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.     

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.     

Retinal nerve fiber layer and optic disc measurements by spectral domain OCT: normative values and associations in young adults

Purpose

To determine normative values and associations of retinal nerve fiber layer (RNFL) and optic disc parameters in normal eyes measured by spectral domain optical coherence tomography (OCT).

Methods

In a population-based setting, 1521 young adults were examined as part of the Sydney Adolescent Vascular and Eye Study (SAVES). Their mean age was 17.3±0.6 years. RNFL and optic disc parameter measurements were made using Cirrus HD-OCT 4000.

Results

The average RNFL was found to be 99.4±9.6 μm. RNFL thickness was least for the temporal quadrant (69.9±11.2 μm), followed by the nasal (74.3±12.8 μm), superior (124.7±15.7 μm) and inferior (128.8±17.1 μm) quadrants. The mean disc area in this population was 1.98±0.38 mm² with a mean rim area of 1.50±0.30 mm² and a mean cup/disc ratio of 0.44±0.18. Multivariate-adjusted RNFL thickness was marginally greater in East Asian than in white participants (100.1 μm vs 99.5 μm; P=0.0005). The RNFL was thinner with greater axial length (P<0.0001), less positive spherical equivalent refractions (P<0.0001), smaller disc area and rim area (P<0.0001).

Conclusion

This study documents normative values for the RNFL and optic disc measured using Cirrus HD-OCT in young adults. The values and associations reported in this study can inform clinicians on the normal variation in RNFL and optic disc parameters.     

Ganglion cell complex thickness in nonexudative age-related macular degeneration

Purpose

To evaluate ganglion cell complex (GCC) thickness with spectral domain optical coherence tomography (SD-OCT) in eyes with nonexudative age-related macular degeneration (NEAMD).

Methods

Forty-seven eyes of 28 patients with nonexudative age-related macular degeneration (NEAMD) and 54 eyes of 28 age-matched healthy subjects were enrolled. Each subject underwent a complete ophthalmic examination before SD-OCT were obtained. Macular scans were taken with software version 6.0 of the ganglion cell analysis (GCA) algorithm. GCC thickness was evaluated automatically as the average, minimum, temporal superior, superior, nasal superior, nasal inferior, inferior, and temporal-inferior segments by SD-OCT and parameters were compared between groups.

Results

The mean age was 68.7±8.73 years in patient group, and 61.51±5.66 years in control group. There were no significant differences in mean age, gender distribution, intraocular pressure, and sferic equivalent at imaging between the groups (P>0.05). The mean (±SD) GCC thicknesses were as follows; average 71.53±16.53 μm, minumum 62.36±21.51 μm, temporal superior 72.23±14.60 μm, superior 72.76±20.40 μm, nasal superior 72.31±20.13 μm, nasal inferior 69.74±20.51 μm, inferior 69.38±19.03 μm, and temporal-inferior 73.12±15.44 μm in patient group. Corresponding values in control group were 81.46±4.90 μm, 78.66±6.00 μm, 81.51±4.66 μm, 82.94±5.14 μm, 81.79±5.86 μm, 80.94±6.18 μm, 80.14±6.30 μm, and 81.75±5.26 μm, respectively. There were significant differences between two groups in each segments (Mann–Whitney U-test, P<0.05).

Conclusion

The average GCC thickness values (in all segments) of NEAMD patients were lower than control group. NEAMD, which is considered as a disease of outer layers of retina, may be accompanied with a decrease of ganglion cell thickness, so inner layers of retina may be affected.     

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.     

Influence of choroidal thickness on subfoveal choroidal thickness measurement repeatability using enhanced depth imaging optical coherence tomography

Purpose

To determine the influence of choroidal thickness (CT) and image setting on repeatability of subfoveal choroidal thickness (SFCT) manual measurement using enhanced depth imaging optical coherence tomography (EDI-OCT).

Methods

This retrospective study included 189 eyes from 189 adults. Two observers (A and B) measured the SFCT from 1 : 1 micron and 1 : 1 pixel images for evaluation of interobserver repeatability. Observer A performed a single additional measurement for intraobserver repeatability.

