Bilateral Lens Subluxation Associated with Atopic Eczema

PURPOSE

Ectopia lentis remains a therapeutic challenge for ophthalmologists. It classically presents with a preceding history of blunt or penetrating ocular trauma, or it may be associated with other ocular disorders such as congenital glaucoma and aniridia, or concomitant hereditary systemic diseases such as Marfan syndrome and homocystinuria.

METHODS

Case report.

RESULTS

The authors describe a previously unreported mechanism of ocular trauma associated with continuous eye rubbing, resulting in bilateral recurrent subluxation of both intraocular lens and crystalline lens.

CONCLUSIONS

It is useful for the ophthalmologist to be aware of this uncommon cause of ectopia lentis, since early advice and appropriate medical or surgical intervention may prevent more severe, sight-threatening complications.

Generalized essential telangiectasia with conjunctival involvement

Generalized essential telangiectasia (GET) is a rare skin disorder characterized by generalized development of dilated venules, which start at the lower extremities and progressively spread to the rest of the body. Mucous and conjunctival involvement is rare. The diagnosis is based on clinical examination, after excluding other primary and secondary causes of telangiectasia.

Spectrum, frequency and penetrance of OPA1 mutations in dominant optic atrophy

Dominant optic atrophy (DOA) is the commonest form of inherited optic neuropathy. Although heterogeneous, a major locus has been mapped to chromosome 3q28 and the gene responsible, OPA1, was recently identified. We therefore screened a panel of 35 DOA patients for mutations in OPA1. This revealed 14 novel mutations and a further three known mutations, which together accounted for 20 of the 35 families (57%) included in this study. This more than doubles the number of OPA1 mutations reported in the literature, bringing the total to 25. These are predominantly null mutations generating truncated proteins, strongly suggesting that the mechanism underlying DOA is haploinsufficiency. The mutations are largely family-specific, although a common 4 bp deletion in exon 27 (eight different families) and missense mutations in exons 8 (two families) and 9 (two families) have been identified. Haplotype analysis of individuals with the exon 27 2708del(TTAG) mutation suggests that this is a mutation hotspot and not an ancient mutation, thus excluding a major founder effect at the OPA1 locus. The mutation screening in this study also identified a number of asymptomatic individuals with OPA1 mutations. A re-calculation of the penetrance of this disorder within two of our families indicates figures as low as 43 and 62% associated with the 2708del(TTAG) mutation. If haploinsufficiency is the mechanism underlying DOA it is unlikely that this figure will be mutation-specific, indicating that the penetrance in DOA is much lower than the 98% reported previously. To investigate whether Leber's hereditary optic neuropathy (LHON) could be caused by mutations in OPA1 we also screened a panel of 28 LHON patients who tested negatively for the three major LHON mutations. No mutations were identified in any LHON patients, indicating that DOA and LHON are genetically distinct.

Intraocular lens implants and risk of endophthalmitis

AIM

To investigate the possible association between the use of three piece foldable silicone polypropylene (SPP) intraocular lenses (IOLs) and an increased risk of postoperative endophthalmitis.

METHODS

A retrospective analysis was conducted of all cases of postoperative endophthalmitis following phacoemulsification surgery in a single unit over a 3 year period. The incidence of postoperative endophthalmitis in eyes with SPP IOLs was compared with the incidence in eyes with single piece polymethylmethacrylate (PMMA) IOLs.

RESULTS

772 cataract extractions by phacoemulsification were performed. One (0.16%) of the 622 patients with PMMA IOLs developed endophthalmitis. Excluding one patient who had aplastic anaemia, five (3.33%) of 150 patients with SPP IOLs developed endophthalmitis. The relative risk for postoperative endophthalmitis associated with the use of the SPP IOL compared with the PMMA IOL was 20.1 (p = 0.015).

CONCLUSION

This study adds further evidence to the concept that SPP IOLs can be a significant risk factor in the development of postoperative endophthamitis.

A prospective controlled study of a 10/0 absorbable polyglactin suture for corneal incision phacoemulsification

PURPOSE

To evaluate the performance of a 10/0 monofilament absorbable polyglactin suture for temporal 5.2 mm corneal incision phacoemulsification.

METHODS

A prospective randomised controlled study of 49 patients undergoing phacoemulsification with a sutured temporal 5.2 mm corneal section was conducted to compare the refractive results and complications of a 10/0 monofilament absorbable polyglactin suture with 10/0 nylon.

