Therefore, we conducted this study "Study the outcomes of scleral fixation of intraocular lens using intraocular endoscopy" to improve the accuracy of surgery, avoid complications, thus
Trang 1INTRODUCTION TO THESIS
1 INTRODUCTION
In patients with inadequate or absence of capsular support, theimplantation of IOL using scleral-fixated technique with the hapticplaced in sulcus, similarly to the natural anatomy of the lens, helpsrestore the physiological structure of the eyeball, thus resulting in goodanatomical and functional outcomes The use of intraocular endoscopyhelps easily approach peripheral structures of the posterior segment(ciliary sulcus,…) especially in difficult conditions such as small,irregularly shaped pupil This allows the surgeon to observe and performmore accurately, improve the quality of the surgery and provide better
outcomes to patient Therefore, we conducted this study "Study the outcomes of scleral fixation of intraocular lens using intraocular endoscopy" to improve the accuracy of surgery, avoid complications,
thus improving the outcomes of treatment, optimizing vision for patientswith the following objectives:
1 Describe clinical features of eyes without lens and posterior capsule.
2 Evaluate the outcomes of scleral-fixated intraocular lens implantation using intraocular endoscopy
3 Analysis of factors related to the outcomes of surgery.
- The scleral fixated technique of cover the suture inside the sclerahelps reduce the incidence of postoperative complication: suture erosion,with the use of the suture 10/0 poly propylene which is very common andcan be used at lower level hospitals
3 OUTLINE: The dissertation consists of 131 pages, including 4
chapters Introduction (2 pages); Chapter 2: Objectives and Methods (17pages), Chapter 3: Results (39 pages), Chapter 4: Discussion (32 pages),Conclusions and Recommended (3 pages)
- There are also references, annexes, tables, charts, picturesillustrating the results of the treatment
Trang 2CHAPTER 1 LITERATURE REVIEW
1 The use of intraocular endoscopy in ophthalmology
Intraocular endoscopy is used in ophthalmology for 2 reasons: first,this device allows surgeon to observe the posterior segment even whenthere’s an opaque in the visual axis which obscures the view as cornealscar, hyphema, small pupil, cataract or subcapsular cataract Second,intraocular endoscopy can help visualize intraocular structures that otherdevices fail to produce, such as behind the iris, sulcus, ciliary body, thepars plana and the peripheral retina
Indication of using intraocular endoscopy:
- Diseases which required intervention but in associated with otherdiseases that obstruct the observation with a non-contact microscope:+ Corneal edema, corneal opaque
+ Damages of cornea, ICE, hyphema
+ Eyes with previous surgery such as iris fixation IOL
+ Cataract, sub-capsular cataract induced by corticosteroid
+ Surgical abnormalities: gas in anterior chamber, subluxation IOL,subluxation lens
2 Scleral fixation of intraocular lens
In 2003, the American Society of Ophthalmology reviewed themethods of placing intraocular lens in patients without capsular supportand concludes that sclera fixation of intraocular lens is a safe andeffective method
* Choose the type of intraocular lens:
- The total intraocular lens diameter must be from 12.5 to 13mm
Trang 3- Optical diameter of the intraocular lens must be 6mm or wider
- Intraocular lens: The angle between the optical part and haptic part
is about 10 degrees, type of intraocular lens which are commonly used:Alcon CZ70BD (Alcon, Fort Worth, Texas), Bausch and Lomb 6190B(Bausch and Lomb, San Dimas, California)
* Calculate the power of the intraocular lens: Formula for intraocularlens power calculation
The constants used for the SRK formula relate to many factors such
as the location of the intraocular lens, the technique to be used, thechoice of the intraocular lens type This formula (P = A-2.5L-0.9K) has aknown A value for each type of intraocular lens so it is easy to use Whenintraocular lens is placed in the ciliary sulcus, the reduction of intraocularlens power to 0.5 D is recommended by the authors
* Suture using in sclera fixation of intraocular lens: The only fixedmaterial used is polypropylene material due to long time stability in theeyeball Depending on the technique selected each author uses the needlewith different shape like straight needles, curved needles but still thesame polypropylene material
* Sclera fixation of intraocular lens: Before sclera fixation ofintraocular lens, vitrectomy should be performed to prevent contraction,the vitreous should be cleaned around the region of ciliary sulcus wherethe needle will go through Sclera fixation of intraocular lens is carriedout through the following main steps:
+ Position selection for suture fixation: the position chosen depends
