SF IOL can be used for visualrehabilitation for aphakia in both adults and children. There are different techniquesof performing SFIOL; suture fixation andsutureless scleral fixation with a range of possible complications like lenstilt, lens decentration and dislocation, suture exposure,cystoids macular edema, glaucoma, and transient vitreous hemorrhage7,9. Suture fixation may be 2 point or 4 pointbut the two-point suture fixation carries a higher risk of axial IOL tilt. Insutureless scleral fixation, IOL haptics are externalized and fixated withinthe sclera without the use of sutures.
In a study on “Comparison of sutured versussutureless scleral-fixated intraocular lenses”, Sindal et al haveconcluded that the sutured technique and sutureless technique appear to beequally good in eyes with aphakia after cataract surgery or trauma 10 .With the reduced risk for corneal endothelial damage and secondary glaucoma, scleral-fixated IOL is apreferred choice over other alternatives like iris-fixated IOL and AC IOL 11. In the present study, we haveshown the visual outcome and complications rates with a modified 4-pointfixation technique in postoperative and post-traumatic cases after more than 18months of follow-up. In this study, out of 30 patients studied, when compared topreoperative CDVA the post-operative CDVA improved in 24 patients (80%). Thisis better compared to the study by Andrew et al, where the CDVA was improved or unchanged in 59eyes (71.9%).9 This is due to a large amount of cataractsurgery-related cases in our present study and trauma related cases being only25%.
The main advantages of this modified technique are the stability of theIOL and non-exposure and non-erosion of the proline suture knot. The finalproline knot remains within the scleral tunnel without gettingexposed or causing any erosion. Covering the suture ends with atriangular flap of sclera is a common technique. These triangular flaps atrophyover a period and leave the suture ends exposed causing erosion. We did not seea single case of suture exposure and suture erosion in the follow-up of ourcases. For the same reason, the risk of endophthalmitis is also reduced.
In thestudy by Andrew S. McAllister et al, there were 11% cases of polypropylenesuture exposure.9 The most common early complication that we haveseen in this series was ocular hypertension. All the 13 patients were managedby anti-glaucoma medications with no case going into chronic glaucoma. Otherstudies have also reported early complications.
Long and colleagues in a studyof transscleral fixation in 48 patients, reported post-operative complicationslike transient corneal edema in 37/48 eyes (77.1 %), temporary hypotony (6–10mmHg) in 11/48 eyes (22.9 %), vitreous hemorrhage in 4/48 cases (8.3 %),temporary intraocular pressure elevation in 8/48 eyes (16.7 %), and cystoidmacular edema in 5/48 cases (10.4 %).12 All these complicationsresolved within 4 weeks. All the post-operative cases in our series weremanaged by a secondary scleral-fixated IOL.
When a posterior capsular ruptureoccurs leaving an inadequate capsular support, the surgeon has to decidewhether to do a primary or a secondary implantation. The factors that affectthe decision-making process are the type of anesthesia, the general conditionof the patient and his compliance, the time spent in managing the complication.The technique of scleral-fixated IOL requiresgood surgical skills and meticulous maneuvering which are quite challenging ina stressful situation of capsular rupture and poor patient compliance.Scleral-fixated IOL is a prolonged procedure requiring some time in creatingscleral tunnels, tying the proline suture to the haptics and maneuvering andpositioning the IOL before tying the knot. Added to this; the time spent inmanaging the cataract surgery and its complication makes it quite prolongedincreasing the possibilities of postoperative inflammation and cystoid macularedema. Lee et al reported higher early postoperative complications and lessfavorable visual outcome in primary scleral fixated IOLs.
13 Suturerupture is reported after many years of SF IOL implantation, particularly inyoung individuals.3 We have not seen any case with this complicationin our follow-up of cases. In the absence of an adequate capsular support, different IOL implantationoptions are pursued. SF IOL, AC IOL, and iris-fixated IOLs have all been foundto be safe and effective in this setting.4 5. CONCLUSION:Scleral-fixated PC IOL insertion can offer favorable visual outcomes, asshown in this study using four-point fixation technique with proper caseselection, in cases of aphakia without adequate capsular support. Open-loop ACIOLs or iris-claw lenses may also offer good visual outcome when there are nocontraindications to their use.
This modified technique allows stable placementof PC IOLs in a series of post-operative and post trauma aphakic eyes.According to our data, parsplana anterior vitrectomy, four point fixation ofthe IOL and placement of the knots inside the scleral pouches give a stable andfavourable outcome. The limitations of this study are its single surgeon,heterogenous pre-operative indications and variable durations of follow-up. Weneed a randomized study with a longer follow-up to show the safety and efficacyof this procedure.