Evaluation of choroidal thickness using spectral-domain optical coherence tomography in migraine patients during acute migraine attacks: a comparative study

Purpose

The purpose of this study was to assess choroidal thickness in migraine patients during acute migraine attacks and compare them with healthy controls, using spectral domain optical coherence tomography (OCT).

Patients and methods

In this prospective case–control study, choroidal thicknesses of 46 migraine patients during acute migraine attacks and 46 age- and sex-matched healthy subjects were measured using a high-speed, high-resolution frequency domain-OCT device. All patients underwent a complete ophthalmic examination before the measurements. OCT measurements were taken at the same time of day (0900 hours), in order to minimize the effects of diurnal variation.

Results

There was a statistically significant difference in mean choroidal thickness between the migraine patients during acute migraine attacks (356.3±21.46 μm) and the controls (302.3±18.34 μm; P=0.000). There were significant differences at all measurement points (P<0.001 for all).

Conclusion

The increased choroidal thickness of the migraine patients during acute migraine attacks might be related to the vascular pathology of the disease. Further studies are needed to evaluate the etiopathologic relationship between choroidal thickness and acute migraine attack.     

Simplified Method to Measure the Peripapillary Choroidal Thickness Using Three-dimensional Optical Coherence Tomography

Purpose

To evaluate a simplified method to measure peripapillary choroidal thickness using commercially available, three-dimensional optical coherence tomography (3D-OCT).

Methods

3D-OCT images of normal eyes were consecutively obtained from the 3D-OCT database of Korea University Medical Center On the peripapillary images for retinal nerve fiber layer (RNFL) analysis, choroidal thickness was measured by adjusting the segmentation line for the retinal pigment epithelium to the chorioscleral junction using the modification tool built into the 3D-OCT image viewer program. Variations of choroidal thickness at 12 sectors of the peripapillary area were evaluated.

Results

We were able to measure the peripapillary choroidal thickness in 40 eyes of our 40 participants, who had a mean age of 41.2 years (range, 15 to 84 years). Choroidal thickness measurements had strong inter-observer correlation at each sector (r = 0.901 to 0.991, p < 0.001). The mean choroidal thickness was 191 ± 62 µm. Choroidal thickness was greatest at the temporal quadrant (mean ± SD, 210 ± 78 µm), followed by the superior (202 ± 66 µm), nasal (187 ± 64 µm), and inferior quadrants (152 ± 59 µm).

Conclusions

The measurement of choroidal thickness on peripapillary circle scan images for RNFL analysis using the 3D-OCT viewing program was highly reliable and efficient.     

Evaluation of ocular pulse amplitude and choroidal thickness in diabetic macular edema

Purpose

The aim of this study is to evaluate the ocular pulse amplitude (OPA) and choroidal thickness (CT) measurements in patients with diabetic macular edema (DME) and healthy subjects.

Methods

A total of 34 patients (12 male and 22 female) who had type 2 diabetes mellitus with DME and 34 sex-matched healthy subjects (13 male and 21 female) were included in this prospective study. The intraocular pressure (IOP) and OPA were measured with Dynamic contour tonometer (Pascal DCT, Switzerland). The subfoveal CT was measured using the Cirrus HD-OCT (Carl Zeiss Meditec). The CT at 1500 μm and 3000 μm nasal and temporal to the central fovea was also measured.

Results

The mean IOP values were 18.4±3.5 and 17.1±2.1 mm Hg in DME patients and healthy controls, respectively (P= 0.091). The mean OPA values in patients with DME (2.58±0.96) and controls (3.52±1.03) were statistically different (P<0.001). The mean subfoveal CT value was 273.5±30.2 μm in the eyes with DME and 321.4±36.5 μm in the control group (P< 0.001). In both groups, linear regression analysis showed no significant association between OPA and CT measurements. The IOP showed a significantly positive correlation with OPA in both DME (P=0.002, r=0.526) and controls (P=0.004, r=0.483).

Conclusions

The current study suggests that both pulsatile choroidal blood flow and CT are decreased in patients with DME.     

