Extracapsular Lens Extraction Research Articles

Animal Study on the Effects of Catalin on Aftercataract and Posterior Capsule Opacification

Purpose: To find out the role of Catalin in the prevention of posterior capsular opacification (PCO), we undertook this experimental study in rabbits. Methods: Twenty rabbits (10 for the Catalin group and 10 for the placebo group) were operated on for extracapsular clear lens extraction in an aseptic environment. In all cases, capsulorrhexis of 8 mm diameter was carried out. Both the test drug and placebo were given at a dose of 4 times/day from the first postoperative day for 8 weeks. Common drugs in both groups were topical corticosteroid, antibiotic and cycloplegic drops. Periodic slitlamp examinations and photographic documentations were carried out to find any evidence of aftercataract. At the end ot 8 weeks, histopathological examination was carried out to document any evidence of aftercataract. Result: Overall, evidence of aftercataract was seen in 6 rabbits in the control group and 3 in the Catalin group; the degree of PCO was higher in the placebo group. Conclusion: We found that Catalin played some role in preventing PCO.

Cell proliferation on the outer anterior capsule surface after extracapsular lens extraction in rabbits

Purpose: To use light microscopy to evaluate the presence and distribution of cells that proliferate on the outer surface of the anterior capsule after experimental lens extraction in rabbit eyes.Setting: Research Laboratory, Department of Ophthalmology, Wakayama Medical College, Wakayama, Japan.Methods: Extracapsular lens extraction, with or without implantation of a poly(methyl methacrylate) intraocular lens, was performed in 10 adult albino rabbits under general anesthesia. Animals were killed 1 month postoperatively. Each eye was embedded in paraffin and examined by light microscopy.Results: A capsular bag composed of the anterior and posterior capsules was observed. Mononuclear cells, presumed to be lens epithelial cells (LECs), had proliferated in the space between the capsules as well as on the outer surface of the anterior capsules, in association with an accumulation of extracellular matrix.Conclusion: After lens extraction, LECs migrated to and proliferated on the anterior surface of the anterior capsule.

Membrane formation and cellular response on the surface of lenses implanted in rabbit eyes

Purpose: To study the pathogenesis of membrane formation and cellular response on the surface of posterior chamber intraocular lenses (IOLs) implanted in rabbits.Setting: Department of Histology and Embryology, Pathology, Ophthalmology, The First Military Medical University, Guangzhou, P.R. China.Methods: Thirty rabbits had extracapsular lens extraction and posterior chamber IOL implantation. The IOLs were removed 4, 7, 15, 30, and 90 days postoperatively. Membrane formation and cellular response on IOL surfaces were evaluated using light (n = 25), transmission (n = 5), and scanning electron (n = 5) microscopy.Results: On 30 IOLs, the incidence of cellular adhesion was 100%. Cellular components comprised macrophages, fibroblast-like cells, epithelioid cells, giant cells, ultralarge giant cells, and lymphocytes. A thin, proteinaceous film was also seen on the surface of the IOLs. The membrane of the IOL surface comprised fibrin, collagen fibrils, macrophages, fibroblast-like cells, giant cells, and fibroblasts.Conclusion: The findings of this study might apply to humans because cellular elements and membranes have been reported in humans.

Inflammatory response after endocapsular phacoemulsification or conventional extracapsular lens extraction in the rabbit eye.

We compared the inflammatory response after phacoemulsification and conventional extracapsular lens extraction in New Zealand albino rabbits. One eye was selected at random and phacoemulsification was performed. Extracapsular lens extraction was done in the fellow eye. In both eyes a polymethylmetacrylate intraocular lens was implanted into the capsular bag and the wound was sutured with a 9-0 polypropylene continuous suture. The levels of prostaglandin E2 in aqueous humour and wet mass of the iris-ciliary bodies were measured at day 1. The number of white blood cells and protein levels in the aqueous humour were measured at day 1, 3, 7, 14 and 30. Corneal thickness was estimated with pachymetry. Prostaglandin E2 levels and wet masses of iris-ciliary bodies were significantly higher after extracapsular lens extraction, which also induced significantly higher white blood cells counts at day 1 and 3 and higher protein levels at day 7. Extracapsular lens extraction caused more corneal edema at day 3, 7 and 14. The results suggest that phacoemulsification induced less surgical trauma with less breakdown of the blood-aqueous barrier.

