Choroidal thickness profile in healthy Indian children

Purpose:

The purpose was to study choroidal thickness and its profile based on location in healthy Indian children using enhanced depth spectral-domain-optical coherence tomography (SD-OCT).

Methods:

In this cross-sectional observational study 255 eyes of 136 children with no retinal or choroidal disease were consecutively scanned using enhanced depth SD-OCT. Eyes with any ocular disease or axial length (AXL) >25 mm or < 20 mm were excluded. A single observer measured choroidal thickness from the posterior edge of the retinal pigment epithelium to the choroid/sclera junction at 500-microns intervals up to 2500 microns temporal and nasal to the fovea. Generalized estimating equations were used to evaluate the correlation between choroidal thickness at various locations and age, AXL, gender and spherical equivalent (SEq).

Results:

Mean age of the subjects was 11.9 ± 3.4 years (range: 5–18 years). There were 62 Females and 74 males. The mean AXL was 23.55 ± 0.74 mm. Mean subfoveal choroidal thickness was 312.1 ± 45.40 μm. Choroid was found to be thickest subfoveally, then temporally. Age, AXL and SEq showed a significant correlation with choroidal thickness, whereas gender did not affect choroidal thickness.

Conclusion:

Our study provides a valid normative database of choroidal thickness in healthy Indian children. This database could be useful for further studies evaluating choroidal changes in various chorioretinal disorders. Age and AXL are critical factors, which negatively correlated with choroidal thickness.     

Retinal nerve fiber layer thickness in normal Indian pediatric population measured with optical coherence tomography

Purpose:

To measure the peripapillary retinal nerve fiber layer (RNFL) thickness in normal Indian pediatric population.

Subjects and Methods:

120 normal Indian children ages 5-17 years presenting to the Pediatric Clinic were included in this observational cross-sectional study. RNFL thickness was measured with stratus optical coherence tomography (OCT). Children with strabismus or amblyopia, with neurological, metabolic, vascular, or other disorders and those with abnormal optic discs were excluded. One eye of each subject was randomly selected for statistical analysis. The effect of age, refraction and gender on RNFL thickness was investigated statistically.

Result:

OCT measurements were obtained in 120 of 130 (92.3%) subjects. Mean age was 10.8 ± 3.24 years (range 5-17). Average RNFL thickness was (± SD) 106.11 ± 9.5 μm (range 82.26-146.25). The RNFL was thickest inferiorly (134.10 ± 16.16 μm) and superiorly (133.44 ± 15.50 μm), thinner nasally (84.26 ± 16.43 μm), and thinnest temporally (70.72 ± 14.80 μm). In univariate regression analysis, age had no statistical significant effect on RNFL thickness (P =0.7249) and refraction had a significant effect on RNFL thickness (P =0.0008).

Conclusion:

OCT can be used to measure RNFL thickness in children. Refraction had an effect on RNFL thickness. In normal children, variation in RNFL thickness is large. The normative data provided by this study may assist in identifying changes in RNFL thickness in Indian children.     

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.     

Changes in choroidal thickness after prophylactic iridectomy in primary angle closure suspect eyes using enhanced depth imaging optical coherence tomography

Purpose:

The aim of the present study was to evaluate the effect of surgical peripheral iridectomy (SPI) on choroidal thickness in primary angle-closure suspect (PACS) eyes.

Materials and Methods:

This was a prospective observational case series of 30 subjects with PACS. Ocular biometry was performed before SPI (baseline) and then 1 week later. Choroid was imaged by enhanced depth imaging optical coherence tomography (EDI-OCT). The choroidal thickness of the subfoveal area at 1 and 3 mm diameter around the fovea was determined. Central anterior chamber depth (ACD), lens thickness (LT), vitreous chamber depth (VCD), and axial length (AL) were measured by A-scan ultrasound. Parameters were compared before SPI (baseline) and 1 week later.

Results:

Thirty eyes of 30 patients with mean age of 61.53 ± 7.98 years were studied. There was no significant difference in the choroidal thickness at all macular locations before and after SPI (all P > 0.05). Mean subfoveal choroidal thickness was 279.61 μm ± 65.50 μm before and 274.54 μm ± 63.36 μm after SPI (P = 0.308). There was also no significant change in central ACD, LT, VCD, and LT after SPI (all P > 0.05).

