Journal of Ophthalmic and Vision Research
Volume:1 Issue: 2, Automn and Winter 2006

To report the early results of transplantation of autologous limbal stem cells cultivated on amniotic membrane (AM) in patients with total unilateral limbal stem cell deficiency (LSCD). Four eyes of 4 patients with total unilateral LSCD confirmed with impression cytology underwent transplantation of autologous limbal stem cell cultivated on AM. At each follow up visit, a complete eye examination with special attention to recurrence or regression of vascularization, corneal opacification, and epithelial defect healing was performed. Digital imaging was performed at each follow up visit. Impression cytology was repeated in all cases after surgery. The patients were followed for 5-13 months. Visual acuity improved in all cases. Decrease in corneal opacification and vascularization was obvious in 3 cases with coverage of the cornea with corneal epithelium. Sectoral conjunctivalization was evident in these 3 cases, however the corneas were ready for transplantation. The procedure failed in one case with total corneal conjunctivalization. Transplantation of autologous stem cells cultivated on AM seems to be an effective way for total LSCD. More definite judgment needs longer follow up together with long-term results of corneal transplantation in these patients.

To evaluate the use of amniotic membrane transplantation (AMT) for management of congenital distichiasis. In this interventional case series, 16 eyelids of 5 patients with congenital distichiasis underwent posterior lamella resection and AMT. All patients were male subjects with mean age of 13.6±15.2 (range 2-42) years. Mean follow up was 17±7.5 (range 6-29) months. Distichiasis did not recur in 11 eyelids (68.7%). Misdirected eyelashes recurred in 3 eyelids (18.8%) outside the AMT area and in 2 eyelids (12.5%) within the AMT area which were successfully treated by gentle laser epilation. Postoperatively, symptoms of dry eye were controlled by medical treatment in all patients. Eyelid contour was not significantly altered in any patient. AMT seems to be an acceptable alternative for surgical management of congenital distichiasis yielding acceptable eyelid contour with low rate of complications.

To compare the results of two different methods of upper lid sling with autogenous fascia lata in the treatment of congenital ptosis. In a randomized clinical trial, patients with congenital upper lid ptosis and poor levator function (< 4mm) were randomly assigned to two different methods of upper lid sling: group A, bitriangular fascia sling (modified Crawford method) and group B, monotriangular fascia sling (modified Fox method). This study included 30 upper eyelids (15 eyelids in each surgical group) of 19 patients (8 unilateral and 11 bilateral cases) with congenital ptosis. Mean increase in eyelid fissure height was 2.7±2.3 mm in group A and 3.4±2.2 mm in group B, respectively. Change in eyelid fissure in both groups was significant (P < 0.001, paired t-test) but intergroup difference was not (P=0.4, independent sample t-test). Early complications such as corneal epithelial defects and entropion, and late complications such as undercorrection were comparable in the two groups. No patient experienced recurrent ptosis requiring reoperation in either group. The monotriangular method of upper lid fascia sling can be used instead of the more popular bitriangular method. Advantages include less need for fascial tissue, less periocular scar formation and a shorter period of anesthesia.

To evaluate the results of pars plana lensectomy in patients with hereditary lens subluxation. Hospital records of patients with hereditary lens subluxation who had undergone pars plana lensectomy at Labbafinejad Medical Center, Tehran-Iran from 1996 to 2003 were reviewed. Patients with more than 6 months of follow up were included. Underlying disorders, best corrected visual acuity (BCVA) before and after surgery, intraocular pressure (IOP), postoperative refraction and complications were evaluated. Overall, records of 87 eyes of 49 patients including 27 male and 22 female subjects were reviewed. Mean follow up duration was 20±18 months. Underlying disorders leading to lens subluxation included Marfan syndrome (79.5%), Weill-Marchesani syndrome (8.2%), simple ectopia lentis (8.2%), and homocystinuria (4.1%). The most common indication for surgery was non-correctable refractive error (92.1%). Mean BCVA was 1.13 LogMAR (20/250) preoperatively, which improved to 0.26 LogMAR (20/30-20/40) postoperatively (P < 0.001). BCVA better than 20/40 was achieved in 82.8% of cases after surgery. Angle-supported anterior chamber intraocular lens (ACIOL) was implanted in 85.1% of the eyes. Prophylactic band was applied in 63 eyes (72.4%). Retinal detachment developed in four eyes (4.6%) and was successfully treated. Lensectomy/anterior vitrectomy with implantation of an angle-supported ACIOL in patients with hereditary lens subluxation improves vision significantly without considerable complications.