Correlation of visual field defects and optical coherence tomography finding in migraine patients

Aim of work

The aim of our work was to detect any structural or functional visual defects during and in between the attacks in patients with migraine.

Patient and methods

Sixty patients with migraine as well as sixty age and sex matched controls were included. All cases were subjected to full ophthalmological examination. Cases with any previously known optic nerve abnormalities or with history of increased intraocular pressure were excluded from this study. A full threshold 24-2 automated perimetry as well as optical coherence tomography (OCT) were performed for retinal nerve fiber layer (RNFL) thickness. Correlations between results of study group with migraine and controls were analyzed and recorded.

Results

There was a statistically significant difference between the patients with migraine and the controls in visual field analysis which was (P < 0.05) for generalized visual field deficits and (P < 0.001) for localized visual field deficits during the attack with no statistically significant difference in visual field in between the attacks (P > 0.05). OCT RNFL thickness had no statistically significant difference between migraine and control groups (P > 0.05).

Conclusion

Migraine can cause functional ocular disorder without any structural abnormalities.     

The effect of head tilt on keratometric measurement using the IOLMaster

Purpose

To investigate the effect of head tilt on keratometric measurement using the IOLMaster.

Methods

Twenty-seven right eyes of 27 volunteers were examined using a manual keratometer (MK), automated keratometer (AK), and an IOLMaster. MK and AK measurements were performed in the upright head position, whereas IOLMaster measurements were performed in five different head positions (upright, 5° or 15° clockwise head tilt, and 5° or 15° counter-clockwise head tilt). The repeatability of IOLMaster was compared with MK and AK. The keratometric measurements (mean keratometric power, magnitude of astigmatism, and steep meridian) in different head positions were compared.

Results

The IOLMaster showed good repeatability of keratometric measurement comparable to MK or AK. 15° and 5° clockwise head tilt resulted in 12.09±9.51 (mean±SD) (P<0.001 vs upright) and 5.51±5.97 (mean±SD) degrees (P<0.001) of clockwise rotation of steep meridian, respectively. 15° and 5° counter-clockwise head tilt resulted in 12.49±7.07 (mean±SD) (P<0.001) and 6.08±5.09 (mean±SD) degrees (P<0.001) of counter-clockwise rotation of steep meridian, respectively.

Conclusions

The patient''s head tilt (5° or 15°, clockwise or counter-clockwise) significantly changed the steep meridian of astigmatism measured using IOLMaster and the steep meridian generally shifted to the direction of head tilt. The importance of maintaining the upright head posture during IOLMaster measurement is demonstrated.     

Comparison of subfoveal choroidal thickness in healthy pregnancy and pre-eclampsia

Purpose

Pregnancy is a known predisposing factor for central serous chorioretinopathy (CSC). Choroidal thickness (CT) increases in patients with CSC. This study was designed to evaluate CT in pregnant women.

Patients and methods

This was a prospective study. Fourteen healthy pregnant women and seven patients with pre-eclampsia were included. Twenty-one normal subjects were also recruited. CT was measured using enhanced-depth imaging optical coherence tomography.

Results

The mean CT of normal subjects, healthy pregnant women and patients with pre-eclampsia were 264.95±21.03, 274.23±29.30 and 389.79±25.13 μm, respectively (normal subjects vs healthy gravidas: P>0.05; normal subjects vs pre-eclampsia: P<0.001; healthy gravidas vs pre-eclampsia: P<0.001). CT decreased from 381.05±22.96 μm to 335.17±9.97 μm 1 week after delivery in patients with pre-eclampsia.

Conclusions

Pregnancy itself did not increase CT, whereas pre-eclampsia did appear to result in increased CT. This suggests that additional unknown factors induce hyperpermeability in pregnant women.     

Evaluation of choroidal thickness using enhanced depth imaging by spectral-domain optical coherence tomography in patients with pseudoexfoliation syndrome

Purpose

To investigate the choroidal thickness using optical coherence tomography in the eyes of patients with unilateral and bilateral pseudoexfoliation syndrome and to compare them with healthy controls.

