Investigation of blood flow regulation and oxygen saturation of the retinal vessels in primary open-angle glaucoma

Purpose

To examine the supply of oxygen to the retina in primary open-angle glaucoma (POAG).

Methods

Forty-one patients with primary open-angle glaucoma (mean age 64.1?±?12.9 years) and 40 healthy subjects (63.6?±?14.1 years) were included. Fundus images, centered at the optic disc, were taken using the Retinal Vessel Analyzer (RVA). The vessel diameters were calculated as central retinal artery (CRAE) and vein equivalent (CRVE) from diameter measurements in the peripapillary vessels. The oxygen saturation of the arteries and veins was investigated employing a two-wavelengths technique. After the measurement at baseline, the vascular response to flicker light exposure was measured.

Results

In glaucoma patients the mean oxygen saturation of the retinal veins at baseline was higher than in the healthy controls (64.36?±?7.11 vs. 59.78?±?8.47, p?=?0.01), whereas the mean arteriovenous oxygen saturation difference was lower (33.07?±?5.24 vs. 37.53?±?6.95, p?=?0.002). The arterial oxygen saturation as well as the arterial and venous diameters showed no difference between the groups. The increase of the CRVE during flicker light stimulation (3.72?±?3.29 % vs. 5.43?±?4.04, p?=?0.039), as well as the change of the venous oxygen saturation (2.08?±?3.74 % vs. 4.18?±?3.88 %, p?=?0.016) and the arteriovenous saturation difference (?2.1?±?3.31 % vs. ?4.43?±?3.6 %, p?=?0.003) were smaller in POAG patients than in the healthy group.

Conclusions

The reduction in the arteriovenous difference in oxygen saturation in POAG patients might show a decreased oxygen demand of the retina caused by the glaucomatous loss of neuroretinal tissue. The lower extent of the flicker light-induced change of the diameter of retinal veins and the venous oxygen saturation could indicate an impairment of blood flow regulation.     

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.     

Bimonthly injections of ranibizumab for age-related macular degeneration

Purpose

To evaluate the efficacy of bimonthly intravitreal injections of ranibizumab for age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV) in a pilot study.

Methods

This study was a prospective, interventional case series. Thirty eyes of 30 patients received prospectively at least three bimonthly intravitreal injections of ranibizumab (0.5 mg/0.05 ml) without loading doses. The best-corrected visual acuity (BCVA) and the central retinal subfield thickness (CRST) were measured before and monthly after the injections.

Results

Twenty-eight patients received the three planned injections; one patient refused the third injection, one patient did not receive the third injection because blood pressure was raised, and one patient received a rescue injection at month 5 because of increased retinal thickness. The mean logarithm of the minimum angle of resolution (logMAR) BCVA was 0.44?±?0.37 before treatment and significantly improved to 0.25?±?0.34 at month 6 (p?p?p?=?0.005). The mean CRST was 360?±?110.8 μm before treatment and decreased significantly to 249?±?57.0 μm at month 12 (p?=?0.025).

Conclusions

Bimonthly injections of ranibizumab may be effective for treating AMD and PCV.     

The influence of axial length on confocal scanning laser ophthalmoscopy and spectral-domain optical coherence tomography size measurements: a pilot study

Purpose

To investigate the influence of axial length on SD-OCT and cSLO size measurements from the Heidelberg Spectralis.

Methods

In this pilot study, eight emmetropic pseudophakic eyes with subretinal visual implant were selected. The axial length was measured in three short (<22.5 mm), three medium (22.51–25.50 mm) and two long (>25.52 mm) eyes. The known size of subretinal implant sensor field (2800?×?2800 μm) was measured on 15 images per eye with cSLO and SD-OCT.

Results

The mean axial length was 20.8?±?0.8 mm in short eyes, 23.3?±?0.4 mm in medium eyes, and 26.3?±?0.5 mm in long eyes respectively. We found in short eyes, in medium eyes and in long eyes a mean value of sensor field size measurements from cSLO of 3327?±?9 μm, 2800?±?9 μm and 2589?±?12 μm and from SD-OCT of 3328?±?9 μm, 2800?±?12 μm and 2585?±?19 μm respectively. The size measurements decreased in SD-OCT and cSLO measurements with longer axial lengths significantly (p?<?0.0001).

Conclusion

The present findings demonstrate accuracy of the scaling in cSLO and SD-OCT measurements of the Heidelberg Spectralis for emmetropic medium eyes. The size measurements from SD-OCT to those from cSLO were approximately equal. Caution is recommended when comparing the measured values of short and long eyes with the normative database of the instrument. Further studies with larger sample sizes are needed to confirm findings.     

