PHACOEMULSIFICATION IN PSEUDOEXFOLIATION CATARACTS. Dr.P.MOHAN

Transcription

1 PHACOEMULSIFICATION IN PSEUDOEXFOLIATION CATARACTS Dr.P.MOHAN

2 INDEX 1. Abstract 3 2 Introduction Material and Methods Results Illustrations/Tables Analysis & Discussion Summary & Conclusions Bibliography Undertaking 21 2

3 Abstract Aim: To study outcome of Phacoemulsification in Pseudoexfoliation cataracts. Design: Prospective Clinical Study at Vasan Eye care Hospital, Bangalore. Material and Methods: Study included 50 patients with PXF cataracts. All patients underwent phacoemusification with foldable IOL implantation under topical anaesthesia by single surgeon. Intraoperative and post operative complications were analysed. Results: Majority of patients were in the age group of yrs with Grade 3+ sclerosis. Pupillary diameter less than 5 mm was seen in 24 cases. Intraoperatively, 1 case had post capsular rent and 1 case had zonular dialysis and both the case underwent PCIOL implantation. Transient corneal oedema was seen in 7 cases and 1 case had fibrin membrane. Capsular contracture was seen in 2 cases and 2 cases had PCO. Visual acuity of 6/6-6/12 was seen in 94% of cases. Conclusion: Cataract surgery in PXF cataracts though challenging due to weak zonules, poor mydriasis and compromised endothelium, good results can be obtained by Phaco. Meticulous planning, clear intra operative strategy, proper IOL selection, liberal use of viscoelastic and post op follow up are mandatory irrespective of the technique used. 3

4 INTRODUCTION Pseudoexfoliation (PXF) cataract forms a part of pseudoexfoliation syndrome (PXS). PXS is characterized by deposition of fibrillar material through out the anterior segment. The dust like material is best seen on the anterior surface of the crystalline lens. PXF material is also seen on schwalbe s line, endothelium and trabecular meshwork. There is a wide range of zonulopathy in cataract patients with pseudoexfoliation, ranging from seemingly normal zonular tension to frank phacodonesis(5). PXS is often associated with cataract and glaucoma. Cataract surgery in these cases are challenging due to rigid & poorly dilating pupil, weak zonules, increase tendency for subluxation, peripheral irido-capsular adhesions, PCR/Zonular dialysis and postoperative FM formation. These cataracts are associated with higher rate of intra operative and post operative complications like intraocular pressure (IOP) spike, corneal edema, iritis, pigment dispersion, cystoid macular edema, posterior capsular opacification (PCO), anterior capsular fibrosis, and subluxation or dislocation of the IOL capsular bag complex compared to cataracts without PXF(2). Various techniques of cataract extraction like extra capsular extraction, SICS and phaco can be done in cases of PXF. Today a lot of emphasis is laid on early visual rehabilitation. In this regard the phacoemusification stands well above the other techniques. Microphaco is another technique where surgery is done through smaller incisions than routine co axial phaco (under 1.5 mm). Surgeons have tried Microphaco in these cases as well (7). Inspite of advancement in techniques, phacoemulsification is still associated with 4

5 complications. Though this technique is routinely employed there is basic concern about safety of this procedure in the eyes with compromised endothelium, weak zonules, tendency for glaucoma after surgery and surgical difficulties. The prevalence of PXF world-wide ranges from 0.5% in those aged <60 years to 15% in those aged 60 years. The prevalence of PXF based on hospital reports from India varies between 1.87% and 13.5%. Population-based studies from south India has reported the prevalence of PXF to be between 3.8% and 6.0% among persons aged 40 years (13). As more and more patients are living longer and many of us will come across more and more of PXF cases. Hence we took up this study to know the outcome of PHACO in PXF cases. Pseudoexfoliation cases 5

6 MATERIALS AND METHODS This was a prospective study done in Vasan eye care Hospital, Bangalore. The study included 50 patients who had cataract complicated by psuedoexfoliation. After taking informed consent, the patients were enrolled in the study. A thorough preoperative examination was done. The visual acuity, IOP, slit lamp assessment of endothelium, extent of PXF, pupillary dilatation and any phacodonesis were noted down. Cases with subluxation were excluded. Patients were advised to use topical gatifloxacin 0.3% drops qid one day prior to surgery. The pupils were dilated using tropicamide plus and cyclopentolate eye drops. Paracain (proparacaine hydrochloride 0.5%) eye drops were used 2-3 times at 5 minutes interval before surgery. Temporal clear corneal incision made using 2.8mm bevel up keratome. Intra cameral lignocaine HC 1% (Oculan) was used in cases where pupil size was less than 5 mm. Capsulorhexis (CCC) was done using 26g bent needle through paracentesis. Viscoelastics used in all cases was HPMC (Hydroxy Propyl Methyl Cellulose 2%). Careful hydro dissection was done without putting any stress on zonules. Phacoemulsification was done by direct chop or by stop and chop technique using Stellaris Phacomachine (Bausch and Lomb). In very hard cataract burst mode was used. In all cases cracking was initiated in mid-peripheral nucleus. In hard leathery cataracts stepped chopping with lateral separation 6