Methods

We studied four groups: (1) affected eyes from 30 patients with unilateral PEX syndrome affecting the right eye of 17 patients and the left eye of 13 patients; (2) clinically unaffected eyes of 30 patients with unilateral PEX syndrome; (3) the eyes of 30 patients with bilateral PEX syndrome; and (4) the eyes of 30 normal healthy subjects. Choroidal thickness was evaluated using high-speed, high-resolution enhanced depth imaging by spectral-domain optical coherence tomography. Optical coherence tomography features were compared in all groups using the statistical package SPSS v 15.0.

Results

The mean subfoveal choroidal thicknesses were 237.35±58.01 μm in group 1; 330.75±47.84 μm in group 2; 206.3±86.75 μm in group 3; and 311.8±51.42 μm in group 4. Significant differences in the mean subfoveal choroidal thickness were found between groups 1 and 2 (P<0.001), groups 1 and 4 (P=0.004), groups 2 and 3 (P<0.001), and groups 3 and 4 (P<0.001).

Conclusion

In this study, it was observed that clinically affected eyes of patients with PEX syndrome have significantly thinner choroids compared with the clinically unaffected eyes of patients with unilateral PEX syndrome and eyes of healthy controls.     

Chorio-retinal thickness measurements in patients with acromegaly

Purpose

To compare choroidal, foveal, and peripapillary retinal thickness between patients with acromegaly and healthy adults.

Methods

This prospective, cross-sectional, and comparative study included 30 patients with acromegaly (study group) and 30 healthy subjects (control group). The subfoveal choroidal thickness (SFCT), foveal thickness, and peripapillary retinal nerve fibre layer thickness were measured with spectral domain optical coherence tomography.

Results

The mean SFCT in the study group and in the control eyes was 374.4±98.1 and 308.6±77.3 μm, respectively (P<0.001). The mean thinnest foveal thickness value was 233.2±22.4 μm in the acromegaly group and 222.8±13.9 μm in the control group (P=0.003). The mean peripapillary retinal nerve fibre layer thickness did not differ significantly between the groups (P=0.34).

Conclusion

The SFCT and foveal thickness were significantly higher in patients with acromegaly, whereas peripapillary retinal nerve fibre layer thickness was similar between the groups.     

Transitioning to intravitreal aflibercept following a previous treat-and-extend dosing regimen in neovascular age-related macular degeneration: 24-month results

Purpose:

To evaluate frequency of injections, visual and anatomical outcomes of neovascular age-related macular degeneration (nAMD) patients transitioned to intravitreal aflibercept after failure to extend treatment interval beyond 8 weeks with prior intravitreal bevacizumab or ranibizumab.

Methods:

Retrospective review of patients with nAMD switched to aflibercept following ≥6 prior intravitreal ranibizumab or bevacizumab injections at 4–8-week intervals. Three monthly aflibercept injections were given followed by a treat-and-extend dosing regimen.

Results:

Twenty-one eyes of 18 patients who had received a mean of 23.8±18.8 (mean±SD; range 6–62) prior ranibizumab or bevacizumab injections were included. Over a mean follow-up of 24 months after the transition, 9.2±2.9 (range 4–21) aflibercept injections were required. Interval between aflibercept injections increased to 57.3 days (range 35–133 days), as compared with 37±6.1 days (range 29–54 days) with the prior agents (P=0.01). Mean best-corrected visual acuity was preserved (0.42±0.31 vs 0.42±0.23 logMAR; P=0.2). Mean OCT central subfoveal thickness (292.1±83.2 μm to 283.6±78.6 μm; P=0.4) and mean macular volume (7.9±0.95 mm³ to 7.67±0.94 mm³; P=0.16) remained stable.

Conclusion:

Patients requiring treatment more frequently than every 8 weeks with ranibizumab and bevacizumab were transitioned to >8-week treatment interval with aflibercept while maintaining the anatomic and visual gains.     