on the number of fixed positions needed, but often symmetric, and oftenavoid the meridian 3-9h due to the large ring of the cornea, easily lead tohemorrhage
+ Suture will be fixed at 0.75 to 1mm from the limbus
+ Tie the suture to the haptic of IOL, insert IOL into anteriorchamber
+ Suture the haptic into the sclera
* Suture knot burried methods used for sclera fixation of intraocularlens:
+ Leave the suture knot on the sclera surface
+ Cover the suture knot by artificial corneal flap
+ Cover the suture knot by the flap of Fascia lata or Dura mater + Cover by the scleral flap
+ Create the continuous suture knot, rotate the suture inside
Trang 4+ Create the grooves near the limbus, put the suture knot at 2 or 4position
+ Burried the suture knot in the sclera tunnel
+ Cover the suture knot by Z shape
* Needle passing technique:
+ Technique to place the needle passed from the internal to theexternal of the eyeballs: This technique less distorts the eyeballs, butbecause the passing area is obscured, therefore, the needle can to pierceinto the ciliary body, ciliary processes causing intraocular hemorrhage + External needle-passing needle technique was first described byLewis (1991) The advantage of this method is to accurately locate theposition for the needle to pass, so the ability to place accurately into theciliary sulcus is very high
* Techniques to tie the suture into the haptic of intraocular lens +Technique for tying a noose: is usually applied in cases where theintraocular lens without holes on the haptic, the surgeon usually usesuegical instrument to clamp the haptic of intraocular lens to be flattenedhead, the noose will not slip
+ Technique of putting the loop suture through the holes on the haptic
of the intraocular lens: The piercing method is only fixed through theholes on the haptic of intraocular lens to force the knot to be made onlyaccording to the twisting technique and to create a continuous noose loop
Picture 1.1 Technique of putting the loop suture through the holes
on the haptic of IOL
* Scleral-fixated of intraocular lens using intraocular endoscopyUsing intraocular endoscopy allows the surgeon to observe theunobserved areas behind the iris of the eyeball, especially the ciliarysulcus The endoscope allows the surgeon to know exactly the rightposition of intraocular lens and at the same time to control thecomplications that can occur during surgery such as bleeding,
Trang 5Picture 1.2 Suture goes through 30G needle and endoscopy inserted
into the eyeball
Picture 1.3 Steps of cover the knot into the scleral
* Complications of posterior chamber IOLs in aphakic patients.+ Cystoid macular edema
The study was conducted at the Trauma Department of Vietnam nationalinstitute of Ophthalmology from December 2010 to December 2015
2.1.1.Inclusion criteria:
Patients over 5 years of age with history of intracapsulcar cataractextraction, aphakia or damages to posterior capsular due to differentcauses, who undergone examination and treatment at the TraumaDepartment, have best visual acuity increasing with Snellen chart
2.1.2 Exclusion criteria: Patients with acute eye diseases such as
conjunctivitis, dacryocystitis, abnormal coagulation, phthisis bulbi,abnormal macular, optic disc atrophy, retinal detachment, heart disease,system diseases, diabetes
Trang 62.2 Research methods
2.2.1 Study design: This is a prospective study, clinical trial, vertical
follow up, no control group Patients were monitored from hospitaladmission, hospital discharge and 1 month, 3 months, 6 months, 1 yearafter discharged The data were collected according to the individual casestudy form
2.2.2 Sample size: The sample size is determined by the formula
From the formula we can calculate the sample size in the study: n =
92 eyes We selected 103 eyes of patients with eligible criteria forinclusion in the study, a follow-up period of at least 12 months
Ophthalmic examination:
* Functional exams: Vision acuity, best corrected vision acuity toprognosis postoperative visual acuity, using Snellen chart Measure IOPusing Maclakop tonometer
* Examination: cornea, iris, pupil, iris, tear, degeneration, iriscoloboma, anterior chamber Ophthalmoscopy to evaluate the posteriorsegment Functional tests
2.2.3.2 Surgical techniques in this research :
Insert a 23G trocar at pars plana, 3,5 mm from the limbus at themeridian of 8h30 in the right eye and at the meridian of 4h30 with theleft eye to keep the eye pressure stable during surgery Open conjunctival
at meridians 2h and 8h or 4h and 10h
+ Make a deep grooves of ½ thickness of sclera (using 15 degreeknife), usually perpendicular and 1 mm to the limbus, two symmetrically
180 degrees at the opening of the conjunctiva Cut the superior of thecornea with 3mm length into the anterior chamber, cut the remainingvitreous (if any), inject viscoat into anterior chamber to protect cornealendothelium
