The same surgical technique was used in all eyes. After a 3.2 mm limbal incision was created, a 4.5 to 5.0 mm anterior CCC was made using sodium hyaluronate vis-coelastic. The crystalline lens was removed using standard, two-handed, divide and conquer phaco-emulsifi cation. Next, the epithelial cells lining the internal surface of the anterior capsule were aspirated and the capsular bag was partially fi lled with sodium hyaluronate.
The posterior capsule was punctured at the center with a needle. Sodium hyaluro-nate was injected through the hole until the central 4.0 mm of the anterior vitreous separated. A 3.0 to 4.0 mm posterior CCC was made with a capsule forceps. In all cases, it was centered within the optical zone.
The IOL was placed in the capsular bag with a standard lens forceps. In-the-bag placement was confi rmed. The sodium hyaluronate was aspirated out of the anterior chamber and the capsular bag and the cornea closed with one 10-0 nylon suture.
A subconjunctival injection of methylprednisolone and gentamicin was given.
Post-operatively, patients received prednisolone and indomethacin eye drops for 1 month.
Patients were evaluated at 1 day, 1 week, 1, 6, 12 and 18 months, and 2 years post-operatively. Best-corrected visual acuity was assessed at each visit. An Nd:YAG laser capsulotomoy was considered when there was a loss of two or more Snellen lines of the best-corrected visual acuity. At 6 and 12 months, pupils were dilated with a mixture of tropicamide and phenylephrine and the eyes evaluated at the slit-lamp;
standard photographs were taken using lateral illumination and retroillumination of the anterior segment (Fig. 1). Anterior capsule fi brosis and contraction was rated as absent, mild or severe. Eyes were also evaluated for posterior capsule fi brosis, contraction and Elschnig pearls and partial or total closure of the posterior capsu-lorhexis (Fig. 2).
Fig. 1.
A. Anterior segment photograph under retroillumination to evaluate Elschnig pearl formation B. Lateral illumination photograph to evaluate fi brosis
A B
cases (Sudhakar et al., 1989; Frezzotti et al., 1990; Ohadi et al., 1991; Apple et al., 1992; Jamal and Solomon, 1993) depending on the length of post-implantation fol-low-up, the type of IOL implanted, the patient’s systemic or ocular diseases and the surgeon. The standard treatment for PCO is neodymium:YAG (Nd:YAG) laser capsulot-omy; however, it is not without risks, especially in highly myopic eyes or those with diabetic retinopathy (Davison, 1988; Dardenne et al., 1989; Koch et al., 1989).
Several techniques have been advocated to reduce the incidence of PCO including the use of lenses with posterior angulation, convexity, or both, to ensure close IOL–capsule
contact (Sterling and Wood, 1986; Sellman and Lindstrom, 1988; Kappelhof and Vrensen, 1992); different IOL materials and coatings (Born and Ryan, 1990) and viscoelastics; and extensive intra-operative polishing of the anterior and posterior capsules (Nishi et al., 1991). Despite these efforts, PCO resulting from diffuse fi -brosis of the posterior capsule still occurs in a considerable number of patients; its incidence increases with time.
This study evaluated whether removing the center of the posterior capsule by creat-ing a posterior continuous curvilinear capsulorhexis (CCC) would help prevent PCO.
IV.3. SUBJECTS AND METHODS
A posterior CCC was performed on 51 eyes of 40 patients at risk for PCO (previous YAG capsulotomy in contralateral eye, young adult eyes, opaque capsule intra-op-eratively), retinal detachment after Nd:YAG laser capsulotomy (highly myopic eyes), or cystoid macular oedema (CME) (eyes with diabetic retinopathy). Follow-up was 6 months in 21 eyes, 1 year in 29 eyes and 2 years in 1 eye. To ascertain whether there was a correlation between secondary posterior CCC closure and underlying ocular or systemic diseases,
patients were divided into six
neodymium:YAG (Nd:YAG) laser capsulotomy; however, it is not without risks, especially in highly myopic eyes or those with diabetic retinopathy (Davison,�1988; Dardenne�et�al.,�1989;
Koch�et�al.,�1989).