Choroidal thickness in both eyes of patients with unilaterally active central serous chorioretinopathy

Objective

To assess the change in the choroidal thickness of the unaffected eyes in patients with unilateral central serous chorioretinopathy (CSC).

Methods

Thirty eyes with unilateral idiopathic CSC and 30 age-matched normal eyes were included in this study. Choroidal thickness was evaluated from images obtained by enhanced depth image optical coherence tomography. The choroidal thicknesses of the affected eyes, unaffected eyes, and normal eyes were analyzed. Choroidal vascular dilation and hyperpermeability on indocyanine green angiography (ICGA) were analyzed and correlated with the changes in choroidal thickness.

Results

The mean choroidal thicknesses of the affected eyes, unaffected fellow eyes, and normal individuals were 445.58±100.25, 378.35±117.44, and 266.80±55.45 μm, respectively. Compared with normal eyes, subfoveal choroidal thickness was increased significantly in the eyes with active CSC and in the unaffected fellow eyes (P<0.001 in both groups). The choroidal thickness was significantly greater in the eyes with active CSC than in the unaffected fellow eyes (P=0.003). ICGA revealed choroidal vascular hyperpermeability in 28 (93.3%) eyes with CSC and in 23 (73.3%) unaffected fellow eyes. Choroidal vascular dilation was detected in 21 (70.0%) eyes with CSC and in 18 (60.0%) unaffected fellow eyes.

Conclusion

Increased choroidal thickness in patients with unilateral CSC was noted not only in the affected eyes, but also in the unaffected fellow eyes. The results of this study suggest that CSC might be an essentially bilateral disorder.     

High intravitreal TGF-β1 and MMP-9 levels in eyes with retinal vein occlusion

Purpose

Vascular endothelial growth factor is a leading target to reduce macular oedema and improve visual acuity in patients with retinal vein occlusion (RVO), whereas the role of vascular destabilizing and fibroproliferative transforming growth factor (TGF)-β1 and matrix metalloproteinases (MMP)-2 and -9 in pathological manifestations of RVO is anticipated but less studied.

Methods

Undiluted vitreous samples were collected from three central RVO and one branch RVO eyes, all with neovascularization and fibrosis-related sight-threatening complications of RVO. Undiluted vitreous samples of 40 eyes operated due to non-ischemic condition either macular hole or pucker were used as controls. Growth factor and protease concentrations were measured by ELISA and gelatin zymography.

Results

Vitreous concentrations of TGF-β1 (92.0±17.4 pg/ml vs 18.3±27.0 pg/ml, mean±SD; P=0.002) and MMP-9 (847.9±1196.4 AU/ml vs 87.7±174.0 AU/ml; P=0.010) were higher in the eyes with ischemic RVO than in the controls.

Conclusions

High intravitreal levels of TGF-β1 and MMP-9 are found in RVO eyes having neovascular and fibrosis manifestation. Further studies are warranted to elucidate whether targeting TGF-β1 and MMP-9 could be beneficial in patients with ischemic RVO.     

Intravitreal Anti-vascular Endothelial Growth Factor for Typical Exudative Age-related Macular Degeneration in Eyes with Good Baseline Visual Acuity

Purpose

To investigate 12-month treatment outcomes of anti-vascular endothelial growth factor therapy in eyes with typical exudative age-related macular degeneration with good baseline visual acuity.

Methods

This retrospective observational case series included 18 eyes (18 patients) with typical exudative age-related macular degeneration with a baseline best-corrected visual acuity of 20 / 25 or better. Patients were treated with anti-vascular endothelial growth factor monotherapy during the 12-month follow-up period. Baseline visual acuity and central foveal thickness were compared to the values at 12 months.

