Cyclosporin A therapy in refractory non-infectious childhood uveitis

AIMS—To assess the immunosuppressive efficacy, steroid sparing effect and adverse effects of cyclosporin A (CsA) therapy in refractory non-infectious childhood uveitis.
METHODS—A retrospective case series review of the medical records of children on CsA therapy attending a tertiary referral centre for refractory endogenous uveitis was performed. Low dose (5.0 mg/kg/day) CsA therapy was started either as monotherapy or in combination with other agents. The CsA immunosuppressive efficacy was assessed by visual acuity and binocular indirect ophthalmoscopy (BIO) score outcomes and steroid sparing effect by growth charts and ability to withdraw or maintain a low steroid dose. Possible CsA adverse effects were monitored by routine biochemistry (including serum creatinine) and haematological tests, blood pressure recordings, and symptoms.
RESULTS—14 patients (25 eyes, 10 males, four females) were recruited with steroid failure as the most common CsA indication. Age (mean (SD)) at start of CsA therapy was 8.7 (4.1) years with a duration of CsA therapy of 20.9 (range 3.5-88.3) months at a maintenance CsA dose of 4.0 (1.0) mg/kg/day. From baseline, visual acuity improved or was maintained in 23 (92%) eyes and BIO score improved in 19 (76%) eyes. Height centiles were preserved and the maintenance prednisolone dose was 6.3 (3.3) mg/day, where required, in 10 (71%) patients. Nephrotoxicity was not observed, with transient systemic hypertension developing in one patient. Minor adverse effects were more common but were well tolerated.
CONCLUSIONS—Cyclosporin A therapy is effective and safe in the medium term, if closely monitored, in refractory non-infectious childhood uveitis.

Keywords: cyclosporin A; childhood uveitis     

Effects of posterior chamber lens implantation on the endothelium of transplanted corneas

AIMS—The morphological changes of the corneal endothelium after posterior chamber lens implantation in the transplanted corneas were investigated.
METHODS—36 patients underwent extracapsular cataract extraction with posterior chamber lens implantation. Among these, penetrating keratoplasty had been performed in 18 patients before cataract surgery. The indications for penetrating keratoplasty in these cases included keratoconus, herpetic keratitis, and macula cornea. 18 cataract patients with normal corneas were also studied as controls. The central corneal endothelium in each subject was examined with a wide field specular microscope at a few days before and 3 months after cataract surgery.
RESULTS—Although the transplanted corneas showed lower endothelial cell densities, marked polymegethism, and pleomorphism in the baseline variables, the endothelial morphological changes in the transplanted corneas after posterior chamber lens implantation were comparable with those in the normal corneas. Also, there was no clinical evidence, especially, of corneal epithelial and/or endothelial rejections and corneal decompensation in all corneas.
CONCLUSION—Even though the transplanted corneas have a lower endothelial cell density and marked polymegethism, it is believed that cataract surgery does not induce corneal decompensation in cases where the peripheral recipient endothelium can be considered to have normal morphology.

     

Effect of mycophenolate mofetil, cyclosporin A, and both in combination in a murine corneal graft rejection model

AIMS—To compare the effectiveness of mycophenolate mofetil (MMF), cyclosporin A (CSA), and both in combination, in preventing rejection following corneal transplantations.
METHODS—Rats of the inbred strains Brown Norway and Lewis were used as donors and recipients respectively. MMF was administered orally in both monotherapy and combination therapy for 14 days in a dosage of 40 mg/kg body weight, and CSA was administered, likewise for 14 days, in an intramuscular dosage of 10 mg/kg body weight. The transplants were examined every third day by slit lamp microscopy. Every transplant was subjected to histological or immunohistological evaluation.
RESULTS—The average transplant survival rate in the allogenic strain combination was 7.9 days (SEM 1.1). Monotherapy with MMF led to a statistically significant prolongation of transplant survival to 11.6 days (SEM 0.9, p< 0.05). Monotherapy with CSA delayed transplant rejection statistically significantly longer than MMF (21 days, 0.0, p< 0.05). The combination therapy with CSA and MMF was statistically significantly superior to the monotherapy with MMF (22.3 days, 0.5, p< 0.05). The combination therapy prolonged transplant survival compared with the CSA monotherapy, albeit not to a statistically significant extent.
CONCLUSIONS—In this study we were able to prove the immunosuppressive effect of oral MMF on acute rejection following corneal transplantation. Double drug therapy with CSA and MMF conferred a marginal benefit without a higher incidence of complications related to drug toxicity or overimmunosuppression.

