Year : 2006 | Volume
: 54 | Issue : 3 | Page : 169--172
Preoperative prediction of posterior capsule plaque in eyes with posterior subcapsular cataract
Abhay R Vasavada, MR Praveen, Urvi D Jani, Sajani K Shah
Iladevi Cataract and IOL Research Centre, Gurukul Road, Memnagar, Ahmedabad, India
Abhay R Vasavada
Iladevi Cataract and IOL Research Centre, Gurukul Road, Memnagar, Ahmedabad
Aim: To determine whether the plaque on the posterior capsule can be predicted preoperatively, in patients with posterior subcapsular cataract (PSC), undergoing cataract surgery.
Materials and Methods: A prospective study of 140 consecutive eyes with PSC, who underwent cataract surgery, was conducted. The prediction of preoperative presence or absence of plaque within the PSC was noted on slit lamp examination, in dilated pupils. A single observer made the observations under oblique illumination, where the slit lamp was placed at an angle of 30° to 45°. Evaluation of the plaque through slit lamp examination was standardized in terms of illumination and magnification. The observations were recorded using a video camera (Image archiving system, Carl Zeiss, Jena Germany) attached to a slit lamp (Carl Zeiss, SL 120 Jena, Germany), keeping the illumination at 100%. The prediction of plaque was noted in terms of its presence or absence on the posterior capsule. All the patients received counseling regarding the presence of plaque. Capsule polishing of the posterior capsule in Cap Vac mode, was done in all cases. The posterior capsule was examined for presence or absence of plaque, either on the first postoperative day, or within a week, with maximal mydriasis. The observer«SQ»s results were tabulated and later analyzed to judge the incidence of predictability of plaque in PSC.
Results: The mean age of the patients was 45±6.2 years (range 32-61 years); 104 (74.3%) were males. One hundred and eight (77.1%) patients were under 50 years. The presence or absence of plaque was predicted correctly in 124 (88.6%) eyes. The prediction of plaque was incorrect in 16 (11.4%) eyes.
Conclusion: The prediction of presence or absence of plaque was accurate in 88.6% cases. We believe that counseling patients with posterior capsule plaque before the surgery is the key to avoiding unpleasant surprises.
|How to cite this article:|
Vasavada AR, Praveen M R, Jani UD, Shah SK. Preoperative prediction of posterior capsule plaque in eyes with posterior subcapsular cataract.Indian J Ophthalmol 2006;54:169-172
|How to cite this URL:|
Vasavada AR, Praveen M R, Jani UD, Shah SK. Preoperative prediction of posterior capsule plaque in eyes with posterior subcapsular cataract. Indian J Ophthalmol [serial online] 2006 [cited 2023 Feb 8 ];54:169-172
Available from: https://www.ijo.in/text.asp?2006/54/3/169/27067
Classically, posterior capsule opacification,, (PCO) is described as postoperative opacification of the posterior capsule after cataract surgery. However, intraoperative posterior capsule opacification, noticed during cataract surgery, is an area of localized opacification in the posterior capsule, known as "posterior capsule plaque", an entity distinguishing it from postoperative PCO.,, This posterior capsule plaque is also distinct from posterior subcapsular cataract (PSC) and coexists with the cataract. In an earlier study, we reported the incidence of 12.5% of posterior capsule plaque in PSC, detected during surgery. Detecting the plaque for the first time during surgery or in the immediate postoperative period is frustrating for the surgeon and the patient. The present study was designed to assess whether it would be possible for the surgeon to predict the posterior capsule plaque in patients with PSC, before they undergo cataract surgery.
