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Spiral intraocular Lens, Rhexis and Phacoemulsification
215
Short Reports
chafing can be made relatively late when permanent damage is already done. Our case is a good example of posterior iris chafing syndrome depicting the difficulty in management and relatively unfortunate clinical outcome with such problems as secondary glaucoma, bullous keratopathy and rhegmatogenous retinal detachment. IOLs that have a 10° angulation of the loops from the plane of the optic reduce, but do not eliminate, the incidence of this complication [6]. Thus, the only way to avoid posterior iris chafing syndrome is to prefer capsular bag fixation instead of ciliary sulcus fixation.
REFERENCES 1 NS Jaffe, MS Jaffe, GF Jaffe. Cataract Surgery and its Complications. St Louis: CV Mosby; 1990, p. 179. 2 TD Gwin, DJ Apple. A study of posterior chamber intraocular lens fixation and loop configuration: An analysis of 425 eyes obtained postmortem. Presented at the American Society of Cataract and Refractive Surgery Meeting, Los Angeles, March, 27, 1988. 3 SA Ostbaum. Biologic relationship between polymethylmethacrylate intraocular lenses and uveal tissue. J. Cataract Refract. Surg., 1992; 18: 219-231. 4 S Mashet. Pseudophakic posterior iris chafing syndrome. J. Cataract Refract. Surg., 1986; 12: 252-256. 5 JR Samples, EM Van Buskirk. Pigmentary glaucoma associated with posterior chamber intraocular lenses. Am. J. Ophthalmol., 1985; 100: 385-388. 6 DJ Apple, N Mamalis, RJ Olson, MC Kincaid. Intraocular lenses: Evolution, Designs, Complications and Pathology. Baltimore: Williams and Wilkins; 1989, p. 153. 7 D Miller, MG Doane. High-speed photographic evaluation of intraocular lens movements. Am. J . Ophthalmol., 1984; 97: 752-759.
Spiral Intraocular Lens, Rhexis and Phacoemulsification
AND PATIENTS: 286 phacoemulsifications and 1189 planned ECCE. Examination post-operation at 7 weeks: centration of the optic in full mydriasis and fluoresceinic angiography of the macula. SETTING: Institut Edith Cavell and Policlinique de Bruxelles (Brussels, Belgium). MEAN OUTCOME AND MEASURES: Comparison of decentration (mainly upward) and CME rate in the two series. RESULTS: The percentage of decentration was definitely lower in the phaco/rhexis series (P = 0.0000001). The rate of postoperative CME was lower in the phaco/rhexis series but the difference was not statistically significant. CONCLUSIONS: Capsulorhexis plus phacoemulsification guarantee a better postoperative centration of spiral IOL than envelope technique does. CME seems to be less frequent after phaco than after planned ECCE but additional data are needed to demonstrate this statistically. Phacoemulsification; Envelope Keywords: technique; IOL centration; Cystoid macular edema
INTRODUCTION When the 'envelope' technique [1] replaced that of the 'can opener' the improvement was evident-capsular bag implantation was safer and easier with better stability of the IOL. However the capsulorhexis proposed by Gimbel [2] and Neuhann [3] appears to be even better as far as IOL centration and stability are concerned. Since 1987 we have used an original IOL [4, 5] with a spiral blade-shaped haptic (Fig. 1), which has 1-'111---- 9 .75 mm - - - - . - l
G.MEURandM.MAENHAUT Department of Ophthalmology, lnstitut Edith Cavell, Brussels, Belgium
OBJECTIVE: To compare the results of capsulorhexis and phacoemulsification versus envelope technique and planned ECCE as far as IOL (spiral lens) centration and cystoid macular edema (CME) are concerned. STUDY DESIGN Correspondence to: G. Meur M.D., lnstitut Edith Cavell, Service d'Ophthalmologie, 1180 Bruxelles, Belgium. Paper read at the lOth European Intraocular Implant Council Congress in Paris, 8 September 1992. Eur J Implant Ref Surg, Vol 5, September 1993
60mm~ Fig. 1 Standard model of spiral lens with a 6 mm optic for planned ECCE
Short Reports
216 0 0
RESULTS
tO
c)