Results

The mean age was 45.1±11.1 years. The mean SFCT from 1 : 1 pixel and 1 : 1 micron images were 315.3±89.2 and 312.6±88.4 μm, respectively. The subjects were divided into three subgroups based on the mean CT from 1 : 1 pixel images: 26 eyes belonged to thin CT group, 111 eyes to intermediate CT group, and 52 eyes to thick CT group. Interclass coefficients (ICCs) exhibited high intraobserver repeatability. Interobserver ICCs were also high, except for thick CT group with 1 : 1 pixel image (ICC≤0.75). Intraobserver correlation coefficients were high regardless of CT. Interobserver correlation coefficients for 1 : 1 pixel images were 0.896 in thin CT group, 0.680 in intermediate CT group, and 0.624 in thick CT group, respectively (P<0.0001). The interobserver ICCs and correlation coefficients from 1 : 1 micron images were slightly higher than from 1 : 1 pixel images.

Conclusions

The repeatability for the two observers was reduced in thick CT group despite high total repeatability. 1 : 1 Micron images provided slightly better repeatability in interobserver measurements. CT measurements should be interpreted cautiously, particularly for a thick choroid.     

Correlation of serum insulin like growth factor-I with retinopathy in Malaysian pregnant diabetics

AIM: To study the association of serum insulin-like growth factor-I (IGF-I) with diabetic retinopathy. METHODS: Serum IGF-1 levels were measured in 25 pregnant diabetic patients and 25 pregnant non-diabetic patients who were matched for age, ethnicity, parity and period of gestation. Fundus examination was performed in both groups at 28, 32 and 36 weeks of gestation. RESULTS: The serum IGF-I level was significantly elevated in pregnant diabetics compared to pregnant non-diabetics (366±199μg/L vs 184±89μg/L, (P=0.0001) at 24 weeks, 535±251μg/L vs 356±89μg/L, (P=0.007) at 32 weeks and 404±166μg/L vs 264±113μg/L, (P=0.003) at 36 weeks of gestation). The pregnant diabetics with established diabetes had significantly higher IGF-1 level than gestational diabetes at 28, 32 and 36 weeks of gestation. The serum IGF-I level in pregnant diabetics with retinopathy was significantly higher than that in those without retinopathy at all periods of gestation. CONCLUSION: Increased serum IGF-1 in pregnancy may increase the risks for retinopathy.     

Comparison of penetration depth in choroidal imaging using swept source vs spectral domain optical coherence tomography

Purpose

To compare signal penetration depth and deep structure-visualization of swept source (SS) and spectral domain (SD)-optical coherence tomography (OCT) with and without enhanced depth imaging (EDI) and B-scan averaging modes.

Methods

Volume scans were obtained from 20 eyes of healthy volunteers by DRI OCT-1, Spectralis using EDI and B-scan averaging, and Cirrus HD-OCT. The signal penetration depth was measured as the distance between the retinal pigment epithelium and the deepest visible anatomical structure at the foveal center. Visibility and contrast of the choroidoscleral junction and of vascular details within the choroid were assessed across the entire volume using an ordinal scoring scale. Outcome measures were compared using paired t-test and rank-sum test.

Results

The mean signal penetration depth was 498±114 μm for Spectralis, 491±85 μm for DRI OCT-1, and 123±65 μm for Cirrus; P=0.9708 Spectralis vs DRI OCT-1, P<0.0001 Spectralis vs Cirrus, and P<0.0001 DRI OCT-1 vs Cirrus. Mean ranks for visibility and contrast of the choroidoscleral junction were 3.83 for Spectralis, 3.98 for DRI OCT-1, and 2.00 for Cirrus; and 3.45 for Spectralis, 2.93 for DRI OCT-1, and 1.58 for Cirrus. Mean ranks for visibility and contrast of vascular details were 3.73 (Spectralis), 3.70 (DRI OCT-1), and 2.23 (Cirrus); and 3.53 (Spectralis), 2.05 (DRI OCT-1), and 1.98 (Cirrus).

Conclusion

Signal penetration depths are similar for SS-OCT and SD-OCT using EDI and frame averaging, and statistically significantly lower without EDI/averaging. Both SD-OCT using EDI/frame averaging and SS-OCT offer excellent visualization capabilities for volumetric imaging of the choroidoscleral interface.     

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.     

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.     

Variations in the cone packing density with eccentricity in emmetropes

Aim

To describe the parafoveal cone arrangement in emmetropic subjects and its variations with eccentricity, meridians and change in axial length in Indian eyes.

Methods

We imaged 25 subjects using compact adaptive optics (AO) retinal camera prototype, the rtx1. Imaging was done at 1, 2, and 3° eccentricity from the fovea in four meridians: nasal, temporal, superior, and inferior.

