Results of hydrophilic acrylic, hydrophobic acrylic, and silicone intraocular lenses in uveitic eyes...

Results of hydrophilic acrylic, hydrophobic acrylic,and silicone intraocular lenses in uveitic eyeswith cataract

Comparison to a control group

Claudette Abela-Formanek, MD, Michael Amon, MD, Jorg Schauersberger, MD,Andreas Kruger, MD, Johannes Nepp, MD, Gebtraud Schild, MD

Purpose: To evaluate the uveal and capsular biocompatibility of hydrophilicacrylic, hydrophobic acrylic, and silicone intraocular lenses (IOLs) in eyes withuveitis.

Setting: Department of Ophthalmology, University of Vienna, Vienna, Austria.

Methods: This prospective study comprised 72 eyes with uveitis and 68 controleyes having phacoemulsification and IOL implantation by 1 surgeon. Patients re-ceived 1 of the following IOLs: foldable hydrophilic acrylic (Hydroview�, Bausch &Lomb), hydrophobic acrylic (AcrySof�, Alcon), or silicone (CeeOn� 911, Pharma-cia). Postoperative evaluations were at 1, 3, and 7 days and 1, 3, and 6 months.Cell reaction was evaluated by specular microscopy of the anterior IOL surfaceand the anterior and posterior capsule reaction, by biomicroscopy.

Results: Small round cell deposition was observed on all IOLs in the immediatepostoperative period, especially in eyes with uveitis. This reaction decreased 3 to6 months after surgery. Although the CeeOn 911 had a higher mean grade ofsmall cells, there was no statistical difference between the 3 IOL types after 6months in the uveitis and control groups. Foreign-body giant cells (FBGCs) in-creased after 1 week to 1 month. The AcrySof IOLs had the highest number ofFBGCs; after 6 months, there was a statistically significant difference between theAcrySof and Hydroview uveitis groups (P � .036) and the AcrySof and CeeOn911 uveitis groups (P � .003) but there was no difference among the 3 IOL typesin the control group. Lens epithelial cell outgrowth persisted on the HydroviewIOLs in control eyes and regressed on all 3 IOL types in uveitic eyes and on theAcrySof and CeeOn 911 IOLs in control eyes (P � .0001). Anterior capsule opaci-fication (ACO) was more severe on all IOL types in uveitic eyes and on the CeeOn911 IOL in control eyes. Posterior capsule opacification (PCO) was more severe inuveitic eyes. The Hydroview group had more severe PCO than the AcrySof andthe CeeOn 911 groups in uveitis and control eyes. Six months postoperatively,the difference was significant (P � .0001). There was no significant difference be-tween the AcrySof and CeeOn 911 IOLs.

Conclusions: Intraocular lens biocompatibility is inversely related to inflammation.Hydrophilic acrylic material had good uveal but worse capsular biocompatibility.Hydrophobic acrylic material had lower uveal but better capsular biocompatibility.Silicone showed a higher small cell count (mild) and more severe ACO butachieved PCO results comparable to FBGC results and better than those with theAcrySof lens 6 months after surgery. Despite the differences in IOL biocompatibil-ity, all patients benefited from the surgery.

J Cataract Refract Surg 2002; 28:1141–1152 © 2002 ASCRS and ESCRS

© 2002 ASCRS and ESCRS 0886-3350/02/$–see front matterPublished by Elsevier Science Inc. PII S0886-3350(02)01425-6

Cataract development in uveitic patients is common,resulting from inflammation and steroid therapy.

Several studies describe the results of cataract extractionand implantation of rigid poly(methyl methacrylate)(PMMA) intraocular lenses (IOLs).1–9 The use ofphacoemulsification and in-the-bag implantation offoldable IOLs in eyes with uveitis has only recently beenaddressed by some research groups.10,11 Besides allow-ing for a smaller incision, foldable IOLs have better bio-compatibility than PMMA IOLs.12–15

The outcome of cataract surgery in uveitic eyes hasgenerally been accepted as safe and depends to someextent on the type and severity of uveitis, careful preop-erative and postoperative management, meticulous sur-gical technique, and knowing when to perform cataractsurgery.1–7 The choice of the right IOL biomaterial inhigh-risk eyes is important, especially in light of severalrisk factors (eg, miosis, posterior synechias, inflamma-tion) in eyes with uveitis. Most modern foldable IOLmaterials are well tolerated in normal cataract eyes.16,17

Modern foldable IOL materials are also considered morebiocompatible than the previously commonly im-planted PMMA lenses.13,14,16 The question is whetherIOL biocompatibility is the same in uveitic eyes as inhealthy cataractous eyes.