Mitomycin against posterior capsular opacification: an experimental study in rabbits.

Posterior capsular opacification is the most common postoperative complication of extracapsular cataract surgery. The purpose of this study was to attempt to inhibit this secondary cataract formation by using mitomycin (an antimitotic drug). A solution containing mitomycin was used to perform hydrodissection (with a 5 minute pause) during extracapsular lens extraction in rabbits. This way of administration was chosen to reduce as much as possible drug diffusion into the anterior chamber. Heparin was added to the irrigating solution to avoid fibrin formation. Its ability to prevent posterior cataract opacification was also evaluated at the end of the study. The animals were sacrificed 4 or 6 months after surgery. Grading concerning two aspects of secondary cataract (proliferation and fibrosis) was obtained on gross examination. Histological analysis was subsequently performed. This study demonstrated that mitomycin has a significant inhibitory effect on secondary cataract formation (proliferation as well as fibrosis) in rabbits whereas heparin does not seem to have the same effectiveness. This work is a preliminary study concerning the use of mitomycin for prevention of posterior capsular opacification. It has proved its effectiveness in rabbits but more in depth studies are still necessary before its application in humans.

Ocular hypertension following cataract surgery in dogs: 139 cases (1992-1993)

Objective To document the incidence of postoperative ocular hypertension (POH) after cataract surgery in dogs. Design Retrospective analysis of medical records. Sample Population 88 dogs that had had cataract surgery. Procedure The effect of several categorical variables on the development of POH was evaluated statistically. Postoperative ocular hypertension was defined as intraocular pressure > 25 and > 30 mm of Hg. Results The incidence of POH > 25 mm of Hg was 48.9%; > 30 mm of Hg, 33.8%; > 40 mm of Hg, 20.1%; and > 50 mm of Hg, 5.8%. Mean onset of POH > 25 mm of Hg was 4.9 hours. The incidence of POH was not affected by the type of surgery. Eyes that had phacoemulsification developed POH significantly more rapidly (mean, 3.9 hours), compared with those that had extracapsular lens extraction (8.4 hours). Mean phacoemulsification duration was greater in eyes that developed POH, and older dogs were more likely to develop POH. Development of POH was not correlated with sex, stage of cataract, type of surgical procedure performed, intraocular lens placement, preoperative lens-induced uveitis, or posterior lens capsule tears and vitrectomy. However, eyes that received intraocular lens implants developed POH more rapidly, compared with eyes without implants. Clinical Implications The high incidence and early onset of POH after cataract surgery suggests that routine use of antiglaucoma medications in the first 12 hours after surgery is warranted. (J Am Vet Med Assoc 1996;209:105–111)

Lens epithelial cell proliferation onto the intraocular lens optic in vitro

Purpose: To determine how lens epithelial cells (LECs) proliferate onto an intraocular lens (IOL) after extracapsular cataract surgery.Setting: Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan.Methods: We cultured the capsular bags retaining LECs of eight human eye-bank eyes and six rabbit eyes that had had extracapsular lens extraction with in-the-bag implantation of a poly(methyl methacrylate) (PMMA) IOL and a PMMA ring. Cell proliferation onto the IOL optic was monitored by a time-lapse video system.Results: Cells proliferated onto the IOL optic via the anterior capsulotomy margin, the inner surface of the anterior capsule, and the posterior capsule. They formed cell sheets similar to the membranes observed in clinical cases.Conclusions: Since the cells proliferated from the anterior capsule as well as from the posterior capsule onto the IOL optic, the membranes observed clinically on the IOL optic may be LEC sheets.

Corticosteroid Suppression of TraumaInduced Hyaluronan in Rabbit Cornea and Aqueous