Several techniques have been advocated to reduce the incidence of PCO including the use of lenses with posterior angulation, convexity, or both, to ensure close IOL–capsule contact (Sterling�and�Wood,�1986; Sellman�and�Lindstrom,�1988; Kappelhof�and�Vrensen, 1992); different IOL materials and coatings (Born�and�Ryan,�1990) and viscoelastics; and extensive intraoperative polishing of the anterior and posterior capsules (Nishi�et�al.,�1991).
Despite these efforts, PCO resulting from diffuse fibrosis of the posterior capsule still occurs in a considerable number of patients; its incidence increases with time.
This study evaluated whether removing the center of the posterior capsule by creating a posterior continuous curvilinear capsulorhexis (CCC) would help prevent PCO.
IV.3. SUBJECTS AND METHODS
Posterior CCC was performed on 51�eyes of 40�patients at risk for PCO (previous YAG capsulotomy in contralateral eye, young adult eyes, opaque capsule intraoperatively), retinal detachment after Nd:YAG laser capsulotomy (highly myopic eyes), or cystoid macular oedema (CME) (eyes with diabetic retinopathy). Follow-up was 6�months in 21�eyes, 1�year in 29�eyes and 2�years in 1�eye. To ascertain whether there was a correlation between secondary posterior CCC closure and underlying ocular or systemic diseases, patients were divided into six groups (Table�1).
All eyes had one of three IOLs implanted: a one-piece, all-poly (methyl methacrylate) (PMMA), 5.5 biconvex optic lens with semicircular haptics (n�=�36); a PMMA C-loop lens (n�=�12); a foldable silicone lens with polypropylene (Prolene®) loops (n�=�3).
Group
1 12 15 73 Opaque capsule intraop or
previous Nd:YAG capsulotomy in contralateral eye
2 8 12 51 High myopia (axial
length > 26.0 mm) 3 9 10 62 Type II diabetes with diabetic
retinopathy
Tabel 1. Study demographics (N = 51 eyes)
Table 1. Study demographics (N = 51 eyes)
Chapter IV SECONDARY CLOSURE OF PCCC
Table 3. Age distribution of patients with partial or total posterior CCC closure. posterior CCC and the contralateral eye did not.
RE = right eye; LE = left eye Table 5. Results of cases in which one eye had a posterior CCC and the contralateral eye, Nd:YAG capsulotomy.
RE = right eye; LE = left eye
Table 3. Age distribution of patients with partial or total posterior CCC closure. posterior CCC and the contralateral eye did not.
RE = right eye; LE = left eye Table 5. Results of cases in which one eye had a posterior CCC and the contralateral eye, Nd:YAG capsulotomy.
RE = right eye; LE = left eye
* Mean age 63 years
† Mean follow-up 8 months
Table 3. Age distribution of patients with partial or total posterior CCC closure.
Table 4. Results of cases in which one eye had a posterior CCC and the contralateral eye did not.
RE = right eye; LE = left eye
Table 3. Age distribution of patients with partial or total posterior CCC closure. posterior CCC and the contralateral eye did not.
RE = right eye; LE = left eye Table 5. Results of cases in which one eye had a posterior CCC and the contralateral eye, Nd:YAG capsulotomy.
RE = right eye; LE = left eye
* Mean age 63 years
† Mean follow-up 8 months
Table 5. Results of cases in which one eye had a posterior CCC and the contralateral eye a Nd:YAG capsulotomy.
RE = right eye; LE = left eye
* Mean age 63 years
† Mean follow-up 8 months
IV.4. RESULTS
There were no intraoperative complications, including vitreous prolapse or IOL haptic or optic capture.
The posterior CCC partially closed in 4 eyes (8 %) but without visual impairment (Table 2). None of the 4 eyes required an Nd:YAG capsulotomy.