Results

Patients received an average of 4.4 ± 1.3 intravitreal anti-vascular endothelial growth factor injections. The mean logarithm of minimum angle of resolution visual acuity was 0.08 ± 0.04, 0.08 ± 0.07, 0.12 ± 0.09, and 0.16 ± 0.11 at baseline, three months, six months, and 12 months, respectively. Visual acuity at 12 months was significantly worse than the baseline value at diagnosis (p = 0.017), and the mean central foveal thickness at the defined time points was 270.2 ± 55.6, 204.4 ± 25.4, 230.1 ± 56.3, and 216.8 ± 48.7 µm, respectively. The central foveal thickness at 12 months was significantly less than the baseline value at diagnosis (p = 0.042).

Conclusions

Deterioration in visual acuity was noted in eyes with typical exudative age-related macular degeneration with good baseline visual acuity, suggesting the need for close patient monitoring and prompt treatment even in patients with good baseline visual acuity.     

Peripapillary nerve fiber layer thickness changes after macular photocoagulation for clinically significant diabetic macular edema

Purpose

To evaluate the effect of macular photocoagulation (MPC) on peripapillary nerve fiber layer (PNFL) thickness measurement in patients with clinically significant diabetic macular edema (CSME).

Methods

This study was a prospective interventional case series. Patients with CSME underwent MPC. Optical coherence tomography (OCT) was used to measure the PNFL and central macular thicknesses before and 3 months after MPC.

Results

Thirty-three eyes of 25 patients with a mean age of 59.4 ± 7.2 years were included. There was no statistically significant difference between pre- and post-MPC mean best corrected visual acuity (0.35 ± 0.29 and 0.40 ± 0.23 LogMAR, respectively, P = 0.2). Mean baseline and 3 months central macular subfield thickness was 305.9 ± 90.7 and 317.5 ± 112.4 microns, respectively (P = 0.1). Peripapillary nerve fiber layer thickness was 105.7 ± 10.0 before and 106.1 ± 9.9 three months after MPC (P = 0.7). No significant differences were found between pre and post MPC measurements in temporal, nasal, inferior and superior nerve fiber layer thickness in each quadrant around optic nerve head (P > 0.05).

Conclusions

Macular photocoagulation has no statistically significant effect on PNFL thickness measurements in patients with CSME.     

Differences in central corneal thickness between the paired eyes and the severity of the glaucomatous damage

Purpose

To evaluate whether a difference in central corneal thickness (CCT) between the paired eyes could be associated to worse glaucoma in the thinner cornea eye.

Methods

From 16 different glaucoma centres, at least 50 glaucomatous patients were saved on the Italian Glaucoma Register. Eight hundred and sixteen glaucomatous patients were found in the register. CCT, ophthalmoscopic cup/disc ratio, mean deviation (MD), pattern SD (PSD), and intraocular pressure (IOP). The difference (Δ) between the paired eyes was calculated for all the considered parameters and two subgroups were created on the basis of ΔCCT. Because the difference between the two eyes could be positive or negative, the absolute value of Δ was considered for all the measurements. Three different ΔCCT cutoffs were selected: 10, 15, and 20 μm. Student''s t-test was used to compare the subgroups.

Results

When the entire group was divided in two subgroups using 20 μm as ΔCCT cutoff, no significant difference was found for ΔIOP (−0.38±2.53 (mean±SD) mm Hg and −0.07±2.35 mm Hg, respectively) between the two subgroups. Significant (P<0.001) difference was found for ΔMD (6.58±7.30 and 3.14±4.22 dB, respectively), ΔPSD (3.92±4.01 and 2.16±2.57, respectively), and ΔC/D (0.11±0.14 and 0.08±0.11, respectively) between the two subgroups. No significant correlation was found between ΔCCT and the other parameters.

Conclusion

The ΔCCT between the two eyes could be associated to a worse glaucoma in the thinner cornea eye.     

The distinguishing anthropometric features of the Saudi Arabian eyes

Purpose

Identifying the peri-ocular anthropometric measurements characteristic of Saudi Arabian eyes.

Methods

A prospective, cohort, hospital-based study.

