Evaluation of changes of macular thickness in diabetic retinopathy after cataract surgery

Purpose

To assess the macular thickness changes after cataract surgery in diabetic patients using optical coherence tomography (OCT).

Methods

We retrospectively reviewed the records of 104 diabetic patients who underwent cataract surgery. We examined the changes of macular thickness using OCT before cataract surgery and 1 week, 1-, 2- and 6-months after surgery. The central subfield mean thickness (CSMT) was used to evaluate macular edema which was defined as an increase of CSMT (ΔCSMT) > 30% from the baseline. The association between prior laser treatment or severity of diabetic retinopathy and macular thickness were also analyzed.

Results

Macular edema occurred in 19 eyes (18%) from the diabetic group and 63% of macular edema developed at 1 month after surgery. Thirteen (68%) out of 19 eyes with macular edema showed the resolution of macular edema by 6 months after surgery without treatment. ΔCSMT of eyes without a history of laser treatment was statistically greater compared to eyes with a history of laser treatment in at 1- and 2-months after surgery, but was not different than eyes who had laser treatment at 6-months after surgery. The severity of diabetic retinopathy was not significantly correlated to macular edema, but there was statistical difference when patients who had a history of prior laser treatment were excluded.

Conclusions

The incidence of macular edema after cataract surgery in diabetic patients was 18%. Its peak incidence was at 1 month post surgery and it resolved spontaneously in 68% of patients by 6 months post surgery. Prior laser treatment might prevent postoperative macular edema until 2 months after cataract surgery in diabetic patients. However, macular edema did not affect the severity of diabetic retinopathy.     

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.     

Regression of early diabetic macular oedema is associated with prevention of dark adaptation

Hypothesis

Dark-adapted rods consume oxygen at high rates and light adaptation decreases this oxygen burden and can have therapeutic effects on diabetic macular oedema (DMO).

Methods

Patients with mild non-proliferative diabetic retinopathy (DR) and early, untreated non-sight-threatening DMO slept for 6 months wearing masks that illuminated the eyelid of one closed eye by 505 nm light. Exclusion criteria were any concomitant eye disease, DR >ETDRS grade 35, and other systemic diseases. Primary outcome: change of OCT retinal thickness in the local region where oedema was present.

Results

A total of 34 out of 40 patients completed the study. Mean baseline OCT macular cube thickness was equivalent for study and fellow eyes. But study eyes had a greater mean thickness in the central subfield zone 1 (282±53 μm) vs (256±19 μm) the fellow eyes. Twenty-eight study eyes showed intraretinal cysts compared with nine in the fellow eyes. At 6 months, only 19 study eyes had cysts while cysts were seen in 20 fellow eyes. After 6 months, the worst affected ETDRS zone and the central subfield zone 1 reduced in thickness in study eyes only by 12 μm (95% CI 20 to −7, P=0.01). The secondary outcomes of change in visual acuity, achromatic contrast sensitivity, and microperimetric thresholds improved significantly in study eyes and deteriorated in fellow eyes.

Conclusions

Sleeping in dim light that can keep rods light adapted may reverse the changes of DMO.     

Predictors of short-term outcomes related to central subfield foveal thickness after intravitreal bevacizumab for macular edema due to central retinal vein occlusion

AIM: To investigate the predictive factors for short-term effects of intravitreal bevacizumab injections on central subfield foveal thickness (CSFT) in patients with macular edema (ME) secondary to central retinal vein occlusion (CRVO). METHODS: This was a retrospective study in 60 eyes treated with intravitreal bevacizumab injections for ME due to CRVO. Follow-up was three months. The Early Treatment Diabetic Retinopathy Study (ETDRS) score and CSFT measured by spectral-domain optical coherence tomography (SD-OCT) were used to observe the changes in best-corrected visual acuity (BCVA). Baseline BCVA, CSFT, age, CRVO duration and the presence of cystoid macular edema (CME) or subretinal fluid (SRF) were analyzed as potential predictive factors of the effects of intravitreal bevacizumab injections. RESULTS: BCVA improved from 0.9 logMAR at baseline to 0.6 logMAR at 3mo, which was associated with a significant reduction in CSFT from 721 µm to 392 μm 3mo after injection. About 50% of CME cases and more than 90% of SRF cases responded to treatment with a complete resolution at 3mo. Age (P=0.036) and low baseline CSFT (P=0.037) were associated with a good 3-month prognosis. Patients >60 years old achieved better CME resolution (P=0.031) and lower CSFT at 3mo (305 μm vs 474 μm, P=0.003). CONCLUSION: Intravitreal bevacizumab significantly improved visual acuity and CSFT in patients with CRVO after 3mo. Older age and lower baseline CSFT were good predictors of short-term CSFT outcomes. The retinal thickness response to bevacizumab might depend on the resolution of CME rather than SRF.     