Neither series showed major decentration of the lens (sunset or sunrise syndrome) in non-dilated pupils. With fully dilated pupils, centration relative to the limbus [7] was perfect in 94% of the phaco series (Table 1). Decentration (6%) was always less than Table 1 Centration of modified spiral lens implanted after rhexis and phacoemulsification (198 cases). Maximal decentration: 0.98 mm Perfect centration: 187 (94%) Upward slight decentration: 8 (4%) Downward slight decentration: 3 (2%) Nasal decentration: 0 Temporal decentration: 0
Table 2 Centration of standard spiral lens implanted after planned ECCE and envelope technique (374 cases). Maximal decentration: 1.5 mm
9.750
Perfect centration: 266 (72%) Upward slight decentration: 76 (20%) Downward slight decentration: 19 (5%) Nasal slight decentration: 5 (1.4%) Temporal slight decentration: 6 (1.6%)
Fig. 2 Modified spiral IOL with a rectangular 6 mm x 4.5 mm optic Table 3 Upward decentration Rhexis/Phaco: 8/198 (4%) Envelope/ECCE: 76/374 (20%)
the advantages of a disc [1]-i.e. filling of the bag without a spring effect-but avoids its disadvantages: increased weight and the need for a large incision. At that time we started using planned ECCE and envelope technique. Recently, in view of the fact that small incision surgery is an improvement, we have modified our initial spiral-IOL design in order to meet the requirements of capsulorhexis and phacoemulsification. The blade-shaped haptic is now narrower and more flexible and the optic (Fig. 2) is rectangular (6 x 4.5 mm) [6]. This paper reports on a series of phacoemulsification operations and bag implantation with the modified spiral implants Morcher 45 S® and Storz-Coburn P375UV®.
Table 4 Angiographic CME Rhexis/Phaco: 5/178 (2.8%) Envelope/ECCE: 26/618 (4.2%)
1 mm. This is definitely better than in the planned ECCE series (Table 2). When comparing the upper decentrations, i.e. those most frequently observed, the rate is obviously lower in the rhexis/phaco series (Table 3). The statistical difference is highly significant: P == 0.0000001. The percentage of cystoid macular edema (CME) appears lower in the phaco series (Table 4), but the difference is not statistically significant: P == 0.35.
PATIENTS AND METHODS
DISCUSSION
In the period 1 April 1991 to 30 June 1992 we implanted 286 modified spiral lenses (rhexis/phaco). At 7 weeks, 198 patients were observed in full mydriasis and 178 underwent an angiography of the macula. These examinations were performed by a colleague who had not taken part in the surgery. This series was compared with a previous one of planned ECCE plus classical spiral lens (1189 IOLs implanted by the same surgeon from 1987 to 1990).
Factors contributing to IOL decentration are haptic design and surgical technique. Capsular bag fixation provides a better guarantee for centration than does sulcus fixation [8]. It is not clear which technique-can opener or envelope linear capsulotomy-is preferable in order to achieve a firm bag fixation [7]. Post-mortem observations [8] show that a certain amount of decentration with classical two loop IOLs is not uncommon with both procedures. Eur J Implant Ref Surg, Vol 5, September 1993
Short Reports
217
The most usual cause is the exit of a loop out of the bag. A pea-podding or capsular shrinkage appears to be a minor factor of intracapsular decentration. The haptic of the spiral lens has definite specificities. It is not a loop but an encircling blade, very rigid in the implant plane but not perpendicular to it. The technique of implantation [4] after envelope capsulotomy and planned ECCE guarantees a stable position of the haptic along the whole bag equator without any spring effect. Escape of the haptic out of the bag cannot occur. However a slight upward decentration may be seen in full dilatation in 20% of cases (Table 2). It is probably due to a pea-podding effect, exerted by the lower bag upon the whole implant and not counteracted by the upper floppy part of the bag. Capsulorhexis without rim tears ensures on the contrary a symmetrical capsular bag. Escape of the rigid encircling haptic out of the bag is impossible. Furthermore, no asymmetrical pea-podding effect can occur. Rhexis and phacoemulsification decrease dramatically the incidence of spiral IOL decentration. This goal is essential if multifocal or small and oval optics are to be successfully used.