Corneal and aqueous hyaluronan have recently been shown to react in response to several different types of trauma, including cataract surgery. In order to find ways to influence the reaction, we have evaluated the effect of topical dexamethasone (Isopto-Maxidex, Alcon Universal Ltd, Fort Worth, Tex) or indomethacin (Confortid, Dumex Ltd, Copenhagen, Denmark) on the postoperative hyaluronan concentration in rabbit cornea and aqueous after extracapsular lens extraction. The drugs were administered as topical eye drops three times daily. The hyaluronan concentration in rabbit cornea and aqueous after extracapsular lens extraction was measured with a radioligand assay. Dexamethasone treatment (1 mg/mL) significantly suppressed the increase in corneal hyaluronan seen after extracapsular lens extraction, 2 (p < or = 0.0022) and 3 weeks (p < or = 0.0002) after surgery, while indomethacin did not induce any significant difference at 2 weeks. When the dexamethasone concentration was lowered to 0.1 and 0.2 mg/mL, there was still a significant decrease (p < or = 0.009) in hyaluronan concentration, but at lower concentrations of dexamethasone (0.01 and 0.02 mg/mL), no significant decrease was seen. The increase in aqueous hyaluronan concentration seen 2 days after surgery in untreated eyes was significantly lowered by both dexamethasone (p < or = 0.0076) and indomethacin (p < 0.036). Dexamethasone lowers reactive corneal and aqueous hyaluronan concentration in vivo after extracapsular lens extraction.

Corneal metabolism and epithelial barrier function after cataract surgery and intraocular lens implantation: a fluorophotometric study

The aim of this study was the assessment of possible changes in corneal metabolism and epithelial barrier function after an extracapsular lens extraction with artificial lens implantation. Ten patients without any eye medication were selected out of 140 patients attending for extracapsular lens extraction with lens implantation at the university hospital. Corneal metabolism was evaluated by fluorophotometric measurement of corneal autofluorescence. The corneal fluorescence values were corrected for interference by the fluorescence of the ocular lens. Corneal epithelial barrier function was evaluated by determination of corneal epithelial permeability. The permeability was calculated from the fluorescein penetration into the cornea after application of an eye bath containing fluorescein. Operated and fellow eyes were investigated 1 week before and 3-4 weeks after the operation. The corneal autofluorescence of the operated eye decreased significantly after surgery (mean decrease: 14%, Wilcoxon paired-sample test: P = 0.038). The corneal epithelial permeability of both eyes increased after surgery above the normal range of healthy controls (mean increase operated eye: 34%, P = 0.015, fellow eye: 32%, P = 0.15). Both corneal autofluorescence and epithelial permeability returned to normal values after one year. The lower corneal autofluorescence in the operated eye after surgery indicates a lower corneal metabolism which may be due to surgery. The increased epithelial permeability of both eyes implies a temporary impairment of the corneal barrier function. The interaction with the fellow eye indicates a consensual reaction which may attributed to damage to the neural system by the surgery.

Synthesis of Glycosaminoglycans in Rabbit Corneal Wounds after Extracapsular Lens Extraction

Objective: To determine the production site of corneal wound hyaluronan. To study glycosaminoglycan synthesis during corneal wound healing. Study Design: Extracapsular lens extractions were performed in pigmented rabbits. The cornea was labelled with [ 3 H]-D-gluocosamine and [ 35 S]-sulphate with in-vitro incubation in enriched medium or with intracameral in vivo injections, 7, 14 and 28 days after surgery. Setting: Ophthalmic Research Department and Department of Medical and Physiological Chemistry, University of Lund, Sweden. Main Outcome Measures: Non-incorporated isotope was eliminated with ionexchange chromatography. The samples were treated with Streptomyces hyaluronate lyase, chondroitinase-ABC or keratanase II and again chromatographed to measure the incorporation of label into individual glycosaminoglycans. Synthesis of individual glycosaminoglycans is shown as the amount of [ 3 H] and [ 35 S] incorporated dpm:s after treatment with the different enzymes. The relative synthesis of glycosaminoglycans was calculated as percentage of the total amount of labelled glycosaminoglycans. Results: There was good correlation between in-vivo and in-vitro labelling. Incorporation of D-[ 3 H] glucosamine into hyaluronan in the operated corneas was found seven, 14 and 28 days after surgery, but could not be demonstrated in control cornea. Seven days after surgery the net synthesis of hyaluronan was about 9.5% in vitro (5% in vivo ). Fourteen days after surgery the net synthesis had increased to around 19.5% in vitro (9% in vivo ) and after 28 days it was around 3.5% in vitro (not detectable in vivo ). The net synthesis and absolute synthesis of keratan sulphate was thoroughly decreased during the healing period in in-vitro labelled corneas. In both keratan sulphate and chondroitin sulphate/dermatan sulphate the [ 35 S]/[ 3 H]-ratio was lowered in the operated corneas. Conclusions: Hyaluronan is synthesized in corneal wounds after extracapsular lens extraction. The synthesis of keratan sulphate is decreased in corneal wounds.