Intravitreal bevacizumab alone versus combined with macular photocoagulation in diabetic macular edema

Purpose

To compare the efficacy between intravitreal bevacizumab and combination treatment (bevacizumab and macular photocoagulation) for the treatment of diabetic macular edema (DME). In addtion, changes of DME type were researched using optical coherence tomography.

Methods

The present study included 90 eyes with bevacizumab injection and 38 eyes with combination treatment. Using chart records, patients were reviewed until 6 months after treatment. The present study compared changes of visual acuity (VA) and macular thickness at each follow up. DME was classified into 4 types and the morphologic pattern was compared.

Results

In patients with the bevacizumab injection only, VA improved from 0.29 ± 0.18 to 0.48 ± 0.26 at 1 month and returned to 0.32 ± 0.20 at 6 months after treatment. In the combination treatment, VA improved from 0.32 ± 0.22 to 0.52 ± 0.26 at 1 month and returned to 0.36 ± 0.18 at 6 months after treatment. There was no significant improvement of VA at the final follow-up with either treatment. There was significant decrease of macular thickness except in the mixed DME type.

Conclusions

The combination treatment did not yield better VA or macular thickness reduction at 6 months than bevacizumab injection alone. By classifying and observing the change of DME type, determining the treatment objectively and predicting the effectiveness of treatment can be helpful.     

Intravitreal Bevacizumab May Increase Diabetic Macular Edema in Eyes with Attached Posterior Vitreous

Purpose

To report 2 eyes of a patient which developed vitreomacular traction (VMT) 1 month after intravitreal bevacizumab (IVB) injection.

Materials and Methods

A 45-year-old female with bilateral diffuse diabetic macular edema (DME) received bilateral IVB.

Results

Her initial visual acuity (VA) was 0.15 and 0.2 in OD and OS, respectively. Central foveal thickness (CFT) was 568 and 662 µm in OD and OS, respectively, without any sign of VMT. Both eyes responded well initially but developed VMT at 1 month. This time, intravitreal triamcinolone (IVTA) injection was performed. One month after IVTA injection, VMT was released and CFT decreased to 163 and 181 µm in OD and OS, respectively. Six months after IVTA injection, CFT was 163 and 153 µm, and VA was 0.7 and 0.9 in OD and OS, respectively.

Conclusion

In eyes with DME and attached posterior vitreous, VMT may develop after IVB injection and increase edema. IVTA injection might be an option to release VMT before considering vitrectomy.Key Words: Bevacizumab, Diabetic macular edema, Posterior vitreous, Vitreomacular traction     

Effect of OCT volume scan density on thickness measurements in diabetic macular edema

Purpose

To evaluate the impact of reducing B-scan frame-sampling density on retinal thickness measurements using spectral domain optical coherence tomography (SD-OCT) in eyes with diabetic macular edema (DME).

Methods

We retrospectively collected OCT data for 64 eyes of 43 patients undergoing imaging for DME using the Cirrus HD-OCT 512 × 128 macular cube protocol. For each case, raw OCT data were imported into the 3D-OCTOR software, and retinal thickness maps were generated using all 128 B-scans and for lower densities of B-scans ranging from every other scan to only four scans (every 30-s B-scan). Maps were generated before and after manual correction of retinal boundary segmentation errors. The foveal central subfield (FCS) and total macular volume (TMV) values were used to compare thickness maps of varying densities.