In six eyes (12 %), the posterior CCC closed completely (Table 3). Two of these eyes (4 %) had visual impairment. One, in a 21-year-old patient in Group 2 (high myopia), lost four Snellen lines, necessitating an Nd:YAG capsulotomy. The other, an 18-year-old in Group 6 (hyperopia), lost two Snellen lines and also required a Nd:
YAG capsulotomy.
In all cases, it was clinically impossible to evaluate whether the fi brosis was located on the posterior surface of the IOL or on the anterior vitreous membrane. No lens decentration, CME, retinal detachment or retinal breaks were noted during the fol-low-up.
Fig. 2.
A. Photograph taken 16 months postoperatively of an eye in patient without ocular or systemic disorders (Group 1), shows partial closure of the posterior CCC.
B. Photograph taken 12 months post-operatively of an eye in a patient with retinitis pigmentosa, classifi ed as uveitis patient (Group 5), shows total posterior CCC closure.
A B
Table 2. Incidence of posterior CCC closure.
Table 2. Incidence of posterior CCC closure.
Based on the patient’s data and taking the underlying diseases out of consideration, two other groups of patients were selected. The fi rst group comprised 8 patients who had both eyes operated on within a short period, one eye with posterior CCC and the other without. With a mean follow-up of 12 months, no eyes needed a Nd:YAG capsulotomy (Table 4). The other group comprised 7 patients who had a posterior CCC because they had a previous Nd:YAG capsulotomy in their contralateral eye. The eyes with the posterior CCC were operated on 2 or more years after the contralateral eye (Fig. 3). With a mean follow-up of 8 months, no eye with posterior CCC required a Nd:YAG capsulotomy (Table 5).
Chapter IV SECONDARY CLOSURE OF PCCC considering the short follow-up period. Moreover, if the young adults were excluded, the Nd:YAG capsulotomy incidence in this series would be 0 %.
The knowledge of the infl uence of a primary posterior CCC on the vitreous and of the interaction of the IOL with the anterior hyaloid face is limited. Although not an aim of this study, we did not encounter any vitreoretinal complications such as macular oedema or retinal detachments.
IV.6. CONCLUSION
Our results show that a posterior CCC cannot completely prevent PCO. Cell prolifera-tion leading to closure of the posterior CCC may occur in a small number of cases, and the incidence may increase with time. It is apparent that the presence of a posterior capsule is not the only condition allowing cell growth and migration. It is too early to state that a posterior CCC can prevent the need for Nd:YAG laser capsulotomy in eyes at risk. However, based on the analysis of this series, we consider young adult eyes, eyes with underlying diabetic retinopathy, and eyes with uveitis at risk for secondary closure of a posterior CCC.
IV.7. REFERENCES
Apple DJ, Solomon KD, Tetz MR, Assia EI, Holland EY, Legler UF, Tsai JC, Castaneda VE, Hoggatt JP, Kostick AM. Posterior capsule opacifi cation. Surv Ophthalmol 1992; 37:73-116
Born CP, Ryan DK. Effect of intraocular lens optic design on posterior capsular opacifi cation. J Cataract Refract Surg 1990; 16:188-192
Dardenne MU, Gerten GJ, Kokkas K, Kermani O. Retrospective study of retinal detachment following neodymium:YAG laser posterior capsulotomy. J Cataract Refract Surg 1989; 15:676-680 Davison JA. Retinal tears and detachments after extracapsular cataract surgery. J Cataract Refract
Surg 1988; 14:624-632
Frezzotti R, Caporossi A. Pathogenesis of posterior capsule opacifi cation. Part I. Epidemiological and clinico-statistical data. J Cataract Refract Surg 1990; 16:347-352
Hooper PL, Rao NA, Smith RE. Cataract extraction in uveitis patients. Surv Ophthalmol 1990;
35:120-144
Jamal SA, Solomon LD. Risk factors for posterior capsular pealing after uncomplicated extracapsular cataract extraction and plano-convex posterior chamber lens implantation. J Cataract Refract Surg 1993; 19:333-338
Kappelhof JP, Vrensen GF. The pathology of after-cataract. A minireview. Acta Ophthalmol Suppl 1992; 205:13-24
Koch DD, Liu JF, Gill EP, Parke DW II. Axial myopia increases the risk of retinal complications after neodymium-YAG laser posterior capsulotomy. Arch Ophthalmol 1989; 107:986-990
IV.5. DISCUSSION
After successful cataract extraction, up to 50 % of patients need a secondary inter-vention (e.g., Nd:YAG or surgical capsulotomy, posterior capsule polishing) because of PCO. Although Nd:YAG laser capsulotomy is the most popular treatment, it is far from innocuous. It can cause intraocular pressure rise, IOL damage or IOL sublux-ation (Terry et al., 1983; Steinert et al., 1991). In addition, the shock waves created by the laser can disrupt the anterior vitreous, causing vitreous prolapse around the IOL. Cystoid macular oedema and retinal detachment resulting from peripheral trac-tional retinal breaks are other known complications of Nd:YAG capsulotomy (Powe et al., 1994). Highly myopic eyes are especially at risk for retinal detachment after Nd:
YAG laser capsulotomy (Koch et al., 1989).