To report the outcomes of trans-scleral fixation of posterior chamber intraocular lens (PCIOL) combined with complete vitrectomy and prophylactic band placement. Hospital records of 18 patients who underwent the procedure were reviewed. Indications for vitreoretinal surgery included previous penetrating ocular trauma, complicated cataract surgery and vitreous incarceration, and chronic cystoid macular edema. All patients had iris and angle damage with inadequate lens capsular support. Age, sex, surgical technique, follow up duration and pre- and postoperative best corrected visual acuity (BCVA) were evaluated. Overall 18 eyes of 18 patients (14 men and 4 women) with mean age of 34.8±23 (range 5-76) years were operated. Mean follow up duration was 36±32.4 (range 6-96) months. Of the 18 operated eyes 7 were aphakic, 6 had complete IOL dislocation into the vitreous cavity, 4 had subluxated cataractous lens and one had a subluxated IOL. The number of eyes with BCVA? 20/40 increased from 3 (16.7%) preoperatively to 9 (50%) postoperatively (P < 0.01). Postoperative complications were encountered in 9 eyes and included uveitis, vitreous hemorrhage, repeat IOL dislocation and retinal detachment. In the absence of adequate capsular support, trans-scleral fixation of a PCIOL combined with vitreoretinal surgery seems to be effective for visual rehabilitation in selected patients with complicated cataracts or previous cataract surgery. Application of this technique in children deserves caution. Larger studies and a randomized clinical trial with long-term follow up are required to confirm these results.

To evaluate the success rate and complications of single-plate Molteno tube implantation in patients with intractable glaucoma. We reviewed the records of patients who had undergone single-plate Molteno tube implantation from 1995 to 2000 with at least 18 months of follow up. Thirty-six eyes of 35 (20 male and 15 female) patients with mean age of 29.7±25.3 (range 3-77) years were enrolled in the study. Preoperative intraocular pressure (IOP) was 34.5±10.4 mmHg with a mean of 2.3±0.8 medications which decreased to 18.0±7.6 mmHg with 1.9±1.2 medications after 32.8±16.1 months of follow up (P < 0.0001). Complete success (IOP: 7-21 mmHg without medications), incomplete success (IOP: 7-21 mmHg with medication) and total success (sum of complete and incomplete success) rates were 19.5%, 55.6%, and 75%, respectively. At final follow up, visual acuity improved 1 line or more in 10 (27.8%), decreased 1 line or more in 8 (22.2%) and remained unchanged in 18 (50%) eyes. Postoperative complications occurred in 20 eyes (55.6%) including encapsulated bleb in 10 eyes (27.8%), tube-iris touch in 4 (11%), flat anterior chamber in 3 (8.4%), tube-cornea touch in 2 (5.6%), and retinal detachment, tube-lens touch, and tube blockage, each in 1 (2.8%). IOP dropped to zero in one eye resulting in visual loss. In eyes at high risk for trabeculectomy failure, implantation of the Molteno tube can be considered as a procedure with acceptable success for control of IOP and preservation of vision. Long term follow-up is recommended to ensure timely management of the frequent complications of this procedure.

