 averaged frames. Short-term and day-to-day reproducibility was evaluated by calculation of intraindividual coefficients of variation (CV) and intraclass correlation coefficients (ICC) for single measurements as well as for seven repeated measurements per study day.

Results

Image brightness, short-term reproducibility, and day-to-day reproducibility were significantly improved using ART of 100 frames compared to one and 16 frames. Short-term CV was reduced from 0.94?±?0.31 % and 0.91?±?0.54 % in scans of one and 16 frames to 0.56?±?0.42 % in scans of 100 averaged frames (P?≤?0.003 each). Day-to-day CV was reduced from 0.98?±?0.86 % and 0.78?±?0.56 % to 0.53?±?0.43 % (P?≤?0.022 each). The range of ICC was 0.94 to 0.99. Sample size calculations for detecting changes of RNFLT over time in the range of 2 to 5 μm were performed based on intraindividual variability.

Conclusion

Image quality and reproducibility of mean peripapillary RNFLT measurements using SD-OCT is improved by averaging OCT images with eye-tracking compared to unaveraged single frame images. Further improvement is achieved by increasing the amount of frames per measurement, and by averaging values of repeated measurements per session. These strategies may allow a more accurate evaluation of RNFLT reduction in clinical trials observing optic nerve degeneration.     

Retinal vessel diameter in normal-tension glaucoma patients with asymmetric progression

Purpose

To investigate the longitudinal changes in the central retinal vessel diameter in asymmetric progressive normal-tension glaucoma (NTG) patients.

Methods

This study included 27 patients with bilateral NTG without any systemic vascular disease who showed glaucomatous progression in one eye at the mean follow-up of 24.3 months (range, 18–29 months). Progression was determined by the development of new retinal nerve fiber layer (RNFL) defects or widening of pre-existing defects on red-free RNFL photographs. The central retinal arteriolar equivalent (CRAE) and the central retinal venular equivalent (CRVE) were measured at baseline and at the mean follow-up of 24.3 months. We classified the eyes of each patient as either progressed or stable eyes, and compared the differences and changes in the CRAE and CRVE.

Results

No significant inter-eye difference was observed at baseline in the mean CRAE (167.5?±?22.2 μm vs. 168.2?±?15.5 μm, p?=?0.809) and in the mean CRVE (276.3?±?18.2 μm vs. 281.6?±?21.9 μm, p?=?0.267) between the progressed and stable eyes. There were significant changes in CRAE in the progressed eyes between baseline and 2 years after baseline (from 167.5?±?22.2 μm to 146.9?±?18.0 μm, p?p?=?0.084).

Conclusions

In our series of NTG patients with asymmetric progression, central retinal artery diameter decreased over time in the progressed eyes, whereas no significant decrease in the central retinal artery diameter was seen in the stable eyes.     

Lamina cribrosa thickness is not correlated with central corneal thickness or axial length in healthy eyes

Background

The aim of this study was to determine the relationship of the central corneal thickness (CCT) and axial length (AXL) with the central lamina cribrosa thickness (LCT) in healthy human eyes.

Methods

This was a prospective observational case series. The optic discs of 189 eyes from 100 healthy subjects with a refractive error smaller than ?8 diopters were scanned using enhanced-depth imaging spectral-domain optical coherence tomography (Spectralis OCT, Heidelberg Engineering, Heidelberg, Germany). The thickness of the lamina cribrosa (LC) was measured on B-scan images obtained at the center of the optic nerve head. A linear mixed-effects model was used to determine the factors associated with LCT, taking into account clustering of eyes within subjects.

Results

The thickness of the central LC was 273.19?±?34.74 μm (mean ± SD; range, 173.73–367.94 μm). Multivariate analysis revealed a significant influence of older age on increased central LCT (p?=?0.001). There was no significant association between central LCT and either CCT or AXL.

Conclusions

In this study, the central LCT increased significantly with older age in healthy human eyes. Neither CCT nor AXL was significantly associated with the central LCT in healthy human eyes with a spherical equivalent within the range from ?7.0 to +3.0 diopters.     

Overestimation of subfoveal choroidal thickness by measurement based on horizontally compressed optical coherence tomography images

Purpose

To measure the difference in subfoveal choroidal thickness between 1:1 pixel (horizontally compressed) images and 1:1 micron images in age-related macular degeneration.