We performed this prospective study to evaluate theoutcomes of phacoemulsification and in-the-bag IOLimplantation of 3 types of 3-piece foldable IOLs in eyeswith uveitis. We evaluated uveal and capsular biocom-patibility from the first postoperative day to 6 monthsafter surgery and compared the results to those in a con-trol group.18

Patients and MethodsTable 1 shows the patients’ characteristics. Sixty-four

consecutive patients with uveitis of various origin and 68 con-trol patients who had senile cataract with no ocular diseasewere prospectively recruited. The inclusion criteria in the uvei-

tis group were visually significant complicated cataract in eyeswith controlled intraocular inflammation for a minimum of 3months before surgery. The inclusion criterion in the controlgroup was senile cataract in an otherwise normal eye. Exclu-sion criteria were juvenile rheumatoid arthritis in the uveitisgroup and intraoperative capsule complications in bothgroups. Diabetes mellitus, asthma, and the use of nonsteroidalantiinflammatory drugs were exclusion criteria in the controlgroup.

Informed consent was obtained before surgery. Surgerywas performed by 1 experienced surgeon (M.A.) using a stan-dardized technique and peribulbar anesthesia. In all eyes, atemporal 3.2 mm clear corneal incision, continuous curvilin-ear capsulorhexis (CCC) of approximately 5.0 mm under so-dium hyaluronate 1% (Healon�), phacoemulsification, in-the-bag IOL implantation, and thorough cortical cleanupwere performed. The capsulorhexis edge overlapped the opticedge.

Patients were operated on consecutively in a series start-ing with the hydrophilic acrylic IOL (Hydroview�, Bausch &Lomb) group followed by the hydrophobic acrylic IOL (Acry-Sof� MA60BM, Alcon) group and the new-generation sili-cone IOL (CeeOn 911�, Pharmacia) group. In eyes with aninadequately dilating pupil and posterior synechias, the tech-nique was modified to include synechiolysis with a phacospatula and pupil dilation in uveitic eyes.

All uveitis patients were free of active intraocular inflam-mation for a minimum of 3 months and at the time of surgery.Treatment included topical and systemic corticosteroids andimmunosuppressive agents in some cases.

Postoperative management was standardized except ineyes with a greater degree of inflammation that required indi-vidual therapy adjustment. All patients were given topical be-tamethasone 0.1% and neomycin 0.5% (Betnesol N�)eyedrops 4 times daily for 4 weeks unless otherwise required.Patients who had started or increased their systemic cortico-steroids before surgery were tapered off them gradually duringthe postoperative period according to the degree of anteriorchamber inflammatory activity.

Postoperative biomicroscopic examinations and specularmicroscopy were performed with a slitlamp (Haag Streit�).First, the entire anterior and posterior IOL surfaces were ex-amined, with attention to the capsule under anterior illumi-nation and retroillumination. Next, specular microscopy wasdone to identify the presence of cell deposits on the IOL’santerior surface. Most commonly used were 25-fold and 40-fold magnifications. Relevant findings were listed and docu-mented by exact drawings according to a protocol. Celldeposits on the anterior lens surface were evaluated.

Semiquantitative analysis of anterior (ACO) and poste-rior (PCO) capsule opacification was performed with the eyefully dilated. Anterior capsule opacification was divided into 2types: opacification of the capsulorhexis rim (ACR) andopacification of the capsule portion in contact with the optic

Accepted for publication March 25, 2002.

From the Department of Ophthalmology, University of Vienna, MedicalSchool, Vienna, Austria.

None of the authors has a financial or proprietary interest in any materialor method mentioned.

Reprint requests to Claudette Abela-Formanek, MD, Department ofOphthalmology, University of Vienna, Medical School, WaehringerGuertel 18-20, 1090 Vienna, Austria. E-mail: claudette.abela-for-manek @akh-wien.ac.at.

BIOCOMPATIBILITY AFTER IMPLANTATION OF VARIOUS IOL MATERIALS IN UVEITIC EYES

J CATARACT REFRACT SURG—VOL 28, JULY 20021142

Table 1. Patients’ characteristics.

