The visual outcome after implantation of the Multifocal Intra Ocular Lens. Dr.Bhargav Dave National Institute of Ophthalmology Pune

Transcription

1 The visual outcome after implantation of the Multifocal Intra Ocular Lens Dr.Bhargav Dave National Institute of Ophthalmology Pune 1

2 The era of cataract surgery has come leaps and bounds since the inception of the first IOL by Sir Harold Ridley. For years we the cataract surgery is being performed with IOL implantation and the need to improvise the IOL has always been motivating the researchers to bring new concepts and new design of IOL The traditional IOL which has been used all these years had a major drawback and that was the fact that it necessitated the use of spectacles for the near vision, as accommodation was lost,though it provided good distance vision. Cataract surgery has become a refractive procedure in true sense. The goal of cataract surgery is not only to have good mono vision but to have a good vision for near, intermediate and distance just like a 20 year old person. Now this can be achieved by multifocal IOLs. To assess the visual out come of the multifocal intraocular lens we conducted this retrospective study of 25 eyes at National institute of Ophthalmology, Pune. All the patients chose the multifocal IOL themselves after discussion with the counsellor regarding various types of IOLs, Pros and cons of mono vs multifocals etc. NO assurance was made regarding post operative freedom from glasses. Possible difficulty in night driving was also informed. All the patients included were of age between 47 and 82 yr (mean age 57.7 SD 7.9). 57% of the patients were male and 43% patients were females. The inclusion criteria were patients with senile or presenile cataract, patients willing to get multifocal lens implanted. The 2

3 eyes with gross corneal pathology, secondary cataract, congenital cataract, traumatic cataract, uvietis secondary glaucoma were excluded. The IOL power calculation was done with Manual Bausch and Lomb type of Keratometer and A scan was done using water immersion technique. The patients were examined on the 1 st post operative day, 7 th post operative day and after 1 month of surgery. Each visit included of examination of distance visual acuity with the help of Snellen s chart and near vision testing with Snellen s near vision chart, measurement of intraocular pressure and refraction. At the end of 1month about 40% patients had monocular distance visual acuity 6/9 or more. About 48% patients had distance visual acuity between 6/9 and 6/12 only 3% patients had distance visual acuity of 6/18 or less. About 88% of the patients had near visual acuity between n6 and n10 and 12% patients had near visual acuity between n10 and n18. Almost all patients were independent of glasses during their day to day activities.3 patients experienced glare and halos. One patient was severely affected by the glare and even discussed the possibility of IOL exchange.3 months later PCO was noted in the same patient and after YAG capsulotomy his glare reduced to a great extent.fundus examination central and peripheral was not a problem in any of the patients 2 more patients developed early PCO within 3 months of follow up period. 3

4 Review of literature The traditional IOL which has been used all these years had a major drawback and that was the fact that it necessitated the use of spectacles for the near vision, as accommodation was lost,though it provided good distance vision. Cataract surgery has become a refractive procedure in true sense.the goal of cataract surgery is not only to have good mono vision but to have a good vision for near, intermediate and distance just like a 20 year old person. Now this can be achieved by multifocal IOLs. The loss of accommodative ability following the cataract surgery has been overcome to an extent by development of the multifocal IOL s. The different types of multifocal IOLs are 1.Diffractive type 2.Refractive type Refractive lenses are of three major types: 1) Two zone / target or center surrounds IOL 2) Three zone or Annulus IOL 3) Five zone spherical curve IOL DIFFRACTIVE IOLS: They are real mutifocal lenses. In these lenses there is conventional refractive surface at the anterior surface of the lens. There are concentric rings on the posterior surface. In these concentric rings the near distance and long distance rings are put alternatively. These lenses are gaining wide acceptance these days mainly because of less pupil dependency and even distribution of near and distance 4

5 vision. They are more difficult to manufacture. These lenses have approximately 25 concentric annular zones 0n the posterior surface. Even if the lens is decentered it still gives good results Certain studies show good results with the diffractive IOLs. 1) A study conducted by Cionni 1 et all concluded that the unilateral implantation of a multifocal IOL provided patients with high levels of spectacle freedom and good visual acuity without compromising contrast sensitivity, overall clinical results favored bilateral implantation. 2) In a prospective study done be Alfonso 2 et al it was concluded that diffractive IOL (Acri, LISA336 D) provided satisfactory full range of vision,high level of uncorrected and corrected distance,intermediate and near visual acuity. 3)Another study be Alio et al 3 says that The diffractive multifocal (Acri.Lisa 366D) IOL gave good efficacy, predictability, and safety and excellent visual acuity at distance and near. 4)In another study Kaushik 4 et al found that the Multifocal IOLs are a good option for those with nonexacting visual requirements. The loss in contrast sensitivity seems to be an acceptable trade-off for satisfactory unaided near vision 5

