A Comparison of Clinical Outcomes of Dislocated Intraocular Lens Fixation between In Situ Refixation and Conventional Exchange Technique Combined with Vitrectomy

Modified Intrascleral Fixation for Repositioning the Dislocated Single-Piece, Rigid PMMA Intraocular Lens

PURPOSE

To describe a modified intrascleral fixation technique for repositioning single-piece rigid polymethyl methacrylate intraocular lenses (IOLs).

METHODS

Four patients with dislocated IOLs were enrolled. Surgical modifications included using ≤1-mm scleral incision for haptic externalization, placing the IOL haptic placement in scleral tunnels, and using 8-0 absorbable sutures. Patients were followed up for 6 months with routine ophthalmic examinations, corneal endothelial cell counts, and ultrasound biomicroscopy (UBM).

RESULTS

The mean follow-up time was 13.5 ± 5.45 months. The IOL was well centered and the spherical refraction improved (+10.25 ± 2.21 vs. -0.81 ± 1.59 D, P < 0.05), whereas the best-corrected visual acuity (pre 20/43 Snellen, 0.42 ± 0.33 logarithm of the minimum angle of resolution equivalent and post 20/36 Snellen, 0.31 ± 0.22 logarithm of the minimum angle of resolution equivalent; P = 0.235), intraocular pressure (pre 13.8 ± 3.21, post 13.55 ± 5.14 mmHg), corneal endothelium density (pre 2,423.8 ± 279.6/mm 2 , post 2,280.25 ± 350.7/mm 2 ), and total astigmatism (pre -1.94 ± 0.43, post -1.69 ± 0.59 D) remained unchanged. The average horizontal and vertical IOL tilt was 0.33 ± 0.22° and 0.81 ± 0.38°, respectively. Intraocular lens decentration was 0.10 ± 0.03 mm horizontally and 0.13 ± 0.06 mm vertically.

CONCLUSION

The modified intrascleral fixation technique shows encouraging midterm results in patients with dislocated single-piece, rigid polymethyl methacrylate IOLs. Larger samples and longer follow-up are required to confirm the outcomes of this technique.

Risk factors for fluctuations in corneal endothelial cell density (Review)

The cornea is a transparent, avascular and abundantly innervated tissue through which light rays are transmitted to the retina. The innermost layer of the cornea, also known as the endothelium, consists of a single layer of polygonal endothelial cells that serve an important role in preserving corneal transparency and hydration. The average corneal endothelial cell density (ECD) is the highest at birth (~3,000 cells/mm²), which then decrease to ~2,500 cells/mm² at adulthood. These endothelial cells have limited regenerative potential and the minimum (critical) ECD required to maintain the pumping function of the endothelium is 400-500 cells/mm². ECD < the critical value can result in decreased corneal transparency, development of corneal edema and reduced visual acuity. The condition of the corneal endothelium can be influenced by a number of factors, including systemic diseases, such as diabetes or atherosclerosis, eye diseases, such as uveitis or dry eye disease (DED) and therapeutic ophthalmological interventions. The aim of the present article is to review the impact of the most common systemic disorders (pseudoexfoliation syndrome, diabetes mellitus, cardiovascular disease), eye diseases (DED, uveitis, glaucoma, intraocular lens dislocation) and widely performed ophthalmic interventions (cataract surgery, intraocular pressure-lowering surgeries) on corneal ECD.

Corneal endothelial cell damage after scleral fixation of intraocular lens surgery

PURPOSE

To analyze corneal endothelial cell damage after scleral fixation of intraocular lens (SFIOL) surgery.

STUDY DESIGN

Retrospective study.

METHODS

Medical records of consecutive eyes undergoing SFIOL surgery performed by a single surgeon were reviewed between January 2011 and June 2019. The patients were classified into three groups according to surgical methods: Group I, re-fixating the existing intraocular lens (IOL) or fixating a new IOL in an aphakic eye; Group II, removing the existing IOL and fixating a new IOL; and Group III, phacoemulsification and fixating a new IOL simultaneously. Preoperative and postoperative specular microscopy (SM) status were compared. Changes in SM were compared among the three groups.

RESULTS

Ninety-four eyes were included. Thirty-four eyes in Group I, 39 in Group II, and 21 in Group III. The endothelial cell density (ECD) loss in Group I was 1.5%, less than the ECD loss of 14.3% (p < 0.001) in Group II and 15.4% (p = 0.005), in Group III. In no eye was there an ECD decrease to < 1000/mm² following the surgical procedure.

CONCLUSIONS

ECD loss was related to IOL removal or phacoemulsification rather than SFIOL surgery. SFIOL using the existing IOL should be considered preferential in eyes with low ECD and dislocated IOL.