7 was done to avoid stress on zonules. After nucleus removal cortex was removed gently using bi-manual I&A probe. Acrylic foldable IOL was implanted. Intra operative difficulties were noted. Patients received routine post op medications like any other cataract surgery (prednisolone acetate 1%-tapering dosage, NSAID drops for 1 month). Patients were followed up on 1 st POD, 1 st week, 3 wks and 3months.During these visits anterior segment was examined along with vision and IOP. Post operative complications were noted down and compiled. Phacoemulsification in progress grade 4 NS and in small pupil case Phaco parameters used for chopping and quadrant removal Gr-1 Nucleus Gr-2 Nucleus Gr-3 Nucleus Gr-4 Nuleus Power Duty cycle Pulse/sec During phaco, the vacuum of mm of Hg was used in all cases. For I&A the vacuum was 400 mm of Hg. 7

8 RESULTS: In our study, majority of the patients were in the age group of years with male preponderance. We had patients ranging from 41to 95yrs. Average pre op IOP recorded was 17 mm of Hg with applanation with the range of mm of Hg. Pupillary diameter after maximum dilatation was less than 5mm in 24 cases. Majority of case had Grade 3+ Nucleus. Out of 50 patients, 15 cases had mature cataract and 13 cases had Grade 4+ sclerosis. During surgery one case had PCR during emulsification of the last fragment and 1 case had zonular dialysis during cortex removal. In both these cases, foldable PCIOL was implanted. In the case with PCR, 3 piece hydrophobic foldable IOL was implanted in the sulcus after performing automated vitrectomy. In the case with zonular dialysis, CTR was implanted and single piece hydrophobic foldable IOL was implanted. The incidence of complications was 4%. Postoperatively transient corneal edema was seen in 7 cases (14%) which resolved in 2-3 days. Most of these cases had Gr-4+ nucleus. Four cases (8%) had transient IOP spike which responded well for topical antiglaucoma medications. Majority of patients had grade I to II anterior chamber reaction on 1 st post operative day. Two patients had grade III reaction and one patient (2%) had fibrin membrane which responded well to frequent topical steroid and cycloplegic drops. One week post operative visual acuity (UCVA) of 6/6-6/12 was seen in 47 (94%) cases, 2 cases had 8

9 6/18 (of which, 1 case had advanced glaucoma and other case had NPDR). Only one case had poor vision of 6/24 which was due myopic chorioretinal degeneration. In our study, 2 patients developed capsular contracture which was seen around 3 months, which required Nd-YAG relaxing cuts. 2 cases had posterior capsular opacification which was treated with Nd-YAG capsulotomy. Post- Op Capsular Contracture 9

10 TYPE OF CATARACT No of Pts PSC NS-II NS-III NS-IV PUPILLARY DIAMETER <4mm 4-5mm 5-6mm >6mm No of Pts 10

11 Intraoperative difficulties and post op complications Complications No. Of pts (%) Pupillary diameter < 5mm 24 (48%) PCR 01 (2%) Zonular dialysis 01 (2%) Transient corneal oedema 07 (14%) Fibrin Membrane 01 (2%) Transient IOP spike 04 (8%) Capsular contracture 02 (4%) PCO 02 (4%) AC Reaction on 1 st POD No of Pts 5 0 Gr-I Gr-II Gr-III FM

12 Visual Acuity (post-op) /6-6/12 6/12-6/18 6/18-6//24 No of Pts 12

13 ANALYSIS & DISCUSSION: Cataract surgery in PXF cases is challenging because of the higher incidence of complications due to rigid and poorly dilating pupil, weak zonules, increased tendency for subluxation, PCR, zonular dialysis and post operative fibrin membrane formation. Patients with poor pupillary dilatation and obvious white accumulation on pupillary margin tend to have more advanced zonular weakness. Shallow chamber with normal axial length and asymmetry in AC depth is also the warning sign for zonular weakness (5). Phacoemulsification is effective method in tackling cataracts with early and good visual recovery. Our study showed that phacoemusification can also be done in PXF cases with minimal complications. Even though most of the PXF cataracts can be done with topical anesthesia it is better to do under peribulbar anaesthesia especially in cases with small pupil, weak zonules and hard cataracts(2). This will also help in converting the case to SICS which one should not hesitate to do so. In our study, we did our surgery on topical anaesthesia only but used Oculan (intracameral) in cases with very small pupils In cases where pupil does not dilate, a visco-adaptive ophthalmic viscosurgical device such as Healon 5(Advanced Medical Optics, Inc., Santa Ana,CA) can be used to create viscomydriasis.(2,11). Small pupil cases can also be managed by many other ways like stretch pupilloplasty (5), using iris hooks and rings - Malyugin ring (Microsurgical Technology, Redmond, 13

