|Year : 2020 | Volume
| Issue : 4 | Page : 1231-1236
Macular thickness changes after neodymium: yttrium–aluminum–garnet laser capsulotomy in diabetic patients
Faried M Wagdy1, Samar M Abdel Elsadek2, Adel G Zaky1
1 Department of Ophthalmology, Menoufia Faculty of Medicine, Shebin El Kom Ophthalmology Hospital, Menoufia, Egypt
2 Department of Ophthalmology, Shebin El Kom Ophthalmology Hospital, Menoufia, Egypt
|Date of Submission||09-Jun-2020|
|Date of Decision||09-Jul-2020|
|Date of Acceptance||12-Jul-2020|
|Date of Web Publication||24-Dec-2020|
Samar M Abdel Elsadek
MBBCh, Shebin El Kom, Menoufia
Source of Support: None, Conflict of Interest: None
The aim was to evaluate the changes in macular thickness (MT) post-neodymium: yttrium–aluminum–garnet (ND: YAG) laser capsulotomy in diabetic patients.
ND:YAG laser capsulotomy has been found to be safe, effective, and easily applied in a short time at an outpatient clinic. However, events such as cystoid macular edema, retinal detachment, and rise in intraocular pressure tend to occur after ND: YAG laser capsulotomy.
Patients and methods
This prospective case series study included 100 eyes of 100 diabetic patients diagnosed as posterior capsule opacification (PCO), following uncomplicated cataract surgery. All patients were examined beforehand ND: YAG laser capsulotomy and on the first, third, and sixth month post-ND: YAG laser capsulotomy for intraocular pressure, MT, and best-corrected visual acuity. Patients were divided into two groups according to the presence or absence of diabetic retinopathy and maculopathy: group A included diabetic patients with no diabetic retinopathy and maculopathy and group B included diabetic patients with diabetic retinopathy and maculopathy.
Group A involving diabetic patients with no diabetic retinopathy and maculopathy suffering from PCO had increased MT at the first, third, and sixth month after laser capsulotomy (P < 0.001). Group B involving diabetic patients with diabetic retinopathy and maculopathy suffering from PCO had increased MT at the first, third, and sixth month after laser capsulotomy (P < 0.001). The two groups showed a statistically significant increase in MT. There was statistically significant increase in MT during the follow-up period in both groups (P < 0.001).
An increase in MT can be detected after ND: YAG laser capsulotomy in diabetic patients especially diabetic patients with diabetic retinopathy and maculopathy.
Keywords: diabetic patients, diabetic retinopathy and maculopathy, macular thickness, neodymium: yttrium–aluminum–garnet laser, optical coherence tomography
|How to cite this article:|
Wagdy FM, Abdel Elsadek SM, Zaky AG. Macular thickness changes after neodymium: yttrium–aluminum–garnet laser capsulotomy in diabetic patients. Menoufia Med J 2020;33:1231-6
|How to cite this URL:|
Wagdy FM, Abdel Elsadek SM, Zaky AG. Macular thickness changes after neodymium: yttrium–aluminum–garnet laser capsulotomy in diabetic patients. Menoufia Med J [serial online] 2020 [cited 2021 Apr 19];33:1231-6. Available from: http://www.mmj.eg.net/text.asp?2020/33/4/1231/304490
| Introduction|| |
Posterior capsule opacification (PCO) is considered as a common troublesome problem following cataract surgery. It is unfeasible to remove all epithelial cells on the posterior capsule during cataract surgery, and subsequently PCO results from the proliferation of remaining lens epithelial cells after surgery. A loss of vision and contrast sensitivity have been reported in many patients, although many surgeons also have a clinical impression that PCO after cataract surgery in diabetic patients is more extensive than in nondiabetic patients; this is still controversial. PCO, in addition to impairing vision, can obscure fundus view and potentially compromise the surveillance and timely treatment of posterior segment pathology such as diabetic retinopathy and macular edema. Neodymium: yttrium–aluminum–garnet (ND: YAG) laser capsulotomy is the treatment of choice; it can be simply performed in a short time. But complications such as intraocular lens (IOL) dislocation and damage, cystoid macular edema (CME), and retinal detachment have been shown post-ND: YAG laser capsulotomy too. CME can be detected as an inflammatory disease of the retina and choroid following intraocular surgery and trauma. Macular edema is caused by movement and damage in the vitreous cavity and release of inflammatory mediators because of damage of the blood–aqueous barrier. The frequency of macular edema after ND: YAG laser capsulotomy is noted in 0–4.3% of cases. Optical coherence tomography (OCT) is more accurate in detecting macular edema than fundus fluorescein angiography (FA) and biomicroscopic examination.