Clear Lensectomy and Intraocular Lens Implantation in Normally Sighted Highly Hyperopic Eyes. Three-year Follow-up

Objective: To present the results, complications and management of a series of 17 normally sighted eyes who have undergone clear lens extraction and IOL implantation for the correction of high hyperopia. The follow-up period was 1 to 3 years (mean: 26.2 months). Main Outcome Measures: Unaided visual acuity, predictability, endothelial cell loss percentage, complications and management. Method: Extracapsular clear lens extraction and posterior chamber IOL implantation was performed in 17 normally sighted eyes of 9 patients, 35 to 55 years old (median 45), with a hyperopic spherical equivalent of + 9.61 ± 0.46 D (range: + 6.75 to + 13.75 D). The axial length range was 17.88 to 22.78 mm. Refraction was aimed at -1.50 to account for the inaccuracy of the SRK II formula in high hyperopic eyes. Results: One case had an uneventful intraoperative posterior capsular tear. Mean unaided visual acuity improved from CF to 0.84 (range: 0.7–1.0) at 3 years. Postoperative correction ranged from −0.87 to + 0.50 D at 1 year and −0.25 to + 0.62 at 3 years. The mean endothelial cell loss percentage at 3 years was 11.2% ± 0.59 (range: 8–13%). Three eyes developed posterior capsular opacification at 20 and 21 months and were uneventfully treated with Nd:YAG laser capsulotomy. Conclusion: The incoming excellent results in accuracy, safety and rapid stability of refraction with longer follow-up show that clear lens extraction and IOL implantation is advantageous over other refractive procedures in high hyperopia. Aiming at −1.50 DS with SRK II formula in highly hyperopic eye with an axial length of 17.88 to 22.78 mm, results in a correction near to emmetropia.

Ocular Manifestations of Diabetes Mellitus: Diabetic Cataracts in Dogs

Cataracts form in diabetic dogs because of the disruption of normal lens metabolism. The pathophysiology seems to be a combination of increased lens cell membrane permeability, reduced cell membrane function, damage from accumulating osmotic products (polyols), glycosylation of lens proteins, and oxidative injury. Lens-induced uveitis must be recognized and managed in presurgical preparation of dogs with diabetes cataracts. Phacoemulsification is the current treatment of choice for diabetic cataracts in dogs and can be performed at an earlier time than traditional extracapsular lens extraction. This may allow for greater success rates after surgery.

Treatment of Postoperative Endophthalmitis

Despite many advances in microsurgery, asepsis, antibiotics and intraocular lenses, postoperative endophthalmitis continues to be responsible for the loss of many eyes. In a series of 153 cases of endophthalmitis with a positive culture, 115 occurred after ophthalmic surgery. Eyes appear to be more vulnerable to this complication after extracapsular lens extraction in particular. The analysis of the patients operated for cataract in our own department shows that the incidence of endophthalmitis is 3 times higher in the extracapsular group with lens implantation than in the group of intracapsular lens extraction without lens implantation. Quick diagnosis and prompt action are essential to successful treatment. The treatment consists of vitrectomy and has the following three purposes: (1) provision of a good specimen for direct bacteriological examination and culture; (2) removal of toxins and cells, and (3) creation of space for the injection of an antibiotic. The authors found highly divergent prognoses and bacteriological patterns for endophthalmitis following vitrectomy, bleb surgery and cataract. Similar bacteriological agents do not give rise to the same prognosis after different operations. The post-lens implantation group (88 cases) permitted a distinction to be made between intracapsular and extracapsular surgery. A statistically significantly higher percentage of infection by low-virulence organisms (e.g. Staphylococcus epidermidis) was seen after extracapsular surgery: 60% compared to 30%. The analysis shows that this difference in bacteriological spectrum is the sole explanation for the better functional results following extracapsular surgery.

Postoperative endophthalmitis caused by an Enterobacter species

Six patients (aged 8 to 75 years) who were operated upon during the same day developed bacterial endophthalmitis on the following day; seven eyes were affected. Two patients had intracapsular cataract extraction, one extracapsular lens extraction, two extracapsular cataract extraction with intraocular lens implantation and one repair of bilateral scleral or corneoscleral perforations. Vitreous cultures taken from six eyes were positive for an Enterobacter sp. Despite antibiotic treatment systemically, subconjunctivally and intravitreally, four eyes had to be eviscerated, while two eyes showed evidence of shrinkage (phthisis); only one eye retained useful vision ( 9 10 ). Cotton swabs used during surgery, prepared manually from cotton wool moistened with saline, were identified as the source of infection; the batch had not been subjected to the prescribed autoclaving process. The importance of proper sterile procedures in association with surgery is emphasized.

