Esculapio - Volume 10, Issue 02 , April - June. 2014

Original Article

PREVALENCE OF POSTERIOR CAPSULAR OPACIFICATION AFTER INTRAVITREAL DEXAMETHAS0NE AND SUBCONJUNCTIVAL MYDRICAINE INJECTIONS IN PAEDIATRIC CATARACT SURGERY

Khalid Waheed. mtu Mussawar Sarni and M. Tayyib

Objective: To determine the prevalence of posterior capsular opacification in congenital cataract surgery after intravitreal dexamethasone and subconjunctival mydricaine injections. Material & Methods: This prospective study was conducted in Eye unit 1, Services Hospital, S11\11S, Lahore from 21/7/2008 to 26/6/2013. During this period we evaluated 30 eyes in 30 children aged 4 months to 2 years with congenita l cataract with no other associated anterior or posterior segment pathology after intravitreal dexamethasone and subconjunctival mydricaine injection. A comprehensive detailed history, demographic data, surgical techniques and the prevalence of delayed post-operative co plication like posterior capsular opacification was noted. Results: The incidence of posterior ca sular opacification was observed in 64% of the congenital cataracts after surg ical int rvent ion w ith intravitreal dexamethasone and subconjunctival mydricaine injections. Conclusion: The present study revealed that use of intravitreal dexamethasone and subconjunctival mydricaine injections durin paediatric cataract surgery provides better surgical outcome in terms of clearer visual axis due to less inflammation and synechiael formation which decreases the incidence of posterior capsular opacification in these cases of congenital cataracts. Keywords: Congenital cataracts , amblyopia, posterior capsular opacification, dexametha­sone, blindness.

Introduction Congenital and developmental cataracts are the most common cause of treatable childhood blind­ness. The global incidence of this congenital disorder has been reported to be 1-15/10,000 li ·e births. ' Foster et ai2 reported that about 200,0(10 children are blind as a result of congenital cataract s. The lack of visual stimulus in these children during the early years of life can adversely affect overall development of the child with far reaching effects on self esteem, psychosocial and peer interactio 1 ,

educational, and occupational aspects.3 Restori r g the vision of one blind child from cataracts may be equivalent to restoring the sight of 10 elderly adul ts due to disability burden in terms of blind yea r. ' I t is o f utmost important to detect and diagnose con,,_ enital cataracts to prevent amblyopia and blind­ness .4 It has been noted that treatment cf congenital cataract is a challenge to op hthal­mologists, patien ts and parents in terms of visu ll development and rehabilitation in the developirg world. ' D uring the last few decades, the advance­ments and development in micro-surgical tech­niques in congenital cataract surg ery ha, e improved the safety and visual status of paediatr c

pa tients. ' Several studies have concluded that posterior capsular opacification is the major delayed complication of congenital cataract surgery which can lead to am blyopia and blindness. -Several techniques have been developed for prevent­ion o f posterior capsular opacification , such as posterior curvilinear capsulorhexis, anterior vitrect­omy, intraocular lens implantation with optic capture and lens in the bag technique,8 but still this major complication needs attention for the prevention of blindness. The objective of this study was to assess the incidence of posterior capsular opacification, after in tra-vitreal dexamethasone and subconjunct­ival mydricaine injections during congenital cataract surgery.

Material & Methods T his prosp ective study was conducted in Eye-unit 1, Services Hospital, Lahore affi liated to Services Institute o f Medical Science, Lahore from 21.7.2008 to 26.5.2013. A total of 30 patients with 30 eyes were completely evaluated before surgical intervention. 22 m ale and 8 female patients were included in this study. 1\.ge range was between 4 mon th s to 2 years. Informed consent was taken from the parents /

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guardians of patients included in this study. O cula trauma, congenital glaucoma, anterior segmen: dysgenesis, Lowe's syndrome, maternal rubelh syndrome, trisomy, optic nerve abnormalities an retinopathy of prematurity were not included i this study. Pre-operative assessment included a comprehensive history, including perinatal history, history of ocular and systemic disorders, anterior and posterior segment examination, retinoscopy, keratometry and ultrasonography to assess retinal status. Pediatric evaluation was done in Paediatric unit of Services Hospital, Lahore. Specific tests like blood complete examination, urine complete examination, chest x-ray, serology for virus, renal function tests, serum calcium, parathyro id hormone and other necessary tests were done accordingly. Before surgical intervention, fitness for general anaesthesia was taken. Dilation of the pupil was done by using cyclopentolate 1 % and phenylepherine 10% at 90, 60, 30 and 15 min tes preoperatively. Surgical procedures incl uded anterior capsulotomy / anterior continuous curvi­linear capsulorhexis, irrigation and aspiration of lens matter, posterior capsulotomy or posterior continuous curvilinear capsulorhexis, an terior vitrectomy, O. lc.c intravitreal dexamethasone and 0.05% mydricaine injections. All cases remained on topical steroids and cycloplegic eye drops for six weeks. Patients were followed on first pos t­operative day and first postoperative week for detection of early postoperative complications. Then patients were followed after three month s, six months and one year. In every visit patient were completely evaluated, including fund oscopy, cycloplegic retinoscopy and record of intraocular pressure.

Results A total of 30 patients with 30 eyes were completely evaluated before surgical intervention. Male were 22 and female were 8 (Fig-1).

73%

Fig-1: Male and female ratio.

• Female

Male

Age range was between 4 months & 2 years. Posterior capsular opacification occurred in 64%, as shown in Fig-2.

Other compl icatio

ns 7%

64%

Fig-2: Complications.