The aim of the study was to evaluate the changes in macular thickness (MT) post-ND: YAG laser capsulotomy in diabetic patients
| Patients and methods|| |
In all, 100 eyes of 100 diabetic patients were registered in this prospective case series study. The study approved from the ethical committee of the hospital and the patient gave an informed consent. A comparison was made between group A, which included 50 eyes with no diabetic retinopathy and maculopathy suffering from PCO and group B, which included 50 eyes with diabetic retinopathy and maculopathy suffering from PCO. Of the 100 diabetic patients, 35 were on insulin treatment 11 patients in group A and 24 in group B; 52 were treated with oral hypoglycemic agents 26 patients in group A and 26 in group B, and in 13 patients, all in group A. the diabetes was controlled by diet alone at the time of cataract surgery. Hemoglobin A1C (percentage) and duration of diabetes (years) were also evaluated to assess the systemic status of diabetes. Furthermore, to identify the presence of diabetic retinopathy, a fundus examination was performed at each scheduled examination. Any eye that developed diabetic retinopathy or maculopathy during the follow-up was included in the retinopathy group; these eyes with retinopathy underwent FA to determine the stage of diabetic retinopathy and type of diabetic maculopathy. Fluid accumulation may be delayed in certain conditions; thus late-phase fluorescein photos, sometimes as long as 20 min or more, may be required to properly evaluate macular edema. The major advantage of FA is its ability to detect macular ischemia denoted by nonperfusion of the retinal capillaries and to detect subtle diabetic macular edema as evidenced by fluorescein leakage from the capillaries. Diabetic retinopathy was classified according to Early Treatment of Diabetic Retinopathy Study (ETDRS) classification. In all, 16 had mild nonproliferative diabetic retinopathy (NPDR); 22 had moderate NPDR; nine had severe NPDR; and three had proliferative diabetic retinopathy (PDR). OCT was done for precise measurement of MT. OCT shows three basic structural changes: retinal swelling, CME, and subretinal fluid. Clinical characteristics of the diabetic patients are also shown in [Table 1].
All study procedures were approved by the Ethics Committee of Menoufia Faculty of Medicine and were in accordance with the Declaration of Helsinki.
All ND: YAG laser capsulotomy were carried out at least 6 months postsurgery at the Ophthalmology Department, Menoufia University Hospital, Menoufia Governorate, Egypt, between March 2018 and December 2018 using ophthalmic ND: YAG laser (Visulas YAG III; Zeiss, Oberkochen, Germany).
All eyes had PCO following uncomplicated cataract surgery. Patients with corneal opacities, corneal dystrophy, corneal edema, patients with past history of uveitis or glaucoma, patients with other systemic disease other than diabetes mellitus, diabetic patients with any other retinal diseases, and presence of dense PCO precluding preoperative OCT were excluded from this study.
All pre ND: YAG and post-ND: YAG laser capsulotomy assessments were performed by one ophthalmologist. Assessments included best-corrected visual acuity (BCVA) using logarithm of the minimum angle of resolution (LogMAR) chart, intraocular pressure measurement by Goldmann's applanation tonometry, slit-lamp evaluation, and posterior segment evaluation were performed using slit-lamp biomicroscopy with +90 and +78 Volk lenses, FA by (Topcon TRC-NW8F retinal camera; Topcon, Tokyo, Japan), central foveal thickness by OCT (3D OCT-2000 Spectral Domain OCT, Tokyo, Japan) [Figure 1] before the procedure and in the first, third, and sixth month post-ND: YAG laser capsulotomy.
|Figure 1: A 66-year-old female patient with right eye DME. The patient was treated with ND: YAG laser capsulotomy: (a) Preprocedure OCT image, (b) OCT image in first month after the procedure, (c) OCT image in the third month after the procedure, (d) OCT image in the sixth month after the procedure. DME, diabetic macular edema; ND: YAG, neodymium: yttrium–aluminum–garnet; OCT, optical coherence tomography.|
Click here to view
Topical anesthesia was then achieved using benoxinate hydrochloride 0.4% eye drops, and capsulotomy contact lenses (double aspheric Capsulotomy lens; Volk Optical Inc., Mentor, Ohio, USA) with lubricating gel (methyl cellulose) was used during the capsulotomy; A plus-shaped capsulotomy was performed using Ophthalmic ND: YAG laser (Visulas YAG III; Zeiss). All procedures were completed in one session.