Results

The mean difference in FCS retinal thickness and TMV increased as the B-scan density was reduced, particularly when the density was reduced to fewer than 16 B-scans over 6 mm. At a density of 16 B-scans, the mean absolute difference in FCS thickness was 2.43 μm (0.79%), with a maximum of 10.1 μm (4.09%). At this density, the mean difference in TMV was 0.012 mm³ (0.13%), with a maximum difference of 0.04 mm³ (0.47%). Manual correction of OCT segmentation errors resulted in a difference in FCS thickness of ≥10 μm in only 12.5% of cases, with a maximum difference of 115.7 μm.

Conclusion

A minimum of 16 equally spaced B-scans appear necessary to generate retinal thickness measurements similar to those produced using all 128 B-scans in eyes with DME. Manual correction of segmentation errors appeared to have a clinically meaningful effect in a small minority of cases. These results may have implications for the design of SD-OCT imaging and grading protocols in clinical trials of DME, particularly when using multiple SD-OCT instruments that acquire varying numbers of B-scans.     

Measurement of retinal thickness in macular region of high myopic eyes using spectral domain OCT

AIM:To investigate the changes of retinal thickness in macula of high myopic eyes using spectral domain optical coherence tomography (OCT).METHODS: Middle-aged and young myopic patients were divided into three groups according to their refractive error/axial length:low and medium myopia group (LMMG), high myopia group (HMG) and super high myopia group (SHMG). Cirrus HD-OCT was used to evaluate total average macular thickness, central subfield thickness, inner/outer macular thickness and macular volume. The differences among experimental groups were analyzed by one-factor analysis of variance. Associations between macular thickness and refractive error/axial length were analyzed by Pearson correlation analysis.RESULTS: There was no significant difference in age among the three groups (P=0.2789). The mean refraction error in the LMMG, HMG, and SHMG groups was -2.49±1.38D, -8.53±1.95D and -13.88±1.76D, respectively (P＜0.001). The central subfield thickness of three groups was 244.56±12.19μm, 254.33±11.61μm and 261.75±11.83μm, respectively, and there were statistically significance between random two groups. The total average macular thickness, inner/outer macular thickness, and macular volume decreased with increased myopia/axial length. Average foveal thickness had negative correlations with refractive error (P＜0.001), and positive correlations with axial length. The inferior and temporal inner macular thickness, all the quadrants of outer ring, total average macular thickness and macular volume featured positive correlations with refractive error, and negative correlations with axial length. Average foveal thickness, superior and temporal inner macular thicknesses, and temporal outer macular thickness was lower in females compared to males.CONCLUSION:With an increase in myopia degree/axial length, the average foveal thickness increased and the inner/outer macular thickness decreased. Females featured thicker average foveal thickness, and thinner macular thickness compared to males.     

Change in subfoveal choroidal thickness after argon laser panretinal photocoagulation

AIM: To evaluate changes in subfoveal choroidal thickness (SFCT) and macular thickness as measured by enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT) after argon laser panretinal photocoagulation (PRP) in patients with severe diabetic retinopathy.METHODS:This prospective, comparative case series included 21 patients (28 eyes) with severe diabetic retinopathy. All patients underwent three sessions of PRP. The SFCT and macular thickness were measured using EDI-OCT at baseline and one week after completion of 3 sessions of PRP.RESULTS:SFCT before PRP was (318.1±96.5)μm and increased to (349.9±108.3)μm (P=0.001) after PRP. Macular thickness significantly increased at one week after PRP (from 273.1±23.9μm at baseline vs 295.8±25.3μm at one week; P<0.001). No significant relationship between the changes in macular thickness and SFCT was observed (r=-0.13, P=0.52).CONCLUSION: PRP induced increases in both SFCT and macular thickness. Changes in SFCT did not correlate with changes in macular thickness.     

Observational study of subclinical diabetic macular edema

Purpose

To determine the rate of progression of eyes with subclinical diabetic macular edema (DME) to clinically apparent DME or DME necessitating treatment during a 2-year period.