The photographs in Fig. 2 show that partial closure of a posterior CCC looks very dif-ferent from the clinical appearance of total closure. In eyes with partial closure, cell proliferation resulted in a thin, transparent capsule closure that did not infl uence fi nal visual outcome. Whether these cells were growing over the anterior hyaloid is speculative but clinically probable.
In eyes with total closure of the posterior CCC, cell proliferation resulted in a mul-tilayered, thick, opaque capsule closure. In our series, total closure was found only in eyes with a wellknown high infl ammatory response to surgery, such as those with diabetic retinopathy (Pollack et al., 1992) or uveitis (Hooper et al., 1990) and in young adult eyes. In this series, 3 of the 40 patients were young adults with high myopia (n = 1) or high hyperopia (n = 2) who had bilateral surgery. Of these 6 eyes, one had partial posterior CCC closure and two total closure, both necessitating a Nd:YAG capsulotomy. This 25 % incidence of Nd:YAG capsulotomy after posterior CCC was signifi cantly higher than the 4 % incidence in the entire study group, especially
Fig. 3. A patient in whom one eye had an Nd:YAG capsulotomy (A) before the contralateral eye was operated on with the posterior CCC method (B). Time between surgeries was 16 months. In both eyes, patches of cells are visible in the center of the posterior capsule opening.
A B
Chapter IV
J. Cataract Refract. Surg. 2003; 29:2330-2338
Veva De Groot1, Mia Hubert2, Jaap A. Van Best3,
Sanne Engelen2, Stefan Van Aelst3, Marie-José Tassignon1.
1Dept. of Ophthalmology, University of Antwerp, Belgium,
2Dept. of Mathematics, Katholieke Universiteit Leuven, Belgium,
3Dept. of Ophthalmology, Coimbra University, Coimbra, Portugal
4Dept. of Applied Mathematics and Computer Science, Ghent University,Belgium
V.1. ABSTRACT
Purpose: To evaluate the integrity of the aqueous–vitreous barrier by assess-ing the fl ow of fl uorescein from the anterior chamber to the anterior vitreous using fl uorophotometry in eyes with a posterior continuous curvilinear capsulorhexis (PCCC) and in eyes without a PCCC.
Setting: University Hospital Antwerp, Edegem, Belgium.
Methods: Ten patients had bilateral extracapsular cataract extraction with im-plantation of an intraocular lens. In 1 eye, a PCCC was performed; the other eye served as a negative control. The eyes of 2 other patients who had complicated cataract surgery with posterior capsule and ante-rior hyaloid membrane rupture served as positive controls. All patients had fl uoro-photometry of both eyes 12 to 18 months after surgery to measure the fl ow of fl uorescein from the anterior chamber to the ante-rior vitreous.
Results: There were no statistically signifi cant differences in the distribution pattern of fl uorescein between eyes with PCCC and eyes without PCCC.
In contrast, enhanced fl ow was detected in both eyes with rupture of the posterior capsule and the anterior hyaloid.