To determine whether angiotensin II (AT II) levels in aqueous humor are related to diabetes mellitus and to evaluate the effect of captopril on this level. We also evaluated the correlation between severity of macular edema and captopril use. In a case-control study, aqueous humor samples were obtained at the onset of cataract surgery from 58 eyes of 58 patients, of whom 37 were diabetic. From these latter subjects, 16 had taken captopril (captopril group) for at least six months and 21 had not taken any angiotensin converting enzyme inhibitor (non-captopril group). AT II level was assessed by radioimmunoassay. Severity of macular edema was evaluated by clinical examination after surgery. The aqueous level of AT II was significantly higher in diabetic patients (31.0±7.3 pg/ml) compared to non-diabetics (6.28±2.8 pg/ml) (Mann Whitney U test, P < 0.0001). In diabetic patients, aqueous concentration of AT II in the captopril group (16.3±6.5 mg/ml) was significantly lower than the non-captopril group (75.73±9.36 mg/ml) (Mann Whitney U test, P < 0.0003). The severity of macular edema was significantly less in the captopril group compared to the non-captopril group: 68.75% of the captopril group vs 33.3% of the non-captopril group had no macular edema (P < 0.005). These findings suggest that the aqueous level of AT II is higher in diabetic eyes and is correlated with the severity of diabetic macular edema. Considering the possible role of AT II in the pathogenesis of diabetic macular edema, modulation of the ocular renin-angiotensin system may become an important target for its treatment.

To describe the association between vitreous traction on the optic disc and nonarteritic anterior ischemic optic neuropathy (NAION). Eighty three eyes of 83 patients with NAION were evaluated by optical coherence tomography (OCT) for detecting vitreous adhesion to the optic nerve head with separation from the adjacent retina (partial posterior vitreous detachment). Eyes which were negative for such adhesion underwent ultrasonography to detect complete posterior vitreous detachment (PVD). Fifty male and 33 female subjects with mean age of 51.9±10 years were studied. Partial PVD with optic nerve head adhesion was found in 54 patients (65.1%) using OCT. Ultrasonography detected complete PVD in all other eyes with optically empty spaces on OCT. Vitreous traction on the optic nerve head from partial PVD may play a causative role in some cases of NAION. This traction may impair vascular supply and/or axoplasmic flow leading to signs and symptoms of NAION.

In an interventional case series, 11 aphakic eyes of 11 patients with previous vitrectomy and silicone oil tamponade underwent passive silicone oil removal under topical anesthesia through a single clear cornea incision with use of a side irrigating phacoemulsification irrigation cannula without performing a sclerotomy. All procedures were simple, short and uncomplicated. The only observed complication was minimal localized corneal edema the day after the procedure, which resolved within 1-2 days. Use of a side irrigating cannula permits safe and simple removal of silicone oil under topical anesthesia through a single clear cornea incision without need for sclerotomy.

The second part of this literature review deals with the comparison of two intraocular (pneumatic retinopexy and primary vitrectomy) and two extraocular (segmental sponge buckle without drainage, i.e. minimal extraocular surgery and the temporary balloon operation) procedures used to seal off the leaking break in primary retinal detachments. The outcomes, rate of complications and reoperations will be compared among these procedures.

To report the clinical and radiological findings and management of a patient with intraorbital arteriovenous malformation (AVM) treated by transcatheter embolization of the feeding artery. CASE REPORT: A 15-year-old female patient was referred with a one year history of left eye proptosis without prior trauma. Orbital CT scan and MRI demonstrated a large intraconal mass lesion extending to the extraconal space in the inferior orbit; angiograms revealed an intraorbital AVM. Superselective catheterization of the feeding artery and embolization with absorbable gelatin particles (Gelfoam) and non-absorbable polyvinyl alcohol particles were performed in two separate sessions followed by surgical debulking. Signs and symptoms were diminished after 14 months. Intraorbital AVMs can be treated by embolization of the feeding artery followed by surgical removal of the AVM nidus when the lesion is accessible.

To report two cases with neovascular glaucoma secondary to ischemic central retinal vein occlusion (CRVO) who were treated with intravitreal bevacizumab. CASE REPORT: Two patients were referred for neovascular glaucoma following CRVO. Visual acuity was light perception. Both eyes had extensive iris neovascularization (NVI), synechial angle closure and high intraocular pressure (IOP) in spite of anti-glaucoma medications. After obtaining informed consent, both eye received an intravitreal injection of 2.5 mg (0.1 ml) bevacizumab (Avastin). Both eyes demonstrated dramatic IOP reduction together with decreased severity and extent of NVI during 4 weeks of follow up. Visual acuity remained unchanged. Despite the dramatic short-term response in terms of IOP reduction and regression of neovascularization, due to limited clinical experience, one should consider this novel indication for bevacizumab cautiously.