Methods

In all, 43 eyes from 39 study participants with subclinical DME, defined as absence of foveal center edema as determined with slit lamp biomicroscopy but a center point thickness (CPT) between 225 and 299 μm on time domain (Stratus, Carl Zeiss Meditec) optical coherence tomography (OCT) scan, were enrolled from 891 eyes of 582 subjects screened. Eyes were evaluated annually for up to 2 years for the primary outcome, which was an increase in OCT CPT of at least 50 μm from baseline and a CPT of at least 300 μm, or treatment for DME (performed at the discretion of the investigator).

Results

The cumulative probability of meeting an increase in OCT CPT of at least 50 μm from baseline and a CPT of at least 300 μm, or treatment for DME was 27% (95% confidence interval (CI): 14%, 38%) by 1 year and 38% (95% CI: 23%, 50%) by 2 years.

Conclusions

Although subclinical DME may be uncommon, this study suggests that between approximately one-quarter and one-half of eyes with subclinical DME will progress to more definite thickening or be judged to need treatment for DME within 2 years after its identification.     

Comparison and interchangeability of macular thickness measured with Cirrus OCT and Stratus OCT in myopic eyes

AIM: To investigate the difference of macular thickness measurements between stratus optical coherence tomography (OCT) and Cirrus OCT (Carl Zeiss Meditec, Dublin, CA, USA) in the same myopic patient and to develop a conversion equation to interchange macular thickness obtained with these two OCT devices. METHODS: Eighty-nine healthy Chinese adults with spherical equivalent (SE) ranging from -1.13 D to -9.63 D were recruited. The macular thickness was measured by Cirrus OCT and Stratus OCT. The correlation between macular thickness and axial length and the agreement between two OCT measurements were evaluated. A formula was generated to interchange macular thickness obtained with two OCT devices. RESULTS: Average macular thickness measured with Stratus OCT (r=-0.280, P=0.008) and Cirrus OCT (r=-0.224, P=0.034) were found to be negatively correlated with axial length. No statistically significant correlation was found between axial length and central subfield macular thickness (CMT) measured with Stratus OCT (r=0.191, P=0.073) and Cirrus OCT (r=0.169, P=0.113). The mean CMT measured with Cirrus OCT was 53.63±7.94 μm thicker than with Stratus OCT. The formula CMTCirrus OCT=78.328+0.874×CMTStratus OCT was generated to interchange macular thickness obtained with two OCT devices. CONCLUSION: Macular thickness measured with Cirrus OCT were thicker than with Stratus OCT in myopic eyes. A formula can be used to interchange macular thickness measured with two OCT devices in myopic eyes. Studies with different OCT devices and larger samples are warranted to enable the comparison of macular values measured with different OCT devices.     

Macular and peripapillary retinal nerve fiber layer thickness in children with hyperopic anisometropic amblyopia

AIM:To compare the retinal nerve fiber layer (RNFL) thickness and macular thickness in the amblyopic eye with that in the sound eye of children with hyperopic anisometropic amblyopia using optical coherence tomography (OCT).METHODS: A prospective, nonrandom, intraindividual comparative cohort study includes 72 children with hyperopic anisometropic amblyopia in a single center. Macular thickness, macular foveola thickness, and peripapillary RNFL thickness were compared between the amblyopia eyes and the contralateral sound eyes.RESULTS:There were 38 male and 34 female patients, with a mean age as 9.7±1.9 years (range, 5–16 years). Hyperopic was +3.62±1.16D (range +2.00D to +6.50D) in the amblyopic eyes, which was significantly higher in the control eyes with +0.76±0.90D (range 0D to +2.00D) (P < 0.01). The mean peripapillary RNFL thickness was 113.9±7.2µm and 109.2±6.9µm in the amblyopic eye and the normal eye, respectively, reaching statistical significance (P = 0.02). The mean macular foveola thickness was significantly thicker in the amblyopic eyes than the contralateral sound eyes (181.4±14.2µm vs 175.2±13.3µm, P < 0.01), but the 1mm, 3mm or 6mm macular thickness central macular thickness was not significantly different. Degree of anisometropia in the contralateral eyes was not significantly correlated with differences of peripapillary RNFL, macular foveola thickness or central macular thickness.CONCLUSION:Eyes with hyperopic anisometropic amblyopia are found thicker macular foveola and peripapillary RNFL than the contralateral eyes in children.     