Power/energy was initially set between 1 and 1.5 mJ power varied according to the density of the PCO. Number of pulses per shot was one, which means one pulse of laser energy is fired at the capsule every time the button was pressed; the offset of the laser was set between 125 and 250 μm posteriorly; the aiming beam was then focused on the posterior capsule and capsulotomy was performed.
All patients were prescribed topical prednisolone acetate 1% four times a day and brimonidine tartrate 0.2% twice a day for 1 week postoperatively (post-laser therapy).
Data were fed to the computer and analyzed using IBM SPSS software package, version 20.0 (IBM Corp., Armonk, New York, USA). Qualitative data were described using number and percent. The Kolmogorov–Smirnov test was used to verify the normality of distribution. Quantitative data were described using range (minimum and maximum), mean, SD, and median. Significance of the obtained results was judged at the 5% level.
| Results|| |
Group A included 26 (52%) male and 24 (48%) female patients, with a mean age of 55.04 ± 8.64 years ranging from 33 to 72. Group B included 23 (46%) male and 27 (54%) female patients, with a mean age of 54.24 ± 9.06 years ranging from 39 to 72. The difference was not statistically significant as shown in [Table 2].
|Table 2: Comparison between the two studied groups according to demographic data|
Click here to view
The mean laser shot number and mean laser shot energy in millijoule were 10.02 ± 1.62 (8.0–13.0) and 2.68 ± 0.65 (2.0–4.0) in group A, respectively, and 10.66 ± 1.91 (8.0–14.0) and 2.86 ± 0.73 (2.0–4.0) in group B, respectively, as shown in [Table 3]. There was no statistically significant difference between groups in these parameters.
|Table 3: Comparison between the two studied groups according to laser settings|
Click here to view
Regarding the studied cases according to grading of diabetic retinopathy and maculopathy in group B, there were 47 (94%) patients with NPDR [16 (32%) patients with mild NPDR, 22 (44%) patients with moderate NPDR, and nine patients with severe NPDR] and three (6%) patients with PDR.
The minimum preoperative BCVA in group A was 6/60 (20/200) on the Snellen chart and 6/120 (20/400) on the Snellen chart in group B. There was a statistically significant improvement in visual acuity (VA) in both groups. Group A showed better VA results than group B. There was a statistically significant difference. The average postoperative VA in group A was 0.48 ± 0.20, 0.53 ± 0.18, and 0.54 ± 0.17 LogMAR at 1, 3, and 6 months, respectively as compared with 0.27 ± 0.18, 0.28 ± 0.18, and 0.29 ± 0.20 in group B, respectively, as shown in [Table 4].
|Table 4: Comparison between the different periods according to best-corrected visual acuity in each group|
Click here to view
Both groups had increased MT at 1 month after ND: YAG laser capsulotomy, with a mean of 226.4 ± 15.09 μm in group A and a mean of 320.8 ± 23.25 μm in group B, which is statistically significant, at the third month after ND: YAG laser capsulotomy, with a mean of 232.3 ± 13.44 μm in group A and a mean of 326.6 ± 21.54 μm in group B, which is statistically significant, and at the sixth month after ND: YAG laser capsulotomy, with a mean of 237.3 ± 10.43 μm in group A and a mean of 332.8 ± 20.77 μm in group B, which is statistically significant. Mean MT was higher in group B than in group A when comparing the results of MT between the two groups at the first, third, and sixth month after capsulotomy and it was statistically significant as shown in [Table 5].