Scleral-fixated intraocular lens implants-evolution of surgical techniques and future developments

Varied options are available for the implantation of secondary intraocular lens implants in the absence of zonular or capsular support. Loss of the capsule can occur in the context of complicated cataract surgery, trauma or inherited conditions such as Marfan syndrome or pseudoexfoliation. Approaches to overcome this include optical measures such as the use of spectacles or contact lenses, and surgical therapy incorporating the use of anterior chamber, iris-fixated or scleral-fixated lenses. Surgical techniques to implant scleral-fixated lenses have undergone various modifications, since the first publication of sutured intrascleral fixation described in the 1980s. However, despite the advances in surgical techniques, studies are limited either by their retrospective nature, small sample size and most importantly small duration of follow-up. This comprehensive review aims to amalgamate the evolution of various surgical techniques with regards to intrascleral lens fixation and suggests areas for future development.

Outcomes of a new suture technique for the treatment of dislocated intraocular lenses: locked loop on the haptic

PURPOSE

To evaluate surgical and refractive outcomes of a new sutured scleral fixation technique in the management of subluxated intraocular lenses (IOLs).

METHODS

Nineteen eyes treated with the new scleral fixation technique were included. The mean corrected distance visual acuity (CDVA), postoperative refraction error, mean endothelial cell count (ECC), and complications were recorded. All patients were evaluated immediately postoperatively, at 1 and 7 days, and then at 1, 3, and 6 months.

RESULTS

The mean duration of follow-up of the patients was 10 months (range, 6-15 months). The mean CDVA was 0.41 ± 0.1 logMAR (logarithm of minimum angle of resolution) preoperatively and was 0.08 ± 0.07 logMAR postoperatively. The mean astigmatism was - 2.22 ± 1.86 D preoperative and was - 0.86 ± 0.58 D postoperative. The mean preoperative and postoperative ECC was 2455 ± 288 and 2352 ± 288, respectively. One patient (5.26%) experienced vitreous hemorrhage, and two (10.52%) experienced intraocular pressure elevation. IOL tilt and decentralization, conjunctival erosion, and cystoid macular edema were not observed in any eyes during follow-up.

CONCLUSION

This new IOL repositioning technique can be applied in a short surgical time and provides a stable IOL centration on long-term follow-up.

Corneal endothelial status in different grades of late spontaneous in-the-bag IOL dislocation

PURPOSE

 To evaluate corneal endothelial cell density (ECD) in the eyes with different grades of late spontaneous in-the-bag intraocular lens (IOL) dislocation.

METHODS

 A prospective study included seventy-eight patients who applied for IOL dislocation. Overall 80 eyes were divided into four grades based on the in-the-bag IOL dislocation classification. All eyes underwent a complete ophthalmological examination. ECD was evaluated using in vivo corneal confocal microscopy.

RESULTS

 Median corneal ECD was 1929 (1022-2958) cells/mm2 of all the patients. The lowest number of ECD was in grade 2 (grade 1 median ECD 1990.33 (1182-2425.33) cells/mm2, grade 2-1577.0 (1022-2958) cells/mm2, grade 3-2205.84 (1259-2807.67) cells/mm2 and grade 4-2072.17 (1045-2581.0) cells/mm2). A statistically significant difference was observed between the median of ECD of grade 2nd and 3rd (p = 0.023). By grouping cases into those with and without glaucoma, we found that corneal ECD was significantly lower in eyes with glaucoma compared with eyes without glaucoma in grades 3 and 4 (p < 0.05), while in other grades, the difference did not reach the significance level. We divided the corneal ECD of all eyes into two categories ≤ 1500 cells/mm2 and  > 1500 cells/mm2. Logistic regression demonstrated that the odds of having corneal ECD less than 1500 cells/mm2 increased by 3.5-fold if patients with IOL dislocation had been diagnosed with glaucoma previously.

CONCLUSION

 Late spontaneous in-the-bag IOL dislocation reduced corneal ECD. Previously diagnosed glaucoma was the most common comorbidity. This condition has a significant impact on corneal ECD for patients with IOL dislocation.

Surgical Outcome of Refixation versus Exchange of Dislocated Intraocular Lens: A Retrospective Cohort Study

We compared the surgical outcomes and complications of refixation vs. exchange of dislocated intraocular lenses (IOLs) in patients who underwent transscleral suture fixation combined with pars plana vitrectomy for the treatment of IOL dislocation. A total of 83 eyes (n = 83 patients) with postoperative follow-up of ≥6 months were evaluated: 40 received refixation of dislocated IOL (refixation group) while 43 received IOL exchange (exchange group) treatment. Treatment outcomes, including best-corrected visual acuity (BCVA), spherical equivalent, corneal cylinder, intraocular pressure (IOP), central macular thickness (CMT), and corneal endothelial cell density (ECD), and postoperative complications were retrospectively reviewed. BCVA improvement at 6 months after surgery was comparable between the groups. Postoperative decrease in corneal ECD was significantly greater in the exchange group than in the refixation group, but no significant differences were found in spherical equivalent, corneal cylinder, IOP, or CMT changes. The exchange group experienced significantly more frequent postoperative vitreoretinal complications, such as retinal detachment, choroidal effusion, cystoid macular edema, and secondary epiretinal membrane, than the refixation group. Without any reason to extract the dislocated IOL, reuse of the dislocated IOL would be a better surgical option for transscleral suture fixation to protect corneal endothelial cells and prevent postoperative vitreoretinal complications.