Keywords: immunosuppressive agents; perforating keratoplasty     

Complicated posterior capsulorhexis: aetiology, management, and outcome

BACKGROUND—A 1 year retrospective analysis of 650 patients, who underwent a posterior capsulorhexis on their intact capsules, was performed to examine the incidence of complications, their aetiologies, and the outcome.
METHODS—Data were analysed on 32 patients with complicated capsulorhexis for type of surgery, preoperative and postoperative factors, and relative risk factors for vitreous issue.
RESULTS—There were six patients with vitreous loss. The posterior capsulorhexis was uncontrolled in 14 cases and difficult to perform in 12 cases. Implantation into the capsular bag was possible in all cases. Systemic vascular hazard and old age (over 80 years) were found to be statistically significant risk factors for vitreous loss (p=0.002 and p=0.03 respectively). The mean follow up was 13.5 months (range 4-25 months). One patient developed a retinal detachment and two had a transient clinical cystoid macular oedema. Visual acuity of ≥ 20/40 was obtained in 93% of the patients.
CONCLUSION—Loss of control of the posterior capsulorhexis has a low incidence but can lead to serious problems during surgery. A good knowledge of the technique is necessary to complete the procedure with a posterior capsulorhexis of the optimum size without vitreous loss.

     

Impact of cataract surgery on car driving: a population based study in Sweden

AIMS—To investigate the outcome of cataract surgery on the patients' self estimation of visual function while driving. Furthermore, the benefit of surgery to the car driving population was determined.
METHODS—A total of 208 consecutive patients (211 cases) with driving licences, who underwent cataract surgery with intraocular lenses, were studied prospectively using self administered questionnaires. Their self estimated degree of visual functional problems while driving were analysed before and after surgery.
RESULTS—Visual problems while driving declined from 82% preoperatively to 5% after surgery. Remaining visual problems with the operated eye were present in only seven patients. Problems in estimating distance while driving decreased from 37% before surgery to 6% after surgery. Twenty three per cent of the patients drove with a visual acuity below the requirements for driving in Sweden before surgery and only 4% after surgery. There was no correlation between the degree of visual problems while driving and visual acuity before surgery.
CONCLUSION—The car driving population greatly benefited from cataract surgery in terms of subjectively improved visual function and distance estimation while driving. Functional visual problems while driving should be considered as an indication for cataract surgery. These findings also indicated that the second eye should be operated on, if necessary, to achieve optimal ability to estimate distance and give best possible road safety.

     

Late reopening of successfully treated macular holes

BACKGROUND—Most idiopathic macular holes can be closed by a surgical procedure combining vitrectomy, posterior hyaloid ablation, and fluid-gas exchange followed by postoperative positioning. Reopening of closed macular holes has been reported, but its frequency is not known. Here the incidence of reopening after successful macular hole surgery is reported.
METHODS—77 consecutive cases of idiopathic macular holes operated with autologous platelet injection between July 1993 and October 1995 were reviewed. The procedure consisted of three port vitrectomy, posterior hyaloid removal, non-expansile fluid-gas exchange, and autologous platelet injection followed by face down positioning. The incidence of reopening was analysed in the cohort of the 72 anatomical successes.
RESULTS—Mean follow up was 12.3 months. The macular hole reopened in five eyes of five patients (five out of 72 patients, 6.9%), in four cases after cataract extraction. In four cases too, an epiretinal membrane was noted, either clinically or during reoperation, and fluorescein leakage in the macular area was present in two cases. Three of the five cases of reopening were reoperated and all three were anatomical successes.
CONCLUSION—Late macular hole reopening occurred in five out of 72 patient, and in four cases after cataract surgery. The presence of an epiretinal membrane around the hole in four of them suggested that tractional forces were responsible for the reopening. Reoperation, performed in three cases, again closed the macular holes.

     

Predicting visual outcome after macular hole surgery using scanning laser ophthalmoscope microperimetry

AIMS—To determine if postoperative visual outcome after successful macular hole surgery can be predicted with preoperative scanning laser ophthalmoscope (SLO) microperimetry.
METHODS—A prospective non-comparative study of 16 eyes in 15 patients examined before the surgery.
RESULTS—Visual outcome following macular hole surgery correlated with the "maximum parahole sensitivity", the highest intensity of stimulus to which the patient did not respond to any of the stimuli around the hole. Preoperative visual acuity, duration of the symptoms, size of the macular hole, and the "minimum parahole sensitivity", the lowest intensity to which the patient responded to all the stimuli around the hole, did not correlate significantly with postoperative visual acuity.
CONCLUSION—Preoperative assessment of patients using SLO microperimetry is a good predictor of visual outcome after macular hole surgery.