Methods

This study included 122 eyes from 122 patients diagnosed with age-related macular degeneration. Choroidal thickness was measured using enhanced-depth imaging optical coherence tomography. The measurement line was drawn as a perpendicular line between Bruch’s membrane and the chorio-scleral interface. The thickness was compared between measurements based on a 1:1 pixel image and a 1:1 micron image. Eyes with a straight vertical measurement line and oblique measurement line were classified into vertical measurement group and oblique measurement group, respectively. Intra-group comparisons of subfoveal choroidal thickness measurements based on the 1:1 pixel images and the 1:1 micron images were performed for the two groups.

Results

The mean subfoveal choroidal thicknesses measured on the 1:1 pixel images and the 1:1 micron images were 232.3?±?106.4 μm and 228.9?±?108.1 μm, respectively (p?=?0.003). In the vertical measurement group (86 eyes), the mean subfoveal choroidal thickness was 226.3?±?109.9 μm and 225.4?±?112.0 μm, respectively (p?=?0.423). In the oblique measurement group (36 eyes), the thickness was 246.5?±?97.3 μm and 237.5?±?98.9 μm, respectively (p?<?0.001).

Conclusions

Significant overestimation of the subfoveal choroidal thickness was noted when it was measured on a 1:1 pixel image. This finding suggests that the measurement of choroidal thickness should be performed based on a 1:1 micron image, especially if the measurement line is not vertical.     

The scleral rigidity of eyes with different refractions

Background

The weakened biomechanical properties of the sclera is an important feature of myopic eyes. The quantitative evaluation in vivo of posterior scleral resistance to the elongation remains a challenge.

Methods

This study comprised 172 eyes from 86 subjects with a mean age of 20.6?years (range, 18–28?years). Ultrasound biometry was performed using an immersion technique and the A-scan device (the Biometer AL-1000 -TOMEY). The axial length of the eye was measured twice: before and during the application of an external pressure of 30?g on the eye. The difference between two mean values of AL measurements before and during the pressure application was considered as a degree of change in the axial length that resulted from the IOP elevation. The data were entered into an Excel spreadsheet (Microsoft Corp.) for subsequent analysis. Statistical analysis was performed using SigmaPlot software (version 11.0, Systat Software, Inc.). A value of 0.05 or less was considered statistically significant.

Results

The means ± SD of axial changes before and during the external pressure for hyperopia, emmetropia, myopia 0.5–3.0 D, myopia 3.25–6.0 D, myopia 6.25–12.0 D and myopia over 12.0 D were as follows: 0.03?±?0.01?mm, 0.05?±?0.01?mm, 0.18?±?0.07?mm, 0.31?±?0.02?mm, 0.38 ±?0.07?mm, and 0.51?±?0.9?mm, respectively. The difference among groups was statistically significant.

Conclusions

In conclusion, our study indicates that the biomechanical properties of the scleral coat, in terms of stretching and AL elongation, are measurable. The hypermetropic and emmetropic eyes possessed stiff sclera. The extent of AL remained practically unchanged during IOP elevation in these eyes. The absolute majority of the myopic eyes revealed a biomechanical weakness of the scleral shell. A higher degree of myopia was associated with increased AL elongation. Our approach to measuring the biomechanical properties of the sclera may have clinical significance in the future.     

Vitrectomy and internal limiting membrane peeling without gas tamponade for myopic foveoschisis

Purpose

To evaluate the efficacy of vitrectomy including internal limiting membrane (ILM) peeling without gas tamponade for myopic foveoschisis (MF).

Method

In this retrospective study, 15 eyes of 13 consecutive patients with MF underwent pars plana vitrectomy and ILM peeling without gas tamponade. The main outcomes were measured using best-corrected visual acuity (BCVA) and central macular thickness (CMT) on optical coherence tomography (OCT).

Result

The mean refractive error was ?11.0?±?8.2 diopters and mean axial length was 30.8?±?2.6?mm. The mean BCVA increased from 0.78?±?0.53 to 0.61?±?0.75 logMAR unit (p?=?0.05), and the mean CMT decreased from 405?±?143?μm to 255?±?47?μm (p?=?0.002) during a follow-up of 11.8?months. OCT showed a complete resolution of the MF, with foveal reattachment in all eyes. Full-thickness macular hole developed in two eyes during follow-up.

Conclusion

ILM peeling without gas tamponade results in favorable anatomical and visual outcomes.     

Pain score of patients undergoing single spot, short pulse laser versus conventional laser for diabetic retinopathy

Background

To compare pain score of single spot short duration time (20 milliseconds) panretinal photocoagulation (PRP) with conventional (100 milliseconds) PRP in diabetic retinopathy.

