Influences of 27-Gauge Vitrectomy on Corneal Topographic Conditions

Complications in Retinal Surgery: A Review of Corneal Changes Following Vitreoretinal Procedures

Purpose:

The purpose of this article is to discuss the early- and late-onset corneal complications that can occur following vitreoretinal surgery.

Methods:

A systematic review of the literature was conducted using PubMed and Google Scholar databases. Articles detailing the clinical findings and the associations between surgical techniques, irrigating solutions, and microsurgical instruments used for vitreoretinal surgery and postoperative corneal complications were included in this review.

Results:

Vitreoretinal surgery can be associated with corneal complications such as persistent corneal epithelial defects, neurotrophic keratopathy, band keratopathy, ocular surface disruption, and endothelial cell damage. Risk factors for the development of cornea complications after posterior segment surgery include history of uncontrolled diabetes mellitus, aphakia or pseudophakia, disrupted anterior lens capsule integrity, use of irrigating solutions without appropriate buffers, use of contact viewing lenses intraoperatively, intraocular gases or silicone oil after vitrectomy, and prolonged duration of surgery.

Conclusions:

Corneal complications secondary to vitreoretinal surgery are multifactorial, but more commonly arise in diabetic patients, those with preexisting ocular comorbidities, and under certain surgical-related conditions. Special pre-, peri-, and postoperative considerations, with a focus on early identification and management of risk factors, are required to help decrease the incidence of corneal complications.

Comparison of postoperative anterior segment changes associated with pars plana vitrectomy with and without vitreous base shaving

AIM

To compare changes in anterior segment topography and axial length (AL) evaluated with Pentacam and IOL Master after pars plana vitrectomy (PPV) performed with and without vitreous base shaving.

METHODS

This prospective study included patients who underwent PPV or phacoemulsification+PPV (Phaco+PPV) for various indications. Patients who underwent total posterior hyaloid detachment and excessive vitreous base shaving with scleral indentation were referred to as complete PPV (c-PPV). The patients whom posterior hyaloid was separated as far as the posterior arcades and vitreous base shaving with scleral depression was not performed were classified as the partial PPV (p-PPV) group. All patients underwent detailed ophthalmologic examinations preoperatively and 1wk, 1, and 3mo postoperatively. Changes in the anterior chamber depth (ACD), anterior chamber volume (ACV), iridocorneal angle (ICA), central corneal thickness (CCT), and keratometric measurements (K₁ and K₂) were evaluated with Pentacam HR. Changes in the AL measurements were analyzed with IOL Master.

RESULTS

A significant increase in ACD was observed in c-PPV cases (P=0.02), but this increase was not significant in the p-PPV group (P=0.053). In contrast, ICA increased significantly in the c-PPV group (P=0.02) but decreased in the p-PPV group (P=0.09). BCVA was significantly improved in the c-PPV group from week 1 (P<0.001) while the increase in the p-PPV group reached significance at 3mo (P=0.035). CCT increased in the first week and later returned to baseline in both groups. No significant differences in the other parameters were observed between the groups, and there were no significant changes in intraocular pressure, ACV, AL, K₁ or K₂ values (P>0.05 for all).

CONCLUSION

Incomplete posterior hyaloid excision and not removing the vitreous base in PPV surgeries may create a more stable anterior chamber, thus preventing the downward movement of the lens-iris diaphragm, and may cause ciliary body retraction, thereby reducing ICA. Awareness of these effects can provide some amount of guidance to physicians in selecting the appropriate PPV procedure and preempting surgical complications.

Surgical outcomes of 27-gauge and 25-gauge vitrectomy day surgery for proliferative diabetic retinopathy

PURPOSE

To compare postoperative outcomes of 27-gauge (G) and 25-G vitrectomy conducted as day surgery for proliferative diabetic retinopathy (PDR).

METHODS

One hundred eighty-five consecutive PDR patients (185 eyes) who underwent primary vitrectomy (27-G in 64 eyes, 25-G in 121 eyes) were analyzed.

RESULTS

The 27-G and 25-G groups did not differ significantly in preoperative Early Treatment Diabetic Retinopathy Study (ETDRS) score, age, or preoperative intraocular pressure. The proportions of simultaneous cataract surgery (27-G vs. 25-G: 59.4% vs. 62.4%) and air-filled eyes (76.6% vs. 85.1%) were not significantly different between two groups. Both groups showed significant improvement in ETDRS score at postoperative 1, 3, and 6 months (all, P < 0.0001). Mean gain in ETDRS score from baseline was apparently better in 27-G group than in 25-G group at 1, 3, and 6 months, but there were no significant differences (1 month: 20.3 vs. 13.1 letters, P = 0.0703; 3 months: 22.9 vs. 17.5 letters, P = 0.1561; 6 months: 24.3 vs. 19.3 letters, P = 0.3313). Operation time was apparently longer for 27-G vitrectomy, but there was no significant difference (54.0 vs. 51.1 min, P = 0.3676). The same was observed for postoperative intraocular pressure at postoperative day 1 (19.7 vs. 18.1 mmHg, P = 0.1353). Incidence of postoperative retinal detachment (1.6% vs. 0.8%) and reoperation due to vitreous hemorrhage (6.3% vs. 6.6%) was not different between two groups.

CONCLUSIONS

The 27G system is as safe and as useful as the 25G system when used for PDR and can be expected to achieve earlier recovery of postoperative visual acuity.

Comparison of 23 Gauge Transconjunctival releasable Suture Vitrectomy with standard 20 gauge Vitrectomy

Objective:

To compare effectiveness of releasable transconjunctival sutures in 23 gauge vitrectomy and standard 20 gauge vitrectomy.

Methods:

This prospective comparative study was conducted in Department of Vitreoretinal Surgery, Al Ehsan Eye Hospital, Lahore from June 2016 to March 2017. It included 84 patients in total (Group-A: 42 patients underwent 23 gauge releasable suture vitrectomy; Group-B: 42 patients who underwent standard 20 gauge vitrectomy). Pre operative and post operative best corrected visual acuity, surgical duration, pre and post operative intraocular pressure and complication profile was compared between two groups.

Results:

The leading cause for vitrectomy was vitreous haemorrhage. (Group-A; n=15 ;35.71%; Group-B; n=17; 40.47%). There was statistically significant improvement in preoperative and postoperative BCVA in both groups (Group A: P-value < 0.05; Group B P-value < 0.05) but there was no significant difference in post operative BCVA between two groups at 3 months (P-value > 0.05). Surgical time for 23G vitrectomy Group was statistically less than 20 G vitrectomy Group (51 +/-18 minutes for Group-A versus 78 +/- 13 minutes for Group-B; p-value < 0.05). Visual analog score for pain / discomfort was also significantly less for Group-A than Group-B. There was no significant difference in intraocular pressures between the two groups.

Conclusions:

Releasable suture technique for small gauge vitrectomy is a safe and easily adaptable technique that has certain significant advantages over 20G absorbable suture vitrectomy.