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.     

The extended clinical phenotype of dome-shaped macula

Purpose

To describe the phenotype, associations, and complications of dome-shaped macula (DSM) through the combination of spectral-domain optical coherence tomography (OCT) imaging and B-scan ultrasonography, when available. This retroprospective cohort study aims to gain further pathophysiological understanding in eyes with DSM.

Methods

Fifty-eight eyes of 36 patients were identified as having OCT features of DSM. Retinal and choroidal thicknesses were determined from enhanced depth imaging (EDI)-OCT image sets, with scleral thickness subsequently calculated by subtraction from the B-scan ultrasound-derived measurements of posterior coat thickness.

Results

DSM was associated with myopia in 81 % of eyes. The underlying clinical diagnosis was variable: central serous chorioretinopathy (CSCR)-like entity, choroidal neovascularization, and inherited retinal disorders. The subfoveal choroidal thickness of the nine highly myopic eyes with a CSCR-like phenotype was thicker than the 25 eyes without CSCR (p?=?0.169). The mean subfoveal scleral thickness of the highly myopic eyes was 585?±?196 μm, which was significantly different from those with a refractive error less than 6 diopters (1133 ± 290 μm) (P?<?0.0001).

Conclusions

This study highlights the novel observation of a thickened choroid when CSCR is present. In addition, we expand the associations of DSM to eyes with hypermetropia and acquired disease, and to those with inherited retinal dystrophies.     

Comparison of Spectralis-OCT, GDxVCC and GDxECC in assessing retinal nerve fiber layer (RNFL) in glaucomatous patients

Background

Glaucomatous optic neuropathy is characterized by a progressive loss of retinal ganglion cells (RGCs). The defects in the peripapillary retinal nerve fiber layer (RNFL) have been reported to be the earliest sign of glaucoma. We determined the agreement between RNFL thickness assessments from spectral-domain OCT (Spectarlis HRA?+?OCT; Heidelberg Engeneering, Heidelberg, Germany), scanning laser polarimetry (SLP) with variable cornea compensation (GDxVCC; Carl Zeiss Meditec, Dublin, CA, USA), and SLP with enhanced cornea compensation (GDxECC; Carl Zeiss Meditec, Dublin, CA, USA) in glaucomatous patients. Furthermore, we investigate the influence of typical scan score (TSS) on the results of GDx assessments.

Methods

The enrolled subjects were devided into different groups by modified HODAPP visual field criteria. The peripapillary RNFL thickness was assessed with the three devices . ANOVA test, Pearson and Spearman correlation coefficient, and Bland-Altman plots were used to analyse the RNFL thickness assessments.

Results

Ninety-two eyes from 92 glaucomatous subjects were analysed. These were divided into four groups: preperimetric glaucoma (n?=?26), mild glaucoma (n?=?18), moderate glaucoma (n?=?21), and severe glaucoma (n?=?27). For Spectralis-OCT, the average RNFL thickness (mean ± SD) was 99.25?±?26.31 μm, 80.52?±?16.63 μm, 71.59?±?21.15 μm, and 63.85?±?20.86 μm for preperimetric, mild, moderate, and severe glaucoma respectively. For GDxVCC, the corresponding assessments were 52.63?±?8.18 μm, 52.95?±?10.20 μm, 46.77?±?10.62 μm, and 49.70?±?13.34 μm. For GDxECC, the assessments were 49.35?±?6.52 μm, 45.92?±?7.21 μm, 42.19?±?8.00 μm, and 39.53?±?8.45 μm. All Spectralis-GDxVCC and Spectralis-GDxECC differences were statistically significant by ANOVA test. The differences between GDxVCC and GDxECC were statistically significant only for severe glaucoma. There was a highly significant correlation between Spectralis-OCT and GDxECC, as well as Spectralis-OCT and GDxVCC, in assessing the RNFL thickness. The best instrument agreement was found between GDxECC and Spectralis-OCT. The RNFL thickness assessed with Spectralis-OCT and GDxECC showed a better correlation to visual field defects than GDxVCC. Evaluating GDx assessments with typical retardation pattern GDxVCC and GDxECC showed very similar RNFL thickness results.