Characteristic

Group

Hydroview AcrySof CeeOn 911

Control patients

Number of eyes 23 22 23

Men:women 8:15 8:14 11:12

Mean age at surgery (years) 70.8 (8.8) 71.3 (11.6) 71.9 (11.0)

Uveitis patients

Number of eyes 16 27 24

Men:women 3:12 10:17 7:17

Mean age at surgery (years) 53.4 � 16.5 57.1 � 19.5 61.2 � 14.0

Mean duration of uveitis (months) 58 � 58 104 � 123 82 � 109

Mean remission (months) 10 � 9 15 � 15 10 � 8

Posterior synechias, n (%)

Preoperative 8 (50) 7 (63) 20 (83)

Postoperative 1 (6) 3 (11) 5 (21)

Preoperative therapy, n (%)

Topical 3 (19) 7 (26) 7 (29)

Systemic 1 (6) 0 2 (8)

Topical and systemic 4 (25) 7 (26) 9 (37)

Postoperative therapy, n (%)

Topical 6 (37) 9 (33) 10 (41)

Systemic 0 0 0

Topical and systemic 3 (19) 1 (4) 2 (8)

IUSG, n (%)

Anterior 4 (25) 6 (22) 2 (8)

Intermediate 2 (12) 10 (37) 17 (71)

Posterior 3 (19) 3 (11) 1 (4)

Panuveitis 7 (44) 8 (30) 4 (17)

Diseases, n (%)

ARN 1 (6.3) 1 (3.7) 0

Behcet’s 1 (6.3) 0 0

Diabetes 0 3 (11.1) 1 (4.2)

FHC 0 1 (3.7) 1 (4.2)

HLA-B27 0 2 (7.4) 4 (16.7)

Keratouveitis herpetica 2 (12.5) 2 (7.4) 1 (4.2)

Lymphoma 1 (6.3) 0 0

Sarcoidosis 1 (6.3) 2 (7.4) 1 (4.2)

Toxoplasmosis 0 0 2 (8.3)

VKH 1 (6.3) 0 0

Unknown 9 (56.3) 16 (59.3) 14 (58.3)

All means � SDIUSG � International Uveitis Study Group, ARN � acute retinal necrosis due to herpes infection; FHC � Fuchs’ heterochromic cyclitis;HLA-B27 � human leukocyte antigen B27; VKH � Vogt-Koyanagi-Harada syndrome


J CATARACT REFRACT SURG—VOL 28, JULY 2002 1143

(ACO). Both types were graded as 0 � none; 1 � mild; 2 �moderate; 3 � severe. Posterior capsule opacification was ex-amined within the central 3.0 mm of the optic and the 3.0 to6.0 mm zone of the posterior capsule. The PCO was graded as0 � none; 1 � transparent, visible only on retroillumination;2 � white–gray fibrosis, flat regenerates, clearly visible onretroillumination; 3 � dense white fibrosis or formation ofElschnig regenerates.

Postoperative evaluation was performed after pupil dila-tion with 1 drop of tropicamide 1% (Mydriatikum�) andphenylephrine 2.5% at 1, 3, 7, 28, 90, and 180 days. Thefrequency of review appointments for patients with uveitiswas adjusted according to the extent of intraocularinflammation.

Variables are expressed as means and standard deviationsor by frequencies. Overall group comparisons were performedusing the Kruskal-Wallis test. All pairwise comparisons wereby the Wilcoxon rank sum test. A P value less than 0.05 wasconsidered statistically significant. The SPSS 9.0 System forWindows was used for statistical analysis.

To present the results clearly, the groups were named asfollows: control group with Hydroview IOL, control-H; con-trol group with AcrySof IOL, control-A; control group withCeeOn 911 IOL, control-C; uveitis group with HydroviewIOL, uveitis-H; uveitis group with AcrySof IOL, uveitis-A;uveitis group with CeeOn 911 IOL, uveitis-C.

ResultsThere was no significant difference in sex among all

groups. Age was significantly higher in all 3 IOL controlgroups than in the 3 uveitis groups (P � .016). Twopatients in the uveitis-H group and 3 in the uveitis-Cgroup were excluded for lack of follow-up at 6 months.We stopped implanting the Hydroview IOL at patient18 in the uveitis group because of the accelerated PCOdevelopment.

Uveal BiocompatibilityFigure 1 shows the course of small round cells in

uveitic and control eyes. There was an initial depositionof small round cells in the immediate postoperative pe-riod and a gradual decrease 3 to 6 months thereafter.Small round cells peaked on the first postoperative dayimmediately after surgery in the uveitis-A and control-Agroups. This was followed by a peak on the third post-operative day in the uveitis-H and control-H groups andat 7 days in the uveitis-C and control-C groups. Thecourse in each uveitis IOL group followed a trend simi-lar to that in its respective control group, with uveiticeyes displaying a stronger reaction than the control eyes.