Trang 7+ Put 10/0 polypropylene through 30G needle, suture 10/0polypropylene is cut in the middle, threaded each end without the needle
of the thread cut into the 30G needle from the tip of the needle towardsthe head needle (drawing)
Picture 2.1 Put the polypropylene suture through the 30G needle
Using the endoscope to see the ciliary sulcus, the endoscope goes intothe eyeball through the corneal incision on the edge of the upper Thesurgeon moves the endoscope into the ciliary processes areacorresponding to the scleral groove, while the other hand inserted 10/0suture from the outside into the eyeball through the incision 1mm fromlimbus Observe under the intraocular endoscopy, the needle is insertedinto the eyeball, the surgeon can adjust the needle to insert accurately tothe right position Withdraw endoscopy from the eyeball, use hook topull the suture outward through the upper corneal incision, the surgeonrepeats the procedure to the opposite side
+ Tie the suture to IOL using continuous knot (Figure) Pull the strapsthrough the hole of IOL CZ70BD, draw up and round through the tip ofthe IOL, then pull the suture to fixed IOL, the straps will be tied stronglyinto the IOL
Picture 2.2 Suture loop fixed on the haptic
+ Corneal incision, insert IOL into posterior chamber Fixated IOLinto the scleral using continuous loop, cover the knot into the scleral.+ Close conjunctive Close corneal incision by 1 or 2 poly propylene10/0 suture
+ Note all details into surgical notes
2.2.4 Study Variables and Indicators
* Preoperative clinical manifestations: Age distribution, sex,
occupation, causes and time since the damages of posterior capsule, type,
Trang 8number of previous surgeries, Visual acuity without glasses and the bestcorrected vision acuity before surgery Characteristics of IOP, refraction
of patients before surgery Eye injuries before surgery: cornea, iris,vitreo, retina
*Study indicators relating to Outcomes
+Post – operative best corrected visual acuity (BCVA): The best
assessment of vision changes after surgery: Vision changes are evaluated
by increasing, decreasing, or unchange visual acuity compared to beforesurgery
Visual Acuity increased
• VA ≥ 20/200: increase at least one row in the Snellen chart
• VA from FC 1m to 20/200: vision increased from 20/400 or above
• VA <1m: Any increase in vision is considered as improvement Visual acuity: no change between before and after treatment
VA reduced:
• VA ≥ 20/200: reduce at least one row in Snellen chart
• VA <20/200: any reduction in vision
+ Intraocular lens
- Assessment of the status and position of the IOL, haptic of IOLthrough ultrasound biomicroscopy of anterior chamber angle assessmentmode at the meridians of fixated suture
- Assessment of IOL balance: Take the intersection between the twomeridians cut through the sclera position of 90 degrees and 180 degrees: a) IOL balance: If IOL center deviated from the intersection betweentwo meridians on the <1mm
b) IOL slightly deviated: If IOL center deviated from the intersectionbetween two meridians 1-2mm
c) IOL deviation medium: If IOL center deviated from the midpoint 2meridians 2 - 3 mm
d) IOL deviation severely: If IOL center deviated from theintersection between 2 meridians over 3 mm - Assessment of IOL tilt: Ifthe IOL tilted over the horizontal of the sclera over 3 degrees
- Assessment of factors affecting the balance of IOL after surgery + Evaluation of the position of the knot fixed IOL on the sclera:
- Good: the knot is only marked good when the head is only fullycovered in the groove of the sclera, conjunctiva covers the knotcompletely
Trang 9- Average: the knot is covered completely in the groove of the sclera,leaving the bridge of the suture loose in the conjunctiva
- Bad: The knot is completely located outside the groove of the sclera.+ Evaluate complications
- Intraopeartive complication: vitreal hemorrhage, choroidaldetachment, corneal incision open, hyphema, inflammation,endophthalmitis, increase IOP
- Late complications: Complications related to knot, uveitis,glaucoma
+ Evaluation of outcomes of surgery
- Good: IOP balance, no complications during and after surgery.Power is equal to or higher than the maximal preoperative best correctedvisual acuity
- Moderate: IOL balance or slight deviation, loose suture bridgesunder the conjunctiva, increased VA
- Failure: IOL deviation moderate or severe, suture erosion,complications during or after surgery VA does not increase or decrease.+ Evaluation of relating factors affecting the outcome of the surgery
- Factors related to visual acuity after surgery
- Factors related to postoperative anatomical outcomes
- Factors related to complications during and after surgery
2.3 Đata processing
