|Year : 2018 | Volume
| Issue : 2 | Page : 106-110
Early changes of choroidal and macular thickness after uneventful phacoemulsification surgery
Sara M Abd El-Mawgoud, Shaimaa A.S Arfeen, Nehal S El-Gendy, Adel M Fathy
Ophthalmology Department, Faculty of Medicine, Cairo University, Giza, Cairo, Egypt
|Date of Submission||04-Sep-2017|
|Date of Acceptance||14-Dec-2017|
|Date of Web Publication||7-Jun-2018|
Shaimaa A.S Arfeen
Al Mokkatam, 7308, Street Number 83, Al Hadaba Al Aolia, Cairo 11571
Source of Support: None, Conflict of Interest: None
Purpose To evaluate the changes in choroidal and macular thickness after uneventful phacoemulsification surgery and to know whether optical coherence tomography (OCT) choroidal thickness normative data should be considered the same preoperatively and postoperatively or not.
Patients and methods A prospective interventional study including 120 eyes of 90 patients with immature senile cataract was carried out. Retinal macular thickness and choroidal submacular thickness were measured preoperatively and 4 weeks after phacoemulsification using Optovue RTVue spectral domain OCT. Changes in thickness of the choroid and macula were evaluated.
Results The mean preoperative choroidal thickness was 211.640±35.7 μm in horizontal and vertical scans, while the mean postoperative choroidal thickness was 239.927±51.33 and 231.789±42.6 μm in horizontal and vertical scans, respectively. There was a statistically significant difference between preoperative and postoperative choroidal thickness (P=0.003 and 0.006) in horizontal and vertical scans, respectively. However, there was no significant change in mean macular thickness (P=0.065).
Conclusion Uncomplicated phacoemulsification induces a nonpathological increase in choroidal thickness probably due to the inflammatory effect of the surgery. However, these changes are not accompanied by significant changes in retinal macular thickness. Postoperative OCT choroidal thickness nomograms should be different from preoperative ones.
Keywords: central macular thickness, choroidal thickness, phacoemulsification
|How to cite this article:|
Abd El-Mawgoud SM, Arfeen SA, El-Gendy NS, Fathy AM. Early changes of choroidal and macular thickness after uneventful phacoemulsification surgery. Delta J Ophthalmol 2018;19:106-10
|How to cite this URL:|
Abd El-Mawgoud SM, Arfeen SA, El-Gendy NS, Fathy AM. Early changes of choroidal and macular thickness after uneventful phacoemulsification surgery. Delta J Ophthalmol [serial online] 2018 [cited 2018 Aug 16];19:106-10. Available from: http://www.djo.eg.net/text.asp?2018/19/2/106/233933
| Introduction|| |
Phacoemulsification is the most common intraocular surgery worldwide. In uncomplicated cases, phacoemulsification does not change the macroscopic, funduscopic appearance of the retina. However, with the development of high-resolution scanning techniques, such as spectral domain optical coherence tomography (SD-OCT), postoperative subtle changes could be detected. Some studies have shown that cataract surgery leads to inflammatory changes in the posterior segment of the eye ,,. These changes may be associated with subclinical macular changes that have been reported in uneventful cataract surgery and may also be related to pathological events such as Irvine–Gass syndrome ,. Several studies have investigated the possibility of increase in choroidal and retinal thickness at the posterior pole after phacoemulsification .
In this study, we considered patients with good visual outcome in uncomplicated cataract surgery and evaluated the nonpathological early changes in choroidal and macular thickness after cataract surgery.
| Patients and methods|| |
The study protocol was approved by the Cairo University Research Ethics Committee. The study and data collection conformed to all local laws and were compliant with the principles of the Declaration of Helsinki. An informed consent was signed by all patients to participate in the study
This is a prospective interventional study that included 120 eyes of 90 patients having immature senile cataract. Patients were recruited from the Ophthalmology Department of Kasr El-Aini Hospital, Cairo University in the period from June 2014 to January 2015. OCT was done at Laser and Investigative Ophthalmic Unit of Kasr El-Aini Hospital. Only patients with cataract grades allowing clear OCT imaging were included. Exclusion criteria included patients with any refractive errors greater than ±6 diopters, any ocular pathology other than cataract, for example, diabetes mellitus, glaucoma, retinal detachment, intraocular inflammation, previous intraocular surgery, or unexpected intraoperative complications, for example, posterior capsular rupture, or vitreous loss.