     

Effects on IOP restoration and blood-aqueous barrier after long term treatment with latanoprost in open angle glaucoma and ocular hypertension

AIMS—To evaluate whether long term treatment with the prostaglandin analogue latanoprost has a deleterious effect on the blood-aqueous barrier (BAB) and to determine the duration of the effect on intraocular pressure (IOP) after withdrawal of treatment.
METHODS—Patients with ocular hypertension or glaucoma were topically treated with latanoprost 50 µg/ml once daily for 6-12 months. In 26 patients IOP was followed for 14 days after withdrawal of treatment. Aqueous flare was measured with a laser flare meter during 6-12 months' treatment in 16 patients.
RESULTS—On the last day of treatment IOP was 6.9 mm Hg (95% CI 5.3-8.5) lower than before treatment. It increased slowly during the follow up period but was still 1.3 mm Hg (95% CI 0.2-2.5) lower than pretreatment IOP 14 days after cessation of treatment. No change in aqueous flare was seen throughout the study.
CONCLUSION—Latanoprost has no clinically significant effect on the permeability of the BAB and IOP will return to pretreatment levels within a few weeks, indicating that latanoprost is safe for long term treatment.

     

Recombinant tissue plasminogen activator in cases with fibrin formation after cataract surgery: a prospective randomised multicentre study

AIMS—This study investigated the effect of tissue plasminogen activator (tPA) in patients with severe intracameral fibrin after extracapsular cataract extraction or phacoemulsification with posterior chamber intraocular lens implantation.
METHODS—A randomised prospective multicentre study was carried out in 86 patients with intraocular fibrin formation 2-8 days after cataract surgery. While the first group (n=41) received only anti-inflammatory drugs, a single anterior chamber injection of tPA (10 µg) as an additional treatment to the standard was given in the second group (n=44). On days 1, 2, 14, and 90 after randomisation, the visual acuities, slit lamp findings, and intraocular pressures were documented in standardised protocols. Efficacy of treatment was judged by the rate of fibrinolysis (primary objective), the frequency of synechiae, and central capsular fibrosis (secondary objectives).
RESULTS—The incidence and quantity of intraocular fibrin were significantly lower in the patients treated with tPA than in the control group (p<0.05). The frequencies of synechiae were reduced by tPA injection. The capsule fibrosis noted after 3 months was significantly lower in the tPA group (p=0.027). No ocular side effects were noted after the tPA injections.
CONCLUSIONS—Lysis of postcataract fibrin formation is accelerated and increased by a single intracameral injection of 10 µg tPA in addition to standard anti-inflammatory treatment. The findings suggest that the tPA injection reduces posterior capsule fibrosis, which still has to be addressed in larger study populations and with a long term follow up.

Keywords: tissue plasminogen activator; cataract surgery; fibrin; fibrinolysis     

Open lacrimal surgery: a comparison of admission outcome and complications after planned day case or inpatient management

AIMS—To assess the outcome, in terms of completion of admission and complication rates, for two series of patients undergoing open lacrimal surgery, one group planned for a day case admission and the other planned for inpatient stay.
METHODS—A retrospective analysis of case notes was performed for 200 patients planned to have day case admission (for 209 open lacrimal operations) and the details compared with those for 200 inpatient admissions (for 228 lacrimal procedures) during the same period of study. The success rates for surgery were not examined.
RESULTS—9% of planned day cases required overnight admission, 5.5% for medical reasons and 3.5% for social or administrative reasons. There was a similar incidence of postoperative complications in planned day cases and inpatients, although 6% of day case patients developed postoperative cellulitis, compared with 1.3% of the inpatients (p= 0.01). Overall, the incidence of cellulitis was greater in cases complicated by intraoperative haemorrhage (p < 0.05) or the use of absorbable nasal packing (p < 0.0001). A similar number of patients in each group attended the accident and emergency department before the planned first postoperative clinic visit.
CONCLUSION—Patients undergoing open lacrimal surgery can be safely managed as day cases if carefully selected for suitability on social and medical criteria. The use of general anaesthesia is not, in itself, a contraindication to day case lacrimal surgery.