Methods

Sixty-six eyes from 33 patients with symmetrical severe non-proliferative diabetic retinopathy (non-PDR) or proliferative diabetic retinopathy (PDR) were enrolled in this prospective randomized controlled trial. One eye of each patient was randomized to undergo conventional and the other eye to undergo short time PRP. Spot size of 200 μm was used in both laser types, and energy was adjusted to achieve moderate burn on the retina. Patients were asked to mark the level of pain felt during the PRP session for each eye on the visual analog scale (VAS) and were examined at 1 week, and at 1, 2, 4 and 6 months.

Results

Sixteen women and 17 men with mean age 58.9?±?7.8 years were evaluated. The conventional method required a mean power of 273?±?107 mW, whereas the short duration method needed 721?±?406 mW (P?=?0.001). An average of 1,218?±?441 spots were delivered with the conventional method and an average of 2,125?±?503 spots were required with the short duration method (P?=?0.001). Average pain score was 7.5?±?1.14 in conventional group and 1.75?±?0.87 in the short duration group (P?=?0.001). At 1 week, 1 month, and 4 months following PRP, the mean changes of central macular thickness (CMT) from baseline in the conventional group remained 29.2 μm (P?=?0.008), 40.0 μm (P?=?0.001), and 40.2 μm (P?=?0.007) greater than the changes in CMT for short time group.

Conclusion

Patient acceptance of short time single spot PRP was high, and well-tolerated in a single session by all patients. Moreover, this method is significantly less painful than but just as effective as conventional laser during 6 months of follow-up. The CMT change was more following conventional laser than short time laser.     

Biometry and spectral domain optical coherence tomography parameters in children with large cupping

Purpose

The purpose of this study is to investigate optic nerve head using spectral domain optical coherence tomography (SD-OCT) in children with large cupping.

Methods

111 eyes (4–10 years) were divided into three groups according to the cup to disc ratio: group 1, ≤0.3; group 2, 0.4–0.6; and group 3, ≥0.7. The rim area, disc area, average cup to disc ratio, vertical cup to disc ratio, and cup volume were investigated using SD-OCT (Cirrus HD-OCT, Carl Zeiss, Jena, Germany), and the axial length and anterior chamber depth (ACD) were measured by IOL master (IOL master 500, Carl Zeiss, Jena, Germany). Next, we compared ocular biometry and SD-OCT between the three groups.

Results

The mean age of group1 was 6.48?±?1.42 years, 7.00?±?1.75 years in group 2, and 6.63?±?1.82 years in group 3 (p?=?0.370). A significant difference was seen in the spherical equivalent between the groups (p?=?0.001). Group 2 had the most myopic refractive errors. As the cup to disc ratio increases, disc area, average cup to disc ratio, vertical cup to disc ratio, and cup volume increase significantly. When the results of ocular biometry and SD-OCT are adjusted for axial length, only disc area showed a significant correlation with cup to disc ratio (ACD: p?=?0.473, rim area: p?=?0.639, disc area: p?=?0.005, and cup volume: p?=?0.325).

Conclusion

Axial length is the key factor determining disc size, which in turn is important for determining cup to disc ratio. Normal children with large cupping should be examined for axial length, myopic refractive errors, and disc size.     

Retikuläre Drusen über die Zeit mittels SD-OCT

Aim

The aim of the study was the analysis of reticular drusen (RDR) in patients with age-related macular degeneration using simultaneous confocal scanning laser ophthalmoscopy (cSLO) and spectral domain optical coherence tomography (SD-OCT) at different time points.

Methods

Included in this retrospective analysis were 47 eyes from 32 patients (median age 80.1 years, range 66–89 years) with RDR at baseline and at least one follow-up visit. Registration of the cSLO near-infrared reflectance image and the SD-OCT B-scan (Spectralis HRA + OCT, Heidelberg Engineering, Heidelberg) at different time points was carried out using the AutoRescan tool.

Results

While either no alterations or increase in the RDR area (n?=?19 eyes) or RDR density (n?=?15) were seen by cSLO imaging, the analysis of the SD-OCT B-scans at different time points revealed a more complex picture. An increase in two well visible lesions at the baseline visit was detected in 8 eyes at the first follow-up and in 3 eyes at the second follow-up examination. A regression was seen in 5 eyes at the first follow-up and in 3 eyes at the second follow-up visit. In most eyes (n?=?23), an increase of one with a parallel decrease of the second RDR lesion in the identical B-scan was identified at the first follow-up visit, whereas individual RDR showed an increase at the second follow-up examination that had initially shown a decrease in size at the first follow-up visit.