Discussion

None

Lt

In this study we assessed the effect of intravitreal dexamethsone on posterior capsular opacification in congenital cataract surgery. Th.is is the main late complication in congenital cataract surgery which can lead to poor visual prognosis due to amblyopia in children. The posterior capsular opacification occurs due to proli fera tion, migration, epithelial to mesen­chymal transition, collagen deposition and lens fiber regeneration of lens epithelial cells. Two main morphological types of posterior capsular opacification can be differentiated; fibrotic and regenerative or pearl. The fibrotic type is caused by the proliferation and migration of lens epithelial cells w hich undergo the epithelial to mesenchymal transition, resulting in the fibrous metaplasia and leading to ignificant visual loss by producing wrinkles and folds in posterior capsule. The pear type is caused by the lens epithelial cells located at the equatorial lens region. They induce regeneration of crystalline-expressing lenticular fibers that form Elschnig's pearls and Soemmerring ring. The histological features of posterior capsular opaci­fication are now well established, but to date the molecular mechanisms influencing the behaviour of residual lens epithelial cells after cataract surgery are not completely understood. Its incidence after cataract surgery is nearly 100% in infants even when posterior capsulorhexis has been performed without disruption o f anterior vitreous phase; opacification, caused by in growth of lens epithelial cells on the

6 vitreous surface, can be found months after surgery. In our study the posterior capsular opacification was noted in 19 (64 %) eyes. Its incidence is very less as

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compared to several other studies. 13

Our study was similar to Muzaffer et al

14 who had noted posterirn

capsular opacification in 51.72% of cases in tbe first 90 days of follow-up. This may be due to anterior vitrectomy which removed the scaffo ld fc r lens epithelial cell migration & intravitreal injection of dexamethasone which inhibits inflammatory process and subconjunctival m ydricaine injectio which keeps the pupil dilated & prevents synechial formation. Our results were also similar ro Hosal and Biglan

15 who have shown decreased risk o f

posterior capsular opacification after p o sterio r capsulorhexis and anteriorvitrectomy.

poor visual outcome.

Conclusion The present study revealed that the use of dexamethasone and subconjunctival mydricaine injections during cataract surgery provides better surgical results which can help in prevention of amblyopia to some extent. Visual outcome can further be improved by parent's guidance and motivation postoperatively.

However, our study is in contrast to Mazar et al in which rate of posterior capsular opacificauon is only 34%.

1' The rate of different ocular compli­

cations in paediatric eyes is almost very high due to excessive fibrosis, in spite of m dern surgical techniques which can be responsible fo r

Further studies with a larger pedriatric patients group are necessary to confirm the optimal treatment of congenital cataract surgery.

Department of Ophthalmology SIMS/ Services Hospital Lahore

www.esculapio.pk

References

1. Rahi JS, Dezateux C. ational cross section study of detection of congenital and infantile cataract in United Kingdom: Role of childhood screening and surveillance. The British Cong­enital Cataract Interest Group. BMJ 1999;318:-362-5

2. Foster A, Gilbert C, Rahi J. E pidemiology of cataract in childhood: a global prespective. J. Cataract Refract Surg 1997:23 Suppl 1 ;601-4.

3. Wilson ME, Pandey SK, Thakuu J. Paediatric cataract blindness in the developing world: Surgical technique and intraocular lens in new millennium. Br J Ophthal­mol 2003;87:14 -9.

4. Lambort SP. Management of monocular congenital cataract Eye.1999:13:474-79.

5. Angra,Mohan SK. Management of Rubella cataract .Ind J Ophth­almol 1982;302: 13-16.

6. Kuk-Hyoe Kim,Kyeon Ahn,Eui Sang Chung, Tae-Young Chung. Clinical outcome of surgical techniques in congenital cat-

aracts. K rean J Ophthalmol 2008;22(2) 87-91 .

7. Jacobson ~G, Ma hindra Held R. DeYelopmc nt of ,~isual acuity in infants wit 1 congenital cataract Br J O phtholmol 1981 :65:727:35.

8. Gouwas P, Hussain HM, Markh­ans RH. Long term results of primary po ,terior chamber intra ocula r lens implantation for congenital l ataract surgery in the firs t \'ear of life. Br J Ophtholmol 2006: 90-97 )-8.

9. Chen TC, BCJ.atti LS, H alpern EF. Risk factor~ for the development of aphakic glaucoma after cong­enital cataract surger y, Tran s Ophthalmc,I Soc;2006; 104:241-51.

10. Rabia h P <.. Frequency and predictors of glaucoma after pediatric cataract surgery. Am J Ophthalmo. 2004;137;30-7.

11. z ,,.;aan J. Pediatric intraocular lens implantation. surgical results and complicatio,s in more than 300 patients, Ophthalmol 1998;105; 112-9.

12. Vishwanath M, Cheong-Leen R,

72

Taylor D. Is early surgery for congenital cataract a risk factor for glaucoma? Br J Ophtholmol 2004:88-905-10.

13. Hosal Biglan AW Risk factor for secondary membrane formation after removal of paediatric cataract. J Cataract Refract Surg 2002:28:302-9.

14.Iqbal M ,Jan S, Khan NM, Iqbal A, Mohammed S. Pediatrics intra ocular lens implantation compli­cations and visual outcome. Pak J Med Res 2004; 4(3):

15.Hasan MU, Umair A. Qidwai UA, Rehman AU, Bhatti N, Alvi RH. Complications & visual outcome after Pediatric cataract surgery with or without intra-ocular lens implantation. Pak J Ophthalmol 2011; 27(1):30-34.