Materials and Methods
This prospective observational study included 140 consecutive eyes with PSC, visiting our clinic for cataract surgery. Each eye was dilated with 1% Tropicamide eye drops, 3 times at 15 minute intervals or till the pupillary dilatation was at least 7 mm in diameter. Patients, in whom cortical opacities, nuclear sclerosis and posterior polar cataracts were detected on dilatation, were excluded from the study. After dilatation, the patient was subjected to slit lamp examination for prediction of plaque in PSC. The presence or absence of plaque within the PSC was observed under oblique illumination, where the slit lamp was placed at an angle of 30° to 45°. The observations were recorded using a video camera (Image archiving system, Carl Zeiss, Jena, Germany) attached to a slit lamp (Carl Zeiss, SL 120 Jena, Germany), keeping the illumination at 100%. All the patients were given preoperative counseling regarding the possibility of occurrence of posterior capsular plaque, following cataract surgery. The patients were also warned about the occurrence of visual disturbances, such as glare at night. Patients were reassured that not all patients with plaque, required intervention. In case intervention was required, the treatment was Nd-YAG laser capsulotomy, which could be administered in the outpatient department. The plaque was recognized as a thickened opacified lesion, firmly adherent on the posterior capsule, distinguishing it from the posterior subcapsular changes which are located in front of the posterior capsule. The plaque appeared as a diffuse area with a well-demarcated thickened border or as small multiple islands of thickened capsule or as a complete or incomplete ring configuration. A single observer recorded all the observations. The presence or absence of plaque on the posterior capsule was noted. A single surgeon (ARV) performed the surgeries, employing the standardized phacoemulsification technique. Capsule polishing of the posterior capsule in Cap Vac mode with aspiration flow rate 5 cc/min and vacuum : 5 mm Hg, was done in all cases with Alcon® Legacy 20000® Phacoemulsifier. The posterior capsule was examined either on the first postoperative day or within a week, with maximal mydriasis. The same observer made all the postoperative observations. Evaluation of the plaque through slit lamp examination was standardized in terms of illumination and magnification [Figure 1]a, b. The observer's results were tabulated and later analyzed, to judge the incidence of predictability of plaque in PSC. The statistical analysis, "Cohen's Kappa", was used to test the "agreement" between the surgeon's prediction and actual postoperative outcome of presence or absence of posterior capsule plaque.
The mean age of the patients was 45 ± 6.2 years (range 32-61 years). In the present study, of the patients with PSC, 104 (74.3%) were men. A majority of the patients (n = 108, 77.1%) were under 50 years. The presence or absence of plaque was predicted correctly in 124 (88.6%) eyes, of which we predicted the presence of plaque correctly in 92 (65.7%) eyes and absence of plaque in 32 (22.9%) eyes. The prediction of plaque was incorrect in 16 (11.4%) eyes, of which, in 12 (8.6%) eyes, we did not predict plaque preoperatively, but found its presence postoperatively and in 4 (2.9%) eyes, plaque was predicted preoperatively, but the posterior capsule was clear, postoperatively [Table 1]. Cohen's Kappa value 0.72 shows that there was a good agreement on the surgeon's prediction of preoperative posterior capsule plaque and the postoperative outcome, with P value statistically significant [Table 2].
Cataract surgeons have noted posterior capsule plaque at the time of cataract surgery, since the advent of extracapsular cataract extraction techniques.,, "Posterior capsule plaque" is distinct from posterior subcapsular cataract and postoperative PCO, [Figure 2] a, b, c, d. In our earlier report, the incidence of posterior capsule plaque was observed to be varied in different types of cataract, including nuclear cataract, white mature cataract, PSC and nuclear cataract with PSC.,, Few studies documented the association between PSC and plaque., If the surgeon anticipates the presence of plaque and counsels the patients preoperatively, it could avoid unpleasant surprises for both of them. Since it would be useful to predict the presence of plaque, we decided to assess whether it would be possible to predict posterior capsule plaque in patients with PSC undergoing cataract surgery, as it is difficult to visualize plaque on the posterior capsule in advanced and white mature cataracts.
In the present study, to avoid bias, a single observer was trained to document for the presence or absence of posterior capsule plaque. For proper visualization and assessment of plaque, an oblique illumination through a slit lamp is desirable. We did not opt for retroillumination for pre and postoperative observations of posterior capsule plaque, as it was difficult to visualize any subtle changes in the posterior capsule [Figure 3]a, b. The posterior capsule plaque was not documented intraoperatively in all the eyes, as we did not have oblique illumination. However, in the last few cases (40 cases), we could document posterior capsule plaque intraoperatively, using Carl Zeiss Visulex surgical slit illuminator (both retro and oblique illumination) mounted on Carl Zeiss Visu 210 surgical operating microscope.
The presence of plaque was confirmed under slit lamp biomicroscopy using oblique illumination performed either on the first postoperative day or within a week after cataract surgery, under maximal mydriasis. At few instances, it was very difficult to differentiate between posterior capsule plaques from plaque- like posterior subcapsular cataracts. However, to some extent, it was possible to identify them, by observing the position of the posterior capsule plaque from the cataract, where the former was firmly adherent to the posterior capsule.
