Evaluation of Axial Length Measurement of the Eye Using Partial Coherence Interferometry and Ultrasound in Cases of Macular Disease

Short-term clinical outcomes after implantation of monofocal intraocular lens with enhanced intermediate function in eyes with epiretinal membrane

Our study evaluated the clinical outcomes after implantation of a monofocal intraocular lens (IOL) with enhanced intermediate function in eyes with epiretinal membrane (ERM). Patients with preexisting ERM who underwent cataract surgery with implantation of monofocal IOL with enhanced intermediate function were included retrospectively. According to the ERM grade and central subfield thickness (CST) obtained from preoperative optical coherence tomography, patients were divided into non-fovea-involving and fovea-involving ERM groups. At 1 month after surgery, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected intermediate visual acuity (UIVA), uncorrected near visual acuity (UNVA), contrast sensitivity, defocus curve, and satisfaction questionnaire were evaluated. Postoperative clinical findings were compared with age-matched controls without ERM. A total of 50 patients' eyes (28 and 22 in the non-fovea-involving and fovea-involving ERM groups, respectively) were compared with 42 control eyes. One month post-surgery, significant differences in UDVA, CDVA, and CST (corrected P was < 0.001, = 0.001, and < 0.001, respectively) were observed between the fovea-involving ERM and control group; however, no significant differences in UIVA and UNVA were observed between the two groups. Contrast sensitivity showed inferior results in the fovea-involving group without significance. Photic phenomena were reported less in the fovea-involving group than in the non-fovea-involving group. More than 70% of patients in both ERM groups were satisfied. Implantation of monofocal IOL with enhanced intermediate function could be a good option for patients with ERM that need intermediate vision.

Vault Height Is a Key Predictive Factor for Anterior Segment Measurement Error by IOLMaster 700 in Eyes With Phakic Intraocular Lens

Purpose

To identify risk factors of ocular anterior segment measurement error by the IOLMaster 700 in eyes implanted with an implantable Collamer lens (ICL).

Methods

In total, 152 patients with clear lens (152 eyes, group 1) and another 32 cataract patients (57 eyes, group 2) who underwent ICL implantation were included, and the presence of measurement error by the IOLMaster 700 was determined based on B-scan images. The risk factors for measurement error were evaluated by logistic regression, and the optimal threshold was determined using receiver operating characteristic analysis.

Results

The ICL was misidentified as the anterior surface of the crystalline lens in 51.97% of eyes (79/152) in group 1 and 80.70% of eyes (46/57) in group 2. For every 100-µm decrease in the vault height, a 3.57- and 5.78-fold increase in the risk of measurement error was observed in group 1 and group 2, respectively. We identified an optimal threshold of the vault height at 389.47 µm for predicting biometric measurement error in eyes implanted with ICL, which showed an area under the curve of 0.93 (95% confidence interval, 0.90-0.97), a sensitivity of 0.87, and a specificity of 0.86.

Conclusions

Patients with ICL implantation, particularly those with a vault height less than 389.47 µm, are at a greater risk of anterior segment biometric measurement error by the IOLMaster 700.

Translational Relevance

The threshold of vault height can help to identify high-risk patients and further optimize biometric measurement.

Assessment of Risk Factors Affecting Refractive Outcomes after Phacovitrectomy for Epiretinal Membrane

PURPOSE

To investigate factors associated with refractive outcomes after phacovitrectomy for epiretinal membrane (ERM).

METHODS

Retrospective review of patients undergoing phacovitrectomy for ERM was done. The main outcome measure was predictive refraction error (PE), defined as observed refraction error - target refraction error, calculated by the SRK/T, Haigis, and SRK II formulae. PE was measured at postoperative 1, 3, and 6 months. Simple and multiple linear regression analysis were used to evaluate factors associated with PE.

RESULTS

A total of 53 eyes of 53 patients were included. The mean PEs at postoperative 1, 3, and 6 months were all negative, implying myopic shift in all patients regardless of the intraocular lens formula used. Haigis formula showed the least myopic shift among the three formulae (p = 0.001, Friedman test). There was no significant difference in PE depending on preoperative central macular thickness (CMT) in subgroup analysis. On stepwise multiple linear regression analysis, ERM etiology (β = 0.759, p = 0.004, SRK/T formula; β = 0.733, p = 0.008, Haigis formula; β = 0.933, p < 0.001, SRK II formula), preoperative anterior chamber depth (β = -0.662, p = 0.013, Haigis formula; β = -0.747, p = 0.003, SRK II formula), and decrease of CMT (β = -0.003, p = 0.025, SRK/T formula) were significantly associated with PE at postoperative 6 months.