Comparison of retinal nerve fiber layer and macular thickness measurements with Stratus OCT and OPKO/OTI OCT devices in healthy subjects

AIM: To compare retinal nerve fiber layer (RNFL) and macular thickness measurements obtained with the Stratus optical coherence tomography (OCT) and OPKO/OTI OCT devices. METHODS: Included in the study were 59 eyes of 30 participants. All measurements for each eye were done on the same day with both devices. Student’s paired t-tests were used to compare the central macular thickness and RNFL measurements of the Stratus OCT and OPKO/OTI OCT. Pearson correlation was used to assess the relationship between the devices. Coefficient of variation (COV) was calculated to assess intersession repeatability. RESULTS: Using both the Stratus OCT and OPKO/OTI OCT, respectively, the measured mean average RNFL thicknesses were 98.9±11.1 μm and 115.1±9.6 μm (P=0.001), and the measured mean central retinal thicknesses (CRT) were 196.2±18.8 μm and 204.5±21.1 μm (P<0.001). Measured by the two devices, the RNFL thickness values were correlated in all quadrants, as were the retinal thickness values except the inferior outer sector. COV for average RNFL and CRT thickness were 2.9% and 4.6% for Stratus OCT, and 2.1% and 4.2% for OPKO/OTI OCT, respectively. CONCLUSION: We found good reproducibility of RNFL and retina thickness measurements for both Stratus OCT and OPKO/OTI OCT devices. However, even though the two OCT systems provided statistically correlated results, the values for both RNFL and macular thickness were statistically different. RNFL and macular thickness measurements with the OPKO/OTI OCT were higher than that of the Stratus OCT; therefore, the two OCT systems cannot be used interchangeably for the measurements of RNFL and macular thickness.     

Results of intravitreal dexamethasone implant 0.7 mg (Ozurdex®) in non-infectious posterior uveitis

AIM:To evaluate the safety and efficacy of dexamethasone implant in patients with non-infectious posterior uveitis withcystoid macular edema (CME).METHODS:Retrospective analysis of patients reports with CME secondary to non-infectious uveitis treated with dexamethasone implant. Data included type of posterior uveitis, any systemic immunosuppressive therapy, Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA), central macular thickness (CMT) on optical coherence tomography (OCT) and signs of intraocular inflammation at baseline and then at 2wk postoperatively and monthly thereafter. Follow-up is up to 10mo. Any per-operative and post-operative complications were recorded.RESULTS:Six eyes of 4 patients with CME due to non-infectious posterior uveitis treated with dexamethasone implant. Diagnosis included idiopathic panuveitis, birdshot chorioretinopathy and idiopathic intermediate uveitis. At baseline mean ETDRS BCVA was 63 letters and mean CMT 556 μm at 2wk postoperatively mean ETDRS BCVA improved to 70 letters and mean CMT decreased to 329 μm. All eyes showed clinical evidence of decreased inflammation. The duration of effect of the implant was 5 to 6mo and retreatment was required in 2 eyes. Two patients required antiglaucoma therapy for increased intraocular pressures.CONCLUSION: In patients with non-infectious posterior uveitis dexamethasone implant can be a short-term effective treatment option for controlling intraocular inflammation.     

Spectral- and time-domain optical coherence tomography measurements of macular thickness in normal eyes and in eyes with diabetic macular edema

Purpose

To report macular thickness values in normal eyes and eyes with diabetic macular edema (DME) using time-domain (TD) and spectral-domain (SD) optical coherence tomography (OCT), and to derive a conversion equation.

Methods

The index study was a prospective investigation conducted on 80 eyes from 40 normal subjects and 130 eyes from 118 patients with DME seen in our clinic. Retinal thickness values from the central 1 mm of the macula and surrounding four ETDRS subfields were acquired using TD-OCT (Stratus OCT) and SD-OCT (SPECTRALIS HRA+OCT). Measurements of the central (C) subfield from both devices were used to derive a conversion equation. The equation was used to predict SD-OCT values using measurements from TD-OCT. Agreement between predicted and actual SD-OCT measurements was assessed.

