Long Term Evaluation of Lasik for the Treatment of High Hyperopia Dr. Ashok P. Shroff, MD, Dr. Hardik A. Shroff, MD Shroff Eye Hospital, Near Railway Station, Navsari – India. Email: email@example.com We do not have any financial interest in this presentation… • Lasik has prevailed over PRK because of preservation of Corneal Epithelium and Bowman’s layer hence it gives better predictability and stability 1,2). • Lasik is quite acceptable procedure world wide to manage low to moderate hyperopia with gratifying results 1 to 6. • It has also been tried in very high hyperopia with long term follow up and good success2. • Various other methods have also been tried like (i) Clear lens extraction with IOL, (ii) Phakic IOL, (iii) Corneal inlays etc. 7,8. • Clear lens extraction with IOL is irreversible with loss of accommodation and has high postoperative risk of complications. • Phakic IOL method is quite predictable and stable with rapid visual recovery. However complications like corneal decompensation, pupil ovaling, uveitis, glaucoma and endophthalmitis can occur. • Corneal inlays is placed within corneal stroma after making flap. However, this method is not practiced everywhere. • In this study, we have included those cases of high hyperopia treated with Lasik and were followed up after 4 years. Purpose: To evaluate the results of lasik procedure in eyes with high hyperopia after 4 years regarding effectivity, stability, predictability and safety of Lasik procedure. Introduction:
Shroff Eye Hospital - India Methods: Demography: Refractive Error (MSE) (Pre op.) • Anterior and posterior segment exam • Did not reveal any abnormality • Intraocular pressure • Within normal limits • Corneal curvature (K Reading) • Mean 41.50 D (Range 40.65 to 41.90 D) • Mild peripheral pachymetry • 625 µm (mean) (Range 610 µm to 655 µm) • Laser ablation was given according to cycloplegic visual acceptance Visual Status (Pre op.) MSE = Mean Spherical Equivalent, UCVA = Uncorrected Visual Acuity, BCVA = Best Corrected Visual Acuity
Shroff Eye Hospital - India • Eye was prepared as usual with topical proparacaine 0.5% drops. • Flap maker microkeratome with 160 µm head was used to create flap. • Gentian violet pen was used to make marks at two different places in UTQ & LTQ of cornea. Corneal flap was made as usual. • After reflecting the flap, the stromal bed was dried, if required, by surgical spears . • Treatment zone was set at 6mm. • Laser ablation was done with MEL60 excimer laser using hyperopic mask. • Stromal bad and inner surface of the flap were cleaned with BSS. • Corneal flap was reposited and aligned and allowed to dry till it would adhere to the stromal bad. • Routine antibiotics, tear substitutes and flurometholone ophthalmic suspension drops were used. • Patients were followed next day, after 2 weeks, 2 months, 6 months, one year and 4 years. Procedure : MEL 60 FLAP Maker
Shroff Eye Hospital - India Results: Change in Refractive Errors (MSE) • Eye with pre op. +5 D ref. was emmetropic at first 3 months (100% reduction) but was at +0.50 D after 4 years (90%reduction). • 2 eyes with +7 D ref. pre op., were at +0.5 D after 3 months (92.86% reduction) and +1.50 D after 4 years (78.57% reduction). • 5 eyes having pre op. +8.0 D had +1.25 D at the end of 3 months (84.28% reduction). However after 4 years they were at +2.0 D (80% reduction). • 4 eyes having pre op. +9.0 D were at +2.0 at the end of 3 months (77.78% reduction) and after 4 years they had +2.25 D (75% reduction). • Range of reduction in refraction after 3 months was from 0 to +2.0 D (77.78% to 100%) and after 4 years it was from +4.50 D to +6.75 D (75% to 90%). • All patients were comfortable during entire postoperative period except at times mild headache or symptoms related to dry eye • 2 patients had some complaints regarding glare or haloes for initial 2 to 3 weeks but gradually disappeared without any additional treatment • There was no complications regarding flap making as all flaps were of adequate size and thickness. • Mid peripheral average pachymetry which was 625 µm was 520 µm after 3 months and 531 µm after 4 years. • Mean K value pre lasik was 41.5 D, 46.2 D after 3 months and after 4 years it was 45.60 D. Observations: Pre Op. Post Op. After 4 years RE LE