Conclusions:

SPI does not appear to alter choroidal thickness in PACS eyes, as assessed using EDI-OCT. Long-term follow-up of PACS eyes treated with SPI may provide further insight into the effects of this treatment modality on the choroid.     

Choroidal thickness changes after dynamic exercise as measured by spectral-domain optical coherence tomography

Purpose:

To measure the choroidal thickness (CT) after dynamic exercise by using enhanced depth imaging optical coherence tomography (EDI-OCT).

Materials and Methods:

A total of 19 healthy participants performed 10 min of low-impact, moderate-intensity exercise (i.e., riding a bicycle ergometer) and were examined with EDI-OCT. Each participant was scanned before exercise and afterward at 5 min and 15 min. CT measurement was taken at the fovea and 1000 μ away from the fovea in the nasal, temporal, superior, and inferior regions. Retinal thickness, intraocular pressure, ocular perfusion pressure (OPP), heart rate, and mean blood pressure (mBP) were also measured.

Results:

A significant increase occurred in OPP and mBP at 5 min and 15 min following exercise (P ˂ 0.05). The mean subfoveal CT at baseline was 344.00 ± 64.71 μm compared to 370.63 ± 66.87 μm at 5 min and 345.31 ± 63.58 μm at 15 min after exercise. CT measurements at all locations significantly increased at 5 min following exercise compared to the baseline (P ˂ 0.001), while measurements at 15 min following exercise did not significant differ compared to the baseline (P ˃ 0.05). There was no significant difference in retinal thickness at any location before and at 5 min and 15 min following exercise (P ˃ 0.05).

Conclusion:

Findings revealed that dynamic exercise causes a significant increase in CT for at least 5 min following exercise.     

Comparison of conjunctival graft thickness after primary and recurrent pterygium surgery: Anterior segment optical coherence tomography study

Objective:

The objective of the following study is to compare the conjunctival graft thickness measured with anterior segment optical coherence tomography (OCT) after primary and recurrent pterygium excision.

Design:

Prospective, interventional and comparative study.

Participants:

A total of 20 eyes of 20 patients with primary pterygium (primary group) and 20 eyes of 20 patients with recurrent pterygium (recurrent group) were enrolled.

Materials and Methods:

All patients underwent pterygium excision with conjunctival autograft transplantation. Conjunctival graft thickness was measured at 1 week, 1 month and 3 months after surgery using the Visante-OCT (Carl-Zeiss Meditec, Dublin, CA, USA). Main outcome measure was the mean conjunctival thickness determined as the mean of three measurements at 1, 2 and 3 mm posterior to the scleral spur.

Results:

There were no statistically significant differences in age, sex, or laterality between the groups. Mean thickness of the graft in primary and recurrent groups, respectively, was 430 ± 127 μm and 461 ± 178 μm at 1 week after surgery (P = 0.587), 114 ± 19 μm and 162 ± 48 μm at 1 month after surgery (P = 0.001) and 109 ± 15 μm and 107 ± 18 μm at 3 months after surgery (P = 0.726).

Conclusion:

The findings revealed that conjunctival thickness after primary or recurrent pterygium excision was greatest at 1 week after surgery and continued to decrease for up to 3 months. Mean graft thickness differed significantly between the two groups only at 1 month after surgery.     

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.     

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.     

Effect of ocular magnification on macular measurements made using spectral domain optical coherence tomography

Aim:

The aim of the present study was to study the effect of ocular magnification on macular measurements made using spectral domain optical coherence tomography (OCT).

Materials and Methods:

One hundred and fifty-one subjects were included from the normative study of foveal morphology carried out at our hospital. Subjects underwent comprehensive eye examination and macular scanning using Cirrus high-definition OCT and axial length (AXL) measurement. Macular cube 512 × 128 scan protocol was used for scanning the macula. Automated measurements of the fovea namely foveal diameter, foveal slope (lateral measurements) and foveal depth (axial measurement) were taken. A correction factor for ocular magnification was done using the formula t = p × q × s, where “t” is the corrected measurement, “p” is the magnification of OCT, “q” is the ocular magnification, and “s” is the measurement on OCT without correction. The difference between corrected and uncorrected measurements was evaluated for statistical significance.