|Table 5: Comparison between the two studied groups according to macular thickness|
Click here to view
Regarding the relation between grading of diabetic retinopathy and MT in group B, MT increased in the first month after ND: YAG laser capsulotomy with a mean of 298.8 ± 12.78 μm, with a mean of 305.9 ± 10.87 μm in the third month after ND: YAG laser capsulotomy, and with a mean of 314.5 ± 10.37 μm in the sixth month after ND: YAG laser capsulotomy in mild NPDR, which is statistically significant. MT increased in the first month after ND: YAG laser capsulotomy with a mean of 324.6 ± 16.07 μm, with a mean of 329.4 ± 10.35 μm in the third month after ND: YAG laser capsulotomy, and with a mean of 334.3 ± 11.41 μm in the sixth month after ND: YAG laser capsulotomy in moderate NPDR, which is statistically significant. MT increased in the first month after ND: YAG laser capsulotomy with a mean of 348.4 ± 11.48 μm, with a mean of 354.8 ± 12.42 μm in the third month after ND: YAG laser capsulotomy, and with a mean of 360.1 ± 14.23 μm in the sixth month after ND: YAG laser capsulotomy in severe NPDR, which is statistically significant. MT increased in the first month after ND: YAG laser capsulotomy with a mean of 327.7 ± 37.86 μm, with a mean of 332.7 ± 39.80 μm in the third month after ND: YAG laser capsulotomy, and with a mean of 337.7 ± 38.66 μm in the sixth month after ND: YAG laser capsulotomy in PDR, which is statistically significant [Table 6].
|Table 6: Relation between grading of diabetic retinopathy and macular thickness|
Click here to view
| Discussion|| |
PCO remains a common complication of modern cataract surgery with IOL implantation. The association between diabetes and risk of PCO after cataract surgery is not firmly established. PCO is thought to be due to disruption in the blood–aqueous barrier with liberation of chemical mediators inducing proliferation of lens epithelial cells. ND: YAG laser capsulotomy is the most common method in the treatment of PCO. ND: YAG laser capsulotomy is considered as an effective method; however, quite a few complications such as damage and dislocation of IOL, CME, increase in intraocular pressure, and retinal detachment have been reported after this procedure. A plethora of studies have been reported on the incidence of CME post-laser capsulotomy, with most experienced physician achieving a figure of between 0.7 and 4.9%. The wide difference probably reflects the different patient samples, such as preexisting ocular disease or age and different follow-up times. The etiology of CME post-ND: YAG capsulotomy most probably involves movement of the vitreous cavity and vitreous damage, which leads to the release of inflammatory mediators. The exact pathogenesis of CME post-ND: YAG capsulotomy is unknown; however, the final common pathway is likely to be increase perifoveolar capillary permeability, associated with generalized intraocular vascular vulnerability. Associated factors include viteromacular traction and inflammation with release of prostaglandins. The release of these mediators such as prostaglandins and leukotrienes is caused by surgical trauma. These mediators are likely to be responsible for the detected increase in parafoveal capillary permeability and serous leakage seen by fundus FA in CME. Dissimilar results were reported in studies assessing MT using OCT post-laser capsulotomy. Of the 50 eyes in each group, group A including 50 eyes with no diabetic retinopathy or maculopathy, and group B including 50 eyes with diabetic retinopathy and maculopathy required ND: YAG laser capsulotomy within 6 months after surgery. Our study clarified that MT increased in both groups and there was statistically significant difference between preoperative and postoperative MT. We also find statistically significant difference between groups A and B. Yilmaz and Yilmaz prescribed 1% fluorometholone after capsulotomy in 22 diabetic patients and studied long-term changes in MT; they measured MT on the first day, first week, first, third, and sixth month post-laser capsulotomy and they found statistically significant increase in MT. Abd-Elhafez et al. found, when comparing values of MT preoperative and postoperative, a significant increase in MT after 1 week and no significant changes at 3 months after laser capsulotomy. Regarding studying factors that affect MT, they found that there was significant effect of diabetes in MT change. Group A showed a spectacular improvement in VA on Snellen chart testing post-ND: YAG laser capsulotomy more than group B. In group B, BCVA was affected by the grade of diabetic retinopathy. Of the patients, 94% were with NPDR, which improved from two to five lines according to the Snellen chart while a Snellen chart VA improvement of one line was recorded for 6% of patients with PDR and no improvement in one case with PDR. It was also noted that there was no further deterioration of VA in any case.
