Learning styles and the prospective ophthalmologist.

PURPOSE: Understanding the learning styles of individual trainees may enable trainers to tailor an educational program and optimise learning. Surgical trainees have previously been shown to demonstrate a tendency towards particular learning styles. We seek to clarify the relationship between learning style and learned surgical performance using a simulator, prior to surgical training. METHODS: The Kolb Learning Style Inventory was administered to a group of thirty junior doctors. Participants were then asked to perform a series of tasks using the EyeSi virtual reality cataract surgery simulator (VR Magic, Mannheim, Germany). All completed a standard introductory programme to eliminate learning curve. They then undertook four attempts of level 4 forceps module binocularly. Total score, odometer movement (mm), corneal area injured (mm(2)), lens area injured (mm(2)) and total time taken (seconds) recorded. RESULTS: Mean age was 31.6 years. No significant correlation was found between any learning style and any variable on the EyeSi cataract surgery simulator. CONCLUSION: There is a predominant learning style amongst surgical residents. There is however no demonstrable learning style that results in a better (or worse) performance on the EyeSi surgery simulator and hence in learning and performing cataract surgery.

New trends in glaucoma risk, diagnosis & management.

Recent advances have seen a surge of new ideas and technologies to aid in the detection, treatment and further understanding of glaucoma. These technologies and advances are discussed to provide information on risk-factors, diagnosis and treatment. Glaucoma has never before seen such an advance in research and therapies coming forward in to the clinical workplace. It is an exciting time for physicians and researchers alike and over the next decade will certainly see advances in early detection, efficacious treatments and neuroprotection.

Orbital adherence with titanium mesh floor implants: a review of 10 cases.

BACKGROUND: Multiple materials have been used in the repair of orbital floor fractures. We report 10 cases of complications relating to the use of titanium mesh orbital floor implants. METHOD: A retrospective review of 10 cases in 2 centres in New Zealand. Patients presented with diplopia or eyelid retraction following repair of an orbital floor fracture with titanium mesh implants. RESULTS: Ten patients (7 male, 3 female) aged between 15-78 years old (mean 39 years) presented with significant restriction of eye movement and/or eyelid retraction following repair of an orbital floor fracture with a titanium mesh implant. Seven patients presented with restriction of eye movement alone. Three patients had lower lid retraction in addition to restriction of eye movement. One patient presented with epiphora following erosion of the implant through the nasolacrimal duct. Seven patients underwent surgical removal of the implant with all patients showing improvement of extraocular movement post-operatively. Three cases did not undergo implant removal with one case showing mild improvement over 9 months, and 2 cases showing no improvement. The mean interval between the initial surgery and removal of the implant was 7.1 months. DISCUSSION: In our series, 7 cases required explantation of the original titanium implant. In these cases a vigorous fibrotic reaction had taken place between the orbital contents and the titanium mesh implant. We postulate that the fibrous reaction between the implant and the orbital contents caused the eye movement restriction and the lid retraction. Implant materials used in orbital floor fracture surgery should be inert with a flat profile rather than a mesh to prevent adhesions through the mesh that may cause cicatricial eye movement restriction and eyelid retraction.

Assessment of fatigue in intraocular surgery: analysis using a virtual reality simulator.

AIM: To determine the effect of fatigue on intraocular surgical performance using a virtual reality simulator. METHODS: Seven experienced ophthalmic surgeons were recruited. The first set of data collection was immediately before a live theatre session. Each surgeon received a standardized orientation to a virtual reality cataract surgery simulator (Eyesi©, VRmagic, Mannheim, Germany). All surgeons then completed ten attempts on level-four forceps module. The parameters recorded were total score, total time, total time score, corneal injury score, lens injury score, odometer score, and operating without red reflex score. To reduce the effect of the learning curve, each surgeon had a "plateau" score calculated for every parameter, which was the average of their final four attempts. The surgeons then returned immediately after their scheduled theatre lists to complete a further ten attempts on the same module and similar parameters were recorded. RESULTS: Following routine theatre lists, simulator parameters slightly improved, with only the total score (97.28 to 98.57, p = 0.028) and total time (44 s to 35 s, p = 0.033) being statistically significant. The mean theatre list operating time was 197 min (SD ± 23.60). CONCLUSIONS: No detrimental effect of fatigue was demonstrated following a routine operating list. The study provides a template for further assessments of fatigue in high-volume cataract surgery lists.

The movement of potential tumour margins with random flap reconstruction-a porcine skin demonstration.

