Clear Corneal Vitrectomy Combined with Phacoemulsification and

1. Clear Corneal Vitrectomy Combined with Phacoemulsification and Foldable Intraocular Lens Implantation. Takeshi Iwase, Tsuyoshi Yoshita and Kazuhisa Sugiyama2 1) Toyama Prefectural Central Hospital, Toyama, Japan 2) Kanazawa University Graduate School of Medical Science, Kanazawa, Japan None of the authors have a financial or proprietary interest in any product mentioned.

2. Purpose Recently, modification in vitrectomy instruments have led to a decrease in size of the instruments and consequently in smaller incisions. It has been introduced a 25-gauge transconjunctival sutureless vitrectomy system (TSV25) and found it to be a safe surgical procedure in a variety of vitreoretinal pathologies. However, sclerostomy is still necessary in the TSV25 and this may induce complications associated with retinal disease. On the other hand, in cataract surgery alone, it is possible to reduce postoperative inflammation with a clear corneal incision rather than a corneoscleral incision. Herein, we have invented a vitrectomy in which all wounds could be closed without suture in simultaneous cataract surgery and vitrectomy from clear corneal incision.

3. Patients Surgery was carried out based on the approval of the institutional review board and the ethical standard established by the Declaration of Helsinki. After an explanation of the purpose of the study, informed consent was obtained from all patients. A total of consecutive seven patients who had cataract and epi-retinal membrane (ERM) underwent phacoemulsification, intra-ocular lens (IOL) implantation and vitrectomy. They were followed up over 3 months after surgery.

4. Excluded criteria • History of intraocular surgery • Uveitis • Retinitis pigmentosa • Pseudoexfoliation syndrome • Retinal tear, retinal detachment • Lattice degeneration

5. Methods • Performing combined cataract surgery with vitrectomy （see surgical technique） • Visual acuity • Intraocular pressure (IOP) • Corneal endothelial cell were collected for each patient. (Snellen visual acuity was converted to their logarithm of the minimum angle of resolution (Log MAR) units to create a linear scale of visual acuity.)

6. Surgical technique • Retrobulbar anesthesia (2% Xylocaine). • Corneal side ports (0.5 mm in width, at 2, 4, 10 o’clock ((and 8 o’clock in right eye)). • CCC (5.0 to 5.5 mm diameter, from the 10 o’clock port). • clear corneal tunnel of 3.0 mm in width. • Hydrodissection. • PEA(a phaco-chop hook was inserted from the 4 o’clock port ） (Fig. 1A). • I/A. • Posterior CCC (25-gauge ILM forceps through the 10 o’clock port ) (Fig. 1B).

7. Infusion cannula (23-gauge) was inserted from the infero-temporal port (Fig. 1C). • 30°contact lens (the brim was partially cut） (Fig. 1D). • 25-G vitrectomy(vitreous cutter and a light guide were inserted from the 2 or 10 o’clock ports) (Fig. 1E). • Replacement to a contact lens for observation of the post pole. • Peeling of ILM（ILM forceps) (Fig. 1F). • Confirmation of the periphery of the vitreoretina (Fig. 1G). • SA60AT (Alcon) was implanted into the capsular bag (Fig. 1H). • The viscoelastic substance was aspirated using a Simcoe needle. • Hydration (all corneal incision wounds).

8. Results • Two patients required sutures to close the 10 o’clock port ． • There was no leakage of aqueous humor from the corneal wounds and no fibrin formation. • The number of inflammatory cells in the anterior chamber seemed to be similar to the one after cataract surgery．（Fig 2)． • The cornea showed neither edema nor wrinkles in the Descemet's membrane • Corneal endothelial cell loss was 8.9 % at the 2 weeks after surgery. • There was neither any residual pre-macular membrane nor retinal detachment or hemorrhage．

9. 7. The condition of the IOL fixed in the capsule was satisfactory ． 8. A paired t test revealed a statistically significant improvement in visual acuity at 1 week (P = 0.011) and 3 months (P = 0.002) postoperatively. 9. There were no significant differences in IOP throughout the follow-up (paired t test).

10. Discussion In the present system, postoperative inflammation was less probably because only corneal incision was performed without conjunctiva and sclera disturbance. Only small sutureless clear corneal incision even in vitrectomy is of great advantage to both patients and surgeons. For patients, it causes less postoperative foreign-body sensation, allows a shorter recovery time, and absence of incision in the conjunctiva and sclera results in better appearance of the operated eye after the surgery due to the absence of conjunctival hemorrhage or congestion. For surgeons, it simplifies operative procedures, not required peritomy, infusion line fixation and suturing the incisions. In the TSV25, high force is required for incision, because of the needle-like design of the trocar and the stepped-up diameter at the transitional area from the trocar to the cannula. In contrast, high force for incision is not needed

11. in the present system. Therefore, the set-up in the system is easier than TSV25. Sclerostomy is necessary and the wounds are closed by incarcerating the vitreous body into the scleral incision ports in the TSV25. Retinal tears may also develop due to traction force on the retina accompanying postoperative contraction of the vitreous fibers, which are incarcerated into the sclerostomy incision. The present system is more advantageous than TSV25 from the aspect of preventing postoperative complications associated with retinal disease.

12. Conclusions Clear corneal incision vitrectomy caused shorter operating time and less postoperative ocular irritation than combined surgery with 25-gauge transconjuntival vitrectomy. Therefore, this procedure would be a good option for selected cased with cataract and vitreoretinal diseases.