Conclusions

The results indicate underlying dynamic processes in the development and changes of RDR over time. For a more accurate analysis, the exact registration of SD-OCT B-scans at different time points and the use of high-resolution very dense volume scans would be helpful in order to assess such discrete changes of miniscule intraretinal lesions over time.     

Macular microcirculation in patients with epiretinal membrane before and after surgery

Background

To investigate blood flow velocity (BFV) in the perifoveal capillaries before and after vitreous surgery for patients with epiretinal membrane (ERM).

Methods

Twenty-one eyes in patients with ERM and 16 eyes in healthy subjects were involved in this study. Fluorescein angiography was performed using a scanning laser ophthalmoscope and BFV was analyzed by the tracing method. Foveal thickness (FT) was measured by optical coherence tomography.

Results

BFV was significantly slower in the ERM patients (1.04?±?0.10?mm/s) than in the healthy subjects (1.49?±?0.11?mm/s ) (p?=?0.0010). BFV in the ERM patients 6?months after vitreous surgery (6?M) (1.21?±?0.02?mm/s) significantly increased compared with BFV before surgery (0?M) (1.04?±?0.10?mm/s) (p?=?0.0061). BFV 1?year after vitreous surgery (1?Y) significantly increased (1.38?±?0.02?mm/s) compared with BFV(6?M) (1.21?±?0.02?mm/s) (p?=?0.0235). FT was significantly greater in the ERM patients (351.7?±?87.1?μm) than in the healthy subjects (158.9?±?16.9?μm) (p?=?0.0011). FT (6?M) significantly decreased (285.3?±?36.9?μm) compared with FT before surgery (0?M) (351.7?±?87.1?μm) (p?=?0.0212). FT did not show significant differences between (6?M) and (1?Y). No significant correlation was found between BFV and FT before surgery.

Conclusions

Perifoveal capillary BFV in patients with ERM was slower than that in the healthy subjects, and significantly improved after vitreous surgery as time progressed. It can be said that perifoveal capillary BFV is related to the development and improvement of ERM in the long term.     

A new method of cornea modulation with excimer laser for simultaneous correction of presbyopia and ametropia

Purpose

To investigate the outcomes of simultaneous correction of presbyopia and ametropia by a bi-aspheric cornea modulation technique, based on the creation of a central area hyperpositive for near vision and leaving the pericentral cornea for far vision in hyperopic, emmetropic, and myopic presbyopic patients.

Setting

Sixty eyes of 30 patients were treated with the PresbyMAX technique by one surgeon (D.U.) at the Eye Hospital Bellevue, Kiel, Germany.

Methods

Twenty eyes with hyperopic presbyopia, 20 eyes with emmetropic presbyopia, and 20 eyes with myopic presbyopia underwent Femto-Lasik, and were assessed up to 6?months postoperatively. All eyes underwent cornea treatment using the PresbyMAX? software, delivering a bi-aspheric multifocal ablation profile developed by SCHWIND eye-tech-solutions (Kleinostheim, Germany). All flaps were created by Ziemer LDV Femtolaser (Port, Switzerland).

Results

The mean binocular distance of uncorrected visual acuity (DUCVA) improved in the hyperopic group from 0.28?±?0.29 logMAR to ?0.04?±?0.07 logMAR, in the emmetropic group from ?0.05?±?0.07 logMAR to 0.02?±?0.11 logMAR, and in the myopic group from 0.78?±?0.27 logMAR to 0.09?±?0.08 logMAR. The mean binocular near uncorrected visual acuity (NUCVA) increased in the hyperopic group from 0.86?±?0.62 logRAD to 0.24?±?0.23 logRAD, and in the emmetropic group from 0.48?±?0.14 logRAD to 0.18?±?0.11 logRAD. The myopic presbyopes showed a decrease of the mean binocular NUCVA from 0.04?±?0.19 logRAD to 0.12?±?0.18 logRAD. The mean postoperative spherical equivalent for distance refraction was ?0.13?±?0.61 D for the hyperopic presbyopia, ?0.43?±?0.35 D for the emmetropic presbyopia, and ?0.68?±?0.42 D for the myopic presbyopia group, whereas the software took aim at ?0.50 D in all groups.

Conclusions

In presbyopic patients without symptomatic cataracts, but refractive errors, PresbyMAX? will decrease the presbyopic symptoms and correct far distance refraction in the same treatment, offering spectacle-free vision in daily life in most of the treated patients. Further investigation is necessary to evaluate the overall benefit of this procedure.