Evaluation of Vitreous Substitutes in Managing Complicated Vitreo-retinal Surgeries

Background

Vitreous substitutes presently in use for intraoperative tamponade are perfluorocarbon liquids (PFCL) and for post operative tamponade are silicon oil (SO), sulphur hexafluoride (SF₆) and perfluorocarbon gas (PFC). Several factors are important for a thorough understanding of each of these vitreous substitutes. The absorption or necessity for removal, indications for use (including clinical studies and special surgical methods), additives and complications of use have to be considered.

Methods

Three port standard pars plana vitrectomy was performed in 60 consecutive cases requiring intra-vitreal intervention. PFCL was used intra-operatively in 30 cases (PFCL group and X group). The eyes were implanted with SO (silicon oil subgroup), PFC (C₃F₈ sub-group) and SF₆ (SF₆ sub-group) in twenty cases each. Apart from best corrected visual acuity (BCVA), the retinal status and the longevity of gas when used, changes and reaction in both the anterior and posterior segments were noted.

Result

The difference of postoperative BCVA in the PFCL and non-PFCL groups was statistically significant with p < 0.001. In both the PFCL and non-PFCL groups the difference between preoperative and postoperative BCVA was statistically significant with p < 0.0001. All three vitreous substitutes studied are effective given the case where they had been utilised.

Conclusion

PFCL is invaluable in the management of complicated retinal detachment (RD). Where a vitreous microsurgery is indicated, the visual outcome is good. SF₆ is useful for short-term tamponade. Silicon oil and C₃F₈ are useful for longer tamponade.Key Words: Tamponade, Perfluorocarbon liquids, Silicon oil, Sulphur hexafluoride, Perfluorocarbon gas, Retinal detachment     

5-Fluoro-Uracil and Low Molecular Weight Heparin in the Management of Proliferative Vitreo-retinopathy

Background

Proliferative vitreo-retinopathy (PVR) is the most common cause of failed repair of a primary rhegmatogenous retinal detachment (RRD). The success rates for the surgery of complicated RRD has doubled with improved vitreous techniques from 35–40% to approximately 65–75% at six months. However, despite these advances, recurrent vitreo-retinal traction leads to re-detachment in more than one-fourths of the initially successful cases. The use of adjunctive treatments to prevent cellular proliferation holds promise for the prevention of PVR or recurrences after surgery. One focus has been on the use of intra-vitreal antimetabolites to prevent the occurrence of PVR.

Methods

Thirty patients of complicated retinal detachment associated with PVR, C1 or more were managed by vitreo-retinal (VR) surgery with the addition of 250 μg / ml of 5-fluorouracil (5FU) and 1 IU / ml of low molecular weight heparin (LMWH) to the vitreous infusion. The patients were examined for any evidence of PVR till 180 days as also for any systemic or other ophthalmic complication.

Result

Out of the 30 cases in the study group, 25 (83.34%) cases had retinal settlement at the end of six weeks, which is similar to the outcomes of conventional VR surgery. There was no case of any serious complication.

Conclusion

The addition of LMWH and 5FU did not enhance the outcome of VR surgery.Key Words: Proliferative vitreo-retinopathy, Rhegmatogenons retinal detachment, 5-fluorouracil, Low molecular weight heparin     

A case of hypomagnesemia with secondary hypocalcemia caused by Trpm6 gene mutation

An offspring of marriage between two first cousins presented with atonic seizures developed on the 20^th day of life. The physical examination of the case was normal. In laboratory results, Ca+² level was 5,7 mg/dl, Mg+²: 0,4 mg/dl (1,3–2,1), PTH: 28,4 pg/ml (12–92), and P-: 4,5 mg/dl. The case was diagnosed as hypomagnesemia with secondary hypocalcemia (HSH) and TRPM6 gene mutation analysis revealed a homozygote mutation of E157X.     

ADAMTS‐4 in oligodendrocytes contributes to myelination with an impact on motor function

Myelination is a late developmental process regulated by a set of inhibitory and stimulatory factors, including extracellular matrix components. Accordingly, chondroitin sulfate proteoglycans (CSPGs) act as negative regulators of myelination processes. A disintegrin and metalloproteinase with thrombospondin motifs type 4 (ADAMTS‐4) is an extracellular protease capable of degrading CSPGs. Although exogenous ADAMTS‐4 has been proven to be beneficial in several models of central nervous system (CNS) injuries, the physiological functions of endogenous ADAMTS‐4 remain poorly understood. We first used Adamts4 /LacZ reporter mice to reveal that ADAMTS‐4 is strongly expressed in the CNS, especially in the white matter, with a cellular profile restricted to mature oligodendrocytes. Interestingly, we evidenced an abnormal myelination in Adamts4 ^?/? mice, characterized by a higher diameter of myelinated axons with a shifting g‐ratio. Accordingly, lack of ADAMTS‐4 is accompanied by motor deficits and disturbed nervous electrical activity. In conclusion, we demonstrate that ADAMTS‐4 is a new marker of mature oligodendrocytes contributing to the myelination processes and thus to the control of motor capacities.     

Effects of whey protein and resistance exercise on body cell mass, muscle strength, and quality of life in women with HIV.

OBJECTIVE: To determine the effects of whey protein, resistance exercise, and combined protein and exercise treatment on body cell mass (BCM), muscle strength, and quality of life (QOL) in HIV-infected women with reduced BCM. DESIGN AND SETTING: Prospective, randomized, controlled trial at a university hospital in New York City. METHODS: A volunteer sample of 30 HIV-infected women were randomized to whey protein (PRO), progressive resistance exercise (PRE), or combined treatment (PRO-PRE) for 14 weeks after a 6-week control period. The main outcome measures were body weight, BCM, skeletal muscle, fat mass, muscle strength, and QOL. RESULTS: There were no significant changes in BCM, strength, or QOL during the control period. PRO patients gained 3.6 kg (P = 0.001), and 2.5 kg fat (P = 0.002) with no change in BCM (0.5 kg; P = 0.07) or skeletal muscle (0.6 kg; P = 0.12). The PRE group increased BCM (0.74 kg;P = 0.03) and skeletal muscle (1.2 kg; P < 0.001) and decreased fat (1.7 kg; P = 0.02). PRO-PRE increased BCM (0.61 kg; P = 0.01) without change in skeletal muscle (0.6 kg; P = 0.30). Strength increased for both exercise groups (range, 40.6-95.3%; P < 0.001). The QOL physical activity score improved for PRE (P = 0.02) and worsened for PRO (P = 0.01). CONCLUSIONS: Resistance exercise significantly increased BCM, muscle mass, muscle strength, and QOL in HIV-infected women with reduced BCM. Whey protein had little effect on BCM accrual. Combined protein and exercise did not increase BCM in excess of gains achieved by exercise alone.