14 Washington (2, 10). In our study we used HPMC 2% for visco mydriasis and we avoided dilating the pupil on the previous day of surgery. Probably the use of cyclopentolate drops prevented the fluttering of pupil and this prevented pupillary miosis during surgery. Corneal endothelium is already compromised in these cases hence liberal use of viscoelastics is needed to decrease the damage to it. Studies have shown that change in endothelial density after surgery in PXF cases is similar to other cataracts (12). Still one should protect endothelium with viscoelastics and to use lower phaco power whenever possible. One should aim for mm of capsulorhexis (3, 10) and adequate care should be taken to reduce stress on zonules. One should not hesitate in using tryphan blue for capsular staining in cases with poor red glow. Wrinkling of capsule during CCC indicates weak zonules (3) and it is better to put CTR in these cases (5). We used sharp bent needle as this prevented stress on zonules. Hence we had to use CTR ring in only one case. This patient already had significant phacodonesis prior to surgery. Capsular contracture can occur postoperatively especially when CCC is small. This issue can be tackled by enlarging CCC after implanting the IOL or by making few relaxing cuts (5). Intra-operative vaccuming of undersurface of anterior capsule will also reduce capsular fibrosis (11). Capsular polishing was strictly followed in our study which reduced the incidence of posterior capsular opacification and capsular fibrosis to 8%. Gentle hydro-dissection has to be done in multiple quadrants (2) and forceful decompression should be avoided. Complete nucleus rotation has to 14

15 be done carefully and bimanual rotation will be better as it reduces the stress on the zonules. Free rotation minimises the stress on the zonules during phacoemulsification. Visco-dissection can also aid in cortico-capsular cleavage (10), facilitate CTR insertion if it is required before the emulsification of nucleus and subsequent removal of epinucleus and cortex will be easier. Mid peripheral chops and emulsification in central pupillary area (10) using low flow and low vacuum technique is recommended (1, 2) to reduce stress on zonules. Anterior chamber depth has to be maintained throughout surgery without sudden shallowing or deepening (10). Central chopping using Sinsky s hook was our preferred technique. The incidence of PCR (1 case) and zonular dialysis (1 case) was thereby reduced in our study. Cortex removal is a crucial step and care should be taken to avoid stress on zonules. Tangential stripping and aspiration of cortex reduces the stress on zonules (10). Bimanual irrigation and aspiration technique is useful in these cases. In cases with weak and lax zonules, cortex can also be removed after IOL implantation. Capsule and iris retractors, CTR, modified CTR, Capsular tension segments are useful adjuncts which can be used when encountered with weak zonular apparatus(2).some surgeons have recommended routine CTR to reduce or delay the post op complications and it may also facilitate scleral fixation of IOL or capsular bag if subluxation occurs. 15

16 CTR can be inserted at any stage of surgery - before nucleus removal or after emptying the capsular bag. The main advantages of CTR in zonular weakness cases are - it keeps bag expanded throughout the surgery and helps to redistribute the pressure around the fornix. The early implantation that is after hydro-dissection prevents damage to the bag during phaco and aids in easy removal of cortex. If the Capsular bag is stable with or without capsular stabilising device Acrylic hydrophobic foldable IOL in the bag is preferred as anterior capsular opacification is less with these IOLs. In the absence capsular bag or unstable bag, scleral fixated IOL and ACIOL can be considered. Accommodating IOLs and plate haptic IOLs have to be avoided as there is increased risk of capsular contracture syndrome. Post op complications: Some patients can have IOP spike in immediate post op period more so in pre-existing glaucoma (10). In such cases topical antiglaucoma medications can be used for few days. Systemic carbonic anhydrase inhibitor can also be used. Anterior capsular contracture and PCO are more common in PXF cases (10) and can occur relatively quickly after surgery. Capsular phimosis is high risk factor for decentration and IOL tilt. If detected it has to be treated at early stage itself by performing 3-4 Nd YAG laser relaxing ant capsulotomy (cuts) and this reduces the chance of progression of capsular phimosis, IOL decentration, tilt and spontaneous IOL subluxation. Significant Post Capsular opacification has to be treated with Nd-YAG capsulotomy. 16