For example, the uveitis-A and control-A groups had thelowest incidence of small round cells in the first postop-erative week. At 6 months, the incidence was interme-diate in the uveitis-A group and the results werecomparable to those in the other IOL control groups.The uveitis-C and control-C groups had a higher inci-dence of small round cells in the first postoperativemonth than the uveitis-H and control-H groups and theuveitis-A and control-A groups. The uveitis-H groupachieved the lowest incidence of small round cells 3months after surgery and had comparable results tothose in the control eyes in the other 2 IOL groups.

At 3 months, the uveitis-A and control-A groupshad a significantly higher grade of cells than the uve-itis-H and control-H groups (P � .004). Similarly, theuveitis-C group had more small round cells than theuveitis-H group at 1 month (P � .019) and 3 months(P � .006). There was no statistically significant differ-ence between the control-C and control-H groups. Theonly statistically significant difference between the Acry-Sof and the CeeOn 911 IOLs was at 1 week in eyes withuveitis (P � .005). Six months after surgery, there wasno statistically significant difference between the 3 IOLtypes in eyes with uveitis or in control eyes.

A comparison of uveitic eyes and control eyesshowed a statistically significantly higher deposition ofsmall round cells in the uveitis-H group than in thecontrol-H group at 7 days (P � .007). The uveitis-Cgroup had significantly higher cell deposition thanthe control-C group at all follow-up examinations

Figure 1. (Abela-Formanek) Mean grade of small round cells.



(P � .032). There was no difference between the uve-itis-A and control-A groups except at 1 day (P � .002).

Figure 2 shows the results of the sum of the epithe-lioid cells and foreign-body giant cells (FBGCs). Onceagain, there was a parallel between the uveitis IOLgroups and their respective control groups except thatthe uveitic eyes had a more severe reaction, as expected.Giant cells accumulated on the IOL in the uveitis-Cgroup within the first postoperative week and in thecontrol-C group within the first month; the cellsgradually decreased by 3 months after surgery. Thenumber of giant cells increased gradually on the AcrySofIOL; after 1 month, there was a steep increase. Thenumber of giant cells persisted 6 months after surgery inthe uveitis-A group. The giant-cell reaction was delayedand mild in the uveitis-H group and milder in the con-trol-H group.

There was a statistically significant difference be-tween the uveitis-H and uveitis-A groups at 3 and 6months (P � .036) and the control-H group at 3months (P � .006). There was no statistically signifi-cant difference between the uveitis-C and control-Cgroups and the uveitis-H and control-H groups. Sixmonths after surgery, there was a statistically significantdifference between the uveitis-A and uveitis-H groups(P � .036) and the uveitis-A and uveitis-C groups(P � .003); however, there was no significant differencebetween the uveitis-H and the uveitis-C groups oramong the 3 control groups.

The only statistically significant difference betweenuveitis and control eyes was in the AcrySof group at 6months (P � .007).

There was no significant difference between the 3IOLs in the incidence of posterior synechias. There wasno correlation between the presence of posterior syn-echias and giant-cell deposition.

Capsular BiocompatibilityFigure 3 shows the mean grade of lens epithelial cell

(LEC) outgrowth. There was a peak at 1 week in allgroups except the control-H, control-A, and uveitis-Hgroups, all of which peaked at 1 month. The peak wasfollowed by a gradual decline thereafter except in thecontrol-H group, in which the LECs persisted.

There was a statistically significant higher grade ofLECs on the Hydroview than on the CeeOn 911 IOL at1 and 3 months in uveitic eyes (P � .009 and P � .025,respectively) and at 1, 3, and 6 months in control eyes(P � .0001). The control-H group had a significantlyhigher grade of LECs than the control-A group at 1, 3,and 6 months (P � .001, P � .0001, and P � .0001,respectively). There was also a statistical difference be-tween the control-A and control-C groups at 1 and 3months (P �.0001 and P � .002, respectively). Thedifference between the uveitis-H and uveitis-A groupswas not statistically significant. Therefore, there was nostatistically significant difference among the 3 IOLs inuveitic eyes 6 months after surgery. However, there was

Figure 2. (Abela-Formanek) Mean number of giant cells. Figure 3. (Abela-Formanek) Mean grade of LEC outgrowth.



a statistically significant difference between the Hydro-view and the AcrySof and the Hydroview and theCeeOn 911 in control eyes.