Results

A statistically significant drop in the cone packing density was observed from 2 to 3° (2° eccentricity=25 350/mm² (5300/mm², 8400–34 800/mm²) 3° eccentricity=20 750/mm² (6000 mm², 9000–33 670/mm²)) P<0.05. The spacing correspondingly increased with increase in distance from the fovea (2° eccentricity=6.9 μm (0.70 μm, 5.95–11.6 μm)) and 3°eccentricity=7.80 μm (1.00 μm, 6.5–13.5 μm) P<0.05. As the axial length increases, the cone density significantly decreases. Interocular variations were noted.

Conclusion

With the advent of AO, visualization at the cellular level is now possible. Understanding the photoreceptor mosaic in the parafoveal space in terms of its density, spacing, and arrangement is crucial so as to detect early pathology and intervene appropriately. Newer therapeutic modalitites that are targeted at the cellular level like yellow micropulse laser, stem cells, gene therapy and so on may be better monitored in terms of safety and efficacy.     

Visual and anatomical outcomes following intravitreal aflibercept in eyes with recalcitrant neovascular age-related macular degeneration: 12-month results

Purpose

To describe the efficacy of intravitreal aflibercept on 12-month visual and anatomical outcomes in patients with neovascular age-related macular degeneration (AMD) recalcitrant to prior monthly intravitreal bevacizumab or ranibizumab.

Methods

Non-comparative case series of 21 eyes of 21 AMD patients with evidence of persistent exudation (intraretinal fluid/cysts, or subretinal fluid (SRF), or both) on spectral domain OCT despite ≥6 prior intravitreal 0.5 mg ranibizumab or 1.25 mg bevacizumab (mean 29.8±17.1 injections) over 31.6±17.4 months who were transitioned to aflibercept.

Results

At baseline, best-corrected visual acuity (BCVA) was 0.42±0.28 logarithm of minimum-angle of resolution (logMAR), central foveal thickness (CFT) was 329.38±102.67 μm and macular volume (MV) was 7.71±1.32 mm³. After 12 months of aflibercept (mean 10.2±1.2 injections), BCVA was 0.40±0.28 logMAR (P=0.5), CFT decreased to 292.71±91.35 μm (P=0.038) and MV improved to 7.33±1.27 mm³ (P=0.003). In a subset of 15 eyes with a persistent fibrovascular or serous pigment epithelial detachment (PED), mean baseline PED greatest basal diameter (GBD) was 2350.9±1067.6 μm and mean maximal height (MH) was 288.7±175.9 μm. At 12 months, GBD improved to 1896.3±782.3 μm (P=0.028), while MH decreased to 248.27±146.2 μm (P=0.002).

Conclusion

In patients with recalcitrant AMD, aflibercept led to anatomic improvement at 12 months, reduction in proportion of eyes with SRF and reduction in PED, while preserving visual acuity.     

Changes in choroidal thickness,axial length,and ocular perfusion pressure accompanying successful glaucoma filtration surgery

Purpose

To investigate the changes in choroidal thickness (CT), axial length (AL), and ocular perfusion pressure (OPP) accompanying intraocular pressure (IOP) reduction after trabeculectomy.

Methods

Thirty-nine eyes of 39 patients with primary open-angle glaucoma uncontrolled by medical therapy were included in this prospective and interventional study. All patients underwent a fornix-based trabeculectomy. The CT was measured by enhanced depth imaging-optical coherence tomography. IOP, AL, and systolic/diastolic blood pressure were also measured, and OPP was calculated. All measurements were performed at baseline and 1 month after surgery.

Results

The mean IOP was 25.0±5.8 mm Hg at baseline and 11.7±2.6 mm Hg after trabeculectomy (P<0.001), and the mean subfoveal CT was 295±84 mm Hg at baseline and 331±82 mm Hg after trabeculectomy (P<0.001). The mean AL was 23.64±0.98 mm at baseline and 23.54±0.96 mm after trabeculectomy (P<0.001), whereas the mean OPP was 38.8±6.2 mm Hg preoperatively, and 51.1±7.3 mm Hg postoperatively (P<0.001). The change in CT negatively correlated with the change in IOP (r=−0.785, P<0.001) and AL (r=−0.693, P<0.001), whereas it positively correlated with the change in OPP (r=0.418, P=0.008).

Conclusion

These results suggest that the large IOP decrease following trabeculectomy causes choroidal thickening. In addition, CT changes are associated with IOP and AL reduction as well as OPP increase.     

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.     

Association of retinal vessel calibre and visual outcome in eyes with diabetic macular oedema treated with ranibizumab

Purpose

The study aims to identify the association between the baseline retinal vascular calibre and visual outcome of patients with diabetic macular oedema (DMO) treated with intravitreal ranibizumab.

