Collagen cross-linking in keratoconus in Asian eyes: visual, refractive and confocal microscopy outcomes in a prospective randomized controlled trial.

To evaluate the safety and efficacy of collagen cross-linking (CXL) in the treatment of keratoconus. A prospective randomized sham-controlled clinical trial was undertaken and 43 eyes with moderate to severe keratoconus were randomized into two groups that is the treatment (n = 23) and the sham (n = 20) group. CXL was performed with riboflavin (0.1 in 20 % dextran) followed by UVA radiation (365 nm, 3 mW/cm(2), 30 min). In the sham group, only riboflavin was administered without UVA radiation. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity, intraocular pressure, corneal thickness, keratometry, endothelial count, confocal microscopy were evaluated at baseline and at 1 week, 1, 3, and 6 months. In cases where CXL was done, UDVA improved by mean 0.11 ± 0.06 logMAR units at 6 months (P = 0.01). The refractive cylinder and spherical equivalent decreased by mean of 0.62 D (P = 0.01) and 0.5 D (P = 0.19), respectively. Ultrasonic central corneal thickness decreased by mean 22.7 ± 10.3 µm (P = 0.01). The maximum and minimum keratometry decreased by mean of 1.2 ± 0.8 D (P = 0.01) and 0.83 ± 1.2 D (P = 0.39), respectively. The specular count and intraocular pressure did not show any significant change. In the sham group, no significant change was observed in any parameter. Confocal analysis showed that the epithelial healing was complete at 1 week after crosslinking. The sub-epithelial plexus showed loss of nerve plexus at 1 month, regeneration of nerve fibers which started at 3 months and was complete at 6 months. The anterior stroma showed loss of keratocytes with honeycomb oedema and apoptotic bodies till 3 months. The regeneration of keratocytes started at 3 months and was complete at 6 months of follow-up. Collagen cross-linking is an effective procedure to halt progression in keratoconus. The confocal microscopic changes correlate with the outcomes in the treatment and the sham groups.

Comparison of umbilical cord serum and amniotic membrane transplantation in acute ocular chemical burns.

PURPOSE: To compare the efficacy of umbilical cord serum (UCS) with amniotic membrane transplantation (AMT) in cases of acute ocular chemical burns. METHODS: In a retrospective, interventional, comparative case series, 55 eyes with grades III, IV and V chemical burns (Dua's classification) who presented within 3 weeks of injury were evaluated. Patients were treated with conventional medical (CM group, 20 eyes) management alone or combined with either UCS (UCS group, 17 eyes) or AMT (AMT group, 18 eyes). The parameters evaluated were time to epithelialisation, epithelial defect diameter, epithelial defect area, corneal clarity, tear break-up time (TBUT), Schirmer test and best-corrected vision. RESULTS: UCS and AMT groups showed early epithelialisation as compared with the CM group (Kaplan-Meier analysis=0.01). Mean time for healing of epithelial defect was 57.7±29.3, 27.4±19.0, 41.1±28.9 days in the CM, UCS and AMT groups, respectively (p=0.02). Mean TBUT at the last follow-up was 8.6±0.7, 10.3±1.1, 9.4±1.2 s in the CM, UCS and AMT groups, respectively (p=0.02). The mean Schirmer value at the last follow-up was 13.7±1.0, 16.9±3.0 and 13.2±1.5 mm in the CM, UCS and AMT groups, respectively (p=0.01). The visual outcomes and the occurrence of corneal vascularisation, symblepheron, ectropion and entropion were comparable in between the groups. CONCLUSIONS: Our study suggests that the UCS therapy may be a better alternative to AMT in acute moderate to severe (grades III, IV and V) ocular chemical burns, as it avoids surgical manoeuvre in already inflamed eyes.

Toric intraocular lens implantation versus astigmatic keratotomy to correct astigmatism during phacoemulsification.

PURPOSE: To compare toric intraocular lens (IOL) implantation and astigmatic keratotomy (AK) in correction of astigmatism during phacoemulsification. SETTING: Tertiary care hospital. DESIGN: Prospective randomized trial. METHODS: Consecutive patients with visually significant cataract and moderate astigmatism (1.25 to 3.00 diopters [D]) were randomized into 2 groups. Temporal clear corneal 2.75 mm phacoemulsification with toric IOL implantation was performed in the toric IOL group and with 30-degree coupled AK at the 7.0 mm optic zone in the keratotomy group. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, keratometry, topography, central corneal thickness, and endothelial cell density were evaluated preoperatively and 1 day, 1 week, and 1 and 3 months postoperatively. RESULTS: The study enrolled 34 eyes (34 patients), 17 in each group. There was no difference in UDVA or CDVA between the 2 groups at any follow-up visit. The mean preoperative and postoperative refractive cylinder was 2.00 D ± 0.49 (SD) and 0.33 ± 0.17 D, respectively, in the toric IOL group and 1.95 ± 0.47 D and 0.57 ± 0.41 D, respectively, in the keratotomy group (P=.10). The mean residual astigmatism at 3 months was 0.44 ± 1.89 @ 160 in the toric IOL group and 0.77 ± 1.92 @ 174 in the keratotomy group (P=.61). All eyes in the toric IOL group and 14 eyes (84%) in the keratotomy group achieved a residual refractive cylinder of 1.00 D or less (P=.17). CONCLUSION: Toric IOL implantation was comparable to AK in eyes with moderate astigmatism having phacoemulsification.