A comparison of the uveitic and control eyesshowed a statistically significantly higher grade of LECsin the control-H group than in the uveitis-H group at 1,3, and 6 months (P � .0001). The LECs in the uveitis-Agroup peaked and declined sooner than in the control-Agroup (P � .015). There was no statistically signifi-cant difference between the uveitis-C and control-Cgroups.

Figure 4 shows the course of ACR, which wasmore severe in uveitic eyes than in control eyes in all 3IOL groups. The ACR increased significantly and sim-ilarly in all 3 uveitis IOL groups between the first weekand the first month. The ACR results in the control-Cgroup were comparable to those in the uveitis-C group.The course of ACR severity increased mildly in thecontrol-A and control-H groups 3 to 6 months aftersurgery.

A comparison of the 3 IOL types showed a statisti-cally significant difference between the uveitis-H anduveitis-C groups at 1 month (P � .028). There was ahighly significant difference between the CeeOn 911and the other 2 IOLs in control eyes at 1, 3, and 6months (P � .008).

A comparison of the uveitic and control eyes in all 3IOL groups showed that ACR was more severe in theuveitic eyes, with statistically significant differences atdifferent time points. Six months after surgery, there

was a statistically higher grade of ACR in the uveitis-H(P � .001) and uveitis-A (P � .0001) groups than intheir respective control groups.

Figure 5 shows the course of ACO opacification.These results were similar to those of the ACR courseexcept the control-H group had a milder grade of ACOthan the other 2 IOL groups.

A comparison of the 3 IOL types showed statisti-cally significant more severe ACO in the uveitis-C groupthan in the uveitis-H and uveitis-A groups at 1 and 6months (P � .016). The same result was found in thecontrol eyes, in which the CeeOn 911 behaved similarly(P � .004).

There was a statistically significant difference at dif-ferent time points between uveitic and control eyes in allIOL groups. Six months after surgery, the eyes withuveitis in all IOL groups had statistically significantlymore ACO than their respective control eyes as follows:Hydroview (P � .0001); AcrySof (P � .0001); CeeOn911 (P � .011).

Figures 6 and 7 show the course of PCO of thecentral 3.0 mm and the 3.0 to 6.0 mm optic zones. Thedata exclude all eyes with primary fibrosis. In general,the hydrophilic and round-edged optic Hydroviewgroup had a higher PCO grade than the other 2 hydro-phobic, sharp-edged optic IOLs in both uveitic and con-trol eyes, indicating the sharp-edged optic delays PCOdevelopment. The PCO appeared sooner in uveitic eyesthan in control eyes in all IOL groups. The first signs ofPCO were at 1 week in the 3.0 to 6.0 mm zone and

Figure 4. (Abela-Formanek) Mean grade of ACR. Figure 5. (Abela-Formanek) Mean grade of ACO.



progressed over time to the 3.0 mm optic zone. At 6months, the grade of PCO was mild with all IOLs. Fig-ures 8 and 9 show the results in all eyes including thosewith primary fibrosis.

There was a statistically higher grade of PCO of the3.0 mm and 3.0 to 6.0 mm zones in the Hydroviewgroup than in the AcrySof and CeeOn 911 groups inboth uveitic and control eyes 6 months after surgery(P � .016). There was no significant difference betweenthe AcrySof and CeeOn 911 IOLs in the uveitic andcontrol eyes.

Excluding eyes with primary fibrosis, there was astatistically significant higher grade of PCO of the3.0 mm zone in the uveitis-H group at 1 and 3 months(P � .006) and in the uveitis-A group at 1 month (P �.028). There was no statistically significant differencewithin the CeeOn 911 group. There was a statisticallyhigher incidence of PCO of the 3.0 to 6.0 mm zone inthe uveitis-A group at 1 and 3 months (P � .028 andP � .013, respectively). There was no significant differ-ence between the uveitic and control eyes in the Hydro-view or CeeOn 911 groups.

Figure 6. (Abela-Formanek) Mean grade of PCO of the central3.0 mm zone.

Figure 7. (Abela-Formanek) Mean grade of PCO of the 3.0 to6.0 mm zone.

Figure 8. (Abela-Formanek) Mean grade of PCO of the central3.0 mm zone including all patients with primary fibrosis.

Figure 9. (Abela-Formanek) Mean grade of PCO of the 3.0 to6.0 mm zone including all patients with primary fibrosis.



