The application of human anterior lens capsule autotransplantation in phacotrabeculectomy: a prospective, comparative and randomized clinical study

Anterior lens capsule: biomechanical properties and biomedical engineering perspectives

Anterior lens capsule, as the thickest basement membrane in the body, has its unique physiology characteristics. In ophthalmology, many attempts have been made to culture different kinds of cells including iris pigment epithelial cells, retinal pigment epithelial cells, corneal epithelium and endothelium cells, trabecular meshwork cells etc and anterior lens capsule has been confirmed to be served as an excellent scaffold for the growth and expansion of different ocular cells. Furthermore, anterior lens capsule also has unique potential in gestation evaluation and the treatment of various ocular diseases, including corneal ulcer, glaucoma, age-related macular degeneration and macular hole, etc. Here, we provide an overview of the biomechanical properties and biomedical engineering perspectives of anterior lens capsule.

LONG-TERM SURGICAL OUTCOMES OF LENS CAPSULAR FLAP TRANSPLANTATION IN THE MANAGEMENT OF REFRACTORY MACULAR HOLE

PURPOSE

To report long-term surgical outcomes of autologous and allogenic lens capsular flap transplantation (LCFT) in refractory macular hole (MH) treatment.

METHODS

Fifty consecutive eyes with refractory MH who received LCFT were reviewed retrospectively. Twelve eyes underwent autologous LCFT (LCF obtained from the same eye in 7 eyes and the fellow eye in 5 eyes) and 38 eyes with allogenic LCFT. All eyes underwent complete vitrectomy, internal limiting membrane peeling if not peeled, LCF transplantation, and 15% perfluoropropane tamponade. Simultaneous autologus whole-blood application was applied in 31 eyes to reduce LCF dislocation. The patients maintained a facedown position for 2 weeks postoperatively. Demographic information, functional results, and structural changes were evaluated.

RESULTS

The mean preoperative MH diameter was 1,102.00 µm ± 561.63 µm. The mean follow-up duration was 18.50 months ± 6.05 months (range, 12.0-38.9 months). The MH was completely closed in 48 eyes (96.00%) (18 eyes receiving autologous LCFT and 30 receiving allogenic LCFT). There are no differences of age, previous MH surgery times, MH diameter, preoperative and postoperative best-corrected visual acuity, and closure rate between the subgroups. The median visual acuity improved from 1.78 (interquartile range, 1.28-1.85) logarithm of the minimum angle of resolution (median Snellen acuity: 20/1,200) preoperatively to 1.00 (interquartile range, 0.90-1.70) logarithm of the minimum angle of resolution (median Snellen acuity: 20/200) (P < 0.01) in all patients.

CONCLUSION

Both autologous and allogenic LCFT application may provide anatomical and visual improvements in refractory MH cases. Blood application can be applied in selected cases to reduce LCF dislocation. LCFT can be performed as first-line treatment for refractory MHs.

Comparison between sutureless scleral tunnel phacotrabeculectomy with and without placement of anterior capsule remnant

PURPOSE

To compare sutureless scleral tunnel phacotrabeculectomy with and without placement of anterior capsule remnant in the tunnel.

METHODS

In this comparative interventional case series, 41 eyes of 40 patients having open-angle glaucoma (OAG) underwent sutureless scleral tunnel phacotrabeculectomy (Group A) and 28 eyes of 24 patients underwent the same procedure with placement of anterior capsule remnant in the tunnel (Group B). Baseline intraocular pressure (IOP) and IOP at 1 day, 1 month and 6 months after surgery were recorded. IOP < 21 mmHg and 20% reduction in IOP from baseline without and with antiglaucoma medication(s) were considered as complete and qualified success, respectively. Any further procedures or complications that require returning the patient to the operating room or becoming no light perception (NLP) were defined as failure.

RESULTS

Mean preoperative IOP was 26.6 ± 10.08 and 26.64 ± 6.31 mmHg in group A and B, respectively (P-value = 0.984). Mean IOP at 1 month was significantly lower in group B (14.24 ± 4.4 versus. 12.07 ± 3.1, P = 0.027) but at 6 months there was no significant difference between groups (14.38 ± 3.56 versus. 14.8 ± 1.85, P = 0.590). The qualified success rate in group B was higher than group A (78.6 versus. 58.5%) at month 1, while the complete success rate was higher in group A than B (34.1% versus. 17.9%). Neither of any group had complete success at month 6. The qualified success rate was 94.7% and 100% in group A and B, respectively, at 6 months.

CONCLUSION

Placement of anterior capsule remnant in the ostomy during combined phacotrabeculectomy may improve the outcome of the procedure.

Efficacy of Phacotrabeculectomy Alone versus Phacotrabeculectomy Augmented with Autologous Anterior Capsule Implantation Beneath the Sclera Flap

PURPOSE

To evaluate the efficacy of autologous anterior lens capsule (ALC) in phacotrabeculectomy.

MATERIAL AND METHODS

In this prospective, randomized case control study, after obtaining institutional ethical clearance and informed consent, 88 eyes posted for phacotrabeculectomy were divided into ALC and non-ALC groups. Combined phacoemulsification, with posterior chamber intraocular lens implantation and trabeculectomy, was performed in both groups. Anterior lens capsule transplantation was done in the first group beneath the sclera flap. Follow-up of three months was carried out and the morphology of bleb, intraocular pressure (IOP), requirement for additional medications, and complications were compared between the two groups.

RESULT

Statistical difference favoring the ALC group was seen in IOP reduction (p < 0.05) at each follow-up, qualified success rate and failure rate at the three-month follow-up (p = 0.006), but no difference in bleb morphology was seen.

CONCLUSION

ALC implantation is beneficial in maintaining filtration in a combined surgery with minimal complications.

Ophthalmic transplantology: anterior segment of the eye - part I

Background

Transplantology is a quickly developing field of ophthalmology. It currently is able to treat many inherited, degenerative, inflammatory, traumatic, and cancerous diseases. This review outlines recent concepts and methods of treating ocular diseases with tissue and cell grafts. Ocular transplants related to the anterior part of the eye, including the conjunctiva and the cornea, are reviewed in Part 1.

Material/Methods

The scientific literature dated from January 2005 to July 2011 was thoroughly searched using Medline and PubMed. Publications dated 2009, 2010, and 2011 were analyzed in detail. Search terms were as follows: auto-, homo-, heterologous transplantation, eyeball, ocular adnexa, anterior segment of the eye, cornea, lamellar keratoplasty, stem cells, cultured cells. Further data were found at the website of the Eye Bank Association of America.

Results

Nearly all tissues of the anterior segment of the eye (the conjunctiva, sclera, eye muscles, and cornea) are transplanted. Because of the recent significant progress in the field, cornea transplantation was analyzed in more detail, specifically procedures such as limbus grafts and anterior and posterior lamellar keratoplasty. Indications, advantages, and drawbacks of the transplant techniques were also reviewed.

Conclusions

Recent progress in the field of cornea transplants allows treatment at the level of the endothelium and the use of cultured limbal epithelial stem cell grafts. However, compared with previous techniques, modern and multilayered transplant techniques of the cornea require much more expertise and longer training of the surgeon, as well as expensive and technologically advanced equipment. The availability of donor tissue is still the main limitation affecting all transplants. Therefore, cell culturing techniques such as stem cells, as well as artificial cornea projects, seem to be very promising.