Results

In normal eyes, the mean difference between TD-OCT and SD-OCT measurements of the C subfield was 76 μm (CI₉₅=74 and 77, respectively). The conversion equation, y=1.029x+72.49, was derived. In eyes with DME, using the equation, SPECTRALIS-predicted values were 5% higher than actual measurements, with 95% of predicted values falling within 9% of the actual measurements. Relocating SD-OCT grids to match the location on TD-OCT resulted in predicted values falling within 7% of actual measurements.

Conclusions

The percent difference between actual thickness measurements from SPECTRALIS and predicted thickness measurements, using the conversion equation, was within reported limits of repeatability of Stratus in eyes with DME. Our equation may help correlate OCT values from both devices in standard care and clinical trials for DME.     

Vitrectomy Combined with Intravitreal Triamcinolone Acetonide Injection and Macular Laser Photocoagulation for Nontractional Diabetic Macular Edema

Purpose

To evaluate the efficacy of vitrectomy combined with intravitreal injection of triamcinolone acetonide (IVTA) and macular laser photocoagulation for the treatment of nontractional diabetic macular edema (DME) refractory to anti-vascular endothelial growth factor (VEGF) therapy.

Methods

Twenty-eight eyes from 28 subjects who were diagnosed with nontractional DME refractory to three or more sequential anti-VEGF injections underwent sequential vitrectomy, IVTA, and macular laser photocoagulation. Changes in best-corrected visual acuity (BCVA) and central subfield thickness (CST) during the six months following vitrectomy were evaluated. Additionally, the CST and BCVA outcomes were compared with those of 26 eyes treated with the same triple therapy for nontractional DME refractory to conventional treatment, such as IVTA or macular laser photocoagulation, or both.

Results

The mean logarithm of the minimum angle of resolution BCVAs before and one, three, and six months after vitrectomy were 0.44 ± 0.15, 0.36 ± 0.18, 0.31 ± 0.14, and 0.34 ± 0.22, respectively. The mean CSTs were 433.3 ± 77.9, 329.9 ± 59.4, 307.2 ± 60.2, and 310.1 ± 80.1 microns, respectively. The values of both BCVA and CST at one, three, and six months were significantly improved from baseline (p < 0.05). The extent of CST reduction during the first month after triple therapy was greater in eyes refractory to conventional treatment than in eyes refractory to anti-VEGF (p = 0.012).

Conclusions

Vitrectomy combined with IVTA and macular laser photocoagulation had a beneficial effect on both anatomical and functional outcomes in eyes with nontractional DME refractory to anti-VEGF therapy.     

Posterior scleral reinforcement combined with vitrectomy for myopic foveoschisis

AIM: To investigate the effects of posterior scleral reinforcement (PSR) combined with vitrectomy for myopic foveoschisis. METHODS: Thirty-nine highly myopic eyes of 39 patients with myopic foveoschisis underwent PSR combined with vitrectomy. Best corrected visual acuity (BCVA), refraction error, and the foveal thickness by optical coherence tomography (OCT) were recorded before and after the surgery, and complications were noted. RESULTS: The follow-up period was 12mo, and the main focus was on the results of the 12-month follow-up visit. The mean preoperative BCVA was 0.96±0.43 logMAR. At the final follow-up visit, the mean BCVA was 0.46±0.28 logMAR, which significantly improved compared with the preoperative one (P=0.003). The BCVA improved in 33 eyes (84.62%), and unchanged in 6 eyes (15.38%). At the end of follow-up, the mean refractive error was -15.13±2.55 D, and the improvement was significantly compared with the preoperative one (-17.53±4.51 D) (P=0.002). Twelve months after surgery, OCT showed complete resolution of the myopic foveoschisis and a reat¬tachment of the fovea in 37 eyes (94.87%) and partial resolution in the remained two eyes (5.13%). The foveal thickness was obviously reduced at 12-month follow-up visit (196.45±36.35 μm) compared with the preoperative one (389.32±75.56 μm) (P=0.002). There were no serious complications during the 12mo follow-up period. CONCLUSION: PSR combined with vitrectomy is a safe and effective procedure for myopic foveoschisis with both visual and anatomic improvement.     