Conclusions

RNFL thickness assessments between GDxVCC, GDxECC, and Spectralis-OCT cannot be directly compared. The assessments are generally higher with Spectralis-OCT than with GDxVCC and GDxECC, because of differences in method of the devices. The atypical retardation pattern has a major impact on the RNFL thickness results of GDx devices. This must be taken into account when evaluating the assessed RNFL thickness results.     

Relationship between disc margin to fovea distance and central visual field defect in normal tension glaucoma

Background

To investigate the relationship between ocular geometric factors, including temporal disc margin to fovea distance (DFD) measured by optic disc stereophotography (ODP) and central visual field (VF) defect, in normal-tension glaucoma (NTG) patients.

Methods

This retrospective, single-center, cross-sectional study included 88 eyes of 88 NTG patients with mild VF defects (MD?>??6.0 dB). NTG patients were divided into two groups according to VF tests: central VF-invading and central VF-sparing groups. Optic nerve head (ONH) parameters including disc dimensions, peripapillary atrophy (PPA), and DFD were obtained by ODP, and retinal nerve fiber layer (RNFL) thickness was measured by Stratus optical coherence tomography (OCT).

Results

In the invading group, DFD was shorter (3.642?±?0.401 mm) than in the sparing group (3.877?±?0.278 mm; p?=?0.002). The sparing group had more vertically oval ONH (p?=?0.023) and wider temporal PPA width (p?=?0.031). The RNFL thickness in the invading group was thinner in the temporal and inferior quadrants, but thicker in the superior quadrant than that of the sparing group. In a multiple linear regression analysis, DFD was the only geometric factor associated with degree of central VF involvement (p?=?0.002). DFD was positively correlated with temporal RNFL thickness in the sparing group (r?=?0.484, p?<?0.001) but not in the invading group (r?=??0.080, p?=?0.631).

Conclusions

Eyes with a shorter DFD should be monitored carefully because central VF involvement appears to be related to shorter DFD in NTG patients with mild VF defects.     

Evaluating retinal vessel diameter with optical coherence tomography in normal-tension glaucoma patients

Purpose

To investigate a novel optical coherence tomography (OCT)-derived variable, circumpapillary mean retinal shadow width (cpMRSW), and to elucidate its association with normal-tension glaucoma (NTG).

Methods

For the purpose of validation, we measured retinal vascular calibers in 68 arterioles and 100 venules of 12 NTG patients and 12 healthy subjects and compared the width of the visible retinal shadows in spectral-domain OCT images and the caliber of retinal vessels in retinal photographs. Then we calculated cpMRSW in 78 NTG eyes and 25 age-matched healthy control eyes. Additionally, we divided the patients into early (mean deviation: MD > ?6 dB), moderate (MD ?6 to ?12 dB), and severe (MD < ?12 dB) NTG groups, and compared cpMRSW in these groups. Finally, we calculated the area under the receiver operating characteristic (ROC) curve in order to determine the power of mean retinal shadow width to distinguish the groups.

Results

OCT retinal shadow width was significantly correlated with photography-measured retinal caliber (r = 0.82, P < 0.001). CpMRSW was significantly different between the control and NTG patients (control: 107.3 ± 7.0 µm, mild: 99.4 ± 8.6 µm, moderate: 99.7 ± 9.5 µm, severe: 90.5 ± 12.0 µm, P < 0.001), despite similar distributions in systemic variables. An ROC analysis revealed that cpMRSW could differentiate NTGs from normal eyes (area under the ROC curve: 0.81).

Conclusions

Our new software for measuring mean retinal shadow width in OCT images may be a valuable tool for detecting NTG and diagnosing its severity.

     

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.     

Retinal venous pressure in the non-affected eye of patients with retinal vein occlusions

Background

To measure the retinal venous pressure (RVP) in both eyes of patients with unilateral central retinal vein occlusions and to compare these values to controls.

Methods

The study included 31 patients with unilateral central retinal vein occlusions (CRVO) and 31 controls who were matched by age, sex, and systemic disease. RVP was measured in all patients bilaterally by means of contact lens ophthalmodynamometry, and the RVP measurements of the affected and unaffected eyes of patients were compared to the RVPs of controls. Ophthalmodynamometry is done by applying an increasing pressure on the eye via a contact lens. The minimum force required to induce a venous pulsation is called ophthalmodynamometric force (ODF). The RVP is defined and calculated as the sum of ODF and intraocular pressure (IOP) [RVP = ODF + IOP].