The few patients who reacted with recurrent uveitiswere controlled with topical steroidal and nonsteroidaltherapy. Postoperative systemic therapy (oral steroids)was necessary in a few patients.

There were no cases of IOL dislocation or clinicallysignificant IOL decentration. Two patients with uveitisrequired a neodymium:YAG (Nd:YAG) laser anteriorcapsulotomy because of incipient anterior capsuleshrinkage, which resolved after the procedure. Of the 2patients, 1 patient had Behcet’s disease and a HydroviewIOL and the other, intermediate uveitis and an AcrySofIOL. Both cases had a small capsulorhexis. No eye witha silicone IOL had visually significant anterior capsulecontraction.

DiscussionImproved visual function, a better standard of liv-

ing, and an unimpaired view of the posterior pole are themain aims of cataract surgery in patients with uveitis. Incontrast to cataract surgery in normal eyes, visual func-tion in these eyes often depends not only on reestablish-ment of the refractive media but also on retinal function.In addition, cataract surgery may present intraoperativeand perioperative challenges to the surgeon. Miosis, pos-terior synechias, and pupillary membrane formationpose intraoperative obstacles for the cataract surgeon,highlighting the importance of meticulous surgery.Postoperative recurrent flare-ups demand careful surgi-cal planning, inflammation control, and patient follow-up. Among other postoperative complications, whichmay also occur after surgery in eyes with age-relatedcataract, the development of posterior synechias and thesubsequent deposition of FBGCs on the IOL surface,anterior capsule contraction, and PCO are sight-threat-ening complications in eyes with uveitis. Because of var-ious factors such as complicated surgery, the course ofuveitis, and a damaged blood–aqueous barrier (BAB),giant-cell deposition is more likely to occur in uveiticeyes after cataract surgery. Differences between IOL bio-materials are more likely to become apparent in thissituation. The choice of the right IOL biomaterial istherefore important for an optimal clinical outcome ineyes with uveitis and cataract.

Most studies have reported the behavior of PMMAor heparin-surface-modified PMMA in eyes with uve-itis.3–9 The advent of phacoemulsification and small-

incision surgery and the introduction of foldable IOLshave reduced perioperative inflammation.19,20 In thisstudy, we evaluated the uveal and capsular biocompat-ibility of 3 commonly implanted IOL biomaterials incataract surgery: hydrophilic acrylic, hydrophobicacrylic, and a new-generation silicone.

Uveal BiocompatibilitySmall round cells originate from monocytes that

migrate through the uveal vasculature through the aque-ous humor to deposit on the IOL surface. These cellsappear soon after surgery as a result of surgical trauma.The presence of these cells is a sign of a damaged BABand ongoing inflammation. The trend of small-round-cell reaction was similar in all 3 IOL groups in our study;the reaction in the uveitic eyes was slightly more severethan in control eyes. Despite a higher grade of small-round-cell reaction on the CeeOn 911 IOL, there wasno statistically significant difference among the 3 IOLtypes after 6 months. The uveitis-C group had signifi-cantly more cells than the control-C group 6 monthsafter surgery. The reaction was mild and had no effect onvisual function.

The small-cell reaction of the 3 biomaterials peakedon different days. This was supported by a similar reac-tion in the respective control groups. In addition to sur-gical trauma, IOL material seems to influence thisreaction.

Epithelioid cells are formed by the differentiation ofmacrophages. If a foreign body persists in situ, FBGCsare formed by the fusion of epithelioid cells. Epithelioidand giant cells are usually found in eyes with a prolongedinflammatory reaction and are therefore a good indica-tor of the uveal biocompatibility of IOL materials.21,22

These cells appear 1 to 3 months after surgery. In ourstudy, the AcrySof IOL had significantly more FB-GCs than the Hydroview and CeeOn 911 IOLs 6months after surgery in the uveitic eyes. This was notthe case in the control eyes. Rauz and coauthors10 andSamuelson and coauthors23 also describe the presenceof FBGCs on AcrySof IOLs in high-risk eyes. Thereason for the higher deposition of FBGCs on theAcrySof lens is unclear. Several factors may influ-ence this reaction including IOL adhesiveness andprotein adsorption,24 –27 surface energy,28,29 and achange in IOL surface properties resulting from thedamaged BAB originating from the uveitis and the



consequently increased and changed immunologicenvironment.