CONCLUSIONS

Myopic shift in PE was observed after combined phacovitrectomy for epiretinal membrane. ERM etiology, preoperative anterior chamber depth, and decrease of CMT were significantly associated with PE at postoperative 6 months. There was no difference in PE after surgery between the two groups defined by CMT (≥500 and <500 μm).

Swept-source OCT reduces the risk of axial length measurement errors in eyes with cataract and epiretinal membranes

AIMS

To compare the biometric data from partial coherence interferometry (PCI) and swept-source OCT (SS-OCT) in patients with age-related cataract and epiretinal membrane (ERM): ERM, ERM with foveoschisis and macular pseudohole.

METHODS

49 eyes of 49 subjects including 36 ERM, 9 ERM foveoschisis and 4 macular pseudohole were analysed to evaluate the axial length (AL) measurements and the presence of AL measurement errors, defined basing on the shape of the biometric output graphs and on the concordance of AL values between instruments. Eyes with ERM were divided in four stages according to OCT features (i.e. presence/absence of the foveal pit, presence of ectopic inner foveal layers, disrupted retinal layers).

RESULTS

The devices provided similar mean AL measurements in all subgroups, with differences <0.1 mm in 41/49 cases (83.6%). AL measurement errors were observed in ERM stages 3 and 4, characterized by ectopic inner foveal layers, and were significantly more frequent with the PCI (8/17, 47%) as compared with the SS-OCT device (2/17, 12%), p = 0.02. The refractive prediction error in cases with AL measurement errors was significantly greater using the PCI compared to the SS-OCT device (p<0.05).

CONCLUSION

Both devices provide reliable biometric data in the majority of patients and can be used in the preoperative assessment of patients with age-related cataract and ERM. In eyes with ectopic inner foveal layers, attention should be paid as AL measurement and refractive prediction errors may occur, more frequently with the PCI device.

Comparison of refractive deviations after phacovitrectomy according to the intraocular lens insertion method

PURPOSE

This study aimed to compare refractive deviations between in-the-bag insertion, trans-scleral ciliary sulcus fixation, ciliary sulcus insertion, and ciliary sulcus insertion with optic capture after phacovitrectomy.

STUDY DESIGN

Single-unit, single-surgeon, retrospective study.

METHODS

Consecutive patients who underwent phacovitrectomy and intraocular lens (IOL) out-of-the-bag insertion simultaneously were retrospectively reviewed. Patients who underwent phacovitrectomy with IOL in-the-bag insertion were also included for comparison with those who underwent phacovitrectomy with out-of-the-bag insertion. Patients were classified into four groups based on the IOL insertion method. The average difference from the target spherical equivalent (SE) to postoperative SE was defined as the refractive deviation. Refractive deviations of the groups were compared.

RESULTS

The refractive deviation for the in-the-bag insertion (43 eyes) was -0.18 ± 0.50 Df, -0.84 ± 0.81 D for the trans-scleral ciliary sulcus fixation (43 eyes), -0.93 ± 0.68 D for the ciliary sulcus insertion (25 eyes), and -0.27 ± 0.50 D for the ciliary sulcus insertion with optic capture group (24 eyes). The trans-scleral ciliary sulcus fixation and ciliary sulcus insertion groups had significantly different deviations than the in-the-bag group (p < 0.001). There was no significant difference between the ciliary sulcus insertion with optic capture and the in-the-bag insertion groups (p = 0.100).

CONCLUSION

Refractive deviation was significantly different between the eyes that underwent trans-scleral ciliary sulcus fixation or ciliary sulcus insertion and the eyes that underwent in-the-bag insertion. However, there was no significant deviation among the eyes that underwent ciliary sulcus insertion with optic capture.

Postoperative Refractive Prediction Error Measured by Optical and Acoustic Biometry after Phacovitrectomy for Rhegmatogenous Retinal Detachment without Macular Involvement

Introduction

The aim of this study was to investigate the postoperative prediction error measured by optical biometry and acoustic biometry in eyes after phacovitrectomy for rhegmatogenous retinal detachment (RRD) with no macular involvement.

Methods

Forty-nine eyes of 49 patients (32 male, 17 female; mean age 62.6 ± 7.5 years) with RRD without macular involvement who underwent phacovitrectomy (RRD group) and 49 eyes of 33 patients (21 male, 12 female; mean age 74.1 ± 7.1 years) without macular disease who underwent cataract surgery (control group) were included in this retrospective comparative study. The difference between the preoperative predictive value and the postoperative refractive value was measured both by optical and acoustic biometry and compared in each group.

Results

The postoperative refractive error calculated by acoustic biometry was -0.81 ± 0.75D and that calculated by optic biometry was -0.44 ± 0.77D in the RRD group. The postoperative refractive error calculated by acoustic biometry was -0.21 ± 0.64D and that calculated by optic biometry was 0.27 ± 0.71D in the control group. Significant myopic shifts were observed in the RRD group using both acoustic biometry and optic biometry but not in the control group.