Ocular examination included thorough history taking and detailed ophthalmic examination in the form of corrected distant visual acuity (CDVA) assessed by tumbling E chart and converted to log-MAR using visual acuity conversion tables, intraocular pressure measured by Goldmann applanation tonometer, crystalline lens status by slit lamp examination, fundus examination using indirect ophthalmoscope, and macular status evaluation using slit lamp biomicroscopy.
The surgical procedure was similar for all patients. Phacoemulsification was performed, using Infiniti Vision System (Alcon, Fort Worth, Texas, USA) with clear corneal 3 mm self-sealing incision and acrylic posterior chamber intraocular lens implantation (EYECRYL-600 acrylic UV; Bio-Tech. Vision Care, Gandhinagar, India) in the capsular bag. Phacoemulsification parameters were varied according to each case. The surgeries were performed under local peribulbar anesthesia. Patients with intraoperative complications were excluded from this study.
Postoperative medications were the same for all cases and consisted of topical antibiotics and steroids four times daily for 3 weeks with gradual tapering of steroids.
Optical coherence tomography
All the patients underwent SD-OCT using the Optovue RTVue model RT100 (Optovue Inc., Fremont, California, USA), 1 day before surgery and then 4 weeks after surgery. The retina crossline scan was used. It consists of two orthogonally oriented 6 mm lines consisting of 1024 A-scans. The image was inverted so that the chorioretinal interface is adjacent to the zero delay. The retina crossline scan has 32 frames averaged, 16 per direction, with tracking in the horizontal and vertical macular scans. Measurements of choroidal thickness were performed manually using the calipers provided by the software at the center of the fovea 500 and 1000 µm away from the fovea in the cardinal directions (vertical, horizontal, nasal, and temporal, [Figure 1]).
|Figure 1 Measuring of choroidal thickness using manual calipers on the center of the fovea 500 and 1000 µm away from the fovea in the cardinal directions: (a) horizontal scan and (b) vertical scan.|
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The mean of these five values was calculated in order to obtain the mean horizontal and mean vertical choroidal thicknesses. Choroidal thickness was measured from the outer limit of the retinal pigment epithelium to the choroid–scleral junction. Two independent observers (two of the authors) measured choroidal thickness perpendicularly from the outer edge of the hyperreflective retinal pigment epithelium to the inner sclera at the fovea. The measurements by the two observers were averaged and analyzed. Macular thickness was evaluated using macular maps (EMM5).
| Results|| |
There were no intraoperative complications in the study patients. During the follow-up period, one eye (0.83%) developed cystoid macular edema (Irvine–Gass syndrome). OCT scans were done before and 4 weeks following cataract extraction ([Figure 2]).
|Figure 2 (a) Preoperative measurements of choroidal thickness and (b) 3 weeks postoperative measurements of choroidal thickness.|
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The patients’ age ranged from 45 to 65 years with a mean value of 55.57±5.80 years. The study included 50 (55.5%) men and 40 (44.4%) women.
Preoperative CDVA ranged from 1.00 to 0.5 log-MAR with a mean value of 0.817±0.18.
The mean preoperative choroidal thickness was 211.640±35.7 µm in both horizontal and vertical scans (P=0.566, [Table 1]). The mean postoperative choroidal thickness was 239.927±51.33 and 231.789±42.6 µm in horizontal and vertical scans, respectively (P≤0.001, [Table 2]). There was a statistically significant difference between preoperative and postoperative choroidal thickness (P=0.003 and 0.006) in horizontal and vertical scans, respectively ([Figure 3]).
|Table 2 Postoperative choroidal thickness (horizontal and vertical) (µm)|
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|Figure 3 (a) Mean values of horizontal choroidal thickness showing significant change between preoperative and postoperative values and (b) mean values of vertical choroidal thickness showing significant change between preoperative and postoperative values.|
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The mean preoperative macular thickness was 220.8±40.845, while the postoperative macular thickness was 208.43±46.3 µm. There was no statistically significant difference in macular thickness before and after cataract extraction (P=0.065,[Figure 4]).
|Figure 4 Mean values of macular thickness showing no significant change between preoperative and postoperative values.|
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There was no significant difference in the delta change of preoperative and postoperative horizontal choroidal thickness between men and women [median 8.6 μm (−13–44), 0 μm (−1.4–23.4) μm, respectively (P=0.4)]. However, there was a significant difference in the delta change of vertical choroidal thickness between men and women (mean 34.2±34.1 and 8±32.1 μm, respectively, P=0.03).