Results:

Mean AXL was 22.95 ± 0.78 mm. Refractive error ranged from −3D to +4D. Mean difference between measured and corrected foveal diameter, slope and depth was 166.05 ± 95.37 µm (P < 0.001), 0.81° ± 0.53° (P < 0.001) and 0.05 ± 0.49 µm (P = 0.178) respectively. AXL lesser than the OCT calibrated value of 24.46 mm showed an increased foveal diameter (r = 0.961, P < 0.001) and a reduced foveal slope (r = −0.863, P < 0.001) than the corrected value.

Conclusion:

Lateral measurements made on OCT varied with AXL s other than the OCT calibrated value of 24.46 mm. Therefore, to estimate the actual dimensions of a retinal lesion using OCT, especially lateral dimensions, we recommend correction for the ocular magnification factor.     

Efficacy of combined intravitreal bevacizumab and triamcinolone for branch retinal vein occlusion

Purpose:

To evaluate the efficacy of combined treatment with intravitreal bevacizumab (IVB) and triamcinolone acetate (IVT) for patients with macular edema secondary to branch retinal vein occlusion (BRVO).

Materials and Methods:

Retrospective analysis of 20 eyes injected with 1.25 mg IVB and 2 mg IVT for clinically identified BRVO within 8 weeks of onset. All patients lacked concomitant ocular pathology and completed 6 months’ follow-up. Clinical examination including LogMAR visual acuity (VA) and central macular thickness (CMT) by spectralis optical coherence tomography (OCT) was performed preoperatively and at 1, 3 and 6 months post-operatively.

Results:

Mean patient age was 61.3 years with a mean BRVO diagnosis time of 3 weeks at presentation. VA improved from logMAR 1.08 preoperatively to Mean logMAR VA of 0.55 ± 0.17 at 1 month (P < 0.001), 0.56 ± 0.21 at 3 months (P < 0.001), and 0.38 ± 0.1 at 6 months (P < 0.001) Mean CMT improved from 482 ± 107 μm preoperatively to 319 ± 53 μm at 1 month (P < 0.001), 344 ± 89 μm at 3 months (P < 0.001), and 241 ± 29 μm at 6 months (P < 0.001). Mean IOP preoperatively was 16.5 mmHg, 21 mmHg at 1 month, and 15 mmHg at 6 months. Six out of 20 patients (30%) were re-injected with IVB and IVT at 3 months.

Conclusions:

Early combined treatment with IVB and IVT is effective in improving anatomic and functional outcomes in patients with macular edema secondary to BRVO.     

Choroidal thickness profile in Retinitis Pigmentosa – Correlation with outer retinal structures

Purpose

To compare the choroidal thickness (CT) of subjects with Retinitis Pigmentosa (RP) with age-matched healthy subjects and to correlate the visual acuity with retinal parameters including central macular thickness (CMT), inner segment/outer segment junction (IS/OS junction) integrity, external limiting membrane (ELM) integrity and choroidal thickness in subjects with RP.

Methods

Eighty-eight eyes (69 patients) with typical RP and 188 eyes of 104 healthy subjects were enrolled between September 2012 and January 2013.All subjects underwent a comprehensive ocular examination including choroidal imaging using enhanced depth imaging with spectral domain optical coherence tomography. Outcome measures were CT difference between RP and age-matched healthy subjects; and correlation of various factors such CMT, IS/OS junction integrity, ELM integrity, and CT with visual acuity.

Results

Among RP subjects, mean age was 31.39 ± 13.4 years with a mean BCVA of 0.99 ± 0.94 logMAR. Mean spherical equivalent was −0.6 ± 1.6D. Mean CMT was 148.48 ± 119 μm. Mean subfoveal CT was 296.9 ± 72 μm. Mean IS/OS and ELM integrity was 42.2 ± 46.6% and 43.75 ± 45.7%, respectively. The mean age was 40.0 ± 13.5 years with a mean spherical equivalent of 0.18 ± 0.6D for the normal age-matched healthy group. Mean subfoveal CT was 283.1 ± 47.8 μm.CT at various locations in patients of various ages in the RP group did not show any statistical significant difference (P = ≫0.05) in comparison with age-matched healthy subjects. On multivariate regression, ELM percentage integrity had the strongest association with best corrected visual acuity, followed by IS/OS junction percentage integrity. Subfoveal choroidal thickness had very weak correlation with visual acuity as well other retinal parameters.There was a significant difference in the outer retinal structure integrity (p = 0.002) and CMT (p = 0.02) between the eyes with good (⩾20/200) and poor vision (<20/200), but not in subfoveal choroidal thickness (p = 0.3).