17 SUMMARY & CONCLUSIONS - 50 Cases with PXF cataracts underwent Phacoemulsification with foldable IOL implantation. - Majority of Pts were in the age group of yrs with male preponderance. - Poor mydriasis less than 5mm was seen in 24 cases (48%). - Majority of patients had Grade III Nucleus - 21 cases. Mature cataracts was seen in 15cases - Intra-operative complications: 1 case of PCR and 1 case had zonular dialysis. - AC reaction on first post-op day - Most of them Grade -1 to 2 reaction - 47 cases and 1 case had fibrin membrane - Transient Corneal edema and IOP spike was seen in 7 and 4 cases respectively - One week Post op visual acuity 94% had 6/6-6/12 - At 3 months post op - 2 cases had capsular contracture and 2 cases had post capsular opacification 17

18 Conclusion: Cataract surgery in PXF cataracts though challenging due to weak zonules, poor mydriasis and compromised endothelium, good results can be obtained with proper preoperative workup, clear intra operative strategy, proper IOL selection, liberal use of viscoelastics and post op followup. Today we have a wider options like SICS, phaco, microphaco to tackle these cataracts without compromising the outcome. Irrespective of the method used, inherent difficulties faced by surgeons are due to complications associated with psuedoexfoliation. So while operating one should obtain maximal dilatation of pupil either pharmacologically or by using intraoperative dilating techniques. The capsule can be stablised by CTR and adequate CCC should be obtained. Hydro-dissection should be gentle to prevent stress on zonules. Chopping especially centrally is preferred. Avoid chopping from periphery as this can lead to zonular dialysis. Thorough cortical cleaning and placing acrylic hydrophobic IOL (preferred IOL) in the bag is absolutely needed. These surgical steps will prevent many disasters on the table. It is also absolutely needed to follow up these patients as they are very prone to develop capsular contracture with IOL displacement and may develop glaucoma. By following these principles, we found that phacoemulsification was an effective method in tackling cataract with pseudoexfoliation with very minimal complications. 18

19 BIBLIOGRAPHY: 1. Alan S Crandall - Weak zonules - How to prepare for this challenging surgery. October 2009, I, Cataract & Refractive Surgery Today. 2. Arup Chakrabarti - Strategies for Pseudoexfoliation and Weak zonules. Kerala Journal of Ophthalmology. Volume XXIV, No 2, June Bradford J. Shingleton - Focus on eyes with zonular weakness: Preventing complications in eyes with pseudoexfoliation. Cataract and Refractive Surgery - June Freyler H, Radax U et al Klin Monatsbl Augenheilkd_- Pseudoexfoliation syndrome - a risk factor in modern cataract surgery? 1994 Nov; 205(5): Jean Shaw, Clinical Update: Cataract - Pseudoexfoliation: Six Strategies for Success. Eyenet Magazine, aao.org/publications/eyenet/200703/cataract.cfm 6. Merkur A.Damje et al - Intraocular pressure decrease after phacoemulsification in patients with pseudoexfoliation syndrome. J Cataract Refract Surg Apr; 27(4): Mohan.P, Mamatha S.R, Tiruvengada Krishnan - Changing Trends in Cataract Surgical Techniques In PXF (Pseudo-Exfoliation) Cataracts. AIOC 2010 PROCEEDINGS. 8. Outcomes of phacoemulsification in patients with and without pseudoexfoliation syndrome. J Cataract Refract Surg Apr; 30(4):733; author reply Shastri L, Vasavada A. - Phacoemulsification in Indian eyes with pseudoexfoliation syndrome, Journal of Cataract Refract Surg. 2001Oct; 27(10):

20 10. Shingleton BJ, Crandall, Ahmed IK -Pseudoexfoliation and the cataract surgeon: preoperative, intra-operative, and postoperative issues related to intraocular pressure, cataract, and intraocular lenses-j Cataract Refract Surg Jun; 35(6): Suresh K. Pandey MS et al Phacoemulsification in Pseudoexfoliation syndrome. DOS Times - Vol 14.No 5, November Wirbelauer C, Anders N, Pham DT, Wollensak J - Corneal endothelial cell changes in pseudoexfoliation syndrome after cataract surgery. Arch Ophthalmol 1998; 116: Ravi Thomas, Praveen Kumar Nirmalan and Sannapaneni Krishnaiah - Pseudoexfoliation in Southern India: The Andhra Pradesh Eye Disease Study Investigative ophthalmology and visual sciences, (4);

21 UNDERTAKING Certified that the study Phacoemulsification in pseudoexfoliation cataracts is the original work undertaken by me in Vasan Eye Care Hospital, Koramangala Branch, Bangalore. I also certify that the work once accepted will hold the copyright for the Boolean Education ( USAIM ) and that the study will not be submitted to any other journal for publication. Dr.P.Mohan Chief Medical Officer Vasan Eye Care Hospital Koramanagala Branch Bangalore Karnataka, India. 21