Results

The RVP group means ± SD were as follows: patient’s affected eyes (45.0?±?11.6 mmHg), patient’s unaffected eyes (38.0?±?11.1 mmHg) ,and (17.7?±?6.7 mmHg) in the eyes of controls. The values of RVP, even in the patients unaffected eyes, were significantly higher than in the eyes of controls (P?< 0.001).

Conclusions

In patients with CRVO, the RVP is increased in both the affected as well as in the unaffected contralateral eye.     

Retinal and optic nerve evaluation by optical coherence tomography in adults with obstructive sleep apnea–hypopnea syndrome (OSAHS)

Objective

To assess the peripapillary retinal nerve fiber layer (RNFL) thickness, optic nerve head (ONH) morphologic parameters, and macular thickness and volume in patients affected by obstructive sleep apnea–hypopnea syndrome (OSAHS).

Methods

This prospective, observational case-control study consisted of 96 eyes of 50 OSAHS patients (mean age of 50.9?±?12.4 years, best-corrected visual acuity ≥20/20, refractive error less than 3 spherocylindrical diopters, and intraocular pressure <21 mmHg) who were enrolled and compared with 64 eyes of 33 age-matched controls. Peripapillary RNFL thickness, ONH parameters, macular thickness and volume were measured by optical coherence tomography (OCT).

Results

OSAHS patients showed a significant reduction of the nasal quadrant RNFL thickness (74.7?±?15.8 μm) compared with those values observed in control patients (81.1?±?16.6 μm, p?=?0.047, Student's t-test). No differences in peripapillary RNFL thickness were observed when dividing the OSAHS group in accordance with disease severity. Vertical integrated rim area (VIRA) (0.67?±?0.41 mm³ in OSAHS vs 0.55?±?0.29 mm³ in controls; p?=?0.043, Student's t-test), horizontal integrated rim width (HIRW) (1.87?±?0.31 mm² in OSAHS vs 1.8?±?0.25 mm² in controls; p?=?0.039, Student's t-test) and disc area (2.74?±?0.62 mm² in OSAHS vs 2.48?±?0.42 mm² in controls; p?=?0.002, Student's t-test) showed significant differences, all of them being higher in the OSAHS group. Severe OSAHS had significant higher disc area (2.8?±?0.7 mm²) than controls (2.5?±?0.4 mm²; p?=?0.016, ANOVA test). Temporal inner macular thickness was significantly higher in mild–moderate OSAHS patients (270?±?12 μm) than in severe OSAHS patients (260?±?19 μm; p?=?0.021, ANOVA test).

Conclusions

OSAHS patients showed decreased peripapillary nasal RNFL thickness, and increased ONH area and volume parameters when they were evaluated by OCT. These findings suggest that neuronal degeneration might be present in the retina of OSAHS patients, as previously observed in some neurodegenerative disorders     

Long-term chorioretinal changes after photodynamic therapy for chronic central serous chorioretinopathy

Purpose

To evaluate morphological and functional chorioretinal changes 5 years after standard photodynamic therapy (PDT) for chronic central serous chorioretinopathy (CSC).

Methods

A retrospective, nonrandomized study, including patients with chronic CSC treated with standard PDT and followed for at least 60 months. All patients underwent a complete ophthalmological examination, and the location and number of treatments were registered. Five or more years after treatment, subfoveal and non-subfoveal treated areas were evaluated with Spectralis optical coherence tomography and microperimetry.

Results

Seventeen eyes of 15 patients were included, with mean age of 48.3?±?8.4 years and a mean follow-up of 80.6?±?12.4 months (range from 62 to 104 months). All eyes had neurosensory detachment (NSD) at baseline. Treatment was performed under the fovea in 58.8 % and in a non-foveal area in 41.2 % of the eyes. At the final visit all eyes had resolution of the NSD, with a statistical significant reduction in central macular thickness (p?=?0.005) and preserved neuroretinal thickness (p?=?0.839). There was a statistical difference between initial and final BCVA (p?<?0.001) and a mean gain of 8.4?±?7.8 letters. Subfoveal morphological changes in external limiting membrane (ELM) and in photoreceptor inner and outer segment junction (IS/OS) were correlated with final BCVA (p?=?0.015 and p?=?0.014 respectively), but not with the variation of BCVA. There was a statistical correlation between morphological changes in IS/OS line and retinal sensitivity in the central 12° and 2° (p?=?0.003 and p?=?0.002 respectively). The morphological changes in the subfoveal layers were not dependent on treatment location (p?=?0.154, p?=?0.644, and p?=?1.0 for ELM, IS/OS line, and retinal pigment epithelium respectively). Subfoveal final mean choroidal thickness was 295.1?±?68.7 μm, and showed no statistical difference from the normal population (p?=?0.633).