Conclusion

Phacovitrectomy for RRD with no macular involvement resulted in a significant myopic shift when compared with cataract surgery alone in patients without macular disease when calculated by both acoustic biometry and optic biometry.

Long-Term Reproducibility of Axial Length after Combined Phacovitrectomy in Macula-sparing Rhegmatogenous Retinal Detachment

There is a myopic shift in the final measured spherical equivalent following combined phacovitrectomy compared to the predicted postoperative value. This change in myopia is known to be associated with gas tamponade, but it also occurs in patients who do not have gas tamponade, and even when vitrectomy is performed in the pseudophakic eye. In this study, we focused on the long-term reproducibility of axial length after combined phacovitrectomy in patients with macula-sparing rhegmatogenous retinal detachment. Before surgery, one year after surgery, and two years after surgery, bilateral axial lengths were measured using partial interferometry. To confirm whether axial lengths changed after surgery, we conducted confidence analyses using the intraclass correlation coefficient (ICC), coefficient of variation (CV), and test–retest standard deviation (TRTSD). The preoperative mean axial length was 25.03 ± 1.69 mm in the affected eyes and 24.96 ± 1.70 mm in the fellow eyes. The ICC, CV, and TRTSD were 0.97, 0.45, and 0.114 in affected eyes and 0.98, 0.66, and 0.167 in fellow eyes, respectively, which shows a high level of reproducibility. Prediction errors for postoperative spherical equivalents measured using partial interferometry were −0.41 ± 0.67 diopters (p = 0.001), respectively, which shows a remarkable myopic shift. Correlation analyses indicated that this myopic shift was significant in eyes with a shallower anterior chamber and a thicker lens. In macula-sparing RRD patients, the axial length showed excellent long-term reproducibility two years after vitrectomy, cataract surgery, and gas tamponade. The myopic shift after surgery was therefore caused by factors that may have affected the intraocular lens position, such as preoperative anterior chamber depth and lens thickness, rather than a change in the axial length.

Intraocular lens power estimation in combined phacoemulsification and pars plana vitrectomy in eyes with epiretinal membranes: a case-control study

PURPOSE

To evaluate the accuracy of postoperative refractive outcomes of combined phacovitrectomy for epiretinal membrane (ERM) in comparison to cataract surgery alone.

MATERIALS AND METHODS

Thirty-nine eyes that underwent combined phacovitrectomy with intraocular lens (IOL) implantation for cataract and ERM (combined surgery group) and 39 eyes that received phacoemulsification for cataract (control group) were analyzed, retrospectively. The predicted preoperative refractive aim was compared with the results of postoperative refraction.

RESULTS

In the combined surgery group, refractive prediction error by A-scan and IOLMaster were -0.305±0.717 diopters (D) and -0.356±0.639 D, respectively, compared to 0.215±0.541 and 0.077±0.529 in the control group, showing significantly more myopic change compared to the control group (p=0.001 and p=0.002, respectively). Within each group, there was no statistically significant difference in refractive prediction error between A-scan and IOLMaster (all p>0.05). IOL power calculation using adjusted A-scan measurement of axial length based on the macular thickness of the normal contralateral eye still resulted in significant postoperative refractive error (all p<0.05). Postoperative refraction calculated with adjusted axial length based on actual postoperative central foveal thickness change showed the closest value to the actual postoperative achieved refraction (p=0.599).

CONCLUSION

Combined phacovitrectomy for ERM resulted in significantly more myopic shift of postoperative refraction, compared to the cataract surgery alone, for both A-scan and IOLMaster. To improve the accuracy of IOL power estimation in eyes with cataract and ERM, sequential surgery for ERM and cataract may need to be considered.

Postoperative refractive error after phacovitrectomy for epiretinal membrane with and without macular oedema

PURPOSE

This study was initiated to investigate whether the presence of macular oedema influenced intraocular lens (IOL) power calculation in eyes with epiretinal membrane.

METHODS

The files of patients undergoing combined phacoemulsification were retrospectively reviewed. Two groups were defined according to presence of macular oedema. The main outcome measure was the IOL power prediction error (PE). Secondary outcome measures were the correlation between preoperative macular thickness, absolute change of macular thickness and dioptric shift. The mean postoperative PE achieved with the Haigis formula was compared with the PE that would have been obtained had the SRKII and HofferQ formulas been used.

RESULTS

We investigated 47 eyes of 47 consecutive patients. Regardless of the IOL formula used, the PE was on average higher in eyes without macula oedema (group 1). The myopic dioptric shift was dependent on preoperative macular thickness and absolute change of macular thickness. This association was more markedly pronounced in group 1.