RESULTS

Thirty-eight patients completed the study. There was no significant difference in induced astigmatism between the two groups. All absorbable sutures were intact at 1 week. Six weeks post-operatively the absorbable suture was still intact in 1 (6%) patient, present but broken in 4 (24%) and completely absent in 12 (70%) patients. All polyglactin sutures had been completely absorbed by 12 weeks. Absorption of the polyglactin sutures was associated with mild localised corneal haze in 3(18%) cases (p = 0.055). One of the 18 patients (6%) in the polyglactin suture group presented with iris prolapse associated with knot failure 1 week post-operatively. There was no significant difference in foreign body symptoms between the two groups.

CONCLUSIONS

10/0 polyglactin sutures maintain adequate tensile strength during the immediate post-operative period for small incision surgery and are associated with minimal induction of astigmatism. Their subsequent absorption obviates the need for routine suture removal. Suture absorption is well tolerated although in some cases a mild degree of local tissue reaction raises concern about possible mechanisms of absorption. The risk of knot failure may be reduced by an alternative suture tying technique. 10/0 monofilament polyglactin is an attractive option when a suture is required during small incision cataract surgery.

Optic nerve sheath fenestration for progressive ischemic optic neuropathy. Results in second series consisting of 21 eyes

OBJECTIVE

To determine the efficacy of optic nerve sheath fenestration in eyes with the progressive form of common anterior ischemic optic neuropathy. This investigation complements a previously reported initial series of 26 similar patients.

PATIENTS AND METHODS

Optic nerve sheath fenestrations were performed in 21 eyes for treatment of common (nonarteritic) ischemic optic neuropathy with documented progressive deterioration of visual function. All patients underwent thorough preoperative and postoperative ocular evaluations by the Neuro-Ophthalmology Service at the Bascom Palmer Eye Institute, Miami, Fla.

RESULTS

During a mean follow-up of 22.5 weeks (range, 3 to 104 weeks), results were as follows: visual acuity increased by 2 or more lines on the Snellen chart in two eyes (9.5%; the combined improvement rate for the two series was 14.9%); visual acuity decreased by 2 more lines in two eyes (9.5%).

CONCLUSIONS

Data from this series of 21 surgical procedures indicate no beneficial effect on visual morbidity in cases of common ischemic optic neuropathy and confirm the generally poor visual outcome implied from the results of optic nerve sheath decompression in our initial series. Based on this experience with a total of 47 eyes, we have discontinued optic nerve sheath decompression as a form of therapy for ischemic optic neuropathy.

Learning phacoemulsification: the surgeon-in-training

With the increasing trend towards phacoemulsification a perceived increased complication rate during the learning curve gives rise to a dilemma as to the best stage at which a surgeon-in-training can safely learn the technique. We prospectively analysed the complications and visual outcome of the first 160 phacoemulsification procedures performed by three surgeons-in-training. The main outcome measures included posterior capsule tear, vitreous and nuclear loss, surgical re-intervention rate and visual outcome. Posterior capsule tear occurred in 7 eyes (4.4%) and vitreous loss in 6 (3.8%). No nucleus was lost in the vitreous. Surgical re-intervention was required in 1 eye. Best corrected visual acuity was 6/12 or better in 88% of eyes. These results compare favourably with reports of surgeons-in-training learning extracapsular surgery and also with recently reported phacoemulsification series. This study indicates that with careful case selection and supervision phacoemulsification can be a safe procedure.

Conjunctival involvement in malignancy-associated acanthosis nigricans

Acanthosis nigricans classically presents with pigmented skin lesions over the neck, groin and axillae. It may involve the mucosal surfaces, particularly the oral mucosa. Conjunctival involvement is very rare, especially in the variety associated with malignancy. We report a case of acanthosis nigricans associated with squamous cell carcinoma of the bronchus where bilateral papillary conjunctivitis, progressing to hypertrophic papillary conjunctival and lid margin lesions, was the presenting feature. Topical treatment with corticosteroid and artificial tear drops resulted in the partial improvement of the ocular symptoms.

Is post-cataract mydriasis necessary?

We report the results of a randomised prospective trial of post-operative cyclopentolate in patients who had uncomplicated endocapsular cataract extraction. We found no significant difference in visual acuity, intraocular lens centration or pupil area achieved after dilatation with tropicamide. There was a marked increase in the incidence of posterior synechiae in the group receiving cyclopentolate (33% vs. 13%).

Learning phaco in a teaching environment

We prospectively analysed the complications and visual outcome of the first 160 phacoemulsification procedures performed by three surgeons in training under supervision. The main complications were posterior capsular tear (4,35%), vitreous loss (3,3%), nuclear loss (none) and surgical reintervention (one). Postoperative visual acuity was 0,7 or better in 94% of eyes without pre-existing pathology. Only one eye did not have a posterior chamber lens implanted.