Shroff Eye Hospital - India Results : Visual Recovery • Eye with +5.0 D had 20/200 UCVA before Lasik which improved to 20/20 after 3 months and remained 20/20 even after 4 years. • 2 eyes with +7.0 D (MSE) had FC 6mt UCVA which improved to 20/20 after 3 months but was 20/40 after 4 years. However, it was 20/20 with correction. • 2 eyes with +8.0 D (MSE) had FC 4mt UCVA before Lasik and 20/80 BCVA (amblyopia) improved to 20/100 UCVA and 20/80 BCVA and both were steady even after 4 years. • However, in this group in 3 eyes BCVA improved to 20/60 from 20/80 at 3 months and remained at same level even after 4 yrs (improvement by one line). • In group of 5 eyes with +9.0 D (MSE), 2 eyes had FC 3mt UCVA and 20/100 BCVA before lasik. After 3 months UCVA improved to 20/100 but BCVA remained at 20/100 (Dense Amblyopia) which did not change even after 4 years. • However, in this group, 2 eyes with UCVA of FC 3mt before Lasik, improved to 20/100 after 3 months and maintained even after 4 years. But, BCVA before operation which was 20/100, improved to 20/80 (one line) after 3 months and remain improved even after 4 years. • Overall 5 eyes (41.06%) showed BCVA improvement by one line.
Shroff Eye Hospital - India Discussion: • In spite of different approaches available, Lasik is still the most popular and accepted procedure to treat hyperopia. • It has been very well documented that it is very effective for mild to moderate degree of hyperopia 6. • Different authors have reported 84% to 93% of eyes were with +1 D of emmetropia at one year follow up 5,9,10,11. • David Z et al have reported almost steady refraction even after 24 months 2. • In this series, Lasik has been done to treat high hyperopia (from +5 D to +9 D MSE) and cases were followed up even after 4 years (mean). Here the range of reduction was from +4.50 D to +6.75 D, which suggests that this procedure is effective, predictable and stable. • Here we have not done any enhancement procedure in any eye as all patients were quite comfortable whatever reduction they had. Discussion: Another way of analyzing results • Previous studies indicates their success as certain % eyes were within +1 D of emmetropia • In our study, we have tried to analyze how much total D were treated and how much could be corrected after 4 years in each group which is rather better way to present because for patients, ultimate concern is their vision without glasses or at least some visual improvement with less no. of glasses.
Shroff Eye Hospital - India Discussion: Another way of analyzing results Grand Table • As hyperopia increases, percentage of reduction was getting less and less. However if done properly, there is substantial reduction which is quite acceptable by patients. • Overall, out of total 95 D, after 4 years there was 76.31% reduction which is quite acceptable. • More important…for total 95 D, we have actually treated 105.50 D (Cycloplegic acceptance). • Suppose we would have treated full cycloplegic refraction then it would have been +115.50 D, means 10 D more means probably reduction in refraction would have been +82.50 D (86.84%) after 4 years. Therefore if we treat 10% more D than even cycloplegic refraction in higher hyperopia, better outcome may be expected, of course enough stroma should be available for necessary ablation. • In eyes with +5 D refractive reduction at 4 years was 90%. • In 2 eyes with +7 D (MSE), out of total 14 D, after 4 years 78.57% was refractive reduction • In 5 eyes with +8 D (MSE), out of total 40 D, after 4 years the reduction was 75%. • In 4 eyes with +9 D (MSE) it was also 75% reduction in refraction. • Therefore, the reduction in refraction after 4 years was between 75% to 90% which suggests Lasik is quite safe & effective even after 4 years.