6 Materials and methods: 25 patients were selected on the following criteria Inclusion criteria: 1. Pateints between age group of 45 to 80 years. 2. Pateints from either sex were included in this study. Exclusion criteria: 1. Patients with Corneal pathology 2. One eyed patients 3. Patient with secondary cataract 4. Patients with advance glaucomatous changes 5. Patients with uvietis 6. Patients with history of ocular trauma 7. Patients with advance retinal pathology Pre operative examination: Prior to surgery complete ocular examination with detailed history was done. Thorough physical check up, presurgical blood investigations including Hemogram, Blood sugar levels, Blood urea levels, Urine examination, Elisa test for HIV were done. Physician s fitness for surgery was taken for all the patients. Patients were informed well about both the monofocal and multifocal IOLs and patients willingly chose to get multifocal IOLs implanted. 6

7 Possible disadvantages like colored halos etc were explained to patients. Patients were also informed about the implantation of the monofocal lens if required. The IOL measurement was done with help of Keratometer and A scan. The keratometer used was of Bausch and Lomb type. The Biometry was done using water immersion mode using SRK II formula. Informed written consent was taken from the patients explaining the possible risk factor of the surgery. The steps of surgery: 1. The informed written consent was taken 2. All the patients were operated by Phacoemulsification 3. All the surgeries were done under topical anesthesia. The surgeries were done by to surgeons with an experience of more than 5 years. 4. The foldable Multifocal IOL was placed in the bag for all the patients 5. All the patients were given topical steroids and antibiotics post operatively for 2 months. Post Operative examination: The post operative complications included High IOP(4 Patients), Significant Corneal edema (4 patients),iris injury(1 patient),iritis (2 Patients). All the patient were discharged on the same day of the surgery(evening).all the patients were asked to follow up next day i.e. first post operative day, then on 7 th post operative day and after 1 month of the surgery. 7

8 Observations: The mean age of 14 men and 9 women was 59 yrs. The mean IOL power was. There were a few complications in all the surgery. Two patients had Iritis on first post operative day of cell more than +++.one patient had iris injury at the time phacoemulsification.4 patients had raised intraocular pressure on first post operative day. Out of these 4 patient one patient had consistnantly high intraoclular pressure which could be due to topical steroids and was put on topical antiglaucoma therapy for a short period. After surgery all the pupils were round and showed good responsiveness to light. In all the cases the IOL were well centered and were not tilted. The mean monocular distance corrected visual acuitywas 6/9 on snellen s distance visual acuity chart.the mean correction of sphere was +/ The mean correction of the cylinder was +/

9 Study Performa ID code: Date: / / Name of patient: Age: Sex: M / F 1.Clinical History: a. Known Diabetes: Yes / No, If yes, duration of diabetes: b. Known H/T: Yes / No, If yes, duration of H/T: c. Previous history of ophthalmic surgery: Yes / No, if yes Specify: 2.Ocular Examination (Pre-operative): RE a. Cataract grading: LE Axis Cyl Spe Axis Cyl Spe b. Refraction: c. Vision (aided): d. Vision (un-aided): Near Distant Near Distant Near Distant Near Distant e. Axial Length (mm): f. Keratometry: K1 K2 K1 K2 3.Post-operative complications: a. Eye operated: RE / LE b. Inflammation Yes / No c. Iris prolapse: Yes / No d. Increased IOP: Yes / No e. Corneal pathology: Yes / No, If yes, specify: 9

10 4.Follow-up Information: Id code: Follow-up 1 st post-op day After 1 week After 1 month After 2 months Date of follow-up Refraction Vision IOP Axis Cyl Spe Near Distant 10

11 Statistical analysis: All the data was entered in computer for analysis. Statistical analysis was done by using 1) Pearson Chi Square(x 2 ) test of significance. X 2 =Σ Σ(O-E) 2 E O = Observed frequency E = Expected Frequency 2) Standard Normal test 11

12 Uncorrected distance visual acuity after 1 month no of pt 1 6/60-6/18 6/12-6/9 6/9-6/6 12