Keywords: day case surgery; dacryocystorhinostomy; open lacrimal surgery; cellulitis     

Conventional routine clinical review may not be necessary after uncomplicated phacoemulsification

AIM—To determine the clinical intervention rate during routine review after uncomplicated phacoemulsification.
METHODS—A review of case notes in 651 consecutive cases of uncomplicated phacoemulsification from 1994 (5.5 mm self sealing wound) was performed. The intervention rate at scheduled routine review visits and at unscheduled visits to the eye casualty service in the first 120 postoperative days was recorded. Interventions were defined as departures from predetermined postoperative care protocols.
RESULTS—Clinical interventions were reported in 2.8% (95% confidence interval 1.5 to 4.1%) of (n=1652) routine follow up visits. Many of these interventions were avoidable or trivial; 90% of patients had no postoperative intervention at any visit. 7.3% of patients made unscheduled visits to the emergency service. The intervention rate in this group was 50% (35.9 to 64.1%).
CONCLUSIONS—The intervention rate in routine clinical review after uncomplicated modern cataract surgery is low. Alternatives to conventional postoperative review, including shared care with non-ophthalmologists and improved perioperative patient education with an open channel for self referral, should be evaluated.

     

Risk of endophthalmitis after cataract extraction: results from the International Cataract Surgery Outcomes study

AIM—To estimate risk of infectious endophthalmitis after cataract extraction in Denmark and to compare results with the risk of this complication in the USA
METHODS—In the national Danish administrative hospital register, 19 426 patients were identified who underwent first eye cataract surgery from 1985 to 1987 and who were 50 years of age or older. Of these, 61 patients had postoperative endophthalmitis.
RESULTS—A 12 month cumulative risk of rehospitalisation for endophthalmitis was estimated at 0.18% (95% CI 0.09-0.26) after extracapsular cataract extraction with lens implant. Advanced age, male sex, intracapsular cataract extraction, and anterior vitrectomy were all associated independently with an increased risk of postoperative endophthalmitis. When restricting the sample to patients aged 65 years or older, in order to allow comparisons to be made with the US National Study of Cataract Outcomes, a 12 month risk of 0.17% (95% CI 0.08-0.25) was estimated. The previously reported US risk of 0.12% is included in the confidence interval of the risk estimated in the Danish sample.
CONCLUSION—Despite considerable differences in the healthcare systems, no statistically significant difference in outcome of surgery as measured by risk of endophthalmitis was shown between Denmark and the USA.

     

Transplanted and repopulated retinal pigment epithelial cells on damaged Bruch's membrane in rabbits

AIMS—The authors studied how artificially damaged Bruch's membrane influenced growth and differentiation of transplanted embryonic retinal pigment epithelial (RPE) cells and of host RPE cells in rabbits.
METHODS—Embryonic RPE cells obtained from pigmented rabbits were transplanted into the subretinal space of adult albino rabbits. The host RPE was removed with a silicone cannula, and Bruch's membrane was damaged by scratching with a microhooked 27 gauge needle under the detached retina in closed vitrectomy. The transplantation sites were examined 3, 7, and 14 days after surgery by light and electron microscopy.
RESULTS—Varying degrees of damage in Bruch's membrane were observed. Pigmented and hypopigmented RPE cells showed a normal polarity and tight junctions were seen at the sites of mild to moderate damage 3-7 days after the surgery. In contrast, fibroblast-like cells with no such features of RPE cells formed multiple layers at the sites of severe damage involving the full thickness of Bruch's membrane and the choriocapillaris even 14 days after the surgery. Without transplantation, host RPE cells repopulated the damaged areas in the same way as transplanted RPE cells.
CONCLUSIONS—Transplanted embryonic RPE cells as well as host RPE cells grew and differentiated on the moderately damaged Bruch's membrane, while the severely damaged Bruch's membrane did not allow differentiation of RPE cells although these cells could grow and cover the damaged areas.

