Bilateral Keratoconus in a Young Albinism Male - Case Study Example

 Case (1) Patient History: The patient is a 22-year-old Asian male Optometry student who had used overnight OK lenses for ten days. His previous history indicates that he has been a spectacle wearer since his teenage years with no earlier experience in contact lens wearing. Subjective refraction was: R: -4.00 DS (6/6+) L: -4.50 DS (6/6), while the slit lamp examination indicated unremarkable findings. His last visit was for clinical assessment after one night of lenses wearing that showed a reduction of -2.50 DS in both eyes and visual acuity of R: 6/6- and L: 6/7.5. Topography maps exhibited a flat slight decentred treatment zone surrounded by a steepness uniform area. A slit lamp evaluation immediately after lenses insertion indicated poor centration and loose lens. Nevertheless, fitting evaluation after 15 minutes showed a great improvement. Therefore, the patient was asked to continue wearing the lenses and an appointment after one week was provided. Current Lenses and Care Schedule: R: 43.25/ -5.75 (0.5 e)/ 7.00/ 10.6 yellow L: 43.25/ -6.25 (0.5 e)/ 7.00/ 10.6 yellow Contex OK lens were fitted empirically and dispensed ten days ago. Daily overnight wearing was advised for eight hours to approach full correction during daytime. Current Visit: This was the second review visit after dispensing the lenses for the purpose of lens and vision evaluation. The patient had followed instructions and he was happy with the outcome with no complaints or serious complications. Clinical Findings and Observations: Visual acuity was R: 6/4.8-2 and L: 6/7.5+ which indicates a significant improvement in unaided vision. Topography maps displayed that the round zone exceeded the pupil margins, but were slightly decentred towards the inferior temporal area in both eyes. Then, the lenses were assessed after settlement by slit lamp with fluorescents. In terms of static evaluation, acceptable characteristics were illustrated in both eyes; lenses were centred with 3 to 4 mm of central touch and clearance at mid-periphery indicates the tear reservoir between the lens and cornea, which indicates acceptable characteristics. On the other hand, although dynamic evaluation showed acceptable lens movement in both eyes, when the patient asked to close his eye and then open it, the lens was rising upward from a decentred location. This means that when the eyes closed during sleep, the lens would be pushed by the upper lid and become decentred inferiorly. The main issue in this improper location is that the lenses were maintained there overnight, which led to the decentre of the treatment zone as the topography maps had shown. Therefore, the upper eyelid may be playing a major role in this situation; however, tightening the lenses can address this issue. Plans: Based on clinical findings, a new pair of lenses is required to address the issues of treatment zone decentration and insufficient correction of the left eye. The parameters of the ordered lenses are as follow: R 43.25/ -5.75/ (0.4 e)/ 7.00/ 10.6 Red L 43.25/ -7.50/ (0.4 e)/ 7.00/ 10.6 Yellow The new lenses were arranged to be sent to the patient’s address and a review appointment was booked after one week. Prognosis: This case is a bilateral moderate myopia that usually has an excellent response to OK treatment. However, evidence has shown that the upper limit of overnight OK correction was -4.00 DS1. This means that the expected results would be full correction of the right eye since it is -4.00 myopia, and under correction of the left eye, which is -4.50 DS. In fact, this was the exact case in the current visit after one week of commencing the treatment with full correction of the right eye and under correction of the left. Nevertheless, there is still room to enhance the lens fitting, which perhaps influences the visual outcome. Therefore, improving the fitting might have positive effect on the quality of vision. However, it is unlikely to reduce a further amount of myopia in this particular case, but it is still hoped that there will be an improved overall quality of vision. Discussion: Asian upper lid features may influence the outcome of OK treatment. Evidence has shown that there are a number of characteristic features in Asian upper lids. Compared to a Caucasian eye, an Asian eye has a thicker upper eyelid and a closer crease to the eyelashes2, which may imply in contact lens practice. One of possible implications is the stronger interaction between the eyelid and lens as seen in this case. Clinical findings such as topographic maps showed a decentered treatment zone. In addition, slit lamp evaluation indicates excessive movement of the lens off the centre. These observations suggest that the lens was forced by the upper eyelid to maintain a decentred location during sleeping, which often results in a decreased quality of visual outcome. The suggested solution was to refit the patient with a steeper lens to challenge the lid force and retain a well-centred treatment zone. Further clinical observations and check up visits are required for further assessment. Summary: This is a case of a young Asian male. He was fitted with overnight OK lenses to correct bilateral moderate myopia. This patient returned to the clinic after ten days of wearing OK for a check up, happy with the outcome and having no complaints. However, clinical findings revealed insufficient correction of the left eye. Moreover, the decentred treatment zone was shown in both eyes as a result of excessive upper lid force on the lens. Thus, a new pair of lenses was ordered with a higher power of the left lens and steeper base curve for both lenses. A well-centred treatment zone would be expected with improved quality of vision yet review appointments were required for further assessment for lens fitting and visual outcome. 