Data processing: Data are collected and processed according tomedical statistical calculations, SPSS 16.0 software
2.4 Ethical in medical studies: Study of compliance with ethical norms
in the biomedical research of the Ministry of Health and approved by theethical board of ethics
CHAPTER 3 RESULTS 3.1 Clinical manifestations of preoperative patients with iol fixation 3.1.1 Demographic data
The study was conducted on 94 patients with 103 eyes We analyzethe general characteristics of the research team
3.1.1.1 Age group
Patients who is aphakia were mainly in working age, distributed fairlyequally in 3 age groups aged 15-30 years, 30-45 years old, 45-60 yearsold (23.4-27.7% with p> 0, 05) Children and the elderly who is aphakiaaccounted for a lower proportion (14.9% and 10.6%)
Trang 103.1.1.2 Gender
Of the 94 patients, the majority of the patients were male, accountingfor 79.8% (p <0.0001) The majority of patients lived in rural areas(85.1%), only 14 out of 94 patients lived in city
3.1.1.4 Occupation
Of the 94 patients, the majority of farmers and workers (62.8%), patientsare students and intellectuals account for a lower proportion (16-20.2%) Eyedisease The study was conducted on 94 patients, 103 eyes were aphakia, ofwhich 47.6% is right eye (49 eyes), left eye accounted for 52.4% (54 eyes)
no difference between right eye and left eye (p> 0.05)
3.1.1.5 Causes of posterior capsule and aphakia
The main cause of the damages to lens is trauma (80.6%), of which bluntocular trauma occurred in 35.9% and penetrating trauma was 44.7% Nextcommon causes are congenital abmornal of lens, accounting for 16.5%
3.1.1.6 Timing of posterior capsule and lens loss
Most of the eyes have time after posterior capsule and lens loss from1-3 months, accounting for 56.3% (p <0.01) The time between the lostand IOL implantation was varied, ranging from 1 to 240 months
3.1.1.7 Number of previous surgeries
The majority of eyes in the study were operated 1 time, accounted for86.4% (89 eyes), the remaining eye was operated 2 times or more, 2times 9.7% (10 eyes), over 3 times 3.9 % ( 4 eyes)
3.1.1.7 Previous surgery
The majority of eyes in the study had undergone vitrectomy andlensectomy (41.7%) 31/93 eyes undergone sclera-cornea suture,vitrectomy and lens extraction accounting for 30.1% The number of eyesundergone vitrectomy with gas or silicone oil tamponade due to retinaldetachment was 8/103 (7.8%) Other surgical procedures such asvitrectomy associated with lens extraction and foreign body removal intrauma eyes, vitrectomy in endophthalmitis + lesectomy with or withoutoil, oil removal account for a small proportion(6.8%)
3.1.2 Functional characteristics
3.1.2.1 Preoperative visual acuity
Prior to surgery, the majority of UCVA is 20/400 (82.5%) After bestcorrected, preop VA significantly improved, only 4,9% of eyes have poor
VA (less than 20/400), up to 47,6% of eyes have VA better than 20/200
Trang 11> 20/200 - 20/7020/60 - 20/30
Chart 3.1: Pre-operative VA 3.1.2.2 Preoperative astigmatism
Only 96/103 eyes were refracted before surgery so the preoperativeastigmatism was analyzed on 96 eyes
Average preoperative astigmatism: 1.13 ± 1.11 (min: 0; max: 6.25) Themajority of eyes had astigmatism below 1 Diop, accounting for 45.6%
3.1.2.3 Preoperative intraocular pressure
Most eyes have intraocular pressure within the normal range, with95.8% of eyes under 21mmHg (98 eyes) The mean preoperativeintraocular pressure is 17.6 ± 2.45 mmHg (min: 14 mmHg max: 32mmHg) Only 3 eyes have intraocular pressure> 25 mmHg (2.9%)
3.1.2.4 Preoperative anatomical features
The eyes in the study group were associated with cornea scar (52.3%);13.6% of the eyes with sclera stitched; iris trauma 59.2%, abnormalpupils 60.2% The number of eyes with different types of retinal lesionswas 36.9%
3.2 Surgical outcomes
3.2.1 Visual acuity
3.2.1.1 Uncorrected visual acuity
At the time of the new hospital, the number of eyes with un-correctedvision less than 20/400 accounted for 18/103 eyes (17.5%) After 1month of surgery, no eye has VA less than 20/400, while the number of
Trang 12eyes have good vision (>20/60) increase from 9,75 to 24,3% Thedifference was statistically significant with p <0.0001.
Chart 3.2 UCVA 1 month post-op
3.2.1.2 Best corrected visual acuity
Table 3.1 The best corrected visual accuity at different time point
Time point Pre -op Discharge 1month 3 months 6 months 12 months BCVA lượnSố
g
% lượnSốg
% lượnSốg
% lượnSốg
% lượnSốg
% lượnSốg
20/30 15 14,6 28 27,2 43 41,7 49 47,6 63 61,2 69 67,0
>=20/25 1 1,0 1 1,0 1 1,0 1 1,0 Total 103 100,
At the time of discharge, 28,2% of the eyes had BCVA better than20/60, 1 month after surgery the propotion increased to 41,7%,significantly higher This index continued to increase significantly in thethird month (48,6%) - p <0.005, then remained stable at the later time (6 months: 62.2%, 12 months : 68%), p <0.0001