AIM: To demonstrate with a visual model the movement of potential tumour recurrence margins with different random flap reconstruction methods. METHODS: A porcine skin model was marked using a skin marker with a tumour and four quadrant margins. Each quadrant was marked in a different color around the tumour. The lesion was excised and repaired using different random flap reconstruction methods; finger, rotation, rhomboid and O-Z flaps. RESULTS: A clear visual demonstration of the relative movement of the edges is seen using the pig-skin model; this is shown with sequence photography. The finger, rotation, and rhomboid flap all create a double margin alignment and an edge free of tumour margins; the O-Z repair produces a linear repair with margins opposing each other. DISCUSSION: The study clearly illustrates the movement of margins when repairing a defect with a random flap. The different flap reconstruction methods are shown to produce areas of the final scar in which double tumour margins exist. Knowledge of the movement of margins is clinically important when re-excision of tumour scars is considered or when following up patients clinically.

Tie hard 2- an in-vitro comparison of first throw tension holding in twisted v straight-first throws; using Polyglycolic acid (Dexon S), Polyglactin 910 (Coated Vicryl).

OBJECTIVE: To compare the first throw tension holding properties of twisted versus straight first throws in two commonly used Oculoplastic braided absorbable sutures. DESIGN: An in-vitro experimental model. METHODS: Variable loads were applied to the first double throw of a surgical knot - either in straight-line configuration or twisting the knot using both 6/0 Polyglycolic acid (Dexon S) and 6/0 Polyglactin 910 (Coated Vicryl). Each suture was tested to the point of knot slipping and the critical tension recorded. Two variations of the experiment were undertaken: Experiment 1 - two metal loops were brought together by the test suture, experiment 2 - two strips of tissue (Permacol - cross-linked porcine dermal collagen) were brought together by the test suture. RESULTS: Experiment 1 straight: Polyglycolic acid 12.2g (11-13.5), Polyglactin-910 2.5 g (2.5- no range). Experiment 1 twisted: Polyglycolic acid 13.33 g (10-15), Polyglactin 910 3 g (2-5). Experiment 2 straight: Polyglycolic acid 33g (30-35), Polyglactin 910 25g (25 - no range). Experiment 2 twisted: Polyglycolic acid 35 (30-40), Polyglactin 910 25g (20-30). CONCLUSIONS: Twisting the suture adds only a modest increase in first throw knot security. Polyglycolic acid (Dexon S) braided absorbable suture has significantly better first throw knot security when compared with Polyglactin-910 (coated Vicryl). This is an important property when suturing tissues under tension as it minimises slippage before the locking throw is tied.

Can virtual reality simulation help to determine the importance of stereopsis in intraocular surgery?

AIM: To establish the effect of acute loss of stereopsis on simulated intraocular surgical performance. METHODS: This study was performed using the EYESi ophthalmic surgical simulator. Thirty junior doctors with no previous ophthalmic surgical experience were enrolled and distance visual acuity (Snellen), near visual acuity and stereoacuity (Frisby) were recorded. All participants completed a standard introductory programme on the forceps module to eliminate the learning curve. They then undertook four attempts of level 4 forceps module binocularly and another four monocularly to simulate an acute loss of stereopsis. Total score, odometer movement, corneal area injured, lens area injured and total time taken were recorded. RESULTS: Mean age was 31 years (SD±9). None had amblyopia, with all demonstrating distance visual acuity of 6/6 or better and N6 for near. Mean stereopsis was 35 s of arc (SD±18). Average total score decreased from 60 while operating binocularly to 47 monocularly (p<0.05). Average corneal area injured increased from 0.95 mm(2) to 2.30 mm(2) (p<0.05), average lens area injured increased from 1.76 mm(2) to 3.53 mm(2) (p<0.05) and average time taken increased from 69.6 s to 77.4 s (p<0.05). CONCLUSION: The importance of stereopsis for intraocular surgery is difficult to establish in a live theatre setting without compromising patient safety. Virtual reality simulators provide a safe alternative. This study demonstrates a statistically significant decrease in simulated intraocular surgical performance with acute loss of stereopsis in potential ophthalmic training applicants. Caution is recommend in using these results to advocate stereopsis testing as a screening tool in interviews because some participants performed well despite an absence of stereopsis.

Safety of nondominant-hand ophthalmic surgery.