Conclusions

Our study results did not show any significant difference in choroidal thickness between subjects with RP and age-matched healthy subjects. Choroidal thickness correlated better with the age but not with the vision or outer retinal structures in eyes with RP. Outer retinal structure integrity and CMT had a better correlation with visual acuity.     

Assessment of the central corneal thickness and intraocular pressure in premature and full-term newborns

Purpose:

To assess the central corneal thickness (CCT) and intraocular pressure (IOP) in premature and full-term newborns.

Materials and Methods:

In this study, we evaluated measurements of CCT and IOP in 45 premature and 45 full-term newborns. IOP was determined with topical anesthesia using a Tono-Pen AVIA, applanation tonometer and a wire lid retractor in premature newborns undergoing screening for retinopathy. Full-term newborns were used as a control group. CCT was determined with a portable pachymeter after IOP measurements had been made in both groups. Because there was high correlation of CCT and IOP between right and left eyes, only the right eye data were used for further analyses.

Results:

The mean gestational age was 31.5 ± 2.7 weeks (ranging 25-35 weeks) and the mean age at measurement after birth was respectively 36.3 ± 0.9 weeks (ranging 33-37 weeks) in premature newborns and 38.2 ± 0.7 weeks (ranging 38-41 weeks) and 42 ± 2.2 weeks (ranging 39-46 weeks) in full-term newborns. The mean IOP was 16.2 ± 2.7 mmHg (ranging 10-22 mmHg) in premature and 16.6 ± 2.3 mmHg (ranging 10-22 mmHg) in full-term newborns. The mean CCT was found 600 ± 50 μm (ranging 515-790 μm) in the premature group and 586 ± 48 μm (ranging 475-730 μm) in the full-term group. Mean CCT was greater in premature newborns than in full-term newborns, but the difference between groups was not statistically significant (P = 0.7). Mean IOP measurement in two groups was found very similar and the difference also was not statistically significant (P = 0.27). There was no correlation between IOP and CCT, gestational age, gestational weight, age at measurement, weight at measurement neither right nor left eye in both groups in multiple regression analysis.

Conclusion:

We found that premature infants have slightly thicker corneas but no high IOP measurements than full-term newborns. It could be concluded that in premature at the mean gestational age of 36 weeks CCT is not different from that of full-term newborns.     

Ocular perfusion pressure and choroidal thickness in eyes with polypoidal choroidal vasculopathy,wet-age-related macular degeneration,and normals

Purpose

To measure the choroidal thickness and ocular perfusion pressure in eyes with polypoidal choroidal vasculopathy (PCV), wet-age-related macular degeneration (AMD), and age-matched normal subjects, and look for a possible association between the two.

Methods

This was a prospective study including 22 eyes with PCV, 33 eyes with wet-AMD, and 35 age-matched normal eyes. Choroidal thickness was measured using enhanced depth imaging (EDI) with spectral-domain optical coherence tomography (SD OCT). Mean ocular perfusion pressure (MOPP) was calculated using the mathematical formula 2/3[DBP+1/3{SBP × DBP}]−IOP (DBP—diastolic blood pressure, SBP—systolic blood pressure, IOP—intraocular pressure). Analyses were carried out using SPSS 14 software and comparisons of mean made using‘t'' tests.

Results

Eyes with PCV showed increased (285.9 μm; subfoveal) choroidal thickness, whereas eyes with wet-AMD (119.4 μm; subfoveal) showed reduced choroidal thickness in comparison with normal eyes (186.77 μm; subfoveal). MOPP in the PCV group was 57.85 mm Hg (P value 0.00), in the wet-AMD group was 52.1 mm Hg (P-value 0.12), and in the normal group was 49.79 mm Hg.

Conclusion

It is postulated that higher MOPP in eyes with PCV could have an etiologic implication in disease manifestation and progression. Larger studies with longer follow-up may help validate these findings.     

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.     

Reproducibility of retinal nerve fiber layer measurements across the glaucoma spectrum using optical coherence tomography

Purpose:

The purpose was to determine intra-session and inter-session reproducibility of retinal nerve fiber layer (RNFL) thickness measurements with the spectral-domain Cirrus optical coherence tomography (OCT)^® (SD-OCT) in normal and glaucomatous eyes, including a subset of advanced glaucoma.