Comparative evaluation of 23- and 25-gauge microincision vitrectomy surgery in management of diabetic macular traction retinal detachment.

PURPOSE: To compare the efficacy, outcomes, and complications of 23-G and 25-G microincision vitrectomy surgery (MIVS) in cases of diabetic tractional retinal detachment (TRD). METHODS: This is a prospective, single-blinded, randomized, comparative study. Fifty eyes of 50 patients with diabetic TRD involving or threatening macula were randomized into 2 groups of 25 each. Group 1 underwent 23-G MIVS and group 2 underwent 25-G MIVS. Patients were followed up at 1 day, 1 week, 1 month, 3 months, 6 months, and 1 year after surgery. The primary outcome measure was anatomic and visual success after surgery. We also compared the 2 alternative MIVS systems and assessed various intraoperative and postoperative parameters. RESULTS: Anatomic achievement was achieved in all eyes and both groups showed a significant improvement in vision after surgery (p = 0.033 and p = 0.004, respectively) and were comparable (p = 0.584). Mean surgical time in 25-G surgery was significantly longer than in 23-G surgery by 4.60 minutes (p<0.001). Postoperative mean astigmatism was comparable in the 2 groups and postoperative hypotony was not encountered in either group. No port-related breaks were seen in either group; however, iatrogenic breaks occurred in 4 eyes in the 23-G group and 5 eyes in the 25-G group (p = 1.000). There was significantly less immediate postoperative pain and foreign body sensation in the 25-G group compared with the 23-G group. CONCLUSIONS: Both 23-G and 25-G MIVS have comparable visual and anatomic results for diabetic TRD; however, 25-G surgery may be associated with less postoperative pain and discomfort than 23-G surgery.

Tapping of Macular Hole Edges: The Outcomes of a Novel Technique for Large Macular Holes.

PURPOSE: To describe the novel technique of tapping macular hole edges for holes with low macular hole index (MHI) and assess its outcomes. DESIGN: A prospective interventional study. METHODS: Twenty-eight consecutive eyes with idiopathic large macular holes (MHI < 0.5) were enrolled. A standardized surgical protocol was performed using vitrectomy with brilliant blue G dye-assisted large internal limiting membrane peeling, intraocular gas tamponade with 18% C3F8, and strict postoperative prone positioning for 5 days. Tapping of macular hole edges was performed on all sides using 23-gauge GreenTip soft tip cannula. Hole closure was examined postoperatively using optical coherence tomography. RESULTS: There were 16 females and 12 males aged 63 ± 14.38 years. The mean MHI was 0.32. Hole closure was seen in 25 eyes (89.29%). MHI was less than 0.25 in the 3 eyes with failed macular hole surgery. Epiretinal membrance (ERM) was present in 22 eyes (78.57%). The presence of ERM did not correlate with hole closure (P = 1.00). Continuity of external limiting membrane was a better predictor of functional success than inner segment/outer segment continuity (P < 0.05). Type I hole closure was seen in 20 (80%) of 25 eyes while the remaining 5 eyes (20%) had type II hole closure on optical coherence tomography. Corrected distance visual acuity improved significantly from 0.86 ± 0.2 logMAR preoperatively 0.43 ± 0.22 logMAR postoperatively (P < 0.0001). CONCLUSIONS: Newer technique of tapping macular hole edges provides acceptable anatomical and functional success rates even in large macular holes (MHI< 0.5).

Secondary rhegmatogenous retinal detachment following intravitreal bevacizumab in patients with vitreous hemorrhage or tractional retinal detachment secondary to Eales' disease.

BACKGROUND: To report the occurrence of secondary rhegmatogenous retinal detachment (RRD) after intravitreal bevacizumab injection in patients with Eales' disease. METHODS: This is a retrospective, non-controlled, comparative case series. We reviewed 14 eyes of 14 patients with Eales' disease who had received pretreatment with intravitreal bevacizumab (1.25 mg/0.05 ml) and subsequently undergone a pars plana vitrectomy for non-resolving vitreous hemorrhage and/or tractional retinal detachment. Clinical records were reviewed. The primary outcome measure was the occurrence of secondary RRD after intravitreal bevacizumab injection. RESULTS: Four patients had developed secondary RRD, with retinal breaks that were localized to the base of tractional retinal bands, within 1 week of receiving intravitreal bevacizumab. On comparative analysis, median age of patients who had developed secondary RRD was 26.5 years, significantly less than the median age of 33.5 years in the rest (P = 0.022). Median post-operative best-corrected visual acuity (BCVA) in patients who developed secondary RRD was logMAR 0.7 (0.3-0.8), significantly worse than the BCVA of logMAR 0.3 (0.0-0.5) in the rest (P = 0.015). None of the patients who developed secondary RRD had a complete posterior vitreous detachment (PVD) at presentation. CONCLUSION: Intravitreal bevacizumab injections may be associated with the serious complication of secondary RRD in patients of Eales' disease within 7 days of injection.