PURPOSE: To establish the safety of nondominant-hand simulated intraocular surgery. SETTING: Horizon Suite Simulation Centre, South Devon Foundation NHS Trust, Devon, United Kingdom. DESIGN: Cohort study. METHODS: Physicians with no previous ophthalmic surgical experience completed an introductory program on the EyeSi ophthalmic surgical simulator to eliminate the learning curve. They then completed the validated level-4 forceps module 4 times with their dominant hand and then 4 times with their nondominant hand. Simulator total score, odometer movement, corneal injury, lens injury, and total time were recorded. Acuity (Snellen near) and stereoacuity (Frisby) were also recorded. RESULTS: All 30 physicians showed good acuity (6/6 and N6 or better) and stereopsis (mean 35 seconds of arc). The total score was lower (mean 60.8 versus 65.6; P=.019), operating times were longer (mean 71.6 versus 70.0; P=.026), and lens injury was greater (mean 0.93 versus 0.79, P=.021) when operating with the nondominant hand than with operating with the dominant hand. Those with higher scores with the dominant hand had higher scores with their nondominant hand. CONCLUSIONS: Simulated nondominant-hand ophthalmic surgery resulted in less efficient, less safe, and slower surgery. This observation was more marked in those with less skill with their dominant hand. This has practical implications for trainee and trainer if 1 surgeon is left handed and 1 right handed. It also suggests that a higher degree of competence with the dominant hand is required before performing nondominant-hand surgery. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Effect of distraction on simulated anterior segment surgical performance.

PURPOSE: To determine the effect of distraction on anterior segment surgical performance using a virtual reality simulator in expert and novice surgeons. SETTING: Horizon Suite Simulation Centre, South Devon Foundation NHS Trust, Devon, England. DESIGN: Cohort study. METHODS: Expert and novice ophthalmic surgeons completed a standardized and validated surgical task 10 times on a virtual reality simulator (EyeSi). They then completed a cognitive task (arithmetic questions), after which they completed 10 attempts on the simulator module while also completing the cognitive task. RESULTS: For experts (n = 7), the distracting cognitive task had no statistically significant effect on operating scores. The rate of correctly answered questions decreased from 12.3 per minute ± 2.1 (SD) while single tasking to 8.6 ± 3.1 per minute while dual tasking (P=.018). For novices (n = 14), the distracting cognitive task had no effect on any operating score except a small reduction in the penalty odometer score. The rate of correctly answered questions decreased from 11.5 ± 4.1 per minute while single tasking to 7.0 ± 3.2 per minute while dual tasking (P=.001). CONCLUSION: A distractive cognitive task reduced the ability of novice surgeons and expert surgeons to deal with that cognitive task, although their simulated surgical performance was not overtly compromised. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Old habits tie hard: an in vitro comparison of first-throw tension holding in Polyglycolic acid (Dexon S) and Polyglactin 910 (Coated Vicryl).

PURPOSE: To compare the first-throw tension holding property of two braided absorbable sutures commonly used in oculoplastic surgery. METHODS: The study was an in vitro experimental model. 6/0 Polyglycolic acid (Dexon S) and 6/0 Polyglactin 910 (Coated Vicryl) were compared using an experimental model to determine first-throw knot security. A polypropylene suture (Surgipro 2) was included as a benchmark to judge the apparatus by, ensuring that our experiment could be designed independently of the test suture materials. Increasing metric loads were applied to the first double throw of a surgical knot. Each suture was tested to the point of knot slipping and the critical tension recorded. All the sutures were kept wet during use. Three variations of the experiment were undertaken: experiment 1 -- two metal loops brought together by the test suture; experiment 2 -- two strips of tissue brought together by the test suture; and experiment 3 -- a knot tied over a metal bar coated in tissue. The tissue used was processed cross-linked porcine dermal collagen (Permacol). Each experiment was repeated three times for each suture type and the mean value taken. RESULTS: Experiment 1: Dexon S 12.2 g (11, 12, 13.5), Coated Vicryl 2.5 g (2.5, 2.5, 2.5) and Surgipro 2 2.3 g (2, 2, 3); experiment 2: Dexon S 33.33 g (30, 35, 35), Coated Vicryl 25 g (25, 25, 25) and Surgipro 2 5 g (5, 5, 5); experiment 3: Dexon S 100 g (100, 100, 100), Coated Vicryl 56.667 g (60, 55, 55) and Surgipro 2 5 g (5, 5, 5). CONCLUSIONS: Dexon S-braided absorbable suture has significantly better first-throw knot security when compared with Coated Vicryl. This is an important property when suturing tissues under tension as it minimizes slippage before the locking throw is tied.

Serial autofluorescence imaging over two years following indocyanine green-assisted internal limiting membrane peel for macular hole.

A 65-year-old patient with an idiopathic full-thickness macular hole underwent a vitrectomy, inner limiting membrane (ILM) peel and gas tamponade. The ILM was stained using 0.5% indocyanine green (ICG). Postoperative autofluorescence imaging shows a central focal hyperfluorescence surrounded by a perifoveal hypofluoresecnt area corresponding to the dyed and peeled ILM. Serial autofluorescence images showed progressive decrease in staining until 2 years later when no signs of ICG autofluorescence were apparent. The visual acuity for this patient improved two Snellen lines from 6/36 to 6/18 at 2 years. ICG may not be clinically toxic as is currently feared.