Conclusions

Morphological and functional chorioretinal changes, observed 5 or more years after standard PDT for chronic CSC, were not correlated with the location of treatment, neither with the progression of visual acuity or with the location of treatment, and are more likely to be related to the disease itself than with the treatment provided.     

The effect of photodynamic therapy on macular sensitivity in eyes with acute central serous chorioretinopathy

Background

To evaluate the effect of half-fluence rate indocyanine green angiography (ICGA)-guided verteporfin photodynamic therapy (PDT) on macular sensitivity (MS) in eyes with acute symptomatic central serous chorioretinopathy (CSC).

Methods

Single-center consecutive case series by retrospective chart review. Sixteen eyes of 16 patients with acute CSC of 3 months duration or less, treated with half-fluence (25 mJ/cm²) ICGA-guided verteporfin PDT were reviewed. At baseline and after 1, 3, and 6 months, all patients underwent MS testing of the central 20 °, MS testing of the retinal area covered by the PDT laser spot (MSLS), and evaluation of fixation stability (FS) for the central two degrees with the MP-1 microperimeter (Nidek, Vigonza, Italy).

Results

Macular sensitivity improved from 16.4?±?3.0 dB at baseline (n?=?16) to 18.2?±?2.4 dB (p?<?0.001) at 1 month (n?=?16). At the 3-month (n?=?13) and 6-month (n?=?12) follow-up, MS stabilized at 19.5?±?0.9 dB (p?=?0.21) and 19.0?±?1.3 dB (p?=?0.74), without changes when compared to respective precedent follow-up. Mean MSLS improved from 12.9?±?5.4 dB at baseline to 16.4?±?4.9 dB (p?<?0.001) after 1 month. At the 3- and 6-month follow-up, MSLS was 19.1?±?1.2 dB (p?=?0.1) and 18.9?±?1.9 dB (p?=?0.8) respectively. Mean FS at the central 2 ° was 78.8?±?30.4 % before treatment and 81.8?±?29.5 % (p?=?0.7), 81.9?±?27.5 % (p?=?0.7) and 83.6?±?17.1 % (p?=?0.5) respectively 1, 3 and 6 months after treatment.

Conclusion

Half-fluence (25 mJ/cm²) PDT significantly increased mean MS of central 20 ° and mean MSLS, in eyes with acute symptomatic CSC. Fixation stability was stable at baseline and throughout 6 months of follow-up.     

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.     

Long-term follow-up of OCT-guided bevacizumab treatment of macular edema due to retinal vein occlusion

Background

To evaluate the long-term outcome of an OCT-guided reinjection scheme for bevacizumab treatment of macular edema (ME) due to retinal vein occlusion.

Methods

Patients with persistent ME (>250 μm) due to central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO) received intravitreal bevacizumab 2.5 mg/0.1 ml. Visual acuity (ETDRS), ophthalmic examination and OCT were performed at baseline and at 6- to 8-week intervals. Reinjections were only performed if OCT showed persistent or recurrent ME.

Results

Sixty-one patients with a minimum follow-up of 25 weeks were included in this analysis. Mean follow-up was 60?±?29 wks. In CRVO patients, central retinal thickness (CRT) decreased from 748?±?265 µm to 372?±?224 µm (p?<?0.001) and visual acuity (VA) improved by 1.9?±?3.2 lines. In BRVO patients, mean CRT decreased from 601?±?206 µm to 386?±?178 µm (p?<?0.001) and VA improved by 1.8?±?2.6 lines. Thirty-three percent of CRVO and 15% of BRVO patients did not show a ME recurrence for ≥25 wks at last visit. Thirty-seven percent of CRVO and 50% of BRVO patients suffered recurrences of ME within the last 25 wks, whereas 30% of CRVO and 35% of BRVO patients did not achieve a complete resolution of ME at any follow-up visit after receiving a minimum of three injections. CRVO patients with dry interval of ≥25 weeks at last visit were significantly younger, had a thinner CRT at baseline and more often had a complete resolution of ME after the first injection. In CRVO and BRVO, final VA was correlated significantly with initial VA, patients’ age and final CRT. Change of VA was correlated with change of CRT in BRVO.