Postoperative astigmatic outcomes based on the haptic axis of intraocular lenses inserted in cataract surgery

Purpose

This study was conducted to compare post-operative astigmatic outcomes of two groups, with-the-rule (WTR) and against-the-rule (ATR) astigmatism patients, according to the haptic axis of intraocular lenses (IOLs) inserted in cataract surgery.

Methods

Seventy-two eyes with WTR astigmatism and 79 eyes with ATR astigmatism had cataract surgery through a clear corneal temporal incision. These two groups of eyes were then each divided into 2 groups based on whether the haptic axis of the inserted IOL was at 180° or 90°. For ATR patients, the outcomes were analyzed according to the three types of IOLs.

Results

There was no difference in corneal astigmatism, but WTR patients with a 180° haptic axis of the inserted IOL and ATR patients with a 90° hepatic axis of the inserted IOL had a significant decrease in postoperative refractive astigmatism (p < 0.05). The changes in ATR astigmatism according to the IOL type were more effective in single-piece acrylic IOLs than in the three-piece polymethylmethacrylate haptic IOL group.

Conclusions

Insertion of the IOL at the 180° haptic axis in WTR patients and at 90° in ATR patients during cataract surgery may have an effect in reducing pre-existing astigmatism. This observed effect was not consistent among the different types of IOLs.     

Macular gradient measurement in myopic posterior staphyloma using optical coherence tomography

Purpose

To evaluate clinical characteristics and the macular gradient in myopic posterior staphyloma with time domain (TD) optical coherence tomography (OCT).

Methods

Sixty-four staphyloma eyes of 40 patients were examined. Macular gradient (tangent θ) and the location of staphyloma were assessed with OCT imaging. The macular gradient was measured at points 1 mm and 2 mm distant from the fovea. The relationships of the macular gradient with age, axial length, and spherical equivalent were analyzed.

Results

In 8 eyes (12.5%), the bottoms of the staphylomas were in the fovea, and there was no macular gradient. However, in the other 56 eyes (87.5%), the bottoms of the staphylomas were not in the foveal area, and macular gradients existed. Staphylomas were commonly located in the infero-nasal retinal area. The mean macular gradient (tangent θ) was 0.26 ± 0.08 at 1 mm distance from the fovea and 0.28 ± 0.10 at 2 mm. No significant relationships were observed between macular gradient and axial length, patient age, or spherical equivalent.

Conclusions

TD OCT reveals staphyloma location. If the location is outside of the fovea, a macular gradient exists and can be measured by OCT. Axial length measurement error may occur in eyes with poor visual fixation and steep macular gradients.     

Correlation of leaking microaneurysms with retinal thickening in diabetic retinopathy

AIM: To investigate the contribution of fluorescein angiographic leaking microaneurysms (leak-MA) versus non-leaking microaneurysms (non-leak-MA) to retinal thickening in diabetic retinopathy. METHODS: A consecutive series of 38 eyes from 24 patients with diabetic retinopathy was included. Leak-MA and non-leak-MA in each eye were selected in pairs at corresponding topographic location. Leaking was defined by late phase fluorescein angiograms compared to early phase. Retinal thickness was measured with Heidelberg Spectralis OCT topographically aligned on early phase angiograms at the MA site and within a 1 mm circle. RESULTS: In all eyes, significant retinal thickening at the site of leaking compared to non-leaking microaneurysms was observed (356±69μm vs 318±56μm, P <0.001), showing a mean increase in thickness in the areas of leak-MA vs non-leak-MA of 38±39μm (95% confidence interval 25-51μm, P<0.001). All 1mm area measurements also showed significant (P<0.001) thickening of the leak-MA with average thickness of leak-MA vs non-leak-MA as 351±67μm vs 319±59μm; minimum thickness 311±62μm vs 284±60μm; maximum thickness 389±78μm vs 352±66μm; and retina volume 26.4±6.0mm vs 23.6±3.7mm3, respectively. CONCLUSION: Leaking of microaneurysms on fluorescein angiography appears to cause focal thickening of retina, which can be measured with high-resolution OCT. Therefore, targeting leaking microaneursyms in diabetic retinopathy has the potential to reduce retinal thickening.