Ocular Pharmacokinetics of Orally Administered Azithromycin in Rabbits

Azithromycin was orally administered to Dutch-belted rabbits following extracapsular lens extraction in one eye. At various times the animals were sacrificed, and serum and ocular tissues were obtained for drug level determination by HPLC-EC. Following a single dose, peak levels of drug in ocular tissues were measured within 8 hours (cornea > 0.5 micrograms/g [15mg/kg]; > 1.5 micrograms/g [3Omg/kg]). Highest levels were obtained in iris and ciliary body ( > 15 micrograms). Measurable tissue levels persisted for at least 120 hours. Trough levels increased proportionately during drug multiple dose administration. Five days following five daily 15mg/kg doses, corneal levels exceeded 0.5 micrograms/g, and iris and ciliary levels were higher than 15 micrograms/g. Aqueous humor and serum levels were equivalent. Vitreous humor levels, though higher than aqueous humor, were consistently < 1 microgram/ml. Extracapsular cataract extraction did not significantly affect drug uptake.

Influence of Anterior Segment Trauma on Endogenous Hyaluronan in the Rabbit Cornea and Aqueous

OBJECTIVE:To monitor probable changes of endogenous hyaluronan in rabbit cornea and aqueous after extracapsular lens extraction. STUDY DESIGN: Rabbit eyes were operated with extracapsular lens extraction and corneal and aqueous hyaluronan were measured at different time intervals after surgery. PATIENT: Pigmented rabbits were used in the study. SETTING: Ophthalmic Research Department, University Hospital of Lund, Sweden. MAIN OUTCOME MEASURES: Hyaluronan concentration in aqueous and cornea. Protein concentration and white blood cell count in aqueous. RESULTS: Total corneal hyaluronan increased from the normal 1.20 ± 2.0 µg/g wet weight to a peak concentration of about 150 µg/g wet weight 14 days after surgery. Sixty days after surgery the corneal hyaluronan concentration was still 10 times that in normal cornea. Aqueous hyaluronan increased more rapidly than in the cornea, from 0.65 ± 0.04 µgml-l to around 6 µgml-l two days after surgery. Sixty days after surgery the aqueous hyaluronan concentration in operated eyes was still twice that in controls. Eyes where a cataract wound was made without removing the lens did not demonstrate the pronounced increase in aqueous hyaluronan. CONCLUSION: An appearance of hyaluronan in corneal wounds after extracapsular lens extraction is shown histochemically and quantitatively. The characteristics of this increase makes it probably that it is synthesized locally. The increase of aqueous hyaluronan probably reflects leakage from the vitreous.

Histochemical identification of hyaluronan in the rabbit anterior segment during the healing period after extracapsular lens extraction

Extracapsular lens extractions were performed in rabbits. The eyes were examined at different time intervals after surgery with a histochemical method visualizing hyaluronan. There was positive staining for hyaluronan in the wound region from 2 to 90 days postoperatively. The staining was most intense and widespread between 7 and 14 days after surgery. A hyaluronan staining in the corneal stroma extended from the wound towards the central cornea 4 to 14 days postoperatively. The iris showed increased staining on the second postoperative day, but much less so at the other times studied. Cells on the posterior lens capsule were surrounded by hyaluronan from the seventh postoperative day throughout the observation time up to 90 days postoperatively. It is concluded that hyaluronan reacts during corneal wound healing.

Changes in corneal shape after suture cutting using the argon laser for postoperative astigmatism following cataract extraction