New Instrument Developed to Assist Splitting of the Nucleus in Cataract Surgery During Phacoemulsification PIETRO LISCHETTI UniversityEyeC/inicofRome 'TorVergata', C./. Columbus, Via della Pineta Sacchetti 506, Rome, Italy
OBJECTIVE: To show the workings of a new instrument designed to split the lens along the cross-shaped grooves during phacoemulsification. SETTING: University Eye Clinic of Rome 'Tor Vergata', C.I. Columbus, Via della Pineta Sacchetti 506 Rome, Italy. PATIENTS: Those in need of cataract surgery. RESULTS: The new forceps operates by exerting pressure on the wall of the nucleus grooves previously performed with the tip of the phacoemulsifier. CONCLUSIONS: The instrument provides an additional and safer step in avoiding the risks of using ultrasound near to the posterior lens capsule. Keywords: Cataract; Phacoemulsification; Forceps; Nucleus; Splitting
CONCLUSIONS
Capsulorhexis and phacoemulsification guarantee a better postoperative centration of Spiral IOL than the envelope technique does. Reduction of the diameter of the optics is therefore possible without losing safety. In this series the percentage of CME is lower after phaco than after planned ECCE but additional data are needed to demonstrate this statistically. REFERENCES 1 A Galand and M Delmelle. Preliminary reort on the rigid disc lens. J. Cataract Refract. Surg., 1986; 12' 394-397. 2 HV Gimbel. Capsulotomy method eases in-the-bag PCL. Ocular Surgery News, 1985; 1: 20. 3 T Neuhann. Theorie und Operationstechnik der Kapsulorhexis. Klin. Mbl. Augenheilk., 1987; 190: 542-545. 4 G Meur. Small incision disc lens. Eur. J. Implant Ref Surg., 1989; 1: 64-66. 5 G Meur, M Maenhaut. Un implant disque rigide pour petites incisions. Bull. Soc. Belge Ophthalmol., 1988; 229: 81-85. 6 G Meur. Cataract Surgery: New Techniques-Part I (letter). Highlights ofOphthalmology, 1992; 20:4-7. 7 A Gaskell and PS Baines. Comparison of flexible loop posterior chamber lens implant centration following intercapsular versus extracapsular cataract surgery. Implant and Refractive Surgery, 1988; 6: 3-4, 88-91. 8 SO Hansen, MR Tetz, KD Solomon, MD Borup, RN Brems, DJC O'Morchoe, 0 Bouhaddou, DJ Apple. Decentration of flexible loop posterior chamber intraocular lenses in a series of 222 postmortem eyes. Ophthalmology, 1988; 95: 344-349. Eur J Implant Ref Surg, Vol 5, September 1993
INTRODUCTION
Phacoemulsification has become one of the most popular procedures in the surgical treatment of cataract. According to· Gimbel ('divide and conquer') and Sheperd's modification, the technique consists of sculpturing the nucleus of the lens with the tip of the phacoemulsifier into two cross-shaped grooves of 90-95% in depth and then fracturing in four parts [1]. This technique permits a simple emulsification of the lens material by offering two major advantages: (1) it allows the surgeon to perform phacoemulsification of any type of cataract and in eyes with mild mydriasis; (2) it allows the surgeon to perform phacoemulsification further away from the cornea thus preventing any contact with the corneal endothelium. This technique requires experienced surgeons [2], since the cutting of deep and definite grooves is the first important step in splitting the lens nucleus into Correspondence to: Pietro Lischetti, Via A. Torlonia 12, 00161, Rome, Italy. The author has no financial interest in the instrument presented in the paper.