Macrophages and giant cells on IOLs explantedfrom rabbit eyes show positive immunostaining for fi-bronectin.30,31 Linnola et al.32,33 and Johnson and co-authors27 showed that AcrySof IOLs have a significantlyhigher concentration of fibronectin adhered to the sur-face than silicone, PMMA, and hydrogel lenses. Fi-bronectin is a specialized protein involved in celladhesion and migration.34 It is conceivable that fi-bronectin and other cell adhesion molecules are presentin higher concentrations in uveitic eyes than in senilecataractous eyes because of intraocular inflammation.Increased adhesion of fibronectin to the AcrySof IOL isprobably a main reason this lens has a higher tendencyto have FBGCs on its surface than IOLs of differentmaterials.

Samuelson and coauthors23 compared the FBGCformation among new-generation silicone, first-genera-tion silicone, and acrylic lens material in high-risk eyes.Formation was significantly greater on first-generationsilicone IOLs than on acrylic or new-generation siliconeIOLs. The deposits were more common on acrylic IOLsthan on new-generation silicone IOLs, although the dif-ference was not clinically or statistically significant. Rauzand coauthors10 also found a higher but not statisticallysignificant incidence of giant cells in uveitic eyes with anAcrySof IOL than in those with a hydrophilic acrylic ornew-generation silicone IOL.

The presence of preoperative posterior synechiaswas different among the 3 uveitis groups in our study,with the incidence 50% in the Hydroview group, 65%in the AcrySof group, and 83% in the CeeOn 911group. The manifestation of postoperative posteriorsynechias was lowest in the Hydroview group (6%); itwas 11% in the AcrySof group and 21% in the CeeOn911 group. The tendency to develop posterior synechiasdepends on the type of uveitis (ie, whether the uveitisinfluences the anterior or posterior segment). Anteriorsegment uveitis was present in 37% of eyes in the Hy-droview group, 59% in the AcrySof group, and 79% inthe CeeOn 911 group. This, rather than the influence ofIOL material, may explain the higher tendency for eyeswith a CeeOn 911 lens to develop posterior synechias.

Posterior synechias to the anterior capsule or theoptic surface act as a bridge between the iris and the IOLsurface. Macrophages migrate along this scaffolding and

deposit on the optic close to the posterior synechias. Insevere cases in which the central visual axis is completelycovered by FBGCs, there is a risk of reduced visual func-tion. Secondary treatment by topical therapy or Nd:YAG laser lens polishing is necessary in such cases tokeep the IOL surface free of FBGCs. Despite the higherincidence of postoperative posterior synechias in theuveitis-C group, more FBGCs were observed on theAcrySof IOL than on the CeeOn 911 6 months aftersurgery. These results confirm the material-dependanteffect on the postoperative clinical outcome. Postopera-tive topical or systemic corticosteroid therapy also influ-ences the deposition of inflammatory cells on the IOL.Because of the varying therapy, we are unable to reach adefinite conclusion on the effect of the various IOL ma-terials on cell reaction.

Capsular BiocompatibilityLens epithelial cells migrate from beneath the ante-

rior capsule onto the capsule-free optic surface.35–37

These cells form a confluent layer. The trend of LECoutgrowth peaked at 1 week to 1 month and decreasedafter 1 to 3 months except in the control-H group, inwhich the cells persisted 6 months after surgery. TheLECs in the uveitis-H group began decreasing after 1week. This is a good example of the difference in behav-ior of different IOL biomaterials in inflamed eyes. Theestablished biocompatibility of IOLs in normal eyes issubject to change in the immunologic environment ofinflamed eyes.

Koch and coauthors38 believe that the formation ofLEC outgrowth on the Hydroview IOL is attributed tothe hydrophilic nature and good biocompatibility of itsmaterial. An increase or a change in the presence ofvarious cytokines in the aqueous humor resulting fromthe primarily damaged BAB in uveitic eyes may causeLECs to loose their capability to adhere to the IOLsurface because of an alteration in the production of celladhesion molecules in uveitic eyes.32,39

Anterior capsule opacification is more severe andaccelerated in uveitic eyes. This trend is reflected by thedevelopment of both ACR and ACO in our study. Thecontrol-C group reacted with similarly strong ACR andACO. There was a statistically significant difference be-tween the eyes with uveitis and the control eyes.