CONCLUSIONS

Increased retinal thickness is the main cause for underestimation of the cornea-photoreceptor layer distance, and therefore could contribute to inaccuracy in IOL power calculations. The current results show that a myopic shift tends to be less pronounced in cases where a macula oedema is present. Eyes with pure traction have less predictable refractive results in terms of higher PE and dioptric shift.

Relationship between retinal lesions and inward choroidal bulging in Vogt-Koyanagi-Harada disease

PURPOSE

To investigate the correlation between choroidal and retinal lesions in eyes with acute Vogt-Koyanagi-Harada disease (VKH) using optical coherence tomography (OCT) by using a new parameter, retinal pigment epithelium (RPE) undulation index, which quantitatively describes choroidal deformations.

DESIGN

Retrospective, observational, cross-sectional study.

METHODS

Spectral-domain OCT (SD OCT) and swept-source OCT images from a consecutive series of 42 eyes in 22 patients with acute VKH who underwent steroid therapy and 20 healthy eyes in 20 volunteers were analyzed retrospectively. Correlations between best-corrected visual acuity (BCVA), axial length change, and OCT parameters were examined. The RPE undulation index was defined as RPE line length to the total scan length ratio on a foveal-centered scan in the SD OCT image.

RESULTS

Eyes with acute VKH showed increased RPE undulation index, choroidal thickness, and retinal thickness compared to normal subjects, which were reduced following steroidal treatment (P < .0001, P = .0003, and P < .0001, respectively). RPE undulation index was related to choroidal thickness (r = 0.624, P = .0043), retinal thickness (r = 0.483, P = .0028), and BCVA (r = 0.588, P = .0002). Meanwhile, no statistically significant relationship was observed between choroidal thickness and retinal thickness. Axial length changes were significantly correlated with both choroidal thickness (r = 0.842, P < .0001) and RPE undulation index (r = 0.600, P = .0139).

CONCLUSIONS

This study demonstrated that the choroid was diffusely undulated and bulged inward in eyes with acute VKH. Correlations between RPE undulation index and choroid morphology, retinal thickness, and poor BCVA suggest that choroidal folding, quantified by RPE undulation index, is useful in assessing VKH disease severity.

Axial length estimation error caused by hidden double-peak on partial coherence interferometry in an eye with epiretinal membrane: a case report

Here we report a patient in whom there was a myopic shift after combined cataract surgery and pars plana vitrectomy against the epiretinal membrane, related to axial measurement estimation error caused by a hidden double-peak appearance on partial coherence interferometry measurement. A 52-year-old female presented with epiretinal membrane and underwent combined cataract surgery and pars plana vitrectomy. Axial length was measured with partial coherence interferometry. Although the signal curve in the summary display showed a single peak, a 1.6 diopter myopic shift occurred. Viewed retrospectively, six of 20 individual signal curves showed a double peak. Most of them showed a higher anterior peak, with only one having a higher posterior peak. The other 14 curves showed a single peak at a similar distance to an anterior peak. The anterior peak appeared to be derived from the epiretinal membrane. The possibility of a double peak should always be considered in patients with epiretinal membrane even if the summary display of the partial coherence interferometry measurement shows a single peak. Checking all signal curves would reduce the risk of missing a hidden double peak.

Intravitreal injection of bevacizumab: changes in intraocular pressure related to ocular axial length

PURPOSE

To evaluate the immediate and short-term effects of intravitreal injection of 1.25 mg/0.05 ml of bevacizumab on intraocular pressure related to different ocular axial lengths.

DESIGN

A prospective case series of consecutive patients referred to the Department of Ophthalmology, San Pietro-Fatebenefratelli Hospital, from September 2011 through January 2011.

METHODS

Twenty-five patients (10 men and 15 women, mean age 70.2 ± 8.98 years) scheduled for intravitreal injection of bevacizumab for the treatment of neovascular age-related macular degeneration were enrolled in this study. Axial length was measured preoperatively using IOLMaster. Intraocular pressure was measured before injection, after 1 min and after 15 min using Tono-Pen XL tonometry.

RESULTS

The mean intraocular pressure change following the intravitreal bevacizumab injection was 21.92 ± 6.95 mmHg after 1 min and 6.24 ± 3.77 mmHg after 15 min. The mean axial length of the examined eyes was 23.2 ± 1.06 mm. A good correlation was observed between the axial length and intraocular pressure rise after both 1 (R (2) = 0.752, p < 0.001) and 15 min (R (2) = 0.559, p < 0.001).

CONCLUSIONS

Patients undergoing intravitreal injection of 0.05 ml of bevacizumab can be exposed to intraocular pressure increases correlated to ocular axial length.