Conclusions

Patients with retinal vein occlusion benefit from treatment with bevacizumab. Favourable long-term results without necessity of further injections were achieved in 33% and 15% of CRVO and BRVO patients respectively. The remaining patients needed repeated injections to treat ME recurrences. However, one third of the CRVO/BRVO patients did not improve in VA, and further injections might be discontinued in these patients.     

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.     

Tocilizumab treatment for refractory uveitis-related cystoid macular edema

Background

This retrospective study investigated the efficacy of tocilizumab (TCZ), a fully humanized antibody that binds both to soluble and membrane bound IL-6 receptors, for the treatment of uveitis-related cystoid macular edema (CME) refractory to immunomodulatory therapy.

Methods

Five refractory patients with uveitis-related CME who received TCZ between January and August 2012 were included. All patients received 8 mg/kg TCZ at 4-week intervals. Data regarding patient demographics, use of immunosuppressive drugs, biologic agents or intravitreal therapies prior to TCZ infusions were collected. Main outcome measure was central foveal thickness (CFT) measured by optical coherence tomography at 6 months. Secondary outcome measures were degree of anterior and posterior chamber inflammation (Standardization of Uveitis Nomenclature Working Group criteria) and visual acuity (logarithm of the minimum angle of resolution [log-MAR]) at month 6. Adverse events (AEs) related to TCZ therapy were also assessed.

Results

Eight eyes from five patients (all females) were included. Mean age was 49.4 years (range, 30–68). Mean follow-up was 8.4 months (range, 6–12). Before TCZ, all patients received and failed conventional immunosuppressive therapy and had received at least another biologic agent. Uveitis diagnoses were Birdshot chorioretinopathy (n?=?3), juvenile idiopathic arthritis (JIA)-associated uveitis (n?=?1), and idiopathic panuveitis (n?=?1). Mean evolution of CME was 13.4 years (range, 2–30). Mean baseline CFT (95 % confidence interval) was 602?±?236 μm at baseline, 386?±?113 μm at month 1 (p?=?0.006), 323?±?103 μm at month 3 (p?=?0.026), and 294.5?±?94.5 μm at month 6 (p?=?0.014). Median best-corrected visual acuity (BCVA) improved from 0.66?±?0.57 at baseline to 0.47?±?0.62 at month 6 (p?=?0.035). After 6 months, an improvement of ≥ 2 lines of BCVA was observed in 50 % of eyes (p?=?0.028) remained stable in 25 % and worsened in none of the patients. Sustained uveitis remission was achieved in all patients. No AEs were reported.

Conclusions

These data suggest that TCZ is effective for treating CME in otherwise treatment-refractory cases of uveitis.     

Retinal vascular changes following intravitreal ranibizumab injections for neovascular AMD over a 1-year period

Purpose

To assess retinal vascular calibre changes in eyes with neovascular age-related macular degeneration (AMD), treated with intravitreal anti-vascular endothelial growth factor agents, over a 1-year period and compare any such changes to untreated fellow eyes.

Methods

Treatment naïve patients with neovascular AMD received three consecutive intravitreal injections of ranibizumab, followed by a pro re nata dosing regimen up to 1 year, with the aim of maintaining a ‘fluid-free'' macula. Retinal arteriolar and venular calibre was measured from digital fundus photographs at baseline and at three monthly intervals to 1 year, and summarised as central retinal artery equivalent (CRAE) and central retinal venular equivalent (CRVE), respectively.

Results

A total of 53 injected eyes and 41 fellow, non-injected eyes were analysed. At baseline, there were no differences in retinal vascular calibre between injected and non-injected eyes (mean CRAE (SD) 144.93 (14.07) vs 145.74 (13.10) μm, P=0.80 and mean CRVE (SD) 216.23 (25.93) vs 219.91 (22.82) μm, P=0.53). Over a 12-month period, retinal venular calibre dilatation occurred in injected eyes (mean CRVE change +5.71 (14.71) μm, P=0.007), with no change in retinal arterioles, +0.69 (14.71) μm, P=0.68. In non-injected eyes, arteriolar narrowing occurred as a whole, mean CRAE change −4.20 (7.00) μm, P=0.001, over 12 months, with a trend for narrowing in venules, −2.16 (11.56) μm, P=0.28. In injected eyes, after controlling for covariates, the changes in CRVE over 12 months mirrored improvements in macular thickness, −0.06 (−0.005, −0.11) μm, P=0.04, and visual acuity, +9.66 (−0.30, +19.32) μm, P=0.06.

Conclusion

Intravitreal ranibizumab significantly dilated retinal venules after a 1-year period.     

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.