The Awan et al. prospective study comprised 25 nondiabetic and 25 diabetic patients. Both groups A and B have achieved a spectacular improvement in VA, but group A nondiabetic patients presented with more improvement in BCVA post-ND: YAG laser capsulotomy. Cetinkaya et al. found a statistically significant improvement in BCVA. Sometimes BCVA cannot increase as we expect. One of the reasons of the worse BCVA is CME.
| Conclusion|| |
We report a significant increase in MT in diabetic patients with diabetic retinopathy and maculopathy, who underwent ND: YAG laser capsulotomy more than diabetic patients with no diabetic retinopathy and maculopathy and continued for 6 months post-laser capsulotomy.
The sample was small and the results were based on a short-term follow-up period.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Bhargava R. A review of posterior capsule opacification. J Ophthalmic Pathol 2014;3
ulie A. Eldred, Jiyun Zheng, Sulin Chen, I. Michael Wormstone; An In Vitro Human Lens Capsular Bag Model Adopting a Graded Culture Regime to Assess Putative Impact of IOLs on PCO Formation. Invest. Ophthalmol. Vis. Sci. 2019;60
113-122. doi: https://doi.org/10.1167/iovs.18-25930
Praveen MR, Vasavada AR, Shah GD, Shah AR, Khamar BM, Dave KH. A prospective evaluation of posterior capsule opacification in eyes with diabetes mellitus: a case–control study. Eye 2014; 28
Steinert R. Nd: YAG laser posterior capsulotomy. Am Acad Ophthalmol 2013; 03
Karahan E, Er D, Kaynak S. An overview of Nd: YAG laser capsulotomy. Med Hypothesis Discov Innov Ophthalmol 2014; 3
Romano V, Angi M, Scotti F, del Grosso R, Romano D, Semeraro F, et al
. Inflammation and Macular Oedema after Pars Plana Vitrectomy. Mediators Inflamm 2013:1–8.
Greenberg PB, Tseng VL, Wu WC, Liu J, Jiang L, Chen CK, et al
. Prevalence and predictors of ocular complications associated with cataract surgery in United States veterans. Ophthalmology 2011; 118
Nekolová J, Pozlerová J, Jirásková N, Rozsíval P. Opacity zadního pouzdra u pacientu s diabetes mellitus 2. typu [Posterior capsule opacification in patients with type 2 diabetes mellitus]. Cesk Slov Oftalmol. 2008;64
:193-6. Czech. PMID: 18988473.
Min JK, An JH, Yim JH. A new technique for Nd: YAG laser posterior capsulotomy. Int J Ophthalmol 2014; 7
Van CT, Tran TH. Incidence of posterior capsular opacification requiring Nd: YAG capsulotomy after cataract surgery and implantation of enVista® M×60 IOL. J Franc Ophtalmol 2018; 41
Kim S, Kim MK, Wee WR. Additive effect of oral steroid with topical nonsteroidal anti-inflammatory drug for preventing cystoid macular edema after cataract surgery in patients with epiretinal membrane. Korean J Ophthalmol 2017; 31
Parajuli A, Joshi P, Subedi P, Pradhan C. Effect of Nd: YAG laser posterior capsulotomy on intraocular pressure, refraction, anterior chamber depth, and macular thickness. Clin Ophthalmol 2019; 13
Daruich A, Matet A, Moulin A, Kowalczuk L, Nicolas M, Sellam A, et al
. Mechanisms of macular edema: beyond the surface. Progr Retinal Eye Res 2018; 63
Yilmaz T, Yilmaz A. Long-term changes in subfoveal choroidal thickness and central macula thickness after Nd: YAG laser capsulotomy. Int Ophthalmol 2017; 37
Abd-Elhafez YE, Ibrahim MM, Elsherbiny MA. Effect of YAG laser posterior capsulotomy on central macular thickness in pseudophakic patients. Egypt J Hosp Med 2019; 76
Awan MT, Khan MA, Al-Khairy S, Malik S. Improvement of visual acuity in diabetic and nondiabetic patients after Nd: YAG laser capsulotomy. Clin Ophthalmol (Auckland, NZ) 2013; 7
Cetinkaya S, Cetinkaya YF, Yener HI, Dadaci Z, Ozcimen M, Acir NO. The influence of size and shape of Nd: YAG laser capsulotomy on visual acuity and refraction. Arq Bras Oftalmol 2015; 78
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]