Short Reports
chafing can be made relatively late when permanent damage is already done. Our case is a good example of posterior iris chafing syndrome depicting the difficulty in management and relatively unfortunate clinical outcome with such problems as secondary glaucoma, bullous keratopathy and rhegmatogenous retinal detachment. IOLs that have a 10° angulation of the loops from the plane of the optic reduce, but do not eliminate, the incidence of this complication [6]. Thus, the only way to avoid posterior iris chafing syndrome is to prefer capsular bag fixation instead of ciliary sulcus fixation.
REFERENCES 1 NS Jaffe, MS Jaffe, GF Jaffe. Cataract Surgery and its Complications. St Louis: CV Mosby; 1990, p. 179. 2 TD Gwin, DJ Apple. A study of posterior chamber intraocular lens fixation and loop configuration: An analysis of 425 eyes obtained postmortem. Presented at the American Society of Cataract and Refractive Surgery Meeting, Los Angeles, March, 27, 1988. 3 SA Ostbaum. Biologic relationship between polymethylmethacrylate intraocular lenses and uveal tissue. J. Cataract Refract. Surg., 1992; 18: 219-231. 4 S Mashet. Pseudophakic posterior iris chafing syndrome. J. Cataract Refract. Surg., 1986; 12: 252-256. 5 JR Samples, EM Van Buskirk. Pigmentary glaucoma associated with posterior chamber intraocular lenses. Am. J. Ophthalmol., 1985; 100: 385-388. 6 DJ Apple, N Mamalis, RJ Olson, MC Kincaid. Intraocular lenses: Evolution, Designs, Complications and Pathology. Baltimore: Williams and Wilkins; 1989, p. 153. 7 D Miller, MG Doane. High-speed photographic evaluation of intraocular lens movements. Am. J . Ophthalmol., 1984; 97: 752-759.
Spiral Intraocular Lens, Rhexis and Phacoemulsification
AND PATIENTS: 286 phacoemulsifications and 1189 planned ECCE. Examination post-operation at 7 weeks: centration of the optic in full mydriasis and fluoresceinic angiography of the macula. SETTING: Institut Edith Cavell and Policlinique de Bruxelles (Brussels, Belgium). MEAN OUTCOME AND MEASURES: Comparison of decentration (mainly upward) and CME rate in the two series. RESULTS: The percentage of decentration was definitely lower in the phaco/rhexis series (P = 0.0000001). The rate of postoperative CME was lower in the phaco/rhexis series but the difference was not statistically significant. CONCLUSIONS: Capsulorhexis plus phacoemulsification guarantee a better postoperative centration of spiral IOL than envelope technique does. CME seems to be less frequent after phaco than after planned ECCE but additional data are needed to demonstrate this statistically. Phacoemulsification; Envelope Keywords: technique; IOL centration; Cystoid macular edema
INTRODUCTION When the 'envelope' technique [1] replaced that of the 'can opener' the improvement was evident-capsular bag implantation was safer and easier with better stability of the IOL. However the capsulorhexis proposed by Gimbel [2] and Neuhann [3] appears to be even better as far as IOL centration and stability are concerned. Since 1987 we have used an original IOL [4, 5] with a spiral blade-shaped haptic (Fig. 1), which has 1-'111---- 9 .75 mm - - - - . - l
G.MEURandM.MAENHAUT Department of Ophthalmology, lnstitut Edith Cavell, Brussels, Belgium
OBJECTIVE: To compare the results of capsulorhexis and phacoemulsification versus envelope technique and planned ECCE as far as IOL (spiral lens) centration and cystoid macular edema (CME) are concerned. STUDY DESIGN Correspondence to: G. Meur M.D., lnstitut Edith Cavell, Service d'Ophthalmologie, 1180 Bruxelles, Belgium. Paper read at the lOth European Intraocular Implant Council Congress in Paris, 8 September 1992. Eur J Implant Ref Surg, Vol 5, September 1993
60mm~ Fig. 1 Standard model of spiral lens with a 6 mm optic for planned ECCE
Short Reports
216 0 0
RESULTS
tO
c)
Neither series showed major decentration of the lens (sunset or sunrise syndrome) in non-dilated pupils. With fully dilated pupils, centration relative to the limbus [7] was perfect in 94% of the phaco series (Table 1). Decentration (6%) was always less than Table 1 Centration of modified spiral lens implanted after rhexis and phacoemulsification (198 cases). Maximal decentration: 0.98 mm Perfect centration: 187 (94%) Upward slight decentration: 8 (4%) Downward slight decentration: 3 (2%) Nasal decentration: 0 Temporal decentration: 0
