[Rhegmatogenous retinal detachment: Topography of breaks and agreement with lincoff's rules]

PURPOSE

To study the topography of retinal breaks and their agreement with Lincoff's rules.

MATERIALS AND METHODS

We performed a retrospective descriptive study of patients with recent rhegmatogenous retinal detachments followed on the ophthalmology service of Abass Ndao Hospital from January 2006 through December 2016. Patients with no prior retinal treatment were included.

RESULTS

Over 11 years, we reviewed 97 patients with 107 eyes with retinal detachments. The mean age of our patients was 51.7 years, range 23-79 years. There were 69 male patients, for a male:female ratio of 2.46. Refraction revealed that 38.1% of patients were myopes. Fourteen percent (14%) of patients had experienced trauma to the eye with the detachment. The right eye was involved in 54.6% of patients. The onset was insidious in 54.6% of cases and sudden in 23.7% of cases. All patients had decreased visual acuity, associated with a scotoma in 26.8% of cases. Visual acuity was decreased to light perception through 7/10. In 64.9% of cases, Lincoff's rules were observed.

DISCUSSION

Lincoff's rules are still relevant for localization of the breaks in retinal detachments.

CONCLUSION

Diagnosis of a retinal detachment is an essential step, since it determines the treatment. Lincoff's rules still have a role in finding the retinal break in retinal detachments.

Critical role of NMDA but not opioid receptors in the acquisition of fat-conditioned flavor preferences in rats

Animals learn to prefer flavors associated with the intake of dietary fats such as corn oil (CO) solutions. We previously reported that fat-conditioned flavor preferences in rats were relatively unaffected by systemic treatment with dopamine D1 and D2 antagonsits. The present study examined whether systemic opioid (naltrexone, NTX) or NMDA (MK-801) receptor antagonists altered the acquisition and/or expression of CO-CFP. The CFP was produced by training rats to drink one novel flavor (CS+, e.g., cherry) mixed in a 3.5% CO solution and another flavor (CS-, e.g., grape) in a 0.9% CO solution. In expression studies, food-restricted rats drank these solutions in one-bottle sessions (2 h) over 10 d. Subsequent two-bottle tests with the CS+ and CS- flavors mixed in 0.9% CO solutions occurred 0.5h after systemic administration of vehicle (VEH), NTX (0.1-5 mg/kg) or MK-801 (50-200 μg/kg). Rats displayed a robust CS+ preference following VEH treatment (85-88%) which was significantly though moderately attenuated by NTX (69-70%). The lower doses of MK-801 slightly reduced the CS+ preference; the high dose blocked the CS+ preference (49%) but also markedly reduced overall CS intake. In separate acquisition studies, rats received VEH or NTX (0.1, 0.5, 1mg/kg) or MK-801 (100 μg/kg) 0.5h prior to 1-bottle training trials with CS+/3.5% CO and CS-/0.9% CO training solutions. Additional Limited VEH groups were trained with intakes limited to that of the NTX and MK-801 groups. Subsequent two-bottle CS+ vs. CS- tests were conducted without injections. Significant and persistent CS+ preferences were observed in VEH (77-84%) and Limited VEH (88%) groups. NTX treatment during training failed to block the acquisition of CO-CFP although the magnitude of the CS+ preference was reduced by 0.5 (70%) and 1.0 (72%) mg/kg doses relative to the Limited VEH treatment (88%). In contrast, MK-801 (100 μg/kg) treatment during training blocked the acquisition of the CO-CFP. These data suggest a critical role for NMDA, but not opioid receptor signaling in the acquisition of a fat conditioned flavor preferences, and at best limited involvement of NMDA and opioid receptors in the expression of a previously learned preference.

Prospective evaluation of deep topical fornix nerve block versus peribulbar nerve block in patients undergoing cataract surgery using phacoemulsification

We compared the efficacy of deep topical fornix nerve block anaesthesia (DTFNBA) versus peribulbar nerve block in patients undergoing cataract surgery using phacoemulsification. We studied 120 patients, allocated randomly to two groups. Group 1 (n = 60) received peribulbar block with 5 ml of a 1:1 mixture of 0.5% plain bupivacaine and 2% lidocaine supplemented with hyaluronidase 300 i.u. ml-1. Group 2 received DTFNBA with placement of a sponge soaked with 0.5% bupivacaine deep into the conjunctival fornices for 15 min. No sedation was given to either group. Analgesia was assessed by the reaction to insertion of the superior rectus suture and by questioning during the procedure. A three-point scoring system was used (no pain = 0, discomfort = 1, pain = 2). Scoring was repeated at keratotomy, hydrodissection and hydrodelineation, phacoemulsification, irrigation and aspiration, and at intraocular lens insertion. If the patient's pain score was 0 or 1, no further action was taken. If the pain score at any stage of the operation was 2, intracameral injection of 1% preservative-free lidocaine was given. One patient in Group 2 needed intracameral lidocaine at the stage of phacoemulsification (P > 0.05) and four experienced discomfort at irrigation and aspiration (P = 0.043). We conclude that DTFNBA may be a useful needle-free anaesthetic technique in patients undergoing cataract surgery using phacoemulsification.