We studied the changes in corneal shape after suture cutting with an argon laser to reduce corneal astigmatism following cataract extraction. Sixty-two patients who exhibited high with-the-rule astigmatism (>3 diopters [D]) following extracapsular lens extraction had argon laser suture cutting. The patients were classified into three groups: Group A comprised 30 patients whose sutures were cut two to three months after planned extracapsular cataract extraction (p-ECCE); Group B consisted of eight patients who had the same treatment five to nine months after p-ECCE; Group C comprised 24 patients who had the treatment one to two months after phaccemulsification (PE). The dioptric reduction of corneal astigmatism (the percent reduction of astigmatism) was 1.83 ± 0.98 D (37.4 ± 18.3%) in Group A, 3.20 ± 2.35 D (55.6 ± 34.4%) in Group B, and 2.08 ± 1.20 D (41.4 ± 20.4%) in Group C. There was no statistical significance in the dioptric reduction and the percent reduction among Groups A, B, and C. This suggests that the wound size and time of cutting are not directly correlated to the effect of argon laser suture cutting. To examine the relationship between the effect and changes in corneal shape from suture cutting, we divided the patients into two subgroups; one was Subgroup (+) in which the percent reduction of astigmatism was above 25%; the other was Subgroup (-) in which the percent reduction was below 25%. Keratometric measurement demonstrated an elongation of corneal curvature in the steeper meridian, a shortening in the flatter meridian, and a shift of axis in Subgroup (+) that were statistically significant compared with Subgroup (-). Corneal topographical analysis demonstrated a flattening of the upper cornea that corresponded to the site of the cut suture and a concomitant steepening of the other part of the cornea in Subgroup (+). In contrast, corneal configuration remained virtually unchanged in Subgroup Our results indicated that a change in the overall corneal shape by argon laser suture cutting was necessary to reduce postoperative astigmatism.

PGE2and leucocyte levels in aqueous humor after lens extraction and intraocular lens implantation

In order to study the inflammatory response after cataract surgery and intraocular lens implantation the leukocyte (WBC) and prostaglandin E(2) (PGE(2)) levels in aqueous humor were measured in rabbit eyes at different time points (1, 3, 7, 14 and 28 days) postoperatively. In the first group lenses were implanted in the anterior chamber of the eye, without lens extraction, while in the second group the lens was removed and the IOL was placed in the capsular bag. A third group of animals was injected with 10 ng endotoxin into the vitreous in order to induce an inflammation of the uvea. In the endotoxin group high levels of WBC and PGE(2) were observed at 24 h postoperatively, followed by a decrease over time. In the intraocular lens groups WBC and PGE(2) were detected at all time points, and at higher levels compared to the endotoxin group. The WBC was high at day 1 and 3, declined over time, and then increased at day 28 postoperatively. The PGE(2) level was highest at day 3 in rabbits with anterior chamber lenses, while it peaked at day 7 in the animals with IOLs implanted in the capsular bag. In animals with the extracapsular lens extraction without an implanted IOL, the levels of WBC and PGE(2) decreased over time, and were statistically lower after one week compared with animals with an IOL placed in the capsular bag. The results demonstrate that the inflammatory response after cataract surgery persists for at least one month, probably due to surgical trauma and foreign body reactions. PGE(2) and WBC could be used to study postoperative trauma and biocompatibility of different IOL materials and designs.

Surgical management of closed angle glaucoma: our experience

In this paper we present our experience of the last three years in the surgical treatment of eyes with closed angle glaucoma. We have performed an extracapsular lens extraction and posterior chamber intraocular lens implantation on 34 eyes of 34 patients. All of them were affected by closed angle glaucoma with variable control after a Yag laser iridotomy: 6 eyes had high I.O.P. notwithstanding maximal therapy, 11 eyes had I.O.P. under control (less than 21 mmHg) without therapy, 9 with I.O.P. controlled with topical therapy, 8 with I.O.P. controlled with maximal therapy (C.A.I. included). The cases with well controlled glaucoma were operated on because of the presence of a more or less significant lens opacities. After a follow-up of up to 40 months (mean = 20.3, range = 1-40), all eyes show satisfactory intraocular pressure and no eye needed a filtering procedure. The results of our studies are as follows (values are mean +/- SD). In the group of 6 eyes with high I.O.P., the mean pre-operative intraocular pressure was 29.7 +/- 5.6 mmHg and the mean post-operative I.O.P. was 15.1 +/- 1.4 mmHg. The mean reduction was 14.5 +/- 6.6 mmHg (p < 0.005). In the 28 eyes with pre-operative I.O.P. under control (17.5 +/- 1.6), the mean post-operative I.O.P. was 14.4 +/- 2.3 mmHg, with a mean reduction of 3.1 +/- 3.1 mmHg (p < 0.005). Before the E.C.C.E., 11 eyes had I.O.P. less than 21 mmHg without anti-glaucoma medication, whereas after the E.C.C.E. 28 eyes did not need such a medication.(ABSTRACT TRUNCATED AT 250 WORDS)