Methods

The 1-M field (as defined in the ETDRS study) of the digital colour fundus photographs of DMO patients who had been treated primarily with ranibizumab in a clinical trial was assessed. Of the 84 patients, 25 had gradable retinal photographs that could be subjected to analyses by the Interactive Vessel Analysis (IVAN) software at baseline. The average retinal vascular calibre of the six largest venules (CRVE) and the six largest arterioles (CRAE) in the peripapillary area (0.5 and 1 disc diameter from the optic disc margin) was measured. The relationship between CRVE and CRAE at baseline and the change in visual acuity at month 12 was assessed using the Mann–Whitney U test.

Results

Ten eyes from 10 patients who had shown an improvement of ≥2 lines of best corrected visual acuity (BCVA) at month 12 had a wider baseline CRVE (248.3±24.5 μm) compared with the 15 eyes from 15 patients who did not show the improvement of ≥2 lines (226.6±44.8 μm, P<0.05). The baseline CRAE did not differ significantly in these patients (156.1±22.7 vs 142±17.5 μm, P=0.17).

Conclusions

A wider baseline retinal venular calibre may be a predictor of better visual outcome in DMO eyes treated with ranibizumab. Further prospective studies with a larger sample size and a broader range of disease severity and visual acuity are needed to confirm this finding.     

Choroid thickness and ocular pulse amplitude in migraine during attack

Aim

To compare the choroidal thickness and ocular pulse amplitude (OPA) measurements obtained during the attack period in migraine patients and age and gender matched control group participants using high definition optical coherence tomography (OCT).

Methods

Thirty eyes at the side of the headache of 30 subjects with a diagnosis of migraine with or without aura and unilateral migraine and 29 age and gender matched healthy participants were enrolled in this observational, cross-sectional study. OCT scans were performed to all participants. Choroidal thicknesses were measured at the fovea, 1500 μm nasal and 1500 μm temporal to the fovea. Intraocular pressure (IOP) and OPA were also measured.

Results

The choroidal thickness measurements obtained during the attack period in migraine patients were (mean±SD) 279.82±35.87, 250.05±29.49, and 239.58±27.92 and in control group were 308.20±44.97, 276.95±41.39, and 281.60±41.38 at foveal, nasal, and temporal measurement points, respectively. Choroidal thickness significantly decreased according to the control group (P<0.05) at all measured points in migraine patients during attack. IOP (mean±SD) values were 16.71±3.26 and17.40±3.19 and OPA (mean±SD) values were 2.26±0.81 and 2.64±1.03 in migraine and control groups, respectively, and did not seem to be changed (P>0.05).

Conclusions

Choroidal thickness was found to be significantly decreased in unilateral migraine patients during the attack period when compared with the control group, whereas OPA did not change. The possible implications of these findings on the association between migraine and glaucoma are discussed.     

Comparison of the visual outcomes between PRK-MMC and phakic IOL implantation in high myopic patients

Purpose

To compare the visual outcomes between PRK-MMC and phakic IOL in patients with more than 8 diopter (D) of myopia.

Methods

This comparative study was performed on 23 eyes under treatment with Artiflex (group A) and 23 eyes under treatment with PRK-MMC (group B). Artiflex phakic IOL (Ophtec BV) was used in group A, and the VISX STAR S4 Excimer Laser (Abbott) was used for PRK-MMC in group B.

Results

The safety index was 1.11±0.23 and 1.05±0.25 (P=0.100) and the efficacy index was 1.02±0.11 and 0.98±0.10 (P=0.266) in group A and B, respectively. At 1 year after surgery, the manifest refraction spherical equivalent was −0.17±1.18 and −0.25±0.18 D in group A and B, respectively (P=0.471). Mesopic CS showed no significant difference between the two groups in any spatial frequency. Total coma was 0.24±0.17 and 0.67±0.40 μm (P<0.001), spherical aberration was −0.11±0.11 and 0.41±0.18 μm (P<0.001), and RMS HOA_T was 0.50±0.20 and 0.96±0.45 μm (P<0.001) in group A and B, respectively.

Conclusion

Phakic IOL implantation was better than PRK-MMC in the correction of high myopia in terms of visual quality, but the two methods had no difference with regard to visual acuity. Therefore, PRK-MMC can be used when the anterior chamber depth is a limiting factor in the implantation of phakic IOLs.     