Severe anterior capsule contraction in nonuveiticeyes has been observed after implantation of first-



generation silicone IOLs.40,41 Werner et al.42 andGonvers and coauthors43 report a significantly higherACO score and change in CCC size with first-genera-tion silicone plate-haptic IOLs than with the 3-piecesilicone IOLs. This is probably caused by large surfaceexposure, which stimulates cell proliferation and fibrosisin the former group. Rauz and coauthors10 and Samuel-son and coauthors23 observed no significant anteriorcapsule contraction in high-risk eyes after the implanta-tion of new-generation silicone IOLs. Similar to ourresults, Rauz and coauthors observed that anteriorcapsule contraction occurred more frequently with hy-drophilic acrylic (61.5%) and hydrophobic acrylic(37.5%) IOLs than with new-generation silicone IOLs(11.8%).

Primary fibrosis is a common feature in eyes withuveitis, making it more difficult to assess PCO objec-tively. The Nd:YAG capsulotomy rate would be inap-propriate to use as a PCO parameter, as it has been inseveral studies.8,11 When patients without primary fi-brosis were eliminated in our study, 47 patients (71%)remained in the uveitis group for evaluation. Despitethis limiting factor, we conclude that the PCO rate ininflamed eyes increases faster than in control eyes. Thehydrophilic Hydroview IOL, with a round-edged optic,had the strongest and earliest development of PCO. Thehydrophobic acrylic and silicone IOLs, with sharp-edged optics, led to better results. Although PCO wasmild in the uveitic eyes, it was higher than in the controleyes. This observation underlines that a sharp-edged op-tic only delays the progression of PCO and does not haltits development even though all eyes in our study had anoverlapping CCC. Although the AcrySof group had aslightly higher rate of PCO than the CeeOn 911 group,the difference was not significant.

The increased rate of PCO in the Hydroview groupsis partially accounted for by the round-edged optic andmaterial. Linnola et al.32 found thick fibrocellular tissueat the junction between the IOL and the anterior capsulein eyes with hydrogel IOLs. The IOL–capsule inter-face in these eyes was mediated by collagen IV. Theypostulate that because of a lower concentration of fi-bronectin adhesion, the IOL–capsule surface attach-ment is weaker than in eyes with an AcrySof IOL,allowing more space for LEC ingrowth and proliferationand for production of extracellular matrix in the earlypostoperative phase.

The lower rate of PCO with AcrySof IOLs has beenattributed to the adhesive properties of its material andsharp-edged optic.14,17,27,32,33,44 In our study, theCeeOn 911 group had more intense whitening of theanterior capsule than the AcrySof and Hydroview IOLs.Linnola et al.32 found that silicone IOLs had collagentype IV at the interface between a thick fibrotic tissueand the IOL surface, which was probably responsible forthe stronger ACO observed in our patients. Collagen is astructural protein produced by LECs. The sharp-edgedoptic of the CeeOn 911 IOL and the anterior capsulecontraction resulting from collagen tissue cause anteriortraction of the posterior capsule onto the IOL posteriorsurface, reducing the space between the IOL and thecapsule for LECs to undergo proliferation and metapla-sia. Therefore, the development of PCO is likely to bereduced by a sharp-edged optic and by certain IOL ma-terials by adhesion of the capsule to the IOL by fibronec-tin soon after surgery on the one hand and by tightwrapping of the capsule around the IOL by anteriortraction forces on the other. This reduces the space be-tween the posterior capsule and the IOL before theLECs have the opportunity to proliferate. In both cases,there is no space for the ingrowth of LECs and subse-quent LEC proliferation. The achievement of the no-space–no-cells theory seems to prevent the developmentof PCO no matter how it is accomplished.

Despite the good uveal biocompatibility of the Hy-droview IOL, it should not be recommended for cata-ract surgery in uveitic eyes because of the early andaccelerated development of PCO. Development andclinical evaluation of other new hydrophilic IOL mate-rials with a sharp-edged optic should provide better per-formance in high-risk eyes.

In this setting, it is possible to evaluate certain bio-material characteristics and biocompatibility, whichonly become apparent once the IOLs are implanted inhigh-risk eyes. The optimal IOL should prevent the dep-osition of FBGCs to an extent that they do not form amembrane-like occlusion of the central visual axis andshould also lead to a low rate of PCO. The clue lies in thebiomaterial and in IOL design; however, the importanceof meticulous surgery and careful perioperative patientmanagement should not be overlooked. Despite the dif-ferences in IOL biocompatibility, all patients in ourstudy benefited from cataract surgery. Long-term fol-low-up of this group of patients would increase knowl-



edge of the influence and the clinical consequence ofinflammation on the various IOL biomaterials and thecourse of the disease of uveitis.

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Results of hydrophilic acrylic, hydrophobic acrylic, and silicone intraocular lenses in uveitic eyes...

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