Shroff Eye Hospital - India Discussion: Visual Acuity In Group of +5 & +7 D Hyperopia • Preoperative UCVA significantly improved to from FC 6mt – 20/200 to 20/40 - 20/20 (UCVA) In Group of +8 D Hyperopia • In 3 eyes, UCVA improved from FC 4 meter to 20/80 after 4 years but BCVA was 20/60 i.e. one line improvement over pre op. BCVA In Group of +9 D Hyperopia • 2 eyes had UCVA of FC 3 meter improved to 20/100 (UCVA) and BCVA to 20/80 i.e. one line improvement with additional correction. In General: • There was significant improvement in UCVA after treatment. • There was one line improvement in 5 eyes. • There was no loss of any line in this study. • There was no flap related complications. • There was significant change in pre and post lasik mid pachymetry and K Reading • There was no complication related to procedure. • No excimer laser has one stage programme to treat any amount of hyperopia. Therefore we need to re-run the treatment programme for additional D. • This may be reason for some residual / under correction. • There was some regression between 3 months and 4 years in all diopter group (83.94% reduction to 73.31%).
Shroff Eye Hospital - India Tips: • Consider full cycloplegic refraction for treatment at least in high hyperopia. • About residual refraction, point should be covered during counseling. Conclusion: • 12 eyes with hyperopia between +5 D to +9 D (MSE) were treated with MEL 60 excimer laser • Flaps of about 160 µm were made by “Flap Maker” - Microkeratome. • Results are analyzed after 4 years follow up. • Treatment of cycloplegic visual acceptance (Diopter) was given to correct manifest hyperopia. • 76.31% reduction in refraction could be achieved after 4 years. • BCVA was improved by one line in 5 eyes. • Lasik is quite effective, predictable, stable and safe procedure to treat hyperopia.
Shroff Eye Hospital - India References: • Pallikaris IG, Siganos DS. Excimer laser in situ keratomileusis and photorefractive keratectomy for correction of high myopia. J Refract Corneal Surg 1994; 10:498–510. • David Zadok,Fredrik Raifup, David Landau, Joseph Frucht-Pery. Long-term evaluation of hyperopic laser in situ keratomileusis. J Cataract Refract Surg 2003; 29:2181–2188. • Dausch D, Klein R, Schro¨der E. Excimer laser photorefractive keratectomy for hyperopia. Refract Corneal Surg. 1993; 9:20–28. • Dausch D, Landesz M. Laser correction of hyperopia; Aesculap-Meditec results from Germany. In: Salz JJ, ed, Corneal Laser Surgery. Philadelphia, PA, Mosby 1995; 237–247. • Ditzen K, Huschka H, Pieger S. Laser in situ keratomileusis for hyperopia. J Cataract Refract Surg 1998; 24:42–47. • Go¨ker S, Er H, Kahvecioglu C. Laser in situ keratomileusis to correct hyperopia from 4.25 to 8.00 diopters. J Refract Surg 1998; 14:26–30. • Siganos DS, Pallikaris IG. Clear lensectomy and intra-ocular lens implantation for hyperopia from +7 to +14 diopters. J Refract Surg 1998; 14:105–113. • Davidorf JM, Zaldivar R, Oscherow S. Posterior chamber phakic intraocular lens for hyperopia of 4 to 11 diopters. J Refract Surg 1998; 14:306–311. • Zadok D, Maskaleris G, Montes M, et al. Hyperopic laser in situ keratomileusis with the Nidek EC-5000 excimer laser. Ophthalmology 2000; 107:1132–1137. • Rashad KM. Laser in situ keratomileusis for the correction of hyperopia from 1.25 to 5.00 diopters with the Technolas Keracor 117C laser. J Refract Surg 2001; 17:113–122. • Tabbara KF, El-Sheikh HF, Islam SMM. Laser in situ keratomileusis for the correction of hyperopia from 0.50 to 11.50 diopters with the Keracor 117C laser. J Refract Surg 2001; 17:123–128. • Cobo-Soriano R, Llovet F, Gonza´lez-Lo´pez F, et al. Factors that influence outcomes of hyperopic laser in situ keratomileusis. J Cataract Refract Surg 2002; 28:1530–1538.