1- Swarbrick HA. Orthokeratology review and update. Clin Exp Optom.2006;89:124–143. 2- Jeong A, Lemke BN, Dortzbach RK, et al. The Asian upper eyelid—an anatomical study with comparison to the Caucasian eyelid. Arch Ophthalmol 1999;117:907–912 Case (2) Patient History: This patient is a young male patient aged 22 years who was referred from Newcastle for a second opinion in an attempt to improve the binocular vision to 6/12 in order to obtain a driving licence. According to the referral letter, he has bilateral keratoconus and albanism. His last spectacle was two years old as follows: R pl -5.25 x32 (6/36), L +2.00 -2.25 x80 (6/24+). He was fitted with RGP Rose-K lenses for one year then refitted with Keratoconus bi-aspheric (KBA) lens design. The patient was struggling with both lens types and then he slowly adapted to wearing them for twelve hours over four days. Despite a decreased level of comfort, his vision was improved with KBA lens slightly one line approaching 6/15 for the right eye and 6/20+ for the left. Subsequently, he underwent Intrastromal corneal rings (INTAC) installation in the right eye just four months ago. The first consultation in Sydney Optometry practice was two weeks ago. The last clinical findings showed nystagmus in both eyes and unaided visual acuity of R 6/60, L 6/30+ and 6/24- of both. K reading was R: 61.80 @80 – 57.8 @170 and L: 52.2 @74 – 46.1 @164. Mini scleral lens was tried and fortunately indicated slight improvement in vision approaching 6/12- with both eyes. A pair of mini scleral lens that showed acceptable fitting was ordered and an appointment was given for dispensing and education. Current Lenses and Care Schedule: The ordered lenses had the following parameters: R KATT/ 7.50/ 5/ 16.50/ -2.00 (VA 6/19) L KATT/ 7.50/ 5/ 16.50/ -4.00 (VA 6/12-) Current Visit: This visit was to dispense the lenses and educate the patient on lens insertion, removal and care. First, the lenses were inserted by the optometrist for clinical evaluation. Then, he taught how to insert the lenses following filling each with saline solution, but he was facing difficulties because of nystagmus. After several times of practicing with encouragement, he showed significant development. Removing the lens was less complicated and straightforward by using a plunger. In terms of lens care, he taught how to clean the lenses and store them. Clinical Findings and Observations: Clinical evaluation indicated acceptable vision and outcome. In terms of visual acuity, corrected vision was R 6/19, L 6/19+ and 6/12- for both eyes. Slit lamp evaluation with an optic section beam as well as OCT image of anterior segment showed liquid reservoir thickness almost similar to the corneal thickness, which indicated an acceptable fitting. The patient was comfortable, happy and excited to commence wearing the lens and hopefully gain a driving licence. Plans: The lenses have been dispensed, and a plunger for lens removal as well as required solutions have been provided. These solutions include saline and cleaning solution. The patient learned and practiced in the clinic lens insertion, removal and care. He was advised to wear the lenses five hours initially then increase wearing them longer gradually. The next appointment was given after one to two weeks for a check up. Prognosis: This case is albinism with bilateral keratoconus and nystagmus. Mini scleral lens fitting was beneficial for him to provide improved vision and comfort. Thus, the current experience with mini scleral lens is expected to be greater than previous ones with RGP and KBA lenses. In addition, the level of improved vision and comfort may be increased after adaptation. This means that there is are increased opportunities to meet the driving licence visual requirements of 6/12 with both eyes. However, follow up visits are required to address any care and management issues in order to achieve the expected results. Discussion: Mini scleral lens have several advantages over RGP lens for advanced conditions of keratoconus. First, a larger diameter provides full corneal coverage and creates a liquid reservoir between the lens and cornea. This liquid reservoir masks and corrects all corneal irregularities, which then result in improved vision. The second advantage of mini scleral lens is comfort enhancement. Compared to RGP, a mini scleral lens is more comfortable because the edges are placed on the sclera instead of the cornea. Finally, the issue of lens decentration in high degrees of keratoconus can be solved by a mini scleral lens. This is due to the fact that it does not touch the corneal cone and the area between the cone, and the lens is filled with liquid, which improves stabilisation. Therefore, this type of lens is beneficial for this patient providing a greater level of vision and comfort. Summary: This is a case of bilateral keratoconus in a young albinism male. This patient was referred from another Optometry clinic in Newcastle as a second opinion to obtain further visual improvement. His medical history indicated previous experience with spectacles, RGP lenses and an INTAC ring in the right eye. Although vision was improved with RGP lenses, this improvement was insufficient to gather a driving licence, and he had comfort issues with the lenses. He was refitted with mini scleral lens in the first consultation in Sydney, though this was the second visit for lens dispensing and evaluation. Clinical evaluation showed acceptable lens fitting with improved level of comfort and vision that was close to driving licence requirements. Moreover, lens education in terms of lens insertion, removal, care and management was provided. An appointment was booked after one to two weeks for ongoing clinical assessment. Read More