There was no significant correlation between the age of the patients and the delta change of preoperative and postoperative horizontal and vertical choroidal thickness (P=0.7 and 0.5, respectively) nor in the change of macular thickness (P=0.8).
Postoperative CDVA ranged from 0.2 to 0.5 log-MAR with a mean value of 0.320±0.12. There was no significant correlation between macular and choroidal thickness changes and postoperative CDVA (P=0.625).
| Discussion|| |
Since cataract surgery induces inflammatory process to the eye, this study hypothesized the possibility of early increase in choroidal and macular thickness following uneventful phacoemulsification procedure. It aimed to elaborate what is considered ‘normal, nonpathologic’ postoperative finding, in order to know what is considered abnormal.
SD-OCT (Optovue model) was used based on a previous study done by Branchini et al. , performed on 28 healthy eyes to compare reproducibility of choroidal thickness measurements directly across three different OCT instruments: Carl Zeiss Meditec Inc., Dublin, California, USA), Heidelberg Spectralis (Heidelberg Engineering, Heidelberg, Germany) and Optovue RTVue (Optovue Inc., Fremont, CA). They concluded that there was good reproducibility among choroidal thickness measurements of images acquired with the three different systems.
The central subfield foveal thickness was assessed, defined as the average retinal thickness of 1 mm central scanned area, using macular maps (MM5). Browning et al.  suggested the use of central subfield foveal thickness due to high reproducibility, being based on more scans than the central foveal thickness, and having higher correlation with other measures of the central macula.
In this study, it was found that there was no significant change in macular thickness following cataract extraction by phacoemulsification at the 4th week. These results are consistent with what was reported by Cagini et al.  who scanned 62 eyes using SD-OCT at 3, 6, 12, 20, and 28 weeks after surgery and found that there was no statistically significant increase in the macular volume except at the 12th week after surgery. Their study showed no correlation between macular changes and CDVA or ultrasound time.
In addition, Giansanti et al.  studied the central foveal thickness in different patient groups (patients with epiretinal membrane, high myopia, diabetic, and healthy individuals) with follow-up OCT at first day, first week, first, third, and sixth month after surgery. They reported central macular thickness changes according to characteristic patterns in the different groups, and they reported an increase in central macular thickness on day 360 (12th week) in healthy individuals.
These results raised different questions: why the change of macular thickness in most of these studies occurred late and not in the early postoperative period? Is this related to the usage of steroids during the early postoperative period. In this study, all the patients received postoperative steroids which were tapered gradually over 1 month. However, the previous studies did not mention the postoperative treatment.
In this study, it was found that following cataract extraction there was a significant increase in postoperative mean choroidal thickness in vertical submacular scans (231.787±42.6 µm) and in horizontal submacular scans (239.92±51.4 µm). These results are similar to the study done by Pierru et al.  which was performed on 115 eyes. They measured the subfoveal choroidal thickness before and 1 day, 7 days, 1 month, and 3 months after surgery using the enhanced depth imaging-OCT technique. It showed that subfoveal choroidal thickness significantly increased at the 7th day postoperatively and reached a peak after 1 month of the surgery with a mean value of 232±76l µm at D1 (P<0.001), 237±78l µm at M1 (P<0.001), and 232±76 µm at M3 (P<0.001). Again, the maximum increase occurred after 1 month of surgery to raise the same possibility of correlation between the inflammatory cascades and the usage of postoperative anti-inflammatory drugs.
However, Falcão et al.  performed a prospective study which showed that there were no significant changes in choroidal thickness in the submacular areas 1 month after surgery where in the vertical scans, there was no significant increase in choroidal thickness (+4.21±20.2 µm; P=0.47), while in the horizontal scans a nonsignificant decrease was recorded (−9.11±39.59 µm; P=0.41). However, this study was done on a small sample size (14 eyes), and so its results may not be so conclusive.
The present study concluded that nonpathologic, nonsignificant changes in retinal macular thickness occurs after uncomplicated phacoemulsification. However, a significant change in choroidal thickness occurs after surgery, probably due to the inflammatory effects of the surgery. At present, the clinical significance of this increase in choroidal thickness which is not accompanied by a significant change in macular thickness is not clear. Thus, it is recommended to carry out a similar study with a larger number of data in order to update SD-OCT choroidal thickness nomograms, that is considered, according to this study, to be different if the patient had undergone recent phacoemulsification surgery. Also, to know whether these changes are transient or persistent with permanent change of postoperative normative data and if it is related to postoperative usage of steroids or not.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2]