Keywords: transplantation; repopulation; retinal pigment epithelial cells; Bruch's membrane; rabbit     

Treatment of ocular symptoms of Behçet's disease with interferon α2a: a pilot study

AIM—To study long term effects of interferon α_2a (IFNα_2a) on panuveitis in seven patients with Behçet's disease in a prospective, open clinical trial.
METHODS—Seven patients were treated with IFNα_2a for a mean of 23.6 months (14-37 months). They received an initial dose of IFNα_2a of 6×10⁶ IU/day, followed by 3×10⁶ IU/day after 1 month and 3×10⁶ IU every other day after 3 months. Two patients received low dose prednisolone (between 0.2 and 0.4 mg/kg/body weight) additionally at the beginning of the therapy. Complete cessation of IFNα_2a was possible in three patients (observation period 22, 6, and 4 months).
RESULTS—Marked improvement occurred in six patients who had ocular manifestations of Behçet's disease for the first time or with minor damage during their course of chronic relapsing panuveitis. In one patient with advanced ocular Behçet's disease, new relapses were prevented. Retinal infiltrates resolved within 2 weeks; vasculitis, macular oedema, infiltration of the anterior chamber and vitreous resolved within 4 weeks. Mean posterior uveitis score before treatment (nine affected eyes) was 6.6, 4 weeks after IFN it was reduced to 0.4. The mean observation period is 27.6 months, ranging from 14 to 42 months.
CONCLUSION—Treatment of ocular symptoms of Behçet's disease with IFNα_2a alone or in combination with low dose steroids led to complete remission of ocular vasculitis in all patients treated in this open, uncontrolled trial. Treatment with IFNα_2a may prevent permanent retinal or optic nerve damage due to vascular occlusion. No severe side effects occurred. Controlled randomised studies are warranted in order to prove the efficacy of IFNα_2a in ocular Behçet's disease and to compare it with other, established treatments such as azathioprine or cyclosporin A.

Keywords: Behçet's disease; uveitis; interferon α_2a     

Factors associated with second eye cataract surgery

AIMS—To analyse the clinical and sociodemographic characteristics associated with second eye cataract surgery.
METHODS—An observational, longitudinal study of patients scheduled for first eye cataract surgery that did not involve a combined procedure was carried at two teaching hospitals and one non-teaching hospital in Barcelona, Spain. Patients were followed for 2 years after first eye cataract surgery to assess whether and when they had undergone second eye cataract surgery. Clinical characteristics, perceived health characteristics (perceived visual function and overall health status), and sociodemographic characteristics were compared between two patient groups—those with surgery in only one eye and those who had undergone surgery in both eyes by the end of the 2 year follow up period.
RESULTS—Of the 242 patients studied, 125 (51.7%) underwent second eye surgery during the 2 year observation period. Patients with visual acuity 6/18 (0.3) or worse in the second eye compared with those with visual acuity over 6/12 (0.5) and patients younger than 65 years compared with patients aged 65-74 were more likely to undergo second eye surgery (adjusted odds ratio 3.9 and 1.8, respectively). 52 (44.5%) patients in the only one eye surgery group had a visual acuity less than 6/18 (0.3) in the second eye.
CONCLUSIONS—Worse visual acuity in the second eye and younger ages are strongly associated with both eyes cataract surgery. There may be a potential increase of demand for this procedure in the near future since almost half of the patients with only one eye surgery presented a low visual acuity in the second eye.

     

Azithromycin for ocular toxoplasmosis

AIMS—To investigate the efficacy of azithromycin in patients with ocular toxoplasmosis.
METHODS—11 immunocompetent patients with ocular toxoplasmosis were treated with azithromycin (500 mg the first day, followed by 250 mg/day for 5 weeks). Ocular and systemic examinations were performed during active retinitis episodes and all patients were followed for at least 1 year.
RESULTS—The intraocular inflammation disappeared within 4 weeks in seven patients, including two cases with progressive retinitis despite previous treatment with pyrimethamine, sulphadiazine, and folinic acid. Recurrence of retinitis occurred in three patients (27%) within the first year of follow up. No systemic side effects of azithromycin were encountered.
CONCLUSION—These results indicate that although azithromycin cannot prevent recurrent disease it may be an effective alternative for patients with ocular toxoplasmosis who cannot tolerate standard therapies.

Keywords: azithromycin; ocular toxoplasmosis     

Long term clinical outcome of a randomised controlled trial of anterior chamber lenses after high volume intracapsular cataract surgery