Materials and Methods:

RNFL measurements of 40 eyes of 40 normal subjects and 40 eyes of 40 glaucomatous patients including 14 with advanced glaucoma were obtained on the Cirrus OCT^® (Carl Zeiss Meditec, Dublin, CA, USA) five times on 1-day (intra-session) and on five separate days (inter-session). Intraclass correlation coefficient (ICC), coefficient of variation (COV), and test-retest variability (TRT) values were calculated for mean and quadrant RNFL in each group separately. Reproducibility values were correlated with age and stage of glaucoma.

Results:

For intra-session reproducibility, the ICC, COV, and TRT values for mean RNFL thickness in normal eyes were 0.993, 1.96%, and 4.02 µm, respectively, 0.996, 2.39%, and 3.84 µm in glaucomatous eyes, and 0.996, 2.41%, and 3.70 µm in advanced glaucoma. The corresponding inter-session values in normal eyes were 0.992, 2.16%, and 4.09 µm, 0.995, 2.62%, and 3.98 µm in glaucoma and 0.990, 2.70%, and 4.16 µm in advanced glaucoma. The mean RNFL thickness measurements were the most reproducible while the temporal quadrant had the lowest reproducibility values in all groups. There was no correlation between reproducibility and age or mean deviation on visual fields.

Conclusions:

Peripapillary RNFL thickness measurements using Cirrus OCT^® demonstrated excellent reproducibility in normal and glaucomatous eyes, including eyes with advanced glaucoma. Mean RNFL thickness measurements appear to be the most reproducible and probably represent the best parameter to use for longitudinal follow-up.     

Comparing acromegalic patients to healthy controls with respect to intraocular pressure,central corneal thickness,and optic disc topography findings

Aims:

The aim was to compare the intraocular pressure (IOP), central corneal thickness (CCT), and optic disc topography findings of biochemically controlled acromegalic patients and the control group and to evaluate the effect of the duration of acromegaly and serum growth hormone and insulin-like growth factor-1 (IGF-1) levels on these ocular parameters.

Materials and Methods:

IOP measurement with Goldmann applanation tonometry, CCT measurement with ultrasonic pachymetry, and topographic analysis with Heidelberg retinal tomograph III were performed on 35 biochemically controlled acromegalic patients and 36 age- and gender-matched controls.

Results:

Mean IOP and CCT were 14.7 ± 2.9 mmHg and 559.5 ± 44.9 μm in the acromegaly patients and 13.0 ± 1.6 mmHg and 547.1 ± 26.7 μm in controls (P = 0.006 and P = 0.15, respectively). A significant moderate correlation was found between the duration of acromegaly and CCT (r = 0.391) and IOP (r = 0.367). Mean retinal nerve fiber layer (RNFL) thickness was significantly lower in the acromegalic patients (0.25 ± 0.05 mm) as compared to controls (0.31 ± 0.09 mm) (P = 0.01). A significant moderate correlation was detected between IGF-1 level and disc area (r = 0.362), cup area (r = 0.389) and cup volume (r = 0.491).

Conclusion:

Biochemically controlled acromegalic patients showed significantly higher CCT and IOP levels and lower RNFL thickness compared to healthy controls and the duration of disease was correlated with CCT and IOP levels.     

Evaluating the change in central corneal thickness in neonates (term and preterm) in Indian population and the factors affecting it

Background and Aim:

Central corneal thickness (CCT) of term and preterm infants in Indian population is not known. We did a prospective noninterventional study to measure the CCT in term and preterm infants.

Materials and Methods:

An ultrasonic pachymeter was used. The data regarding the date of birth, expected date of delivery, birth weight were recorded. The preterm and the term infants were followed up at 8 weeks, 20 weeks and at 1-year.

Results:

A total of 85 (170 eyes) children were included in the study. The mean age was 264.6 ± 21.8 days postconception. The mean birth weight and CCT were 1834.4 ± 512.1 g and 595.8 ± 72.4 μ respectively. A comparison of CCT on the basis postgestational age showed a mean thickness of 620.7 ± 88.8 and 574.4 ± 78.3 μ in the <260 days and >260 days age groups respectively. The difference was statistically significant (Student''s test, P = 0.002). The CCT of preterm infants (<260 days) decreased from a mean value of 620.7 ± 88.8 μ to 534.1 ± 57.6 μ at the end of 1-year.

Conclusion:

We present the data of CCT in term and preterm infants in Indian population. We believe that the premature babies have slightly thicker corneas than mature term babies.     

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.