We believe that there would be no development of postoperative PCO within the first week. The prediction of plaque was incorrect in 16 eyes. We believe that the fibrous nature of the PSC made it difficult to accurately predict the presence of plaque, preoperatively. Although surgical instruments to polish residual capsule opacities have been designed, there are few published studies of residual capsule opacity.,, Blumenthal and co-authors suggested the use of posterior circular curvilinear capsulorhexis (PCCC) in dense posterior capsular scars, in adults. Galand and colleagues believe that PCCC can be a routine procedure during cataract surgery, in adults with intact and clear capsule. They performed PCCC in 319 adult eyes and concluded that it is safe enough to be proposed as a surgical method, to prevent central secondary opacification. In the present study, the posterior capsule was polished intraoperatively in cap vac mode, to remove the residual lens fibers. However, we do not recommend polishing the plaque, as it is ineffective in removing the plaque and sometimes may tear the capsule while polishing. However, any residual fibers surrounding or adjacent to the plaque are removed, using the cap vac mode. In the present study, capsule polishing was done in all cases, as a standardized protocol in the surgical strategy. We believe that no surgical intervention is necessary in presence of posterior capsule plaque. However, PCCC has become an established procedure for removal of plaques in pediatric cataracts, but not for adult posterior capsule plaques. However, performing PCCC has its own limitations. While attempting PCCC, at times, it can cause vitreous disturbance, which may sometimes necessitate vitrectomy.
Postoperatively, not all patients with the presence of plaque in PSC have disabling visual disturbances. We believe that most of the patients in this part of the world do not have high visual demands to have an intervention for removal of plaques. However, we recommend performing Nd: YAG capsulotomy, only when the patient requests. In our previous report on incidence of posterior capsular plaque in cataract surgery, no patient with plaque voluntarily reported visual complaints.
We believe that counseling patients pre-operatively regarding the possibility of presence of plaque and warning them about visual disturbances in the form of glare at night, is essential. They need to be told that not all patients with plaque require intervention, unless their visual demands warrant it. If necessary, we reassure patients that Nd: YAG laser capsulotomy can be used for removal of posterior capsular plaque.
The limitation of the study is, that the prediction of plaque was done only in PSC. Finally, the impact of location of the plaque with visual acuity was not noted in the study. This could have been useful in establishing a link to post-operative visual acuity or it could have been used to predict the need for Nd: YAG laser capsulotomy in future. Long-term studies are required to determine whether posterior capsule plaque contributes to the formation of PCO over time.
In conclusion, the prediction of presence or absence of plaque was accurate in 88.6% cases. It is mandatory for the surgeon to prepare the patient psychologically before the surgery, to cope with any possible under-performance of the eye, postoperatively. Preoperative counseling is especially warranted, given the difficulty in establishing a visual impact from the posterior capsule plaque. Ample attention should be given to counseling the patients preoperatively, to avoid the occurrence of a situation that will leave patients and surgeons disappointed.
|1||Pandey SK, Apple DJ, Werner L. Malof, AJ, Milvertom EJ. Posterior capsule opacification: A review of the aetiopathogenesis, experimental and clinical studies and factors for prevention. Indian J Ophthalmol 2004;52:99-112.|
|2||Apple DJ, Ram J, Foster A Pen Q. Posterior capsule opacification (secondary cataract). Surv Ophthalmol 2000;45;S100-30.|
|3||Apple DJ, Solomon KD, Tetz MR, Assia EI. Holland EY, Legler UF, et al . Posterior capsule opacification. Surv Ophthalmol 1992;37;73-116.|
|4||Vasavada AR, Chauhan H, Shah G. Incidence of posterior capsular plaque in cataract surgery. J Cataract Refract Surg 1997;23:798-802.|
|5||Peng Q, Hennig A, Vasavada AR, Apple DJ. Posterior capsular plaque: A common feature of cataract surgery in the developing world. Am J Ophthalmol 1998;125:621-6. |
|6||Wilhelmus KR, Emery JM. Posterior capsule opacification following phacoemulsification. Ophthalmic Surg 1980;11:264-7.|
|7||Mootha VV, Tesser R, Qualls C. Incidence of and risk factors for residual posterior capsule opacification after cataract surgery. J Cataract Refract Surg 2004;30:2354-8.|
|8||Dahan E, Allarakhia L. Irrigation, aspiration and polishing cannula. J Cataract Refract Surg 1991;17:97-8.|
|9||Khalifa MA. Polishing the posterior capsule after extracapsular extraction of a senile cataract. J Cataract Refract Surg 1992;18:170-3.|
|10||Blumenthal M, Assia E, Naumann D. The round capsulorhexis capsulotomy and the rationale for 11.0 mm diameter IOL. Eur J Implant Refract Surg 1990;2:15-9.|
|11||Galand A, van Cauwenberge F, Moosavi J. Posterior capsulorhexis in adult eyes with intact and clear capsules. J Cataract Refract Surg 1996;22:458-61.|