BACKGROUND—Age related cataract remains the major cause of blindness throughout the world. In many countries, the majority of cataract surgery continues to be done by the intracapsular cataract extraction (ICCE) method. The results of a large randomised controlled trial of multiflex open loop anterior chamber intraocular lenses (ACIOL) were reported from a busy eye hospital in Nepal.
METHODS—There was a randomised controlled trial of 2000 people with bilateral cataract reducing vision to less than 6/36. Interventions were ICCE with an ACIOL compared with ICCE with aphakic spectacles (+11 dioptres). Participants were followed at discharge, 6 weeks, 1 year, and 11/2-5 years after surgery. Visual acuity and clinical outcome were measured. A poor outcome was defined as vision <6/60.
RESULTS—Visual outcome was comparable in the two groups. More of the control group experienced functional blindness due to loss of aphakic spectacles at 1 year. The majority of cases of poor outcome occurred in the first year after surgery. There was no indication of any lens related problems after 1 year.
CONCLUSION—Multiflex open loop anterior chamber lenses are safe for up to 1 year of follow up when used by experienced surgeons, and the available evidence of 2-5 years of follow up suggests that the complication rate is reasonably low. An ACIOL at the time of cataract surgery offers benefits over routine ICCE surgery with aphakic spectacle correction as it avoids the problem of replacing lost and broken spectacles.

     

Endogenous cortisol profile in patients with central serous chorioretinopathy

AIM—To study the endogenous cortisol levels in patients with central serous chorioretinopathy (CSCR).
METHODS—Endogenous cortisol levels in urine and plasma were determined in 30 patients with acute CSCR and compared with 30 age and sex matched controls.
RESULTS—The mean values of the 8 am plasma cortisol (29.97 µg/dl v 18.76 µg/dl), 11 pm plasma cortisol (22.03 µg/dl v 13.06 µg/dl), and 24 hour urine cortisol (11.01 mg/24 h v 7.39 mg/24 h) revealed significantly higher values in the patient group (p<0.001).
CONCLUSIONS—Increased levels of endogenous cortisol are present in patients with CSCR.

     

Peroperative microbial contamination of anterior chamber aspirates during extracapsular cataract extraction and phacoemulsification

BACKGROUND—The normal conjunctival flora is one of the main sources of intraocular contamination during cataract surgery. The theory that the positive anterior chamber (AC) pressure during phacoemulsification (phaco), and the smaller wound utilised, might reduce the rate of contamination was studied.
METHODS—The peroperative AC aspirates of 210 consecutive patients undergoing cataract surgery were assessed. In group 1, 100 patients underwent a standard extracapsular cataract extraction (ECCE). In group 2, 110 patients underwent phacoemulsification of the crystalline lens through a scleral tunnel. AC aspirates from the Simcoe irrigation/aspiration cannula (group 1) and phaco probe (group 2) were collected and microbiological studies performed after direct and enrichment cultures.
RESULTS—There were 29 (29%) positives in the ECCE group compared with 22 (20%) positive cultures from AC aspirates in the phaco group. Coagulase negative staphylococcus (CNS) was the commonest contaminant in both groups.
CONCLUSION—Although there was a higher rate of AC contamination during ECCE, the difference was not statistically significant (p> 0.10, χ²=2.31).

     

Lens epithelial cell regression on the posterior capsule with different intraocular lens materials

BACKGROUND/AIMS—Posterior capsular opacification (PCO) is caused by proliferation and migration of lens epithelial cells (LECs) across the posterior capsule and is the commonest cause of reduced vision after cataract surgery. The influence of intraocular lens (IOL) material on the process of LEC migration was studied.
METHODS—90 eyes underwent standardised extracapsular surgery, with capsulorhexis and "in the bag" IOL placement. They were randomised to receive a three piece 6 mm lens of PMMA, silicone, or polyacrylic (AcrySof, Alcon, Fort Worth, TX, USA). On days 7, 30, 90, 180, and years 1 and 2 high resolution digitised retroillumination images were taken of the posterior capsule. The presence of LECs was determined at 90 days and 2 years, and their progression or regression was established by serial examination of images.
RESULTS—LECs were seen in 93% of silicone and 97% of PMMA IOLs at 90 days, compared with 46% of polyacrylic (p<0.001). At year 2 LECs were present in all patients with silicone or PMMA lenses, whereas 62% of patients with polyacrylic IOLs had LECs (p<0.001). Of those patients with LECs at day 90 LEC regression occurred in 8% with silicone IOLs and 15% of PMMA cases, compared with 83% of patients with polyacrylic IOLs (p<0.0001).
CONCLUSION—The presence of LECs on the posterior capsule was considerably lower with polyacrylic than PMMA or silicone IOLs and LEC regression occurred more frequently. The lower incidence of LECs and the higher rate of regression may explain why PCO formation appears to be reduced with polyacrylic lenses. This has important clinical implications for the prevention of PCO.

Keywords: lens; cell; implant; posterior capsular opacification