Table 2 Centration of standard spiral lens implanted after planned ECCE and envelope technique (374 cases). Maximal decentration: 1.5 mm
9.750
Perfect centration: 266 (72%) Upward slight decentration: 76 (20%) Downward slight decentration: 19 (5%) Nasal slight decentration: 5 (1.4%) Temporal slight decentration: 6 (1.6%)
Fig. 2 Modified spiral IOL with a rectangular 6 mm x 4.5 mm optic Table 3 Upward decentration Rhexis/Phaco: 8/198 (4%) Envelope/ECCE: 76/374 (20%)
the advantages of a disc [1]-i.e. filling of the bag without a spring effect-but avoids its disadvantages: increased weight and the need for a large incision. At that time we started using planned ECCE and envelope technique. Recently, in view of the fact that small incision surgery is an improvement, we have modified our initial spiral-IOL design in order to meet the requirements of capsulorhexis and phacoemulsification. The blade-shaped haptic is now narrower and more flexible and the optic (Fig. 2) is rectangular (6 x 4.5 mm) [6]. This paper reports on a series of phacoemulsification operations and bag implantation with the modified spiral implants Morcher 45 S® and Storz-Coburn P375UV®.
Table 4 Angiographic CME Rhexis/Phaco: 5/178 (2.8%) Envelope/ECCE: 26/618 (4.2%)
1 mm. This is definitely better than in the planned ECCE series (Table 2). When comparing the upper decentrations, i.e. those most frequently observed, the rate is obviously lower in the rhexis/phaco series (Table 3). The statistical difference is highly significant: P == 0.0000001. The percentage of cystoid macular edema (CME) appears lower in the phaco series (Table 4), but the difference is not statistically significant: P == 0.35.
PATIENTS AND METHODS
DISCUSSION
In the period 1 April 1991 to 30 June 1992 we implanted 286 modified spiral lenses (rhexis/phaco). At 7 weeks, 198 patients were observed in full mydriasis and 178 underwent an angiography of the macula. These examinations were performed by a colleague who had not taken part in the surgery. This series was compared with a previous one of planned ECCE plus classical spiral lens (1189 IOLs implanted by the same surgeon from 1987 to 1990).
Factors contributing to IOL decentration are haptic design and surgical technique. Capsular bag fixation provides a better guarantee for centration than does sulcus fixation [8]. It is not clear which technique-can opener or envelope linear capsulotomy-is preferable in order to achieve a firm bag fixation [7]. Post-mortem observations [8] show that a certain amount of decentration with classical two loop IOLs is not uncommon with both procedures. Eur J Implant Ref Surg, Vol 5, September 1993
Short Reports
217
The most usual cause is the exit of a loop out of the bag. A pea-podding or capsular shrinkage appears to be a minor factor of intracapsular decentration. The haptic of the spiral lens has definite specificities. It is not a loop but an encircling blade, very rigid in the implant plane but not perpendicular to it. The technique of implantation [4] after envelope capsulotomy and planned ECCE guarantees a stable position of the haptic along the whole bag equator without any spring effect. Escape of the haptic out of the bag cannot occur. However a slight upward decentration may be seen in full dilatation in 20% of cases (Table 2). It is probably due to a pea-podding effect, exerted by the lower bag upon the whole implant and not counteracted by the upper floppy part of the bag. Capsulorhexis without rim tears ensures on the contrary a symmetrical capsular bag. Escape of the rigid encircling haptic out of the bag is impossible. Furthermore, no asymmetrical pea-podding effect can occur. Rhexis and phacoemulsification decrease dramatically the incidence of spiral IOL decentration. This goal is essential if multifocal or small and oval optics are to be successfully used.