Change in subfoveal choroidal thickness in central serous chorioretinopathy following spontaneous resolution and low-fluence photodynamic therapy

Purpose

To assess the change in subfoveal choroidal thickness (SFCT) in central serous chorioretinopathy (CSC) following spontaneous resolution and low-fluence photodynamic therapy (PDT) using the enhanced depth imaging optical coherence tomography (EDI-OCT).

Methods

A total of 36 consecutive eyes of 36 patients were included in this retrospective study: 16 eyes with spontaneously resolved CSC and 20 eyes with PDT-treated CSC. Best-corrected visual acuity and SFCT were evaluated at each visit until complete absorption of the subretinal fluid. SFCT of 32 normal subjects were also measured, as the control group. Wilcoxon''s singed-rank test was used to evaluate the effects of spontaneous resolution and PDT. To compare the SFCT of the eyes with resolved CSC with that of the normal eyes, Mann–Whitney U-test with Bonferroni correction was also employed.

Results

SFCT of patients was 459.16±77.50 μm at the baseline, and decreased to 419.31±54.49μm after a spontaneous resolution (P=0.015). However, SFCT was not normalized in comparison with that of the normal subjects (P<0.001). SFCT in PDT group was also reduced from 416.43±74.01 to 349.50±88.99 μm (P<0.001), with no significant difference with the normal value (P=0.087).

Conclusions

SFCT in patients with CSC decreased both after spontaneous resolution and low-fluence PDT. However, only in the PDT group, after disappearance of subretinal fluid, did it decrease to that of normal subjects.     

Association between various types of obesity and macular pigment optical density

Purpose

To elucidate the association between macular pigment optical density (MPOD) and various types of obesity in the South-Indian population.

Patients and methods

In total, 300 eyes of 161 healthy volunteers of South-Indian origin were studied. MPOD was measured psychophysically at 0.25°, 0.50°, 1.00°, and 1.75° eccentricities from fovea. Anthropometric measurements included waist circumference (WC) and waist-to-hip ratio (WHR) and body mass index (BMI). Using the WHO Expert Consultation guidelines, obesity was defined based on BMI alone (BMI≥23 kg/m²), based on WC alone (WC≥90 cm for men and ≥80 cm for women), and based on WHR alone (≥0.90 for men and ≥0.85 for women). Isolated generalized obesity was defined as increased BMI and normal WC. Isolated abdominal obesity was defined as increased WC and normal BMI. Combined obesity was defined as increased BMI and increased WC.

Results

Mean MPOD at all eccentricities was not significantly different between men and women. Mean MPOD values did not significantly differ in various types of obesity, when compared with the normal subjects. On subgroup analysis, in age group ≥60 years, mean MPOD values were significantly higher in subjects with obesity based on BMI (0.61 vs0.41, P=0.036), obesity based on WHR (0.67 vs0.41, P=0.007), and isolated generalized obesity (0.66 vs0.41, P=0.045) in comparison with normal subjects at 0.25° eccentricity.

Conclusion

We found lack of an association between MPOD and obesity in the South-Indian population. A similar finding was also noted on age group- and gender-wise analyses.     

Corneal changes after a single session of selective laser trabeculoplasty for open-angle glaucoma

Purpose

To investigate the changes in endothelial cell count, central corneal thickness (CCT), and refractive error after a session of selective laser trabeculoplasty (SLT) for open angle glaucoma (OAG).

Methods

This prospective cohort study recruited 111 eyes of 66 consecutive subjects with OAG. Subjects received SLT to 360° of the trabecular meshwork. Endothelial cell count, CCT, and spherical equivalent were measured at baseline before SLT as well as at 1 week and 1 month post SLT. A repeated measure nested ANOVA with Tukey''s multiple comparison test was performed to compare the outcome measures before and after SLT.

Results

In 111 eyes of 66 subjects, the mean number of laser applications per treatment was 166.9±41.4 with a mean energy level of 1.0±0.07 mJ. The mean endothelial cell count decreased significantly from 2465.0±334.0 cells/mm² at baseline to 2355.0±387.0 cells/mm² at 1 week (P=0.0004) but increased to baseline levels at 1 month post SLT (2424.0±379.4 cells/mm², P=0.3). The CCT, which decreased from a baseline of 549.4±37.6 to 543.9±40.2 μm at 1 week post SLT (P=0.02), also returned to the baseline level by 1 month (P=0.2). The spherical equivalent was static from baseline. A positive correlation was found between total laser energy and CCT at 1 month post treatment (r=0.3, P=0.005).

Conclusion

The transient reductions in endothelial cell count and CCT following SLT returned to baseline levels 1 month after the procedure. Patients undergoing SLT should be aware of the risk of potential corneal changes.