Results

Measurements were made on 668 subjects (mean age 33.8 years; 58.7% female). The horizontal palpebral aperture was 30.1 ± 2.9 mm (mean ± SD), vertical palpebral aperture was 10.1 ± 0.85 mm, upper lid skin fold height was 3.6 ± 1.9 mm, upper lid crease height was 9.6 ± 0.8 mm, eyebrow height was 10.2 ± 2.7 mm, and intercanthal distance was 32 ± 2.7 mm. There was a statistically significant correlation between gender and eyebrow height (P = 0.001) and gender and horizontal palpebral aperture (P = 0.016), but no significant correlations were noted between any measurement and age.

Conclusions

Saudi Arabian eyes are unique in exhibiting a higher upper lid skin fold, higher lid crease.     

Trabeculectomy ab interno (trabectome): yet another possibility in the treatment of uncontrolled glaucomatocyclitic crisis under systemic valganciclovir therapy?

Purpose

To assess the outcome of trabectome surgery in the treatment of glaucomatocyclitic crisis (Posner–Schlossman syndrome) in patients with uncontrolled intraocular pressure (IOP).

Patients/Methods

Trabectome surgery was performed in seven patients with diagnosed glaucomatocyclitic crisis and uncontrolled IOP where cytomegalovirus DNA was verified by polymerase chain reaction in aqueous humour samples. All patients were treated with oral valganciclovir. After surgery the patients were followed-up for 12 months.

Results

Mean IOP before trabectome surgery was 40±10 mm Hg (range 33–58 mm Hg). The mean number of antiglaucoma medication prior to surgery was 3.1±0.4. By the end of the 12 months, IOP in all patients was reduced to normal level (13±1 mm Hg) and their antiglaucoma medication was decreased to 0.8±1.1. No recurring attack of glaucomatocyclitic crisis occurred.

Discussion

In addition to oral valganciclovir therapy, trabectome surgery seems to be a reliable and effective tool for the management of glaucomatocyclitic crisis with uncontrolled IOP.     

Fellow eye effect of unilateral intravitreal bevacizumab injection in eyes with diabetic macular edema

Aims

Anti-vascular endothelial growth factor compounds are routinely used for the treatment of diabetic macular edema (DME). We aim to evaluate for the existence and magnitude of treatment effect on fellow un-injected eyes.

Methods

A consecutive group of patients with bilateral DME who received unilateral bevacizumab injections was retrospectively evaluated. Data collected included demographics, ophthalmic and systemic findings, and optical coherence tomography (OCT) measurements of macular thickness.

Results

Thirty-five patients were evaluated. Mean follow-up was 245 days (range: 30–800), and the mean number of bevacizumab injections was 3.6 (range: 1–11). At end of follow-up, the mean (SD) OCT central subfield thickness reduced by 72±112 micron in the injected eye (from 469±139 to 397±120 micron; P=0.001), while in the non-injected eye it reduced by 49±75 micron (from 380±130 to 331±106 micron; P<0.001). Sixteen injected eyes (45.7%) showed central subfield thickness reduction of ≥50 micron while 10 (28.6%) non-injected eyes showed such thickness reduction. Improved VA following treatment was detected in 14 (40%) injected eyes and in 15 (43%) non-injected eyes.

Conclusions

Unilateral bevacizumab injections in patients with bilateral DME are often associated with bilateral response.

Summary Statement

Anti-vascular endothelial growth factor compounds are routinely used for the treatment of diabetic macular edema (DME). In this retrospective study, we show that unilateral bevacizumab injections often result in reduction of the macular thickness in the fellow un-injected eye.     

Clinical outcomes between optical path difference custom aspheric treatment and optimized prolate ablation photorefractive keratectomy in myopia exceeding 8 diopters

Purpose

Comparison of visual acuity, refractive, and wavefront outcomes associated with optimized prolate ablation (OPA) and optical path difference custom aspheric treatment (OPDCAT) algorithms for correction of myopia exceeding 8 diopters (D).

Patients and Methods

Patients were randomly assigned to have photorefractive keratectomy (PRK) with OPA (n=32) or OPDCAT (n=21) algorithms. Visual acuity, manifest refraction, ocular and corneal higher-order aberrations, corneal asphericity, modulated-transfer function, and point-spread function were compared 1, 3, and 6 months postoperatively.