New Instrument Developed to Assist Splitting of the Nucleus in Cataract Surgery During Phacoemulsification PIETRO LISCHETTI UniversityEyeC/inicofRome 'TorVergata', C./. Columbus, Via della Pineta Sacchetti 506, Rome, Italy
OBJECTIVE: To show the workings of a new instrument designed to split the lens along the cross-shaped grooves during phacoemulsification. SETTING: University Eye Clinic of Rome 'Tor Vergata', C.I. Columbus, Via della Pineta Sacchetti 506 Rome, Italy. PATIENTS: Those in need of cataract surgery. RESULTS: The new forceps operates by exerting pressure on the wall of the nucleus grooves previously performed with the tip of the phacoemulsifier. CONCLUSIONS: The instrument provides an additional and safer step in avoiding the risks of using ultrasound near to the posterior lens capsule. Keywords: Cataract; Phacoemulsification; Forceps; Nucleus; Splitting
CONCLUSIONS
Capsulorhexis and phacoemulsification guarantee a better postoperative centration of Spiral IOL than the envelope technique does. Reduction of the diameter of the optics is therefore possible without losing safety. In this series the percentage of CME is lower after phaco than after planned ECCE but additional data are needed to demonstrate this statistically. REFERENCES 1 A Galand and M Delmelle. Preliminary reort on the rigid disc lens. J. Cataract Refract. Surg., 1986; 12' 394-397. 2 HV Gimbel. Capsulotomy method eases in-the-bag PCL. Ocular Surgery News, 1985; 1: 20. 3 T Neuhann. Theorie und Operationstechnik der Kapsulorhexis. Klin. Mbl. Augenheilk., 1987; 190: 542-545. 4 G Meur. Small incision disc lens. Eur. J. Implant Ref Surg., 1989; 1: 64-66. 5 G Meur, M Maenhaut. Un implant disque rigide pour petites incisions. Bull. Soc. Belge Ophthalmol., 1988; 229: 81-85. 6 G Meur. Cataract Surgery: New Techniques-Part I (letter). Highlights ofOphthalmology, 1992; 20:4-7. 7 A Gaskell and PS Baines. Comparison of flexible loop posterior chamber lens implant centration following intercapsular versus extracapsular cataract surgery. Implant and Refractive Surgery, 1988; 6: 3-4, 88-91. 8 SO Hansen, MR Tetz, KD Solomon, MD Borup, RN Brems, DJC O'Morchoe, 0 Bouhaddou, DJ Apple. Decentration of flexible loop posterior chamber intraocular lenses in a series of 222 postmortem eyes. Ophthalmology, 1988; 95: 344-349. Eur J Implant Ref Surg, Vol 5, September 1993
INTRODUCTION
Phacoemulsification has become one of the most popular procedures in the surgical treatment of cataract. According to· Gimbel ('divide and conquer') and Sheperd's modification, the technique consists of sculpturing the nucleus of the lens with the tip of the phacoemulsifier into two cross-shaped grooves of 90-95% in depth and then fracturing in four parts [1]. This technique permits a simple emulsification of the lens material by offering two major advantages: (1) it allows the surgeon to perform phacoemulsification of any type of cataract and in eyes with mild mydriasis; (2) it allows the surgeon to perform phacoemulsification further away from the cornea thus preventing any contact with the corneal endothelium. This technique requires experienced surgeons [2], since the cutting of deep and definite grooves is the first important step in splitting the lens nucleus into Correspondence to: Pietro Lischetti, Via A. Torlonia 12, 00161, Rome, Italy. The author has no financial interest in the instrument presented in the paper.