Results

Mean manifest-refraction spherical equivalents at 6 months were −0.24 D in both groups. All patients in both groups had an uncorrected-distance visual acuity of 20/20 or better. Predictability (±1 D from intended refraction) at 6 months was 94% in the OPA group, and in the OPDCAT group it was 86%. The OPA group had less induced corneal and ocular spherical aberrations (SAs) than the OPDCAT group. Postoperative corneal asphericity change was lowest in the OPA group. Both the groups exhibited significantly-improved AreaRatio-Total value and insignificantly deteriorated AreaRatio-HO value throughout the postoperative period. The OPA group had significantly-higher AreaRatio-Total compared with OPDCAT group at both 1 and 6 months after the operation. Six months after surgery, the Strehl ratio had decreased in both groups, and there was no significant difference between the groups.

Conclusion

The OPA algorithms yielded higher-objective visual quality and predictability, induced less corneal and ocular SAs, and preserved more preoperative-corneal asphericity than the OPDCAT algorithms.     

Posterior sub-tenon’s bevacizumab injection in diabetic macular edema; a pilot study

Purpose

To evaluate the short-term results of sub-tenon’s injection of bevacizumab in patients with clinically significant macular edema (CSME).

Methods

In this prospective non-comparative interventional case series, sub-tenon’s injection of 2.5 mg/0.1 ml bevacizumab was performed for eyes with CSME. Macular thickness and best corrected visual acuity measurements were performed before and one month after injections.

Results

Nineteen eyes of twelve patients with a mean age of 59.8 ± 5.7 years were evaluated. Thirteen eyes (68.4%) had center-involving macular edema. No significant difference was observed between pre- and post-injection central subfield retinal thickness measurements (P = 0.3). Central subfield thickness measurements improved or remained unchanged in 13 eyes (68.4%). Baseline BCVA of 0.48 ± 0.35 LogMAR improved to 0.36 ± 0.26 LogMAR after injection (P = 0.01). Improvement of >2 lines in BCVA was found in 5 eyes (26.3%), and no eye lost >2 lines of BCVA. No complication associated with sub-tenon’s injection was observed.

Conclusion

Sub-tenon’s injection of bevacizumab resulted in significant short-term visual improvement in eyes with CSME. Retinal thickness changes were not significant.     

Macular thickness measurements using Copernicus Spectral Domain Optical Coherence Tomography

Purpose

To provide normal macular thickness measurements using Spectral Domain Optical Coherence Tomography (SDOCT, Copernicus, Optopol Technologies, Zawierci, Poland).

Methods

Fifty-eight eyes of 58 healthy subjects were included in this prospective study. All subjects had comprehensive ophthalmic examination including best-corrected visual acuity (BCVA). All the subjects underwent Copernicus SDOCT. Central foveal thickness (CFT) and photoreceptor layer (PRL) thickness were measured and expressed as mean and standard deviation. Mean retinal thickness for each of the 9 regions defined in the Early Treatment Diabetic Retinopathy Study was reported. The data were compared with published literature in Indians using Stratus and Spectralis OCTs to assess variation in instrument measurements.

Results

The mean CFT in the study sample was 173.8 ± 18.16 microns (131–215 microns) and the mean PRL thickness was 65.48 ± 4.23 microns (56–74 microns). No significant difference (p = 0.148) was found between CFT measured automated (179.28 ± 22 microns) and manually (173.83 ± 18.1 microns). CFT was significantly lower in women (167.62 ± 16.36 microns) compared to men (180.03 ± 18 microns) (p = 0.008). Mean retinal thickness reported in this study was significantly different from published literature using Stratus OCT and Spectralis OCT.

Conclusion

We report the normal mean retinal thickness in central 1 mm area to be between 138 and 242 microns in Indian population using Copernicus SDOCT. We suggest that different OCT instruments cannot be used interchangeably for the measurement of macular thickness as they vary in segmentation algorithms.